CA1280588C - High temperature guar based fracturing fluid - Google Patents
High temperature guar based fracturing fluidInfo
- Publication number
- CA1280588C CA1280588C CA000553334A CA553334A CA1280588C CA 1280588 C CA1280588 C CA 1280588C CA 000553334 A CA000553334 A CA 000553334A CA 553334 A CA553334 A CA 553334A CA 1280588 C CA1280588 C CA 1280588C
- Authority
- CA
- Canada
- Prior art keywords
- zirconium
- crosslinking agent
- fracturing fluid
- ppm
- set forth
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C09K8/00—Compositions for drilling of boreholes or wells; Compositions for treating boreholes or wells, e.g. for completion or for remedial operations
- C09K8/60—Compositions for stimulating production by acting on the underground formation
- C09K8/62—Compositions for forming crevices or fractures
- C09K8/66—Compositions based on water or polar solvents
- C09K8/68—Compositions based on water or polar solvents containing organic compounds
- C09K8/685—Compositions based on water or polar solvents containing organic compounds containing cross-linking agents
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10S507/00—Earth boring, well treating, and oil field chemistry
- Y10S507/903—Crosslinked resin or polymer
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10S507/00—Earth boring, well treating, and oil field chemistry
- Y10S507/922—Fracture fluid
Landscapes
- Chemical & Material Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Organic Chemistry (AREA)
- Detergent Compositions (AREA)
- Compositions Of Macromolecular Compounds (AREA)
- Inks, Pencil-Leads, Or Crayons (AREA)
- Decoration By Transfer Pictures (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
A fracturing fluid based on quar gum exhibiting good viscosity and stability at temperatures from about 80°C to at least about 120°C. The fracturing fluid includes a guar gum, a zirconium or hafnium cross-linking agent, and a bicarbonate salt in an aqueous solution at a pH from about 8 to about 10.
A fracturing fluid based on quar gum exhibiting good viscosity and stability at temperatures from about 80°C to at least about 120°C. The fracturing fluid includes a guar gum, a zirconium or hafnium cross-linking agent, and a bicarbonate salt in an aqueous solution at a pH from about 8 to about 10.
Description
lX8~)588 HIGH TEMPERATUR~ GUAR-BASED
PRACTURING ~LUID
Field of the Invention The invention relates to a composition and method of 5 fracturing subterranean formations at high temperatures utilizing natural guar-based fluid.
Technoloov Review The treatment of subterranean formations penetrated by a well bore to stimulate the production of hydrocarbons there-10 from or the ability of the formation to accept injectedfluids has long been known in the art. One of the most common methods of increasing productivity of a hydrocarbon-bearing formation is to subject the formation to a fracturing treatment. This treatment is effected by injecting a liquid, 15 gas or two-phase fluid which generally is referred to as a fracturing fluid down the well bore at sufficient pressure and flow rate to fracture the subterranean formation. A
proppant material such as sand, fine gravel, sintered bauxite, glass beads or the like can be introduced into the 20 fractures to keep them open. The propped fracture provides larger flow channels through which an increased quantity of a hydrocarbon can flow, thereby increasing the productive capability of a well.
PRACTURING ~LUID
Field of the Invention The invention relates to a composition and method of 5 fracturing subterranean formations at high temperatures utilizing natural guar-based fluid.
Technoloov Review The treatment of subterranean formations penetrated by a well bore to stimulate the production of hydrocarbons there-10 from or the ability of the formation to accept injectedfluids has long been known in the art. One of the most common methods of increasing productivity of a hydrocarbon-bearing formation is to subject the formation to a fracturing treatment. This treatment is effected by injecting a liquid, 15 gas or two-phase fluid which generally is referred to as a fracturing fluid down the well bore at sufficient pressure and flow rate to fracture the subterranean formation. A
proppant material such as sand, fine gravel, sintered bauxite, glass beads or the like can be introduced into the 20 fractures to keep them open. The propped fracture provides larger flow channels through which an increased quantity of a hydrocarbon can flow, thereby increasing the productive capability of a well.
~. ., . . - , .. . . .
lZ80~;88 Certain hydrophilic materials, hereinafter referred to as "gelling agents", have been used to increase the viscosity of a liquid fracturing fluid. High viscosity aqueous fracturing fluids are useful in the development of wider 5 fractures to improve productivity further into the forma-tions, increase the proppant carrying capacity of the fracturing fluids, and permit better fluid loss control.
High viscosity treating fluids are useful in carrying out subterranean well completions, for transporting sand in 10 sand and gravel packing procedures and in various other well treating procedures. Also, high viscosity treating fluids have utility in cleaning applications such as in the cleaning of tubular goods, production eguipment, and industrial eguipment. Eguipment typically cleaned includes oil well 15 piping tubes, tanks and process eguipment, boilers, heat exchangers, conventional and nuclear power plants and accessory eguipment and the like.
Hydrophilic gelling agents, such as partially hydrolyzed polyacrylamides, natural gums and modified natural gums, 20celluloses and xanthan polymers, have been utilized before to increase the viscosity of agueous solutions. However, the gells produced with such gelling agents generally have limited stability at elevated temperatures, i.e., the viscosity of the gelled agueous solutions decreases 2ssubstantially after only a short period of time. Chemicals ~X80588 which cross-link or complex hydrated gelling agents have also been utilized heretofore for further increasing their -viscosity. For example, U.S. Pat. Nos. 3,888,312; 4,021,355 and 4,0~3,415 describe and claim organotitanate, permanganate 5 salts, and antimony cross-linking agents respectively. u.s.
Pat. No. 3,959,003 teaches the use of a water soluble cellulose complexed with a polyvalent metal salt as a thixotropic agent for cementing compositions. U.S. Pat. No.
lZ80~;88 Certain hydrophilic materials, hereinafter referred to as "gelling agents", have been used to increase the viscosity of a liquid fracturing fluid. High viscosity aqueous fracturing fluids are useful in the development of wider 5 fractures to improve productivity further into the forma-tions, increase the proppant carrying capacity of the fracturing fluids, and permit better fluid loss control.
High viscosity treating fluids are useful in carrying out subterranean well completions, for transporting sand in 10 sand and gravel packing procedures and in various other well treating procedures. Also, high viscosity treating fluids have utility in cleaning applications such as in the cleaning of tubular goods, production eguipment, and industrial eguipment. Eguipment typically cleaned includes oil well 15 piping tubes, tanks and process eguipment, boilers, heat exchangers, conventional and nuclear power plants and accessory eguipment and the like.
Hydrophilic gelling agents, such as partially hydrolyzed polyacrylamides, natural gums and modified natural gums, 20celluloses and xanthan polymers, have been utilized before to increase the viscosity of agueous solutions. However, the gells produced with such gelling agents generally have limited stability at elevated temperatures, i.e., the viscosity of the gelled agueous solutions decreases 2ssubstantially after only a short period of time. Chemicals ~X80588 which cross-link or complex hydrated gelling agents have also been utilized heretofore for further increasing their -viscosity. For example, U.S. Pat. Nos. 3,888,312; 4,021,355 and 4,0~3,415 describe and claim organotitanate, permanganate 5 salts, and antimony cross-linking agents respectively. u.s.
Pat. No. 3,959,003 teaches the use of a water soluble cellulose complexed with a polyvalent metal salt as a thixotropic agent for cementing compositions. U.S. Pat. No.
3,979,303 teaches an oil well drilling fluid containing 10 complex polysaccharides, and U.S. Pat. Nos. 4,313,834 and 4,324,668 disclose and claim acidic treating fluids of a hydratable gelling agent and a zirconium cross-linking agent which further increases the viscosity.
U.S. Patent 4,579,670 describes cross-linked fracturing lS fluids including a hydratable polysaccharide in aqueous solution, a transition metal chelate cross-linking initiator, and a cross-linking rate controller which is either a rate accelerator or a rate retarder.
Among hydratable gelling agents, natural guar gum is 20 relatively $nexpensive, and requires little processing.
However, crosslinked fracturing fluids prepared with a natural guar gum provide lower viscosities at high tempera-tures. It would be desirable to crosslink a natural guar gum fracturing fluid and obtain high temperature performance . .
~'~80588 comparable to fluids prepared by crosslinking the more expensive polymers.
SUMMARY OF THE INVENTION
The present invention provides a fracturing fluid based on natural guar gum useful at high temperatures. The natural guar gum based fracturing fluid of the present invention exhibits good viscosity and is particularly stable at moderate and high temperatures. As used herein, moderate temperatures refer to temperatures of about 80C and above, and high temperatures refer to temperatures of about 120C and above. The present invention therefore provides a particularly inexpensive and convenient fracturing fluid.
The composition of the present invention is a high temperature fracturing fluid comprising a guar gum, and a cross-linking agent, and a stabilizing agent, in an aqueous solution.
The method of the present invention includes using the composition of the invention for well stimulation to increase well productivity by creating wider fractures through which hydrocarbons may flow. The method of the present invention ~0 provides improved transport and placement of proppant material in subterranean formations.
