US2828823A - Reinforced inflatable packer - Google Patents

Description

April 1, 1958 w. D. MQUNcE REINFORCED INFLATABLE PACKER 3 Sheets-Sheet 1 Filed July 7, 1955 A TTOR/VEY.

prl l, 1958 w. D. MoUNcE REINFORCED INFLATABLE PACKER s sheets-sheet 2 Filed July 7, 1955 2 L ,..Ctb

INVENTOR.

Whitman D. MOL/nce /V/J/ @y 1f-M 21x12 3 Sheets-Sheet 3 Filed July 7, 1955 F/AG. Z

INVENTOR. WIr/'Iman D. Mou/we,

#Ma TM A T TORNE Y.

United States Patent O REINFORCED INFLATABLE PACKER Whitman D. Mounce, Houston, Tex., assigner, by mesue assignments, to Esso Research and Engineering Company, Elizabeth, N. J., a corporation of Delaware Application July 7, 1955, Serial No. 520,424

Claims. (Cl. 16o-187) This invention relates to well packers. More particuularly, this invention relates to an improved well packer of sturdy construction which will not leas or brealsunder the high pressures often found in well operations.

This invention is a continuation-in-part of my copending application Serial No. 417,559 filed March 22, 1954, in the name of Whitman D. Mounce, now Patent No.A 2,779,419.

In well operations, a packer is often used to seal off a portion of the well in order to carry out certain operations above or below the location of the packer. instances, two packers are used vertically spaced from each other in order to seal off specific formations for tlie purpose of taking drill stem tests. It is essential while carrying out the aforementioned operations that one have a packer which can be depended on under very high pressures. A great many packers have been devised which usually include a Yrubber resilient member which is inflated in order to seal off the area to be investigated. These rubber packers have often been not sturdy enough to withstand the high pressures which may reach 50G In some pounds per square inch or more, and have tended to leak i.

Vor break. In attempts to provide a packer which can withstand the high pressures often found within a well, packers have been constructed which include a resilient expansible tubular member mounted about a shaft or tubing. The resilient expansible tubular member is connected, at its extremities, to an upper plate and a lower plate, at least one of said plates being slidable. Reinforcement cables, such as steel cables, may be included in the resilient expansible tubular member. However, if the platel at the high pressure end is free to move on the shaft and the load of the hydrostatic head is carried by the plate at the low pressure end, there is a tendency for the reinforced rubber packer to be forced into the annular space between the low pressure end plate and the borehole wall. This produces sharp kinks in the reinforcing cables which prevent the packer from returning to its original diameter when deflated. On the other hand, if the end plate at the high pressure end of the packer is fixed and the low pressure end is free to slide, no cable kinking occurs, but the full load of the fluid column is carried by the reinforcing cables, which limits the load which can be carried to the tensile strength of these cables. The reason the full load is carried by the cables is that if the plate on the low pressure end is free to slide without restraint,

it offers no support to the load and the entire load is carexpansible tubular member a very sturdy packer can be constructed which will withstand a very high pressure. The combination of my new reinforcing means included f. ICC

in the expansible tubular member and a hydraulic load adjusting system produces a well packer which is very sturdy and capable of withstanding pressures far greater than the pressures which former well packers have been able to withstand.

Briefly described, my new inflatable well packer has a means for maintaining tension on the resilient inflatable packer thereby preventing the formation of kinks in the packer. The tensioning means may, for example, include a hollow cylindrical top support, which is filled with liquid before the packer is inflated and slidably mounted about a shaft. The cylindrical topV supportY has dise posed therein a cylindrical. member which isrelatively stationary and rests on the bottom of the cylinder when the packer is not inflated. The cylindrical member extends laterally from said shaft. At least one liquid passageway is provided within the shaft and leads from the hollow cylinder so as to permit the flow of liquid from the cylinder upon any downward movement of said hollow cylinder, the downward movement causing the cylindrical member to force the liquid through the liquidpassageway. The liquid passageway leads to a space defined by a second cylindrical member also mounted upon the shaft and having an upturned flanged portion and a lower packer plate. The second cylindrical member serves to confine the liquid flowing into it and also serves to guide said lower packer plate. By thismeans, after the well packer has been inflated, any pressure exerted against the packer, such as the pressure of a fluid column, is transmitted through the liquid passageway to the upper cylindrical support thereby tensioning the inflatable resilient packer andv dividing theload of the fluid column between the top support member and bottom support member. The reinforcing means of my newimprovedV packer may include a pleated sock which is arranged about reinforcing cables to aid in the reinforcement of thetubular expansible member. The cylindrical sock which is pleated about its periphery, preferably is located along the lower por-v tion of the tubular expansible member as it is along this portion that knking Vand breaking of the tubular expansible member occurs."V An alternative reinforcing means disclosed consists of a braided tubular member which is disposed between aninner expansible tubularrmember and an outer eXpansible' tubular member.

