CA1071098A - Cleanout procedure for well with low bottom hole pressure - Google Patents
Cleanout procedure for well with low bottom hole pressureInfo
- Publication number
- CA1071098A CA1071098A CA280,207A CA280207A CA1071098A CA 1071098 A CA1071098 A CA 1071098A CA 280207 A CA280207 A CA 280207A CA 1071098 A CA1071098 A CA 1071098A
- Authority
- CA
- Canada
- Prior art keywords
- string
- well
- pipe
- gas
- sand
- 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
Links
- 238000000034 method Methods 0.000 title claims abstract description 43
- 239000012530 fluid Substances 0.000 claims abstract description 49
- 239000004576 sand Substances 0.000 claims abstract description 45
- 239000004020 conductor Substances 0.000 claims abstract description 18
- 238000004519 manufacturing process Methods 0.000 claims description 12
- 230000003068 static effect Effects 0.000 claims description 11
- 238000005406 washing Methods 0.000 claims description 6
- 230000004087 circulation Effects 0.000 claims description 4
- 208000036366 Sensation of pressure Diseases 0.000 claims description 2
- 230000003134 recirculating effect Effects 0.000 claims 2
- 230000015572 biosynthetic process Effects 0.000 description 5
- 238000005755 formation reaction Methods 0.000 description 5
- 238000010586 diagram Methods 0.000 description 4
- 239000003129 oil well Substances 0.000 description 4
- 238000004140 cleaning Methods 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 102000004726 Connectin Human genes 0.000 description 1
- 108010002947 Connectin Proteins 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 229910052729 chemical element Inorganic materials 0.000 description 1
- 230000002844 continuous effect Effects 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000006260 foam Substances 0.000 description 1
- 230000008595 infiltration Effects 0.000 description 1
- 238000001764 infiltration Methods 0.000 description 1
- 229920000136 polysorbate Polymers 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B21/00—Methods or apparatus for flushing boreholes, e.g. by use of exhaust air from motor
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B37/00—Methods or apparatus for cleaning boreholes or wells
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH DRILLING; MINING
- E21B—EARTH DRILLING, e.g. DEEP DRILLING; OBTAINING OIL, GAS, WATER, SOLUBLE OR MELTABLE MATERIALS OR A SLURRY OF MINERALS FROM WELLS
- E21B43/00—Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells
- E21B43/34—Arrangements for separating materials produced by the well
- E21B43/35—Arrangements for separating materials produced by the well specially adapted for separating solids
Abstract
CLEANOUT PROCEDURE FOR WELL
WITH LOW BOTTOM HOLE PRESSURE
(D#50,000 TTrin-56-F) Abstract of the Disclosure A cleanout procedure for use in a well with low bottom hole pressure that has become filled with sand. It employs a conductor string of pipe and a wash string of pipe inside the conductor string, both inserted in the well.
A high pressure gas is applied to the inner annulus formed by the conductor and wash string, and the workover wash fluid is circulated down the wash string up the outer an-nulus formed by the well casing and the conductor string, to be joined by the gas and so wash out the sand through the outer annulus. Sand is spearated at the surface.
-I-
WITH LOW BOTTOM HOLE PRESSURE
(D#50,000 TTrin-56-F) Abstract of the Disclosure A cleanout procedure for use in a well with low bottom hole pressure that has become filled with sand. It employs a conductor string of pipe and a wash string of pipe inside the conductor string, both inserted in the well.
A high pressure gas is applied to the inner annulus formed by the conductor and wash string, and the workover wash fluid is circulated down the wash string up the outer an-nulus formed by the well casing and the conductor string, to be joined by the gas and so wash out the sand through the outer annulus. Sand is spearated at the surface.
-I-
Description
~87~098 8ACKGRO~JND OF THE INVh'NTION
Field of the inven*ion This in~ention concerns oil well procedures in general, and particularl~ reIates to a cleanout pE~cedure for oil wells with lo~ ~ottom hole pressure w~ch ~a~e become sanded up.
Description of the- Prior Art Heretofore, when low pressure oil wells ~ecame clogged up by the infiltration of sand, it was necessary to remove such and ~y use of a wire line ~ailer. It was a relatively slow and consequently expensive procedure.
While other procedures are known, suc~ as the use of foam to circulate out the sand from the ~ott~m of t~e well, they may adversely affect the producing formation.
Another prior proposal is described in U.S. Patent No. 3,163,226. It employed special equipment and tools, which would have to be inserted downhole for the cleanout procedure and then remo~ed thereafter prior to producing ; once more.
Consequently, it is an object of this invention to provide a method of cleaning out a low pressure well, which method is very effective and time saving, without ha~ing any ad~erse effect on the producing formation or formations downhole.