According to one aspect of the present invention there is provided an aqueous fracturing fluid having a pH from about 8 to about 10, consisting essentially of:
; guar gum in an amount from about 0.2 to about 1.25 weight percent to produce a fracturing fluid, at least one zirconium crosslinking agènt in an amount s B
l~so~a from about 5 ppm to about 50 ppm to crosslink said yuar gum, and a bicarbonate salt in an amount from about 250 ppm, to about 3000 ppm, and sufficient to provide a relatively low viscosity at ambient temperature and a relatively high viscosity at elevated temperatures.
According to a further aspect of the present invention there is provided a process for hydraulically fracturing a subterranean formation penetrated by a wellbore, comprising:
preparing an aqueous fracturing fluid having a pH from about 8 to about 10 consisting essentially of guar gum in an amount from about 0.2 to about 1.25 weight percent to produce a fracturing fluid, at least one zirconium crosslinking agent in an amount from about 5 ppm to about 40 ppm to crosslink said guar gum, and a bicarbonate salt in an amount from about 250 ppm to about 3000 ppm, and sufficient to provide a relatively low viscosity at ambient temperature and a relatively high viscosity at elevated temperatures, and introducing said aqueous fracturing fluid into said : formation from said wellbore at a flow rate and pressure sufficient to produce a fracture in said formation.
According to another aspect of the present invention there is provided an aqueous fracturing fluid having a pH from about 8 to about 10, consisting essentially of:
guar gum in an amount from about 0.2 to about 1.25 weight percent to produce a fracturing fluid, 5a B
~ 280588 at least one organic hafnium crosslinking agent in amount from about 5 ppm to about 50 ppm to crosslink said guar um, and a bicarbonate salt in an amount from aboùt 250 ppm to about 3000 ppm and sufficient to provide a relatively low viscosity at ambient temperature and a relatively high viscosity at elevated temperatures.
5b .:
lZ8~588 DETAILED DESCRIPTION OF THE INVENTION
The high temperature fracturing fluids of the present invention are prepared from natural guar gum, a cross-linking agent, and a stabilizing agent for use in the pH range of 8 to 10. By proper selection of the crosslinker composition and the stabilizing agent concentration, crosslinked natural guar gum fluids may be prepared which exhibit delayed crosslinking and improved high temperature performance.
In Table 1, the viscosity of cross-linked hydroxypropyl guar (HPG) (fluid 1) is compared to the viscosity of cross-linked guar (fluid 2). By comparing the apparent viscosity after 4 hours at 121C (250F) it is seen that the apparent viscosity of HPG at high temperature is clearly superior to that of cross-linked guar. Due to the poor high-temperature performance of cross-linked guar, other more expensive polymers have been used at high temperatures.
"~,. . .. .
i28~5Z38 TABL~ 1 Comparison of the Viscosity of Cross-linked HPG and Guar - Fluid Composition:
Additive Concentration Fluid 1 Hydroxypropyl Guar 0.42% by weight KC1 2% by wei~ht Na2S2O3 5H20 0.12% by weight Na2C3 to pH 8.5 Zr Triethanolamine 0.0025% Zr by weight Fluid 2 Guar 0.42% by weight KC1 2% by weight Na2S2O3 5H2o 0.12% by weight Na2CO~ to pH 8.5 Zr Trlethanolamine 0.0025% Zr by weight Fluid Performance:
Apparent viscosity (centipoise) @ 170 sec~
e 121C after Fluid #0 hours l hour 2 hours 3 hours 4 hours Table 2 compares the performance of two pH-control agents, sodium bicarbonate and sodium carbonate. Tests performed with cross-linked guar show that both sodium bicarbonate and sodium carbonate maintain the desired pH
S after 4 hours at 121C (250F).
1'~80588 TABLE ~
Performance of pH-control Agents - Fluid Composition:
Additive Concentration Guar 0.42% by weight KC1 2% by weight Na2S2O3~5H2o 0.12% by weight Zr Triethanolamine 0.0025% Zr by weight Fluid Performance:
pH-control Conc.pH before pH after 4 hours Additive ~g/1?test at 121C
NaHCO3 0,5 9.0 8.83 Na2C3 9-0 8.75 *6uf f icient to produce pH=8.5 Surprisingly, although both sodium bicarbonate and sodium carbonate were egually suited to maintain pH-control in pH range of 8 to 10 as illustrated in Table 2, crosslinked fluids containing sodium bicarbonate and sodium ~arbonate did not exhibit similar fluid performance. Using the same fluid composition described in Table 2, the apparent viscosity of a solution containing sodium bicarbonate was compared with the apparent viscosity of a solution containing sodium carbonate at 24C (75F), and at 121C (250F). As can be seen from Table 3, the solution containing bicarbonate provides a lower viscosity at ambient temperature (24C), and a higher viscosity at 121C (250F).
1~80588 T~ 3 The Effect of pH-control Agents on Cross-linked Fluid Viscosity Fluid Composition:
From Table 2 Fluid Performance:
Apparent viscosity (centipoise) e 170 sec~
pH-control Conc. e 24C aftere 121C
Additive (q/1) 3 minutes0 hours 1 hour 2 hours NaHCO3 0.5 92 117 113 89 Na2CO3 * 308 23 23 25 *sufficient to produce pH=8.5 Wlthout limiting the invention, it is believed that the lower viscosity observed at ambient temperature indicates delayed cross linking. Delayed cross linking is an advantageous property of fracturing fluids because it avoids excessive frictional losses during introduction of the fracturing fluid into the wellbore. The discovery that only the bicarbonate containing fluid exhibits a low viscosity at ambient temperature and a higher viscosity at elevated temperature is both surprising and very desirable.
; 10 Table 4 illustrates the effect of bicarbonate concentra-tlon on the rate of viscosity development at ambient temperature and the fluid viscosity at high temperature.
Viscosity development of cross linked fluids was measured using the Vortex closure test. The Vortex closure test is ~80588 described in u.s. Patent Nos. 4,657,080 and 4,657,081. AS
described therein, longer vortex closure times indicate slower crosslinking rates. As illustrated in Table 4, increasing the bircarbonate concentration increased the vortex closure time, increased the fluid viscosity at 121C, and stabilized the fluid pH during the test. However, as illustrated by the data in Table 4, the bicarbonate concentration must lie within a certain range to obtain the desired performance with a given crosslinking compound. For example with fluid #l (crosslinker zirconium triethanolamine), the bicarbonate concentration had to be greater than or equal to about 363 ppm and less than about 3000 ppm to obtain optimum high temperature performance. At bicarbonate concentrations below about 363 ppm, fluid #1 provided no improvement in viscosity at elevated temperature. At a bicarbonate concentration of about 2179 ppm, the viscosity of fluid #1 at 121C was diminished. For fluid #2, the minimum bicarbonate concentration reguired for optimum performance was about 1089 ppm.
While the mechanism responsible for improved performance obtained with crosslinksd guar and bicarbonate is not understood, it does not appear to be simply pH-control and/or simply delayed crosslinking. If the improved performance was due simply to delayed crosslinking, fluid compositions 1 12805~38 and 2 from Table 4 delayed with compounds other than bicarbonate should provide performance at elevated temperature s$milar to fluids 1 and 2 conta~ning the optimum concentration of bicarbonate. In Table 5, fluid compositions 1 and 2 are delayed with compounds reported in the literature. Fluid 1 was delayed with 2,4 pentanedione and the pH was adjusted with triethanolamine. Fluid 2 was delayed with triethanolamine and the pH was maintained with a non-delaying amount of NaHC03 (see U.S. Patent 4,579,670).
The results contained in Table 5 show two fluids with delay tlmes similar to the fluids in Table 4 which provided improved performance. The performance of these fluids (lC
and 2E) at 121C is compared to the performance of fluids lD
and 2A (fluid compositions containing no delay additive) in Table 6. Note the delayed fluid compositions lC and 2E
performed only slightly better than the non-delayed compositions lD and 2A. Furthermore, neither lC nor 2E
matched the performance of the fluids reported in Table 4 ~hlch contain-d an optimum concentration of N~H~03 only.