Various other objects, advantages and features of my invention will become more apparent from the following description taken in conjunction with the accompanying drawing, in which Fig. 1 is a sectional elevational View of one embodiment of my improved packer shown in the deflated position;

of Fig. 1 shown in an inflated position;

Fig. 3 is an elevational View showing the manner in which the reinforcing sock is arranged to reinforce the cables of the embodiment of Fig. 1; l

Fig. 4 is a View taken along line 4 4 of Fig. 3 showing the position of the sock when the packer is in the deflated position;

Fig. 5 is a view similar to Fig. 4 showing the position of the sock when the tubular expansible member is in the inflated position;

Fig. 6 is a sectional elevational view of another modification of my new improved well packer;

Fig. 7 is an elevational view partly in section showing the braided tubular member utilized in the embodiment shown in Fig. 6; and

Fig. 8 is an elevational view partly in section showing the braided tubular member utilized in the embodiment shown in Fig. 6 when the packer has been inflated.

Referring to the drawing, and specifically to Fig. 1,

Fig. 2 is a sectional elevational view of the embodiment numeral 3 indicates a well into which my new packer has been inserted. Though one packer is shown in the drawing, it is to be understood that if it is desired to carry on operations which necessitate the use of two or more packers, my invention can be equally effective by utilizing any number of packers each of which is of a similar construction to that shown in Fig. l. The packer is supported by a cylindrical shaft 4 about which are disposed an upper cylindrical plate member `5 and a lower cylin drical plate member 6. Plate members 5 and d are coaxial lwith the shaft 4 and are vertically spaced from each other. Connected to said plate members 5 and 6 by vulcanization and bonding is a resilient and expansible tubular member 7. Plates 5 and 6 are movable longitudinally along shaft 4 and 'hence move toward Vone another when Vthe resilient member 7 is inflated. in order to provide a sturdier resilient member 7, a plurality of reinforcement cableslS may be imbedded longitudinally in said resilient and expansible member '7. Cables 8 may desirably be made of steel although it will be understood that other suitable material may be employed. To further reinforce my new packer at the lower portion of the tubular member 7, where failure would most likely occur, a spring sock 30 is also imbedded within the rubber expansible tubular member 7. As an alternative, the sock 3G may be made of nylon cord.

In order to iniiatethe packer 7, a tubular passageway 10 is provided. This passageway is connected to a pump (not shown) or any other suitable means for inflating and deflating the packer member 7 and opens into the annular space between resilient member 7 and shaft 4. A lower end plate cylindrical receiving member 11 having an annular flanged portion 12 is integrally connected to the cylindrical shaft 4, the cylindrical receiving member 11 serving to slidably receive the lower end plate member 6. The lower end plate member 6 has a reduced diameter portion 13. The reduced diameter portion 13 fits snugly into the annular flanged portion 12 of the receiving member 11.

A cylindrical cap 14 is integrally connected to the top support plate 5 thereby formingwith said top support plate 5 a hollow cylindrical member 156. Integrally connected to the cylindrical shaft member 4 is a solid cylindrical member 15 which is disposed within the hollow cylinder. This cylindrical member 15 is stationary and downward movement of the hollow cylinder 16, when the inllatablepacker 7 is inflated, results in the solid cylindricalv member 15V forcing liquid contained within the hollow cylinder 16 through a liquid passageway`17 located in shaft 4 and into a chamber 18 (Fig. 2) defined by plated and receiving member 11.

When the packer is utilized for taking drill stem tests,

l an additional passageway 9 (shown in'dotted lines) must be put into shaft 4, passageway 9 serving to conduct to the surface the formation fluid to be tested.

in Fig. 2 there is shown my new improved packer in an inflated position. As is shown in Fig. 2,- the upper plate 5 and the lower plate 6 have moved toward each other thereby forcing the liquid contained within the hollow cylindrical member 16 through the passageway 17 into the space 18 which is formed between the lower plate member 6 and the receiving member 11 due to the upper movement of the lower plate member 6. The liquid contained in space 19, the liquid passageway 17 and the space 18, remains the'same in volume because any decrease in volume in space 19 results in an equal increase in volume in space 1S since the cross sectional areas of the spaces 19 and 18 are the same. Hence there is no longitudinal movement of the resilient tubular member 7 during its lateral expansion.