S~nD~RY OF Tn~ INVENTION
Briefly, the in~ention concerns a cleanout pro-cedure for a low pressure ~ell containing sand fill, which procedure comprise~ the steps o insertin~ a first string of pipe in said well and forming an outer annulus there around in the ~eIl. T~e said first string extends ~elow .~, ~ ~7~0~8 the static fluid level in said well. The procedure also comprises inserting a second string of pipe inside said first string, and forming an inner annulus ~etween said strings. The said second str~ng extends adjacent to the top of said sand fill. The procedure also comprises appl~-ing gas under pressure to one of said annuli, and c~rcu-lating a wash fluid down said second string of pipe to wash out sand with gas entrained fluid through the other of said annuli.
Again briefly, the in~ention concerns a cleanout procedure for a low pressure well ha~ing a casing head and a string of producing tubing therein, and containing sand fill. The procedure comprises the steps of removing said production string, and determining the static fluid level a~d the level of sand fill in said well. It also comprises inserting a first string of conductor pipe in said well to form an outer annulus between the walls of said well and the outside of said conductor pipe string. It also com-prise~ landing said first string of conductor pipe for sup--~ 20 port thereof at said casing head, with the bottom above said sand fill level but below said static fluid, and con-necting an inlet connector for high pressure gas to the inside of said first string of conductor pipe. It also compriqes connecting an outlet connector for a return line to carry effluent from said outer annulus to a separator, and in~erting a second string of circulating fluid pipe -inside said first string of conductor pipe to form an înner annulus be~ween said first and second string~ It also comprises attaching said second string of pipe to a swiYel ` with the bottom of the string at the leveI of said sand
Field of the inven*ion This in~ention concerns oil well procedures in general, and particularl~ reIates to a cleanout pE~cedure for oil wells with lo~ ~ottom hole pressure w~ch ~a~e become sanded up.
Description of the- Prior Art Heretofore, when low pressure oil wells ~ecame clogged up by the infiltration of sand, it was necessary to remove such and ~y use of a wire line ~ailer. It was a relatively slow and consequently expensive procedure.
While other procedures are known, suc~ as the use of foam to circulate out the sand from the ~ott~m of t~e well, they may adversely affect the producing formation.
Another prior proposal is described in U.S. Patent No. 3,163,226. It employed special equipment and tools, which would have to be inserted downhole for the cleanout procedure and then remo~ed thereafter prior to producing ; once more.
Consequently, it is an object of this invention to provide a method of cleaning out a low pressure well, which method is very effective and time saving, without ha~ing any ad~erse effect on the producing formation or formations downhole.
S~nD~RY OF Tn~ INVENTION
Briefly, the in~ention concerns a cleanout pro-cedure for a low pressure ~ell containing sand fill, which procedure comprise~ the steps o insertin~ a first string of pipe in said well and forming an outer annulus there around in the ~eIl. T~e said first string extends ~elow .~, ~ ~7~0~8 the static fluid level in said well. The procedure also comprises inserting a second string of pipe inside said first string, and forming an inner annulus ~etween said strings. The said second str~ng extends adjacent to the top of said sand fill. The procedure also comprises appl~-ing gas under pressure to one of said annuli, and c~rcu-lating a wash fluid down said second string of pipe to wash out sand with gas entrained fluid through the other of said annuli.
Again briefly, the in~ention concerns a cleanout procedure for a low pressure well ha~ing a casing head and a string of producing tubing therein, and containing sand fill. The procedure comprises the steps of removing said production string, and determining the static fluid level a~d the level of sand fill in said well. It also comprises inserting a first string of conductor pipe in said well to form an outer annulus between the walls of said well and the outside of said conductor pipe string. It also com-prise~ landing said first string of conductor pipe for sup--~ 20 port thereof at said casing head, with the bottom above said sand fill level but below said static fluid, and con-necting an inlet connector for high pressure gas to the inside of said first string of conductor pipe. It also compriqes connecting an outlet connector for a return line to carry effluent from said outer annulus to a separator, and in~erting a second string of circulating fluid pipe -inside said first string of conductor pipe to form an înner annulus be~ween said first and second string~ It also comprises attaching said second string of pipe to a swiYel ` with the bottom of the string at the leveI of said sand
-2-: , , - . . . ..
107~098 fill, and applying high pressure gas to said inlet connector for unloading fluid from said inner annulus via said outer annulus. ~t also comprises starting to circulate wash fluid down through said second string of pipe while adj~st-ing said application of high pressure gas to maintain circu-lation in gentle surges, and washing down wit~ said second string of pipe to clean out said sand.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other o~jects and benefits of the invention will be more fully set fort~ ~elow in connec-tion with the best mode contemplated ~y the inventor of carrying out the invention, and in connection with which there are illustrations provided in the drawings, wherein:
FIG. 1 is a schematic sectional view, illustrating a well with equipment therein for carrying out a procedure according to this invention;
FIG. 2 is a block diagram illustrating a system including the various elements that are employed in carry-ing out a procedure according~to this invention; and FIG. 3 is a schematic diagram illustrating the details of a gas metering manifold, which is one of the elements indicated in FIG. 2.