.,~
~.~80588 T~3L~ ~
Vortex Closure Results - Fluid Composition:
Additive Concentration Fluid 1 Guar 0.42% by weight KCl 2% by weight ~a2S2O3 5H2O 0.12% by weight Zr Triethanolamine 0.0022% Zr by weight Fluid 2 Guar 0.42% by weight KCl 2% by weight Na2S2O3 5H20 0.12% by weight Zr Lactate 0.0025% Zr by weight Fluid Performance:
viscosity pH Before pH After cp e 170 sec~l pH
Fluid HCO3~ Conc. X-linker Closure X-linker at 121-C after After + (~Dm) Addition Time 4s) Addgit29On 22 23 22 10.1 1 182 7.9238 9.19 17 11 11 ~.93 1 363 8 16101 9.13 117 89 67 8.83 1 726 8 43~900 9.03 156 91 62 8.83 1 1089 8 35>900 8.88 147 101 52 8.85 1 1452 8 47>900 8.88 149 87 50 8.85 1 2179 8 70~900 8.91 78 56 -- 8.75 2 0 8 4918 6.56 7 4 5 6.94 2 182 8.0552 7.80 17 11 15 7.22 2 363 8.1768 7.73 11 9 19 6.90 2 726 8.40103 8.16 17 30 29 7.83 2 1089 8 50>900 8.40 70 95 96 7.40 i 2 1452 8 53>900 8.40 143 184 149 8.26 2 2179 8.71>900 8.68 139 107 81 8.10 ; - 12 -lZ80588 vortex Closure Results Fluid Composition:
Additi~e Concentration Fluid 1 Guar 0.42~ by weight RCl 2% by weight Na2S2O3 5H2o 0.12% by weight Zr Triethanolamine 0.0022% Zr by weight Fluid 2 Guar 0.42~ by weight ~C1 2% by weight Na2S2O3 5H2O 0.12% by weight Zr Lactate 0.0025% Zr by weight Fluid Performance:
Fluid pH-Control Delay Conc. Vortex Time pH after # Additive Conc. PH Additive* (q/1) (min:sec) x-linkin~
lA TEA 0.48 g/l 8.5 2,4 Pdione 0.24 00:22 8.97 lB TEA 0.86 g/l 8.5" " 0.48 3:16 --lC TEA 1.39 g/l 8.5" " 0.96 >20 minutes 8.70 lD NaCO3 to pH 8.5 ---- -- 00:44 9.05 2A NaHCO3 0.1 g/l 8.4 None 0.00 00:22 --2B NaHCO3 0.1 g/l 8.5 TEA 0.29 2:27 8.51 2C NaHCO3 0.1 g/l 8.5 " 0.43 4:37 --2D NaHCO3 0.1 g/l 8.5 " 0.72 >10 minutes --2E NaHCO3 0.1 g/l 8.5 " 0.86 >10 minutes 8.90 * 2,4 Pdione is 2,4-pentanedione.
1~30588 The Effect of Delay Additives on Cross-linked Viscosity ~ Fluid Composition:
From Table 5 Fluid Performance:
Apparent Viscosity (centipoise) ~ 170 sec~l 24C after ~ 121~C after Fluid # 3 minutes 0 hours l hour 2 hours 3 hours 4 hours lC 68 108 45 33 30 --lD 308 23 23 25 28 25 2A 171 16 14*
* Viscosity after 0.5 hours at 121C
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In order that those skilled in the art may better understand how the present invention may be practiced, the following Examples are given by way of illustration and not 5 by way of limitation. All parts and percentages are by weight unless otherwise noted.
The compositions of the present invention may be prepared by mixing deionized water, 2% potassium chloride, and 0.025% (vol/vol) of polypropylene glycol (an antifoaming 10 agent) to form a mixwater. The mixwater is placed in a blender, and mixed at approximately 2000 rpm, while the required guantity of guar gum is added. The guar gum is mixed for approximately 30 minutes to fully hydrate the guar. Thereafter the desired amount of sodium bicarbonate - is added along with 0.12% of sodium th$osulfate (a high temperature gel stabilizer). The solution is mixed for about 30 minutes to effect solubilization. The resulting gel is aged for at least about one hour.
The zirconium cross-linking agent may, if necessary, be diluted with deionized water before use. The diluted solution is allowed to age for at least about 30 minutes prior to use.
The guar gel is mixed at about 2000 rpm, and the z$rconium solution is added to the vortex. The viscosity of the solution thus prepared is measured in a Fann model 50C
viscometer with a R1/BS rotor/bob configuration. The sample is pressurized to 400 psi and sheared at 100 rpm ~85 sec~1) for three minutes. To measure ambient viscosity, a shear rate ramp is used in S0 rpm increments from 250 rpm to 50 rpm. Upon completion of the ambient temperature measurement, the shear rate is returned to 100 rpm. The bath temperature is then increased at about 5.5C per minute to the test temperature. When the sample temperature is within 3DC of the set point, another shear rate ramp is performed, which is the test "T=0".
1~80S88 ExamDle ~ 1 Test temperature: 121C
Guar gum concentration: 0.42%
8icarbonate concentration: 1453 ppm Crosslinker: zirconium sodium trilactate Zirconium concentration: 29 ppm Crosslinked pH: 8.5 Time (hrs.) RT O 0.5 1 1.5 2 2.5 3 3.5 4 Visc. (cps) 62 143 156 157 191 184 178 167 158 149 Exam~le #2 Test temperature: 121C
Guar gum concentration: 0.42%
Bicarbonate concentration: 1453 ppm Crosslinker: zirconium diisopropylamine lactate Zirconium concentration: 29 ppm Crosslinked pH: 8.5 Time ~hrs.) RT O 0.5 1 1.5 2 2.S 3 3.5 4 Visc. (cps) 68 149 95 76 64 54 --- --- --- ---ExamDle #3 Test temperature: 121C
Guar gum concentration: 0.42%
Bicarbonate concentration: 1453 ppm Crosslinker: zlrconium triethanolamine lactate Zirconium concentration: 29 ppm Crosslinked pH: 8.5 Time (hrs.) RT O 0.5 1 1.5 2 2.5 3 3.5 4 Vlsc. (cps) 63 107 119 111 107 99 90 88 85 ----lZ80~;88 Example #4 Test temperature: 121C
Guar gum concentration: 0.42%
Bicarbonate concentration: 756 ppm Crosslinker: zirconium triethanolamine Zirconium concentration: 22 ppm Crosslinked pH: 9.0 Time (hrs.) RT 0 0.5 1 1.5 2 2.5 3 3.5 4 Visc. (cps) 55 94 108 120 111 103 96 87 - -ExamPle #5 Test temperature: 135C
Guar gum concentration: 0.60%
Bicarbonate concentration: 1453 ppm Crosslinker: zirconium triethanolamine Zirconium concentration: 26 ppm Crosslinked pH: 9.0 Time (hrs.) RT 0 1 2 3 4 5 6 7 8 Visc. ~cps) 115 247 274 235 199 180 155 137 133 109 Exam~le #6 Test temperature: 149C
Guar gum concentration: 0.72%
Bicarbonate concentration: 1453 ppm Crosslinker: zirconium triethanolamine Zirconium concentration: 26 ppm Crosslinked pH: 9.0 Time ~hrs.) RT O 0.5 1 1.5 2 2.' 3 3.5 4 Visc. ~cps) 167 394 307 269 226 196 157 138 115 100 ~;~8(~588 Exam~le ~7 Test temperature: 163C
Guar gum concentration: 0.72%
Bicarbonate concentration: 1453 ppm Crosslinker: zirconium triethanolamine Zirconium concentration: 26 ppm Crosslinked pH: 9.0 Time (hrs.) RT O 0.5 1 1.5 2 2.5 3 3.5 4 Visc. (cps) 154 236 140 58 27 --- --- --- --- ---The cross-linking agent is preferably an organic zirconium or an organic hafnium compound. Suitable organic zirconium compounds include either zirconium lactate or a zirconium complex of lactic acid, also known as 2-hydroxypropanoic acid. Suitable zirconium complex lactates include zirconium ammonium lactate, zirconium triethanolamine lactate, zirconium diisopropylamine lactate, and zirconium sodium trilactate salts. Corresponding hafnium lactate and hafnium complexes of lactic acid may be used as cross-linking agents. Titanium containing compounds such as titanium ammonium lactate and titanium triethanolamine may also be used as cross-linking agents in the practice of the present invention.
Other organic zirconium or organic hafnium compounds useful as cross-linking agents include monoalkylammonium, dialkylammonium and trialkylammonium zirconium or hafnium compounds obtained by reacting an organozirconate or an lZ80~88 organohafnate with monomethylamine, dimethylamine andtrimethylamine, monoethylamine, diethylamine, and - triethylamine, monoethanolamine, diethanolamine and triethanolamine, methyldiethanolamine, ethyldiethanolamine, dimethylethanolamine, diethylethanolamine, monoisopropanolamine, diisopropanolamine and triisopropanolamine, methyldiisopropanolamine, ethyldiisopropanolamine, dimethylisopropanolamine, diethylisopropanolamine, n-butylamine, sec. butylamine, dibutylamine and diisobutylamine. For example, a zirconium triethanolamine complex (Zr TEA) may be used as the cross-linking agent in the practice of the present invention. Zr TEA complexes are described in U.S. Patent 4,534,870 and U.K. Patent Application 2,108,122.
Other organozirconium compounds useful as cross-linking agents include citrates and tartarates such as zirconium sodium citrate and zirconium sodium tartarate.
The compositions of the present invention include a cross-linking agent as described above, a guar gum gelling agent, and a bicarbonate salt. The gelling agent is present in the agueous composition in a concentration in the range of from about 0.2 to 1.25%, preferably from about 0.2 to about 1.0% and most preferably from about 0.3 to about 0.8% by weight of the agueous fluid. A concentration of guar .~
lzso~aa gum of less than 0.2% by weight of the agueous flu$d is not sufficient to permit effective cross-linking.