To prevent the escape of liquid through the small spaces between the slidingsurfaces of Vmy new packer, it is advisablerto include rubber O-ring 20 in a'groove formed in cap 14, rubber O-ring 21, placed in a groove'formed in the cylindrical member 15, rubber O-ring 22, in a the packer leaves the wall of the hole.

groove formed in place member 5 and rubber O- rings 23 and 24 in grooves formed in plate member 6.

Figs. 3, 4 and 5 illustrate the arrangement of the lower portion of the cables 8 and the soclr member 30. The sock member 3d is of a substantially cylindrical shape having its periphery folded to form outwardly facing pleats 31 and inwardly facing pleats 32. Both the outwardly facing pleats 31 and the inwardly facing pleats 32 are formed by fitting steel or other strong reinforcing material about the cables 8 so as to provide vertically stacked pleats.

The sock member 3Q may be formed by winding annealed spring wire about a series of pins of the proper size and position, and then heat treating them in place to obtain the desired tensile strength and elasticity of the spring material. The sock member is then taken olf the forming pins and snapped into position on the vertical supporting cables at the low pressure end of the packers. Rubber is then moulded onto the packer. Each of the cables 8 is disposed within an outwardly facing pocket 33 formed by a vertical stack of inwardly facing pleats.

Fig. 4 and Fig. 5 are views showing the positions of the cables and pleats when the expansible tubular member 7 is deflated and inflated, respectively. As shown in Fig. '4, when the packer is in the deflated position the base of the pockets formed by the pleats 31 and 32 are relatively nar'- row and the height is relatively long when compared to the base and height of the pockets formed by the pleats 31 and 32 when the expansiible tubular member 7 is in the inflated position. This expansion of the base of the pockets is caused by the tension on the pleats 31 andv 32 as a result of the pressure applied against the inflatable member 7 by the inllation iluid.

As previously stated, when a packer is inflated 'under high pressures there is a strong tendency of the'deformable rubber tubular member to extrude through the reinforcing means. This extrusion most often occurs at the lower end of the tubular member below the point where For this'reason, the spring sock 30 is placed just above the lower 'plate member 6, as shown in Figs. l and 2. A reinforcing means, inorder to prevent the extrusion of the rubber material when high pressures are applied, must lbe ableto stretch to half again its Yoriginal length Vand return `toits original length when the packer is dellated.` ,"Former'reinforcing means, such as barrel hoops, do not satisfy the foregoing requirements. My new spring sock 30,"however, satisfies these requirements. The springsock 30, when expanded under high pressures, flexibly retains the expanding rubber tubular member 7. Also, the pressure exerted against the pockets formed by the outwardly facing pleats is transmitted to the cables 8. Furthermore, the spring sock 30 does not restrain the vertical supporting cables from assuming the curvature they tend to as'- sume where the inflated packer leaves the wall of the hole.

Fig. 6 shows a further modification of my new improved inatable packer utilizing an inner expansible tubular member 40 and an outer expansible tubular member 41 separatedby a braided reinforcing means 42 in place of the single expansible tubular member 7 and the cables 8 reinforced by the spring sock 30, as shown in the modification of Figs. l and 2. Located at each end of the expansible tubular member 40 is a sleeve 43. Sleeve 43 is arranged coaxially with shaft 4 and 'is of a cylindrical shape having a continually decreasing outside diameter. Provided within each of the sleeves 43 is a cup 44 having a rounded bottom 4S and llared sides 46. The outer expansible tubular member 41'is bonded to a wedge member 47. The wedge member 47 serves to wedge the longitudinal ends of braided means 42 against the sleeve member 43. To provide an additional gripping action against the ends of the braided member 42 the tapering surface '43 of sleeve member 43 is knurled.