DESCRIPTION OF THE PREFERRED EMBODIMENT
It has been found that because of the low bottom hole pressure in depleted oil wells, the normal procedure . for cleaning out sand b~ circulation was not possible.
The conventional method was wire line bailing of the sand, and that was found uneconomic especially whexe long down-hole intervals were involved. Furthermore, the wells tend-ed to sand up quickly after cleanout had ~een accomplished.
. . ., . . ~ . .
1~71098 And in addition, gelled fluids which have ~een used on wells with low fluid levels to o~tain circulation, have caused results which indicated that there was formation damage. Consequently, bailing of sand has remained the most usual clean out procedure.
In man~ oil fields, the num~er of weIls that are maintained on production is reduced ~ecause of the uneconomic ~ituation in re~ard to the necesæary cleanout for continuing production. Cleanout activ~t~ under the prior known arrangements is lim~ted ~y the economics of low producing wells. However, this invention pro~ides a circulating cleanout procedure that is useful for wells with low bottom hole pressure. It employs a high pressure gas to establish a fluid with sand return to the surface.
The procedure utilizes no special equipment, but makes use of a available high pre~sure gas source and a convenient circulating fluid~
Referring to the drawings, it will be observed from FIG. 1 that there is illustratad a ~-ased well 11 that has a casing head l2 at the surface. As indicated, the well 11 has become filled with sand 15 opposite the producing interval. And, because the well is a low pres-sure one, this sand 15 has choked off the production of oil and/or gas. Above the sand 15, there is well fluid 16 which has reached a static ~luid leval 17, illustrated.
Before the well 11 bec~me sanded up, there would have ~een production tu~in~ ~not shown~ for carrying the produced oil and/or gas from down hole to the surface.
Consequently, the cleanout method according to this inven-tion may involve a first step of moving o such production _4_ string in order to be able to proceed. Then a next stepof the procedure is to insert a first strin~ of conductor pipe 20 that forms an outer annulus 21 ~etween it and the walls of the well 11. This str~ng of conauctor pipe 20 will be extended down in the hole ~ith its ~otto~ end 22 above the level of the sand fill 15, fiut ~elow t~e level of the static fluid 16. The stri-ng 2Q-is landed Cfor sup-port) at the casing head 12, at a predetermined depth in the well.
There is an inlet flu~d connector 24 at the top of the ccnductor string 20, for introducing high pressure gas to the interior of the string. Also there is an outlet connector 25 that makes connection with the outer annulus 21 and is employed for carrying aerated fluid out from this outer annulus 21.
The source of high pressure gas might involve any feasible arrangement. However, there may be available at the field a suitable high pressure source being employed in gas lifting of oil from wells.
A second string of circulating fluid pipe 28 is inserted inside the first conductor string 20. It goes through appropriate equipment 29 at the well head which includes a blow-out preventer ~not shown) and a stripper (not shown). The string 28 forms an inner annulus 32 be-tween it and the conductor string 20, and it will be noted that the connector 24 connects with that inner annulus.
The top of the string 28 has a swivel 33 con-nected thereto. And, circulating fluid from a tank 36 is driven ~ a pump 37 down through the string 28 to the the level of the` sand 15 in the well.
.. . . .
-~7~98 Other equipment at the surface includes a sep~-rator 40 that has a gas vent line 41 from the top thereof.
It also has fluid connections 44 and 45 whic~ carry the effluent from the well, and the ret~rn of circulatin~
fluid respectively.
The separator 40 also has an outlet line 48 for removing sand from the bott~m of-the ~eparator 40. The removal is accomplished by washing it out using a water line inlet 49. The washed out sand will be accumulated in a sand pit (not shown~.~
FIG. 2 illustrates, ~y a schematic diagram, the various elements which are employed in carrying out a cleanout method according to the invention. It will ~e appreciated that a pulling unit 52 is needed. It is not illustrated in FIG. 1, but as indicated in FIG. 2 it pro-vides for the mechanical equipment to be located at the well head for accomplishing the necessary pulling of pro-duction tubing, as well as the inserting of the pipe strings which are employed in the cleanout procedure. Such mechan-ical relationship is illustrated in FIG. 2 by a dashedline 53. In the FIG. 1 illustration, there is an element of the pulling unit indicated by a schematic showing of a pulley block and hook combined unit 56. The hook supports the swivel 33 and the wash string 28, both described above.
FIG. 2 is in the nature of a ~lock layout diagram which shows fluid flow lines with val~es indicated at ap-propriate locations. Also, there are s~ne additional ele-ments that are not indicated in FIG. 1. For exarnple there is a storage tank 59 that is connected in parallel with the circulating tank 36. And there is a gas metering ... ~ . . : -. , . ~
~071(~98 manifold 63 that has some of the details thereof illus-trated in FIG. 3.