- The cross-linking agent is present in an amount from about 5 ppm to at least about 50 ppm of the agueous fluid, and preferably in an amount from about 10 ppm to about 35 ppm.
The pH in the agueous fracturing fluid is preferably in the range from about 8 to about 10 depending on the cross-linking agent. Generally the bicarbonate salt stabilizing agent will be present in an amount from about 250 ppm to about 3000 ppm, and preferably in an amount from about 350 ppm to about 2250 ppm.
It is understood that various other modifications will be apparent to and can readily be made by those skilled in the art without departing from the scope and spirit of this invention. Accordingly, it is not intended that the scope of the claims appended hereto be limited to the description set forth above, but rather that the claims be construed as encompassing all the features which res~de in the present ~nvent~on, including all features which would be treated as eguivalents thereof by those skilled in the art to which this invention pertains.
U.S. Patent 4,579,670 describes cross-linked fracturing lS fluids including a hydratable polysaccharide in aqueous solution, a transition metal chelate cross-linking initiator, and a cross-linking rate controller which is either a rate accelerator or a rate retarder.
Among hydratable gelling agents, natural guar gum is 20 relatively $nexpensive, and requires little processing.
However, crosslinked fracturing fluids prepared with a natural guar gum provide lower viscosities at high tempera-tures. It would be desirable to crosslink a natural guar gum fracturing fluid and obtain high temperature performance . .
~'~80588 comparable to fluids prepared by crosslinking the more expensive polymers.
SUMMARY OF THE INVENTION
The present invention provides a fracturing fluid based on natural guar gum useful at high temperatures. The natural guar gum based fracturing fluid of the present invention exhibits good viscosity and is particularly stable at moderate and high temperatures. As used herein, moderate temperatures refer to temperatures of about 80C and above, and high temperatures refer to temperatures of about 120C and above. The present invention therefore provides a particularly inexpensive and convenient fracturing fluid.
The composition of the present invention is a high temperature fracturing fluid comprising a guar gum, and a cross-linking agent, and a stabilizing agent, in an aqueous solution.
The method of the present invention includes using the composition of the invention for well stimulation to increase well productivity by creating wider fractures through which hydrocarbons may flow. The method of the present invention ~0 provides improved transport and placement of proppant material in subterranean formations.
According to one aspect of the present invention there is provided an aqueous fracturing fluid having a pH from about 8 to about 10, consisting essentially of:
; guar gum in an amount from about 0.2 to about 1.25 weight percent to produce a fracturing fluid, at least one zirconium crosslinking agènt in an amount s B
l~so~a from about 5 ppm to about 50 ppm to crosslink said yuar gum, and a bicarbonate salt in an amount from about 250 ppm, to about 3000 ppm, and sufficient to provide a relatively low viscosity at ambient temperature and a relatively high viscosity at elevated temperatures.
According to a further aspect of the present invention there is provided a process for hydraulically fracturing a subterranean formation penetrated by a wellbore, comprising:
preparing an aqueous fracturing fluid having a pH from about 8 to about 10 consisting essentially of guar gum in an amount from about 0.2 to about 1.25 weight percent to produce a fracturing fluid, at least one zirconium crosslinking agent in an amount from about 5 ppm to about 40 ppm to crosslink said guar gum, and a bicarbonate salt in an amount from about 250 ppm to about 3000 ppm, and sufficient to provide a relatively low viscosity at ambient temperature and a relatively high viscosity at elevated temperatures, and introducing said aqueous fracturing fluid into said : formation from said wellbore at a flow rate and pressure sufficient to produce a fracture in said formation.
According to another aspect of the present invention there is provided an aqueous fracturing fluid having a pH from about 8 to about 10, consisting essentially of:
guar gum in an amount from about 0.2 to about 1.25 weight percent to produce a fracturing fluid, 5a B
~ 280588 at least one organic hafnium crosslinking agent in amount from about 5 ppm to about 50 ppm to crosslink said guar um, and a bicarbonate salt in an amount from aboùt 250 ppm to about 3000 ppm and sufficient to provide a relatively low viscosity at ambient temperature and a relatively high viscosity at elevated temperatures.
5b .:
lZ8~588 DETAILED DESCRIPTION OF THE INVENTION
The high temperature fracturing fluids of the present invention are prepared from natural guar gum, a cross-linking agent, and a stabilizing agent for use in the pH range of 8 to 10. By proper selection of the crosslinker composition and the stabilizing agent concentration, crosslinked natural guar gum fluids may be prepared which exhibit delayed crosslinking and improved high temperature performance.
In Table 1, the viscosity of cross-linked hydroxypropyl guar (HPG) (fluid 1) is compared to the viscosity of cross-linked guar (fluid 2). By comparing the apparent viscosity after 4 hours at 121C (250F) it is seen that the apparent viscosity of HPG at high temperature is clearly superior to that of cross-linked guar. Due to the poor high-temperature performance of cross-linked guar, other more expensive polymers have been used at high temperatures.
"~,. . .. .
i28~5Z38 TABL~ 1 Comparison of the Viscosity of Cross-linked HPG and Guar - Fluid Composition:
Additive Concentration Fluid 1 Hydroxypropyl Guar 0.42% by weight KC1 2% by wei~ht Na2S2O3 5H20 0.12% by weight Na2C3 to pH 8.5 Zr Triethanolamine 0.0025% Zr by weight Fluid 2 Guar 0.42% by weight KC1 2% by weight Na2S2O3 5H2o 0.12% by weight Na2CO~ to pH 8.5 Zr Trlethanolamine 0.0025% Zr by weight Fluid Performance:
Apparent viscosity (centipoise) @ 170 sec~
e 121C after Fluid #0 hours l hour 2 hours 3 hours 4 hours Table 2 compares the performance of two pH-control agents, sodium bicarbonate and sodium carbonate. Tests performed with cross-linked guar show that both sodium bicarbonate and sodium carbonate maintain the desired pH
S after 4 hours at 121C (250F).
1'~80588 TABLE ~
Performance of pH-control Agents - Fluid Composition:
Additive Concentration Guar 0.42% by weight KC1 2% by weight Na2S2O3~5H2o 0.12% by weight Zr Triethanolamine 0.0025% Zr by weight Fluid Performance:
pH-control Conc.pH before pH after 4 hours Additive ~g/1?test at 121C
NaHCO3 0,5 9.0 8.83 Na2C3 9-0 8.75 *6uf f icient to produce pH=8.5 Surprisingly, although both sodium bicarbonate and sodium carbonate were egually suited to maintain pH-control in pH range of 8 to 10 as illustrated in Table 2, crosslinked fluids containing sodium bicarbonate and sodium ~arbonate did not exhibit similar fluid performance. Using the same fluid composition described in Table 2, the apparent viscosity of a solution containing sodium bicarbonate was compared with the apparent viscosity of a solution containing sodium carbonate at 24C (75F), and at 121C (250F). As can be seen from Table 3, the solution containing bicarbonate provides a lower viscosity at ambient temperature (24C), and a higher viscosity at 121C (250F).
1~80588 T~ 3 The Effect of pH-control Agents on Cross-linked Fluid Viscosity Fluid Composition:
From Table 2 Fluid Performance:
Apparent viscosity (centipoise) e 170 sec~
pH-control Conc. e 24C aftere 121C
Additive (q/1) 3 minutes0 hours 1 hour 2 hours NaHCO3 0.5 92 117 113 89 Na2CO3 * 308 23 23 25 *sufficient to produce pH=8.5 Wlthout limiting the invention, it is believed that the lower viscosity observed at ambient temperature indicates delayed cross linking. Delayed cross linking is an advantageous property of fracturing fluids because it avoids excessive frictional losses during introduction of the fracturing fluid into the wellbore. The discovery that only the bicarbonate containing fluid exhibits a low viscosity at ambient temperature and a higher viscosity at elevated temperature is both surprising and very desirable.
; 10 Table 4 illustrates the effect of bicarbonate concentra-tlon on the rate of viscosity development at ambient temperature and the fluid viscosity at high temperature.
Viscosity development of cross linked fluids was measured using the Vortex closure test. The Vortex closure test is ~80588 described in u.s. Patent Nos. 4,657,080 and 4,657,081. AS
described therein, longer vortex closure times indicate slower crosslinking rates. As illustrated in Table 4, increasing the bircarbonate concentration increased the vortex closure time, increased the fluid viscosity at 121C, and stabilized the fluid pH during the test. However, as illustrated by the data in Table 4, the bicarbonate concentration must lie within a certain range to obtain the desired performance with a given crosslinking compound. For example with fluid #l (crosslinker zirconium triethanolamine), the bicarbonate concentration had to be greater than or equal to about 363 ppm and less than about 3000 ppm to obtain optimum high temperature performance. At bicarbonate concentrations below about 363 ppm, fluid #1 provided no improvement in viscosity at elevated temperature. At a bicarbonate concentration of about 2179 ppm, the viscosity of fluid #1 at 121C was diminished. For fluid #2, the minimum bicarbonate concentration reguired for optimum performance was about 1089 ppm.