To effect the. wedging action of wedge 47 and the knurled surface 43' of sleeve '43 extensions 48 are provided inthe upper plate and the lower plate 6. YThe upper cylindrical member i6 and the lower plate member -6 are screwed upon the base of sleeve members 43 into tight engagement against the ibase 49 of the wedge members 47. The pressure of extensions 48 against the bases 49 of wedge members-47 presses the longitudinal exten* sions of braided mem-ber 42 against the knurled surfaces of sleeve 43 to hold the braided member in tight engagement. The ends of the inflatable sleeve 4t) form lip portions 40' which are fittingly arranged in the cups 44 of the members 43. As seen more clearly in Fig. 6, the lip portions 40 extend along the shaft 4 to provide chambers 44 which fluidly communicate with passageway 1f? upon the application of fluid pressure to the inflatable member 40. The pressure is applied to the interior of the packer and enterslthe fluid chambers 44 to seal the interior of the lip portions 40 of the inflatable member 4l) against the shaft 4` thereby preventing escape of fluid pressure.

,'Figs. 7 and 8 are views showing the positions of the braided tubular member 42 in the deflated position and inflated position, respectively. in Figs. 7 and 8 the outer tubular expansible member di has been partially removed to more'clearly show the action and configuration of the braided member 42. The braided member consists of interwoven metal bands 50. Each of the interwoven metal bands 50 is made from elongated strings of metal which are arranged closely adjacent one another to form the :metal bands 50. The bands 50 are each arranged helically between. theupper support member. and the lower support member.

In operation, therefore, the packer is first lowered into the well to the location where it is desired to either seal ofi` the well against the well bottom, or in the case where two packers are utilized, to seal off the formation 'between the two packers, to take tests of specific formations within the well. The packer is then inflated by means of tube 10 until it fits firmly against the side of the well. After the packer has been inflated, any pressure such as that due to the hydrostatic mud column exerted on the packer tends to push plate member 6 downwardly. This pressure is transmitted through the liquid in space 1S, tube 17 and space 19 to the upper portion of the hollow cylindrical member 16. The upper portion of member 16 is integrally connected to the upper plate 5 so that the force exerted against the upper portion of the cylindrical member is also exerted on the upper plate 5. Hence the expansible packer members are maintained under tension and no kinks will form within the members. Also, the hydrostatic load is divided between end plates 5 and 6 in order that a greater load may be carried than would be possible otherwise. Further reinforcement of the tubular expansible members thus permitting an even higher pressure to be exerted upon the tubular packer member is provided by reinforcing means such as the spring sock Sti or the braided tubular member 42.

The above described packer -apparatus is given only for illustrative purposes and should not be regarded as limiting the invention the scope of which is set forth in the following claims.

I claim:

1. A well packer comprising a shaft, first and second spaced apart supporting means slidably arranged on said shaft, spaced apart members each having outer inwardly tapering knurled surfaces and inner cup shaped surfaces connected to each of said supporting means, respectively, a reinforcing sleeve engaging with said knurled surfaces adjacent the ends thereof, first and second wedge members engaging with said first and second supporting means respectively `and having inwardly tapering surfaces parallel to said first and second knurled surfaces respectively engaging with said reinforcing sleeve adjacent the ends thereof, an outer expansible sleeve member secured to said wedge members adjacent each end thereof, an inner inflatable sleeve member surrounding said shaft and forming sealing means including vcups adjacent the ends thereof, a fluid passageway in said shaft communi` cating with the interior of said inflatable member adapted to supply fluid to inflate said inflatable member and to fluidly communicate with said fluid chambers to` seal said inflatable member to said shaft adjacent the ends thereof.

2. A device as recited in claim l including a first stationary member arranged on said shaft cooperating with said first supportingmeans to provide a first fluid chamber above said stationary member, a second stationary member arranged on said shaft cooperating with said second supporting means to provide a second fluid chamber below said second supporting means and means in said shaft fluidly intercommunicating saidfirst and second chambers.

3. A device as recited in claim 1 wherein said reinforcing sleeve comprises helically arranged braided bands.

4. A well packer comprising a shaft, rst and second spaced apart supporting means slidably'arranged on said shaft, reinforcing means surrounding said shaft, wedging means arranged on said shaft adapted to secure the ends of said reinforcing means, an inflatable sleeve member surrounding said shaft and formed to provide means including cups adjacent the ends thereof adapted to seal off fluid how between said sleeve and said shaft, a first stationary member arranged on said shaft co-operating with said first supporting meansn to provide alrst fluid chamber above said first stationary member, a second stationary member arranged on said shaft co-operating with said second supporting means to provide a second fluid chamber below said second supporting means, means in said shaft uidly intercommunicating said first and second chambers and a fluid passageway in said shaft communicatingv with the interior of said inflatable member adapted to supply fluid to inflate said inflatable member and seal the ends of said inflatable member to said shaft.