It will be understood that the hig~ pressure gas which is introduced int~ the well auring t~e cleanout process according to the invention, is controlled by the elements of the gas metering manifold 63. T~is ~anifold 63 is connected on the downstrea~ s~de of a ~alve 64.
The manifold 63 is employed for adjusting the introduct~on of the high pressure gas and controlling the flow thereof. It includes conventional meter connectors 67 and 68 plus a valve 69 and an adjusta~le choke 72. In addition, there is a pressure gauge 73 for determining the gas pressure that is being applied to the well.
CLEAN-OUT PROCEDURE
The procedure as it is carried out according to this invention, involves at least some of the following steps which (it will be appreciated) may or may not be necessarily in the order described.
First, the sanded well may have its production string (not shown) pulled by use of the pulling unit 52.
Then, or in conjunction therewith, there will be a deter-; mination made as to the static fluid level 16 in the well.
Also, the depth to the top of the sand fill 15 may be de-termined at that time.
Next, the conductor string 20 will be run into the well 11 to a predetermined depth. It will be run into the well and landed for support at the casin~ head 12.
This will be done with the bottom ab~ve the sand fill 15, at some predetermined depth ~eneath the static fluid leYel 17. , : ' . ' ~ ' ' ' : . ' - ' ~07~Q9~
Then, after connectin~ the necessary ~low-out ~reventer (not shown~ and a stripper ~ead ~not shown~ as part of the indicated equipment 29, the circulating fluid string 28 will be run into the well until it reac~es the top of the sand fill 15. Prefera~ly, th~s string of pipe will have at the bottom end 23 a full ~ore, special bit and a non-re~urn valve ~not shownl whic~ will assist in : the washing procedure as the well is cleaned out.
As the wash string 28 is run into the well, the swivel 33 which is attached to t~e top thereof, is con-nected to a circulating fluid line 76 that goes from the pump 37 to the swivel 33.
The gas metering manifold 63 will be connected to the inlet connector 24 via a gas line 77. And, the outlet connector 25 will be coupled up to the separator tank inlet connector 44 via a fluid line 80.
When the foregoing connections have been made, it is appropriate to test the connections for any leaks.
Thereafter the metering control valve, i.e. adjustable .
choke 72, will be opened wide, and also the unloader valve 69 in order to unload the fluid from the annuli 32 and 21. :
: Thereafter the unloader valve 69 will be closed and the wash fluid will be made to circulate down the wash string - 28 at an appropriate rate.
Then the choke 72 will be adjusted to maintain : sufficient gas preqsure down the inner annulus 32 so that , . .
.. . ..
., ~ ~ - . : . . :
- ~
1~71098 the flow of fluid will continue in gentle surges up the outer annulus 21 and out throu~h the connector 25 and fluid line 80 to the separator 40.
It will be appreciated that the washing fluid flow will pick up sand 15 and mix it with the well fluid 16 so that as the gas aerates the mixture it will all flow up the outer annulus 21 and out through the connector 25, the fluid line 80 and t~e connection 44 to the separator 40.
The washing operation is continued ~own the well as far as required to clean out all the sand 15. This may include adding sections of pipe to the circulating string 28, and this should ~e done with a minimum of delay. How-ever, if it is accomplished without shutting off the choke or metering control valve 72, the operation will be con-tinuous so as to avoid the necessity of offloading and re-adjusting at the metering manifold 63.
It will be understood that the procedure could be carried out with reversal of the direction of flow in the outer and inner annuli 21 and 32 respectively although the procedure described a~ove is preferred.
It may be noted that the procedure lends itself to the use of oil as the circulating fluid and consequently there will be no damage to the producing formation.
It will be understood that the gas which is used in this procedure ma~ be taken from the same source as that used in gas lift operations. Consequentl~, care must be exercised to maintain saety precautions.
While a particular em~odiment of the invention has been descri~ed a~ove in considera~le detail in accor-dance with the applicable statutes, this is not to be taken _g_ , ~07~098 aq in any way limiting the invention ~ut merely as being de~criptive thereof.
.
107~098 fill, and applying high pressure gas to said inlet connector for unloading fluid from said inner annulus via said outer annulus. ~t also comprises starting to circulate wash fluid down through said second string of pipe while adj~st-ing said application of high pressure gas to maintain circu-lation in gentle surges, and washing down wit~ said second string of pipe to clean out said sand.
BRIEF DESCRIPTION OF THE DRAWINGS
The foregoing and other o~jects and benefits of the invention will be more fully set fort~ ~elow in connec-tion with the best mode contemplated ~y the inventor of carrying out the invention, and in connection with which there are illustrations provided in the drawings, wherein:
FIG. 1 is a schematic sectional view, illustrating a well with equipment therein for carrying out a procedure according to this invention;
FIG. 2 is a block diagram illustrating a system including the various elements that are employed in carry-ing out a procedure according~to this invention; and FIG. 3 is a schematic diagram illustrating the details of a gas metering manifold, which is one of the elements indicated in FIG. 2.