While the mechanism responsible for improved performance obtained with crosslinksd guar and bicarbonate is not understood, it does not appear to be simply pH-control and/or simply delayed crosslinking. If the improved performance was due simply to delayed crosslinking, fluid compositions 1 12805~38 and 2 from Table 4 delayed with compounds other than bicarbonate should provide performance at elevated temperature s$milar to fluids 1 and 2 conta~ning the optimum concentration of bicarbonate. In Table 5, fluid compositions 1 and 2 are delayed with compounds reported in the literature. Fluid 1 was delayed with 2,4 pentanedione and the pH was adjusted with triethanolamine. Fluid 2 was delayed with triethanolamine and the pH was maintained with a non-delaying amount of NaHC03 (see U.S. Patent 4,579,670).
The results contained in Table 5 show two fluids with delay tlmes similar to the fluids in Table 4 which provided improved performance. The performance of these fluids (lC
and 2E) at 121C is compared to the performance of fluids lD
and 2A (fluid compositions containing no delay additive) in Table 6. Note the delayed fluid compositions lC and 2E
performed only slightly better than the non-delayed compositions lD and 2A. Furthermore, neither lC nor 2E
matched the performance of the fluids reported in Table 4 ~hlch contain-d an optimum concentration of N~H~03 only.
.,~
~.~80588 T~3L~ ~
Vortex Closure Results - Fluid Composition:
Additive Concentration Fluid 1 Guar 0.42% by weight KCl 2% by weight ~a2S2O3 5H2O 0.12% by weight Zr Triethanolamine 0.0022% Zr by weight Fluid 2 Guar 0.42% by weight KCl 2% by weight Na2S2O3 5H20 0.12% by weight Zr Lactate 0.0025% Zr by weight Fluid Performance:
viscosity pH Before pH After cp e 170 sec~l pH
Fluid HCO3~ Conc. X-linker Closure X-linker at 121-C after After + (~Dm) Addition Time 4s) Addgit29On 22 23 22 10.1 1 182 7.9238 9.19 17 11 11 ~.93 1 363 8 16101 9.13 117 89 67 8.83 1 726 8 43~900 9.03 156 91 62 8.83 1 1089 8 35>900 8.88 147 101 52 8.85 1 1452 8 47>900 8.88 149 87 50 8.85 1 2179 8 70~900 8.91 78 56 -- 8.75 2 0 8 4918 6.56 7 4 5 6.94 2 182 8.0552 7.80 17 11 15 7.22 2 363 8.1768 7.73 11 9 19 6.90 2 726 8.40103 8.16 17 30 29 7.83 2 1089 8 50>900 8.40 70 95 96 7.40 i 2 1452 8 53>900 8.40 143 184 149 8.26 2 2179 8.71>900 8.68 139 107 81 8.10 ; - 12 -lZ80588 vortex Closure Results Fluid Composition:
Additi~e Concentration Fluid 1 Guar 0.42~ by weight RCl 2% by weight Na2S2O3 5H2o 0.12% by weight Zr Triethanolamine 0.0022% Zr by weight Fluid 2 Guar 0.42~ by weight ~C1 2% by weight Na2S2O3 5H2O 0.12% by weight Zr Lactate 0.0025% Zr by weight Fluid Performance:
Fluid pH-Control Delay Conc. Vortex Time pH after # Additive Conc. PH Additive* (q/1) (min:sec) x-linkin~
lA TEA 0.48 g/l 8.5 2,4 Pdione 0.24 00:22 8.97 lB TEA 0.86 g/l 8.5" " 0.48 3:16 --lC TEA 1.39 g/l 8.5" " 0.96 >20 minutes 8.70 lD NaCO3 to pH 8.5 ---- -- 00:44 9.05 2A NaHCO3 0.1 g/l 8.4 None 0.00 00:22 --2B NaHCO3 0.1 g/l 8.5 TEA 0.29 2:27 8.51 2C NaHCO3 0.1 g/l 8.5 " 0.43 4:37 --2D NaHCO3 0.1 g/l 8.5 " 0.72 >10 minutes --2E NaHCO3 0.1 g/l 8.5 " 0.86 >10 minutes 8.90 * 2,4 Pdione is 2,4-pentanedione.
1~30588 The Effect of Delay Additives on Cross-linked Viscosity ~ Fluid Composition:
From Table 5 Fluid Performance:
Apparent Viscosity (centipoise) ~ 170 sec~l 24C after ~ 121~C after Fluid # 3 minutes 0 hours l hour 2 hours 3 hours 4 hours lC 68 108 45 33 30 --lD 308 23 23 25 28 25 2A 171 16 14*
* Viscosity after 0.5 hours at 121C
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In order that those skilled in the art may better understand how the present invention may be practiced, the following Examples are given by way of illustration and not 5 by way of limitation. All parts and percentages are by weight unless otherwise noted.
The compositions of the present invention may be prepared by mixing deionized water, 2% potassium chloride, and 0.025% (vol/vol) of polypropylene glycol (an antifoaming 10 agent) to form a mixwater. The mixwater is placed in a blender, and mixed at approximately 2000 rpm, while the required guantity of guar gum is added. The guar gum is mixed for approximately 30 minutes to fully hydrate the guar. Thereafter the desired amount of sodium bicarbonate - is added along with 0.12% of sodium th$osulfate (a high temperature gel stabilizer). The solution is mixed for about 30 minutes to effect solubilization. The resulting gel is aged for at least about one hour.
The zirconium cross-linking agent may, if necessary, be diluted with deionized water before use. The diluted solution is allowed to age for at least about 30 minutes prior to use.
The guar gel is mixed at about 2000 rpm, and the z$rconium solution is added to the vortex. The viscosity of the solution thus prepared is measured in a Fann model 50C
viscometer with a R1/BS rotor/bob configuration. The sample is pressurized to 400 psi and sheared at 100 rpm ~85 sec~1) for three minutes. To measure ambient viscosity, a shear rate ramp is used in S0 rpm increments from 250 rpm to 50 rpm. Upon completion of the ambient temperature measurement, the shear rate is returned to 100 rpm. The bath temperature is then increased at about 5.5C per minute to the test temperature. When the sample temperature is within 3DC of the set point, another shear rate ramp is performed, which is the test "T=0".
1~80S88 ExamDle ~ 1 Test temperature: 121C
Guar gum concentration: 0.42%
8icarbonate concentration: 1453 ppm Crosslinker: zirconium sodium trilactate Zirconium concentration: 29 ppm Crosslinked pH: 8.5 Time (hrs.) RT O 0.5 1 1.5 2 2.5 3 3.5 4 Visc. (cps) 62 143 156 157 191 184 178 167 158 149 Exam~le #2 Test temperature: 121C
Guar gum concentration: 0.42%
Bicarbonate concentration: 1453 ppm Crosslinker: zirconium diisopropylamine lactate Zirconium concentration: 29 ppm Crosslinked pH: 8.5 Time ~hrs.) RT O 0.5 1 1.5 2 2.S 3 3.5 4 Visc. (cps) 68 149 95 76 64 54 --- --- --- ---ExamDle #3 Test temperature: 121C
Guar gum concentration: 0.42%
Bicarbonate concentration: 1453 ppm Crosslinker: zlrconium triethanolamine lactate Zirconium concentration: 29 ppm Crosslinked pH: 8.5 Time (hrs.) RT O 0.5 1 1.5 2 2.5 3 3.5 4 Vlsc. (cps) 63 107 119 111 107 99 90 88 85 ----lZ80~;88 Example #4 Test temperature: 121C
Guar gum concentration: 0.42%
Bicarbonate concentration: 756 ppm Crosslinker: zirconium triethanolamine Zirconium concentration: 22 ppm Crosslinked pH: 9.0 Time (hrs.) RT 0 0.5 1 1.5 2 2.5 3 3.5 4 Visc. (cps) 55 94 108 120 111 103 96 87 - -ExamPle #5 Test temperature: 135C
Guar gum concentration: 0.60%
Bicarbonate concentration: 1453 ppm Crosslinker: zirconium triethanolamine Zirconium concentration: 26 ppm Crosslinked pH: 9.0 Time (hrs.) RT 0 1 2 3 4 5 6 7 8 Visc. ~cps) 115 247 274 235 199 180 155 137 133 109 Exam~le #6 Test temperature: 149C
Guar gum concentration: 0.72%
Bicarbonate concentration: 1453 ppm Crosslinker: zirconium triethanolamine Zirconium concentration: 26 ppm Crosslinked pH: 9.0 Time ~hrs.) RT O 0.5 1 1.5 2 2.' 3 3.5 4 Visc. ~cps) 167 394 307 269 226 196 157 138 115 100 ~;~8(~588 Exam~le ~7 Test temperature: 163C
Guar gum concentration: 0.72%
Bicarbonate concentration: 1453 ppm Crosslinker: zirconium triethanolamine Zirconium concentration: 26 ppm Crosslinked pH: 9.0 Time (hrs.) RT O 0.5 1 1.5 2 2.5 3 3.5 4 Visc. (cps) 154 236 140 58 27 --- --- --- --- ---The cross-linking agent is preferably an organic zirconium or an organic hafnium compound. Suitable organic zirconium compounds include either zirconium lactate or a zirconium complex of lactic acid, also known as 2-hydroxypropanoic acid. Suitable zirconium complex lactates include zirconium ammonium lactate, zirconium triethanolamine lactate, zirconium diisopropylamine lactate, and zirconium sodium trilactate salts. Corresponding hafnium lactate and hafnium complexes of lactic acid may be used as cross-linking agents. Titanium containing compounds such as titanium ammonium lactate and titanium triethanolamine may also be used as cross-linking agents in the practice of the present invention.