5. A device as recited in claim 4 wherein said reinforcigig means therefor comprises helically arranged braided ands.

6. A device as recited in claim 4 wherein said reinforcing means comprises a cylindrical sock arranged adjacent one end of said inflatable sleeve member and cables extending the length of said inflatable sleeve member, the sock being cylindrically configured and formed to provide inwardly and outwardly facing pleats, said cables being arranged in said inwardly facing pleats.

7. A well packer comprising a shaft, first and second spaced apart supporting means slidably arranged onsaid shaft, reinforcing means surrounding said shaft, means arranged on said shaft adapted to secure the ends of said reinforcing means, an inflatable sleeve member surrounding said shaft and formed to provide means including cups adjacent the ends thereof adapted to seal oil. fluid flow between said sleeve and said shaft, a rst stationary member arranged on said shaft cooperating with said first supporting means to provide a first fluid chamber above said first stationary member, a second stationary member arranged on said shaft cooperating withv said second supporting means to provide a second fluid chamber below said second supporting means, means' in said i shaft fluidly intercommunicating lsaid first and second chambers and a fluid passageway in said shaft communieating with the interior of said inflatable member adapted to supply fluid to inflate said inflatable member and seal the ends of said inflatable member to said shaft.

8. A well packer comprising a shaft, first and second spaced apart supporting means slidably arranged on said shaft, reinforcing means surrounding said shaft, means arranged on said s haft adapted to secure the ends of said reinforcing means, an inflatable sleeve member surrounding said shaft, the ends of which are formed to provide lip portions engaging with saidshaft, said lip portions forming uid chambers, a fluid passageway in said shaft communicating with the interior of said inflatable member and said fluid chambers adapted to supply fluid to inflate said inflatable member and seal the ends of said asaasas inflatable member to said shaft, said reinforcing means comprising a single layered cylindrical helically configured ybraided sheath, a first stationary member arranged on said shaft cooperating with said rst supporting means to provide a first fluid chamber above said first stationary member, al second stationary member arranged on said shaft cooperating with said second supporting means to provide a second fluid chamber below said second supporting means, and means in said shaft fluidly intercommunicating said rst and second chambers.

9. A well packer comprising a shaft, first and second spaced apart supporting means slidably arranged on said shaft, reinforcing means surrounding said shaft, means arranged on said shaft adapted to secure the ends of said reinforcing means, an inflatable sleeve member surrounding said shaft, the ends of which `are formed -to provide lip portions engaging with said shaft, said lip portions ,forming fluid chambers, a fluid passageway in said shaft communicating with the interiorfof said inflatable member and with said fluid chambers adapted to supply fluid to inflate said inatable member and ,seall the ends of said inatablemember tosaid shaft, said reinforcing means comprising a single layered cylindrical helicallyI braided sheath extending substantially the length of said sleeve member. j

l0. A well packer comprising a shaft, rst and second lsupporting means slidably arranged on said shaft, spaced apart members each having outer inwardly tapering knurled surfaces and inner cup-shaped surfaces screwthreadedly connected to said supporting means, reinforcing means surrounding said shaft and engaging with said ltnurled` surfaces adjacent the ends thereof, said reinforcing means including a cylindrical pleated sock arranged adjacent one end of said inflatable sleeve member and cables extending the length of said inflatable sleeve member, first and second wedge members engaging with said first Iand second supporting means, respectively, and having inner inwardly tapering surfaces parallel to said rst and second knurled surfaces, respectively, engaging with said reinforcing means adjacent the ends thereof, an outer eX-pansible sleeve member secured to said wedge members adjacent the inner ends thereof, an inner inatable sleeve member arranged adjacent said shaft and having sealing lip portions at the ends thereof, said lip portions being fittingly arranged on said cup-shaped surfaces and the surfaces of said shaft adjacent thereto to provide cups in said inflatable sleeve, a fluid passageway in said shaft communicating with the interior of said inatable member adapted to supply fluid to inflate said inflatable member and seal said inflatable member to said shaft adjacent the ends thereof.

References Cited in the le'of this patent UNITED STATES PATENTS Fewel Aug. 16, 1.955

Images