DESCRIPTION OF THE PREFERRED EMBODIMENT
It has been found that because of the low bottom hole pressure in depleted oil wells, the normal procedure . for cleaning out sand b~ circulation was not possible.
The conventional method was wire line bailing of the sand, and that was found uneconomic especially whexe long down-hole intervals were involved. Furthermore, the wells tend-ed to sand up quickly after cleanout had ~een accomplished.
. . ., . . ~ . .
1~71098 And in addition, gelled fluids which have ~een used on wells with low fluid levels to o~tain circulation, have caused results which indicated that there was formation damage. Consequently, bailing of sand has remained the most usual clean out procedure.
In man~ oil fields, the num~er of weIls that are maintained on production is reduced ~ecause of the uneconomic ~ituation in re~ard to the necesæary cleanout for continuing production. Cleanout activ~t~ under the prior known arrangements is lim~ted ~y the economics of low producing wells. However, this invention pro~ides a circulating cleanout procedure that is useful for wells with low bottom hole pressure. It employs a high pressure gas to establish a fluid with sand return to the surface.
The procedure utilizes no special equipment, but makes use of a available high pre~sure gas source and a convenient circulating fluid~
Referring to the drawings, it will be observed from FIG. 1 that there is illustratad a ~-ased well 11 that has a casing head l2 at the surface. As indicated, the well 11 has become filled with sand 15 opposite the producing interval. And, because the well is a low pres-sure one, this sand 15 has choked off the production of oil and/or gas. Above the sand 15, there is well fluid 16 which has reached a static ~luid leval 17, illustrated.
Before the well 11 bec~me sanded up, there would have ~een production tu~in~ ~not shown~ for carrying the produced oil and/or gas from down hole to the surface.
Consequently, the cleanout method according to this inven-tion may involve a first step of moving o such production _4_ string in order to be able to proceed. Then a next stepof the procedure is to insert a first strin~ of conductor pipe 20 that forms an outer annulus 21 ~etween it and the walls of the well 11. This str~ng of conauctor pipe 20 will be extended down in the hole ~ith its ~otto~ end 22 above the level of the sand fill 15, fiut ~elow t~e level of the static fluid 16. The stri-ng 2Q-is landed Cfor sup-port) at the casing head 12, at a predetermined depth in the well.
There is an inlet flu~d connector 24 at the top of the ccnductor string 20, for introducing high pressure gas to the interior of the string. Also there is an outlet connector 25 that makes connection with the outer annulus 21 and is employed for carrying aerated fluid out from this outer annulus 21.
The source of high pressure gas might involve any feasible arrangement. However, there may be available at the field a suitable high pressure source being employed in gas lifting of oil from wells.
A second string of circulating fluid pipe 28 is inserted inside the first conductor string 20. It goes through appropriate equipment 29 at the well head which includes a blow-out preventer ~not shown) and a stripper (not shown). The string 28 forms an inner annulus 32 be-tween it and the conductor string 20, and it will be noted that the connector 24 connects with that inner annulus.
The top of the string 28 has a swivel 33 con-nected thereto. And, circulating fluid from a tank 36 is driven ~ a pump 37 down through the string 28 to the the level of the` sand 15 in the well.
.. . . .
-~7~98 Other equipment at the surface includes a sep~-rator 40 that has a gas vent line 41 from the top thereof.
It also has fluid connections 44 and 45 whic~ carry the effluent from the well, and the ret~rn of circulatin~
fluid respectively.
The separator 40 also has an outlet line 48 for removing sand from the bott~m of-the ~eparator 40. The removal is accomplished by washing it out using a water line inlet 49. The washed out sand will be accumulated in a sand pit (not shown~.~
FIG. 2 illustrates, ~y a schematic diagram, the various elements which are employed in carrying out a cleanout method according to the invention. It will ~e appreciated that a pulling unit 52 is needed. It is not illustrated in FIG. 1, but as indicated in FIG. 2 it pro-vides for the mechanical equipment to be located at the well head for accomplishing the necessary pulling of pro-duction tubing, as well as the inserting of the pipe strings which are employed in the cleanout procedure. Such mechan-ical relationship is illustrated in FIG. 2 by a dashedline 53. In the FIG. 1 illustration, there is an element of the pulling unit indicated by a schematic showing of a pulley block and hook combined unit 56. The hook supports the swivel 33 and the wash string 28, both described above.
FIG. 2 is in the nature of a ~lock layout diagram which shows fluid flow lines with val~es indicated at ap-propriate locations. Also, there are s~ne additional ele-ments that are not indicated in FIG. 1. For exarnple there is a storage tank 59 that is connected in parallel with the circulating tank 36. And there is a gas metering ... ~ . . : -. , . ~
~071(~98 manifold 63 that has some of the details thereof illus-trated in FIG. 3.