Other organic zirconium or organic hafnium compounds useful as cross-linking agents include monoalkylammonium, dialkylammonium and trialkylammonium zirconium or hafnium compounds obtained by reacting an organozirconate or an lZ80~88 organohafnate with monomethylamine, dimethylamine andtrimethylamine, monoethylamine, diethylamine, and - triethylamine, monoethanolamine, diethanolamine and triethanolamine, methyldiethanolamine, ethyldiethanolamine, dimethylethanolamine, diethylethanolamine, monoisopropanolamine, diisopropanolamine and triisopropanolamine, methyldiisopropanolamine, ethyldiisopropanolamine, dimethylisopropanolamine, diethylisopropanolamine, n-butylamine, sec. butylamine, dibutylamine and diisobutylamine. For example, a zirconium triethanolamine complex (Zr TEA) may be used as the cross-linking agent in the practice of the present invention. Zr TEA complexes are described in U.S. Patent 4,534,870 and U.K. Patent Application 2,108,122.
Other organozirconium compounds useful as cross-linking agents include citrates and tartarates such as zirconium sodium citrate and zirconium sodium tartarate.
The compositions of the present invention include a cross-linking agent as described above, a guar gum gelling agent, and a bicarbonate salt. The gelling agent is present in the agueous composition in a concentration in the range of from about 0.2 to 1.25%, preferably from about 0.2 to about 1.0% and most preferably from about 0.3 to about 0.8% by weight of the agueous fluid. A concentration of guar .~
lzso~aa gum of less than 0.2% by weight of the agueous flu$d is not sufficient to permit effective cross-linking.
- The cross-linking agent is present in an amount from about 5 ppm to at least about 50 ppm of the agueous fluid, and preferably in an amount from about 10 ppm to about 35 ppm.
The pH in the agueous fracturing fluid is preferably in the range from about 8 to about 10 depending on the cross-linking agent. Generally the bicarbonate salt stabilizing agent will be present in an amount from about 250 ppm to about 3000 ppm, and preferably in an amount from about 350 ppm to about 2250 ppm.
It is understood that various other modifications will be apparent to and can readily be made by those skilled in the art without departing from the scope and spirit of this invention. Accordingly, it is not intended that the scope of the claims appended hereto be limited to the description set forth above, but rather that the claims be construed as encompassing all the features which res~de in the present ~nvent~on, including all features which would be treated as eguivalents thereof by those skilled in the art to which this invention pertains.
Claims (20)
1. An aqueous fracturing fluid having a pH from about 8 to about 10, consisting essentially of:
guar gum in an amount from about 0.2 to about 1.25 weight percent to produce a fracturing fluid, at least one zirconium crosslinking agent in an amount from about 5 ppm to about 50 ppm to crosslink said guar gum, and a bicarbonate salt in an amount from about 250 ppm to about 3000 ppm, and sufficient to provide a relatively low viscosity at ambient temperature and a relatively high viscosity at elevated temperatures.
guar gum in an amount from about 0.2 to about 1.25 weight percent to produce a fracturing fluid, at least one zirconium crosslinking agent in an amount from about 5 ppm to about 50 ppm to crosslink said guar gum, and a bicarbonate salt in an amount from about 250 ppm to about 3000 ppm, and sufficient to provide a relatively low viscosity at ambient temperature and a relatively high viscosity at elevated temperatures.
2. The aqueous fracturing fluid set forth in claim 1, wherein said zirconium crosslinking agent is zirconium lactate.
3. The aqueous fracturing fluid set forth in claim 1, wherein said zirconium crosslinking agent is zirconium ammonium lactate.
4. The aqueous fracturing fluid set forth in claim 1, wherein said zirconium crosslinking agent is zirconium triethanolamine lactate.
5. The aqueous fracturing fluid set forth in claim 1, wherein said zirconium crosslinking agent is zirconium diisopropylamine lactate.
6. The aqueous fracturing fluid set forth in claim 1, wherein said zirconium crosslinking agent is zirconium sodium trilactate.
7. The aqueous fracturing fluid set forth in claim 1, wherein said zirconium crosslinking agent is a zirconium triethanolamine complex.
8. The aqueous fracturing fluid set forth in claim 1, wherein said zirconium crosslinking agent is zirconium sodium citrate.
9. The aqueous fracturing fluid set forth in claim 1, wherein said zirconium crosslinking agent is a zirconium sodium tartrate.
10. The aqueous fracturing fluid set forth in claim 1, wherein said zirconium crosslinking agent is a zirconium monoalkylammonium complex.
11. The aqueous fracturing fluid set forth in claim 1, wherein said zirconium crosslinking agent is a zirconium dialkylammonium complex.
12. The aqueous fracturing fluid set forth in claim 1, wherein said zirconium crosslinking agent is a zirconium trialkylammonium complex.
13. A process for hydraulically fracturing a subterranean formation penetrated by a wellbore, comprising:
preparing an aqueous fracturing fluid having a pH
from about 8 to about 10 consisting essentially of guar gum in an amount from about 0.2 to about 1.25 weight percent to produce a fracturing fluid, at least one zirconium crosslinking agent in an amount from about 5 ppm to about 40 ppm to crosslink said guar gum, and a bicarbonate salt in an amount from about 250 ppm to about 3000 ppm, and sufficient to provide a relatively low viscosity at ambient temperature and a relatively high viscosity at elevated temperatures, and introducing said aqueous fracturing fluid into said formation from said wellbore at a flow rate and pressure sufficient to produce a fracture in said formation.
preparing an aqueous fracturing fluid having a pH
from about 8 to about 10 consisting essentially of guar gum in an amount from about 0.2 to about 1.25 weight percent to produce a fracturing fluid, at least one zirconium crosslinking agent in an amount from about 5 ppm to about 40 ppm to crosslink said guar gum, and a bicarbonate salt in an amount from about 250 ppm to about 3000 ppm, and sufficient to provide a relatively low viscosity at ambient temperature and a relatively high viscosity at elevated temperatures, and introducing said aqueous fracturing fluid into said formation from said wellbore at a flow rate and pressure sufficient to produce a fracture in said formation.
14. The process of hydraulically fracturing a subterranean formation set forth in claim 13, wherein said zirconium crosslinking agent is zirconium lactate.
15. The process for hydraulically fracturing a subterranean formation set forth in claim 13, wherein said zirconium crosslinking agent is zirconium ammonium lactate.
16. The process for hydraulically fracturing a subterranean formation set forth in claim 13, wherein said zirconium crosslinking agent is zirconium triethanolamine lactate.
17. The process for hydraulically fracturing a subterranean formation set forth in claim 13, wherein said zirconium crosslinking agent is zirconium diisopropylamine lactate.
18. The process for hydraulically fracturing a subterranean formation set forth in claim 13, wherein said zirconium crosslinking agent is zirconium sodium trilactate.
19. The process for hydraulically fracturing a subterranean formation set forth in claim 13, wherein said zirconium crosslinking agent is zirconium triethanolamine complex.