It will be understood that the hig~ pressure gas which is introduced int~ the well auring t~e cleanout process according to the invention, is controlled by the elements of the gas metering manifold 63. T~is ~anifold 63 is connected on the downstrea~ s~de of a ~alve 64.
The manifold 63 is employed for adjusting the introduct~on of the high pressure gas and controlling the flow thereof. It includes conventional meter connectors 67 and 68 plus a valve 69 and an adjusta~le choke 72. In addition, there is a pressure gauge 73 for determining the gas pressure that is being applied to the well.
CLEAN-OUT PROCEDURE
The procedure as it is carried out according to this invention, involves at least some of the following steps which (it will be appreciated) may or may not be necessarily in the order described.
First, the sanded well may have its production string (not shown) pulled by use of the pulling unit 52.
Then, or in conjunction therewith, there will be a deter-; mination made as to the static fluid level 16 in the well.
Also, the depth to the top of the sand fill 15 may be de-termined at that time.
Next, the conductor string 20 will be run into the well 11 to a predetermined depth. It will be run into the well and landed for support at the casin~ head 12.
This will be done with the bottom ab~ve the sand fill 15, at some predetermined depth ~eneath the static fluid leYel 17. , : ' . ' ~ ' ' ' : . ' - ' ~07~Q9~
Then, after connectin~ the necessary ~low-out ~reventer (not shown~ and a stripper ~ead ~not shown~ as part of the indicated equipment 29, the circulating fluid string 28 will be run into the well until it reac~es the top of the sand fill 15. Prefera~ly, th~s string of pipe will have at the bottom end 23 a full ~ore, special bit and a non-re~urn valve ~not shownl whic~ will assist in : the washing procedure as the well is cleaned out.
As the wash string 28 is run into the well, the swivel 33 which is attached to t~e top thereof, is con-nected to a circulating fluid line 76 that goes from the pump 37 to the swivel 33.
The gas metering manifold 63 will be connected to the inlet connector 24 via a gas line 77. And, the outlet connector 25 will be coupled up to the separator tank inlet connector 44 via a fluid line 80.
When the foregoing connections have been made, it is appropriate to test the connections for any leaks.
Thereafter the metering control valve, i.e. adjustable .
choke 72, will be opened wide, and also the unloader valve 69 in order to unload the fluid from the annuli 32 and 21. :
: Thereafter the unloader valve 69 will be closed and the wash fluid will be made to circulate down the wash string - 28 at an appropriate rate.
Then the choke 72 will be adjusted to maintain : sufficient gas preqsure down the inner annulus 32 so that , . .
.. . ..
., ~ ~ - . : . . :
- ~
1~71098 the flow of fluid will continue in gentle surges up the outer annulus 21 and out throu~h the connector 25 and fluid line 80 to the separator 40.
It will be appreciated that the washing fluid flow will pick up sand 15 and mix it with the well fluid 16 so that as the gas aerates the mixture it will all flow up the outer annulus 21 and out through the connector 25, the fluid line 80 and t~e connection 44 to the separator 40.
The washing operation is continued ~own the well as far as required to clean out all the sand 15. This may include adding sections of pipe to the circulating string 28, and this should ~e done with a minimum of delay. How-ever, if it is accomplished without shutting off the choke or metering control valve 72, the operation will be con-tinuous so as to avoid the necessity of offloading and re-adjusting at the metering manifold 63.
It will be understood that the procedure could be carried out with reversal of the direction of flow in the outer and inner annuli 21 and 32 respectively although the procedure described a~ove is preferred.
It may be noted that the procedure lends itself to the use of oil as the circulating fluid and consequently there will be no damage to the producing formation.
It will be understood that the gas which is used in this procedure ma~ be taken from the same source as that used in gas lift operations. Consequentl~, care must be exercised to maintain saety precautions.
While a particular em~odiment of the invention has been descri~ed a~ove in considera~le detail in accor-dance with the applicable statutes, this is not to be taken _g_ , ~07~098 aq in any way limiting the invention ~ut merely as being de~criptive thereof.
.
Claims (10)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. Cleanout procedure for a low pressure well containing sand fill, comprising the steps of inserting a first string of pipe in said well and forming an outer annulus therearound in the well, said first string extending below the static fluid level in said well, inserting a second string of pipe inside said first string and forming an inner annulus between said strings, said second string extending adjacent to the top of said sand fill, applying a gas under pressure to one of said annuli, and circulating a wash fluid down said second string of pipe to wash out sand with gas entrained fluid through the other of said annuli.
2. Cleanout procedure according to Claim 1, further comprising separating said washed out sand for disposal, and recirculating said wash fluid.
3. Cleanout procedure according to Claim 2, further comprising a first step of removing any production string of pipe from said well.
4. Cleanout procedure according to Claim 3, further comprising separating said gas from said gas entrained fluid.
5. Cleanout procedure according to Claim 1, wherein said gas is applied to said inner annulus.
6. Cleanout procedure according to Claim 2, wherein said gas is applied to said inner annulus.
7. Cleanout procedure according to Claim 3, wherein said gas is applied to said inner annulus.
8. Cleanout procedure according to Claim 4, wherein said gas is applied to said inner annulus.
9. Cleanout procedure for a low pressure well having a casing head and a string of production tubing therein and containing sand fill, comprising the steps of removing said production string, determining the static fluid level and the level of sand fill in said well, inserting a first string of conductor pipe in said well to form an outer annulus between the walls of said well and the outside of said conductor pipe string, landing said first string of conductor pipe for support at said casing head with the bottom above said sand fill level but beneath said static fluid level, connecting an inlet connector for high pres-sure gas to the inside of said first string of conductor pipe, connecting an outlet connector for a return line to carry effluent from said outer annulus to a sepa-rator, inserting a second string of circulating fluid pipe inside said first string of conductor pipe to form an inner annulus between said first and second strings, attaching said second string of pipe, to a swivel with the bottom of the string at the level of said sand fill, applying a high pressure gas to said inlet connector for unloading fluid from said inner annulus via said outer annulus, starting to circulate wash fluid down through said second string of pipe while adjusting said application of high pressure gas to maintain circulation in gentle surges, and washing down with said second string of pipe to clean out said sand.
10. Cleanout procedure for a well with low bottom hole pressure containing sand fill, comprising the steps of first removing any production string of pipe from said well, inserting a first string of pipe in said well and forming an outer annulus therearound in said well, said first string extending below the static fluid level in said well, inserting a second string of pipe inside said first string and forming an inner annulus between said strings, said second string extending adjacent to the top of said sand fill, applying a gas under high pressure to said inner annulus, circulating a wash fluid down said second string of pipe to wash out said sand with gas entrained fluid through said outer annulus, separating said washed out sand for disposal, separating said gas from said gas entrained fluid, and recirculating said wash fluid while continuing the foregoing steps until said sand fill has been removed from the well.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US05/700,624 US4060130A (en) | 1976-06-28 | 1976-06-28 | Cleanout procedure for well with low bottom hole pressure |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1071098A true CA1071098A (en) | 1980-02-05 |
Family
ID=24814253
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA280,207A Expired CA1071098A (en) | 1976-06-28 | 1977-06-09 | Cleanout procedure for well with low bottom hole pressure |
Country Status (7)
| Country | Link |
|---|---|
| US (1) | US4060130A (en) |
| AR (1) | AR216464A1 (en) |
| BR (1) | BR7701709A (en) |
| CA (1) | CA1071098A (en) |
| DE (1) | DE2717267A1 (en) |
| GB (1) | GB1562559A (en) |
| MX (1) | MX5065E (en) |
Families Citing this family (33)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4921577A (en) * | 1988-08-02 | 1990-05-01 | Eubank Dennis R | Method for operating a well to remove production limiting or flow restrictive material |
| US5113941A (en) * | 1990-11-07 | 1992-05-19 | Baker Hughes Incorporated | Surface sand detection monitoring device and method |
| GB9110451D0 (en) * | 1991-05-14 | 1991-07-03 | Schlumberger Services Petrol | Cleaning method |
| US5462118A (en) * | 1994-11-18 | 1995-10-31 | Mobil Oil Corporation | Method for enhanced cleanup of horizontal wells |
| US6189617B1 (en) * | 1997-11-24 | 2001-02-20 | Baker Hughes Incorporated | High volume sand trap and method |
| DK177747B1 (en) * | 1998-03-20 | 2014-05-26 | Mærsk Olie Og Gas As | Method for stimulation of an oil / gas well and equipment for use therewith |
| CN1071397C (en) * | 1998-11-16 | 2001-09-19 | 辽河石油勘探局欢喜岭采油厂 | Negative pressure sand-scouring technology and mechanism |
| US7073595B2 (en) | 2002-09-12 | 2006-07-11 | Cdx Gas, Llc | Method and system for controlling pressure in a dual well system |