20. An aqueous fracturing fluid having a pH from about 8 to about 10, consisting essentially of:
guar gum in an amount from about 0.2 to about 1.25 weight percent to produce a fracturing fluid, at least one organic hafnium crosslinking agent in amount from about 5 ppm to about 50 ppm to crosslink said guar gum, and a bicarbonate salt in an amount from about 250 ppm to about 3000 ppm and sufficient to provide a relatively low viscosity at ambient temperature and a relatively high viscosity at elevated temperatures.
guar gum in an amount from about 0.2 to about 1.25 weight percent to produce a fracturing fluid, at least one organic hafnium crosslinking agent in amount from about 5 ppm to about 50 ppm to crosslink said guar gum, and a bicarbonate salt in an amount from about 250 ppm to about 3000 ppm and sufficient to provide a relatively low viscosity at ambient temperature and a relatively high viscosity at elevated temperatures.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US080,738 | 1987-08-03 | ||
| US07/080,738 US4801389A (en) | 1987-08-03 | 1987-08-03 | High temperature guar-based fracturing fluid |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1280588C true CA1280588C (en) | 1991-02-26 |
Family
ID=22159293
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000553334A Expired - Lifetime CA1280588C (en) | 1987-08-03 | 1987-12-02 | High temperature guar based fracturing fluid |
Country Status (5)
| Country | Link |
|---|---|
| US (1) | US4801389A (en) |
| EP (1) | EP0302544B1 (en) |
| CA (1) | CA1280588C (en) |
| DE (1) | DE3871642T2 (en) |
| NO (1) | NO176731C (en) |
Families Citing this family (66)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2680827B1 (en) * | 1991-08-28 | 1999-01-29 | Inst Francais Du Petrole | USE OF NEW GEL COMPOSITIONS FOR REDUCING THE PRODUCTION OF WATER IN OIL OR GAS PRODUCING WELLS. |
| FR2668490B1 (en) * | 1990-10-29 | 1994-04-29 | Elf Aquitaine | SCLEROGLUCANE GEL APPLIES TO THE OIL INDUSTRY. |
| EP0506934B1 (en) * | 1990-10-29 | 1995-01-18 | Institut Francais Du Petrole | Use of gel-based compositions in reducing water inrush in oil or gas-producing wells |
| US5246073A (en) * | 1992-08-31 | 1993-09-21 | Union Oil Company Of California | High temperature stable gels |
| US5335733A (en) * | 1992-08-31 | 1994-08-09 | Union Oil Company Of California | Method for delaying gelation of a gelable polymer composition injected into a subterranean formation |
| US5957203A (en) * | 1992-08-31 | 1999-09-28 | Union Oil Company Of California | Ultra-high temperature stable gels |
| US5617920A (en) * | 1992-08-31 | 1997-04-08 | Union Oil Company Of California | Method for modifying gelation time of organically crosslinked, aqueous gels |
| US5305832A (en) * | 1992-12-21 | 1994-04-26 | The Western Company Of North America | Method for fracturing high temperature subterranean formations |
| US5363916A (en) * | 1992-12-21 | 1994-11-15 | Halliburton Company | Method of gravel packing a well |
| US5304620A (en) * | 1992-12-21 | 1994-04-19 | Halliburton Company | Method of crosslinking cellulose and guar derivatives for treating subterranean formations |
| US5681796A (en) * | 1994-07-29 | 1997-10-28 | Schlumberger Technology Corporation | Borate crosslinked fracturing fluid and method |
| US5614475A (en) * | 1995-04-25 | 1997-03-25 | Rhone-Poulenc Inc. | Carboxyalkyl substituted polygalactomannan fracturing fluids |
| US6024170A (en) * | 1998-06-03 | 2000-02-15 | Halliburton Energy Services, Inc. | Methods of treating subterranean formation using borate cross-linking compositions |
| US6230805B1 (en) * | 1999-01-29 | 2001-05-15 | Schlumberger Technology Corporation | Methods of hydraulic fracturing |
| US6737386B1 (en) * | 1999-05-26 | 2004-05-18 | Benchmark Research And Technology Inc. | Aqueous based zirconium (IV) crosslinked guar fracturing fluid and a method of making and use therefor |
| US6810959B1 (en) * | 2002-03-22 | 2004-11-02 | Bj Services Company, U.S.A. | Low residue well treatment fluids and methods of use |
| US8895480B2 (en) * | 2004-06-04 | 2014-11-25 | Baker Hughes Incorporated | Method of fracturing using guar-based well treating fluid |
| US7297665B2 (en) * | 2005-04-07 | 2007-11-20 | Halliburton Energy Services, Inc. | Fluids comprising zirconium isopropylamine crosslinking agents and associated methods |
| EP1885816A1 (en) * | 2005-04-07 | 2008-02-13 | Halliburton Energy Services, Inc. | Fluids comprising zirconium isopropylamine crosslinking agents and associated methods |
| US7264054B2 (en) * | 2005-04-07 | 2007-09-04 | Halliburton Energy Services, Inc. | Fluids comprising zirconium isopropylamine crosslinking agents and associated methods |
| US20070187098A1 (en) * | 2006-02-14 | 2007-08-16 | Putzig Donald E | Permeable zone and leak plugging using cross-linking composition comprising delay agent |
| US20070187102A1 (en) * | 2006-02-14 | 2007-08-16 | Putzig Donald E | Hydraulic fracturing methods using cross-linking composition comprising delay agent |
| US7122690B1 (en) | 2006-02-14 | 2006-10-17 | E. I. Du Pont De Nemours And Company | Process to prepare metal complex of N,N-bis(2-hydroxyethyl)glycine |
| US7732382B2 (en) * | 2006-02-14 | 2010-06-08 | E.I. Du Pont De Nemours And Company | Cross-linking composition and method of use |
| US20080108522A1 (en) * | 2006-11-07 | 2008-05-08 | Bj Services Company | Use of anionic surfactants as hydration aid for fracturing fluids |
| US20090078410A1 (en) | 2007-09-21 | 2009-03-26 | David Krenek | Aggregate Delivery Unit |
| RU2010122306A (en) * | 2007-11-02 | 2011-12-10 | Е.И.Дюпон де Немур энд Компани (US) | HIGH-TEMPERATURE ZIRCONIUM-CONTAINING WATER-BASED LIQUID AND ITS APPLICATION |
| US7857055B2 (en) * | 2007-12-07 | 2010-12-28 | Schlumberger Technology Corporation | High temperature fracturing fluids and method of use |
| US7754660B2 (en) * | 2007-12-18 | 2010-07-13 | E.I. Du Pont De Nemours And Company | Process to prepare zirconium-based cross-linker compositions and their use in oil field applications |
| DE602008002316D1 (en) * | 2008-01-28 | 2010-10-07 | Allessa Chemie Gmbh | Stabilized aqueous polymer compositions |
| MX364304B (en) * | 2008-02-29 | 2019-04-22 | Texas United Chemical Company Llc | Methods, systems, and compositions for the controlled crosslinking of well servicing fluids. |
| EP2166060B8 (en) | 2008-09-22 | 2016-09-21 | TouGas Oilfield Solutions GmbH | Stabilized aqueous polymer compositions |
| US9102855B2 (en) * | 2008-12-18 | 2015-08-11 | Schlumberger Technology Corporation | Removal of crystallinity in guar based materials and related methods of hydration and subterranean applications |
| US8030250B2 (en) * | 2009-07-17 | 2011-10-04 | Baker Hughes Incorporated | Method of treating subterranean formations with carboxylated guar derivatives |
| US8371383B2 (en) * | 2009-12-18 | 2013-02-12 | Baker Hughes Incorporated | Method of fracturing subterranean formations with crosslinked fluid |
| US9194223B2 (en) | 2009-12-18 | 2015-11-24 | Baker Hughes Incorporated | Method of fracturing subterranean formations with crosslinked fluid |
| US10538381B2 (en) | 2011-09-23 | 2020-01-21 | Sandbox Logistics, Llc | Systems and methods for bulk material storage and/or transport |
| USD703582S1 (en) | 2013-05-17 | 2014-04-29 | Joshua Oren | Train car for proppant containers |
| US8827118B2 (en) | 2011-12-21 | 2014-09-09 | Oren Technologies, Llc | Proppant storage vessel and assembly thereof |
| US9718610B2 (en) | 2012-07-23 | 2017-08-01 | Oren Technologies, Llc | Proppant discharge system having a container and the process for providing proppant to a well site |
| US9809381B2 (en) | 2012-07-23 | 2017-11-07 | Oren Technologies, Llc | Apparatus for the transport and storage of proppant |
| US8622251B2 (en) | 2011-12-21 | 2014-01-07 | John OREN | System of delivering and storing proppant for use at a well site and container for such proppant |
| US10464741B2 (en) | 2012-07-23 | 2019-11-05 | Oren Technologies, Llc | Proppant discharge system and a container for use in such a proppant discharge system |
| FR2988730B1 (en) | 2012-04-03 | 2015-01-16 | Snf Sas | NOVEL AQUEOUS FRACTURING FLUID COMPOSITION AND FRACTURING METHOD USING THE FLUID |
| US9340353B2 (en) | 2012-09-27 | 2016-05-17 | Oren Technologies, Llc | Methods and systems to transfer proppant for fracking with reduced risk of production and release of silica dust at a well site |