| US8297377B2 (en) | 1998-11-20 | 2012-10-30 | Vitruvian Exploration, Llc | Method and system for accessing subterranean deposits from the surface and tools therefor |
| US6679322B1 (en) | 1998-11-20 | 2004-01-20 | Cdx Gas, Llc | Method and system for accessing subterranean deposits from the surface |
| US7025154B2 (en) | 1998-11-20 | 2006-04-11 | Cdx Gas, Llc | Method and system for circulating fluid in a well system |
| US6662870B1 (en) | 2001-01-30 | 2003-12-16 | Cdx Gas, L.L.C. | Method and system for accessing subterranean deposits from a limited surface area |
| US8376052B2 (en) | 1998-11-20 | 2013-02-19 | Vitruvian Exploration, Llc | Method and system for surface production of gas from a subterranean zone |
| US7048049B2 (en) | 2001-10-30 | 2006-05-23 | Cdx Gas, Llc | Slant entry well system and method |
| US6280000B1 (en) | 1998-11-20 | 2001-08-28 | Joseph A. Zupanick | Method for production of gas from a coal seam using intersecting well bores |
| US6988548B2 (en) * | 2002-10-03 | 2006-01-24 | Cdx Gas, Llc | Method and system for removing fluid from a subterranean zone using an enlarged cavity |
| US7360595B2 (en) | 2002-05-08 | 2008-04-22 | Cdx Gas, Llc | Method and system for underground treatment of materials |
| US6991048B2 (en) * | 2002-07-12 | 2006-01-31 | Cdx Gas, Llc | Wellbore plug system and method |
| US6991047B2 (en) | 2002-07-12 | 2006-01-31 | Cdx Gas, Llc | Wellbore sealing system and method |
| US7025137B2 (en) | 2002-09-12 | 2006-04-11 | Cdx Gas, Llc | Three-dimensional well system for accessing subterranean zones |
| US8333245B2 (en) | 2002-09-17 | 2012-12-18 | Vitruvian Exploration, Llc | Accelerated production of gas from a subterranean zone |
| US6964308B1 (en) | 2002-10-08 | 2005-11-15 | Cdx Gas, Llc | Method of drilling lateral wellbores from a slant well without utilizing a whipstock |
| US7264048B2 (en) | 2003-04-21 | 2007-09-04 | Cdx Gas, Llc | Slot cavity |
| US7134494B2 (en) | 2003-06-05 | 2006-11-14 | Cdx Gas, Llc | Method and system for recirculating fluid in a well system |
| US7100687B2 (en) | 2003-11-17 | 2006-09-05 | Cdx Gas, Llc | Multi-purpose well bores and method for accessing a subterranean zone from the surface |
| US7207395B2 (en) | 2004-01-30 | 2007-04-24 | Cdx Gas, Llc | Method and system for testing a partially formed hydrocarbon well for evaluation and well planning refinement |
| US7703529B2 (en) * | 2004-02-13 | 2010-04-27 | Schlumberger Technology Corporation | Gel capsules for solids entrainment |
| US7222670B2 (en) | 2004-02-27 | 2007-05-29 | Cdx Gas, Llc | System and method for multiple wells from a common surface location |
| US7571771B2 (en) | 2005-05-31 | 2009-08-11 | Cdx Gas, Llc | Cavity well system |
| EP2813664B1 (en) * | 2005-10-20 | 2018-08-22 | Transocean Sedco Forex Ventures Ltd. | Apparatus and method for managed pressure drilling |
| CN102383750B (en) * | 2011-09-28 | 2014-04-02 | 张作阳 | Continuous positive and negative integrated sand washing device for oil well |
| CN103233693B (en) * | 2013-05-08 | 2016-03-30 | 中铁隧道集团一处有限公司 | Drilled pile pile foundation secondary pile hole cleaning device and clear hole method |
| CN106677727A (en) * | 2016-12-20 | 2017-05-17 | 西安迈克斯石油技术有限公司 | Continuous negative pressure sand washing device and system thereof |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US1484601A (en) * | 1922-11-06 | 1924-02-19 | Robert E Carmichael | Well cleaner |
| US2768694A (en) * | 1952-03-26 | 1956-10-30 | Union Rheinische Braunkohlen | Method for forming and renewing wells |
| US2726063A (en) * | 1952-05-10 | 1955-12-06 | Exxon Research Engineering Co | Method of drilling wells |
| US3268017A (en) * | 1963-07-15 | 1966-08-23 | Shell Oil Co | Drilling with two fluids |
| US3464495A (en) * | 1967-09-11 | 1969-09-02 | Exxon Production Research Co | Washing a well |
| US3534822A (en) * | 1967-10-02 | 1970-10-20 | Walker Neer Mfg Co | Well circulating device |
| US3497020A (en) * | 1968-05-20 | 1970-02-24 | Archer W Kammerer Jr | System for reducing hydrostatic pressure on formations |
-
1976
- 1976-06-28 US US05/700,624 patent/US4060130A/en not_active Expired - Lifetime
-
1977
- 1977-03-21 BR BR7701709A patent/BR7701709A/en unknown
- 1977-03-31 GB GB13724/77A patent/GB1562559A/en not_active Expired
- 1977-04-19 DE DE19772717267 patent/DE2717267A1/en not_active Withdrawn
- 1977-04-29 AR AR267425A patent/AR216464A1/en active
- 1977-05-02 MX MX775689U patent/MX5065E/en unknown
- 1977-06-09 CA CA280,207A patent/CA1071098A/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| GB1562559A (en) | 1980-03-12 |
| DE2717267A1 (en) | 1978-01-05 |
| MX5065E (en) | 1983-03-09 |
| AR216464A1 (en) | 1979-12-28 |
| BR7701709A (en) | 1978-07-04 |
| US4060130A (en) | 1977-11-29 |
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