| US20190135535A9 (en) | 2012-07-23 | 2019-05-09 | Oren Technologies, Llc | Cradle for proppant container having tapered box guides |
| US9421899B2 (en) | 2014-02-07 | 2016-08-23 | Oren Technologies, Llc | Trailer-mounted proppant delivery system |
| USRE45713E1 (en) | 2012-11-02 | 2015-10-06 | Oren Technologies, Llc | Proppant vessel base |
| USD688351S1 (en) | 2012-11-02 | 2013-08-20 | John OREN | Proppant vessel |
| USD688772S1 (en) | 2012-11-02 | 2013-08-27 | John OREN | Proppant vessel |
| USD688350S1 (en) | 2012-11-02 | 2013-08-20 | John OREN | Proppant vessel |
| USD688349S1 (en) | 2012-11-02 | 2013-08-20 | John OREN | Proppant vessel base |
| US9446801B1 (en) | 2013-04-01 | 2016-09-20 | Oren Technologies, Llc | Trailer assembly for transport of containers of proppant material |
| USD688597S1 (en) | 2013-04-05 | 2013-08-27 | Joshua Oren | Trailer for proppant containers |
| CN103275689A (en) * | 2013-04-26 | 2013-09-04 | 亳州市顺兴植物胶有限责任公司 | Association fracturing fluid densifier and preparation method thereof |
| USD694670S1 (en) | 2013-05-17 | 2013-12-03 | Joshua Oren | Trailer for proppant containers |
| US11873160B1 (en) | 2014-07-24 | 2024-01-16 | Sandbox Enterprises, Llc | Systems and methods for remotely controlling proppant discharge system |
| US9676554B2 (en) | 2014-09-15 | 2017-06-13 | Oren Technologies, Llc | System and method for delivering proppant to a blender |
| US9670752B2 (en) | 2014-09-15 | 2017-06-06 | Oren Technologies, Llc | System and method for delivering proppant to a blender |
| EP3400188A4 (en) | 2016-01-06 | 2019-08-07 | Oren Technologies, LLC | Conveyor with integrated dust collector system |
| US10518828B2 (en) | 2016-06-03 | 2019-12-31 | Oren Technologies, Llc | Trailer assembly for transport of containers of proppant material |
| FR3064004B1 (en) | 2017-03-20 | 2019-03-29 | S.P.C.M. Sa | HYDRATED CRYSTALLINE FORM OF 2-ACRYLAMIDO-2-METHYLPROPANE SULFONIC ACID |
| CN108795402A (en) * | 2017-04-28 | 2018-11-13 | 深圳市百勤石油技术有限公司 | A kind of guanidine gum fracturing fluid and preparation method thereof for superhigh temperature reservoir |
| JP7127466B2 (en) * | 2018-10-04 | 2022-08-30 | 株式会社大林組 | Addition material |
| CN113583653A (en) | 2020-04-30 | 2021-11-02 | 爱森（中国）絮凝剂有限公司 | Novel aqueous fracturing fluid composition and fracturing method using the same |
| FR3126988A1 (en) | 2021-09-15 | 2023-03-17 | S.N.F. Sa | WATER SOLUBLE POLYMER DISPERSION FOR HYDRAULIC FRACTURING |
Family Cites Families (21)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3301723A (en) * | 1964-02-06 | 1967-01-31 | Du Pont | Gelled compositions containing galactomannan gums |
| US4021355A (en) * | 1970-12-14 | 1977-05-03 | Halliburton Company | Compositions for fracturing well formations |
| US3959003A (en) * | 1972-04-10 | 1976-05-25 | Halliburton Company | Thixotropic cementing compositions |
| US4033415A (en) * | 1973-03-30 | 1977-07-05 | Halliburton Company | Methods for fracturing well formations |
| US3979303A (en) * | 1974-01-21 | 1976-09-07 | Merck & Co., Inc. | Oil well drilling fluid |
| US3888312A (en) * | 1974-04-29 | 1975-06-10 | Halliburton Co | Method and compositions for fracturing well formations |
| US4313834A (en) * | 1978-10-02 | 1982-02-02 | Halliburton Company | High viscosity acidic treating fluids and methods of forming and using the same |
| US4324668A (en) * | 1978-10-02 | 1982-04-13 | Halliburton Company | High viscosity acidic treating fluids and methods of forming and using the same |
| AR247709A1 (en) * | 1981-10-29 | 1995-03-31 | Dow Chemical Co | Zirconium crosslinkers for solvatable polysaccharide solutions |
| US4683068A (en) * | 1981-10-29 | 1987-07-28 | Dowell Schlumberger Incorporated | Fracturing of subterranean formations |
| US4455241A (en) * | 1982-02-16 | 1984-06-19 | Phillips Petroleum Company | Wellbore fluid |
| NO824020L (en) * | 1982-04-22 | 1983-10-24 | Key Fries Inc | ZIRKONATFORTYKNINGSMIDLER. |
| NO824042L (en) * | 1982-04-22 | 1983-10-24 | Key Fries Inc | BISALKYL-BIS (trialkanolamine) zirconate. |
| US4534870A (en) * | 1982-06-28 | 1985-08-13 | The Western Company Of North America | Crosslinker composition for high temperature hydraulic fracturing fluids |
| US4477360A (en) * | 1983-06-13 | 1984-10-16 | Halliburton Company | Method and compositions for fracturing subterranean formations |
| US4579670A (en) * | 1984-03-26 | 1986-04-01 | Big Three Industries, Inc. | Control of crosslinking reaction rate of aqueous fracturing fluids |
| GB2165066B (en) * | 1984-09-25 | 1988-08-24 | Sony Corp | Video data storage |
| US4553601A (en) * | 1984-09-26 | 1985-11-19 | Halliburton Company | Method for fracturing subterranean formations |
| US4686052A (en) * | 1985-07-08 | 1987-08-11 | Dowell Schlumberger Incorporated | Stabilized fracture fluid and crosslinker therefor |
| US4657080A (en) * | 1986-02-19 | 1987-04-14 | Dowell Schlumberger Incorporated | Method of fracturing a subterranean formation using delayed crosslinker compositions containing organic titanium complexes |
| US4657081A (en) * | 1986-02-19 | 1987-04-14 | Dowell Schlumberger Incorporated | Hydraulic fracturing method using delayed crosslinker composition |
-
1987
- 1987-08-03 US US07/080,738 patent/US4801389A/en not_active Expired - Lifetime
- 1987-12-02 CA CA000553334A patent/CA1280588C/en not_active Expired - Lifetime
-
1988
- 1988-07-13 DE DE8888201498T patent/DE3871642T2/en not_active Expired - Fee Related
- 1988-07-13 EP EP88201498A patent/EP0302544B1/en not_active Expired - Lifetime
- 1988-08-02 NO NO883427A patent/NO176731C/en not_active IP Right Cessation
Also Published As
| Publication number | Publication date |
|---|---|
| NO176731C (en) | 1995-05-16 |
| NO176731B (en) | 1995-02-06 |
| US4801389A (en) | 1989-01-31 |
| NO883427L (en) | 1989-02-06 |
| DE3871642D1 (en) | 1992-07-09 |
| EP0302544A3 (en) | 1989-05-10 |
| NO883427D0 (en) | 1988-08-02 |
| DE3871642T2 (en) | 1992-12-10 |
| EP0302544A2 (en) | 1989-02-08 |
| EP0302544B1 (en) | 1992-06-03 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CA1280588C (en) | High temperature guar based fracturing fluid | |
| US6214773B1 (en) | High temperature, low residue well treating fluids and methods | |
| US4619776A (en) | Crosslinked fracturing fluids | |
| US5759964A (en) | High viscosity well treating fluids, additives and methods | |
| US4428432A (en) | Method for stimulating siliceous subterranean formations | |
| RU2490298C2 (en) | Method of preparing compositions of zirconium-based cross-linking agent and use thereof at oil deposits | |
| US4462917A (en) | Method and compositions for fracturing subterranean formations | |
| US4464270A (en) | Method and compositions for fracturing subterranean formations | |
| US4780223A (en) | Stabilized fracture fluid and crosslinker therefor | |
| US4477360A (en) | Method and compositions for fracturing subterranean formations | |
| CA2291245C (en) | Improved polymer expansion for oil and gas recovery | |
| US4502967A (en) | Method and compositions for fracturing subterranean formations | |
| US4514309A (en) | Cross-linking system for water based well fracturing fluids | |
| US5217632A (en) | Process for preparation and composition of stable aqueous solutions of boron zirconium chelates for high temperature frac fluids | |
| US6911419B2 (en) | High temperature seawater-based cross-linked fracturing fluids and methods | |
| US20050126778A1 (en) | Hydraulic fracturing using non-ionic surfactant gelling agent | |
| EP0677642B1 (en) | Method of breaking downhole viscosified fluids | |
| US20090114390A1 (en) | High temperature aqueous-based zirconium crosslinking composition and use | |
| US20010007850A1 (en) | Polymer expansion for oil and gas recovery | |
| EP0104927B1 (en) | Method and compositions for fracturing subterranean formations | |
| US20040235675A1 (en) | Oilfield treatment fluid stabilizer | |
| US4524003A (en) | Method of viscosifying aqueous fluids and process for recovery of hydrocarbons from subterranean formations | |
| US5798320A (en) | Gelation additive for hydraulic fracturing fluids | |
| US4566979A (en) | Stable mixture of crosslinkable components promptly activatable as acting treating agents | |
| EP0225873B1 (en) | Crosslinked fracturing fluids |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |