US3327785A - Fluid ejection apparatus for well completion tools - Google Patents

Description

June 27, 1967 E. F. BRIEGER FLUID EJECTION APPARATUS FOR WELL COMPLETION TOOLS heat 5 Sheet -S Filed March 11, 1965 INVENTOR.

June 27, 1967 E. F. BRIEGER 3,327,785

FLUID EJECTION APPARATUS FOR WELL COMPLETION TOOL Z1 Filed March ll, 1965 {'3 $heets-$heet fmme 2 f. B/vegev INVENTOR.

june 27, 1967 E. F. BRIEGER 3,327,785

FLUID EJECTION APPARATUS FOR WELL COMPLETION TOOLS Filed March 11, 1965 5 Sheets-Sheet. 3

I N VENTOR United States Patent 9 3,327,735 FLUID EJECTION APPARATUS FDR WELL COMPLETION TOOLS Emmet F. Brieger, Needville, Tern, assignor, by mesne assignments, to Schlurnherger Technology (Iorporation, Houston, Tex., a corporation of Texas Filed Mar. 11, 1965, Ser. No. 438,872

4 Claims. (Cl. 166-165) ABSTRACT OF THE DISCLOSURE The present disclosure concerns formation-treating apparatus adapted for injecting substances into earth formations by employing the hydrostatic pressure of well control fluids as a motivating source to develop a substantially greater injection pressure.

The increased injection pressure is obtained by slidably telescoping an enclosed, hollow body over a piston that is secured to the body of the formation-treating apparatus by a tension member. One end of this hollow body is arranged as a slidable piston for displacing treating fluids from a cylinder in the apparatus. By admitting well control fluids into the interior space in the hollow body between the secured piston and its end carrying the slidable piston as well as maintaining the remainder of the interior of the hollow body at a low pressure, the hydrostatic pressure acting on the other end of the cylinder will provide an added force suflicient to increase the pressure developed in the treating cylinder above the hydrostatic pressure that is developed in the cylinder by the slidable piston itself.

Accordingly, as will subsequently become apparent, this invention relates to apparatus for completing wells; and, more particularly, pertains to apparatus utilizing the hydrostatic pressure of well control fluids to eject materials from a well-completion tool at a substantially higher pressure than the hydrostatic pressure.

The present trend in well-completion techniques is to rely upon only one or, at most, a very few perforations at each of carefully selected points in a well rather than indiscriminately scattering a large number of perforations along a wide interval. Where such perforations are made in a particularly loose or unconsolidated formation, sand particles and the like, will, however, be displaced into the well bore as connate fluids are produced from the formation. Thus, unless preventative measures are taken, these sand particles will either settle out so as to eventually fill the well bore or be carried to the surface by the produced fluids and severely damage production equipment.

Accordingly, to solve this problem, apparatus and methods have been devised whereby as soon as a loose formation is perforated, a suitable bonding or consolidating agent is injected through the perforation into the formation where, in time, it will react and harden. Although it will depend upon the particular agent, generally these agents will bond the sand particles to one another but leave adequate pore spaces. Thus, the consolidated zone will act as a support to keep the loose formation sand behind it in place.

Typical of such treating agents, apparatus and methods are those disclosed in Patent No. 3,153,449 granted to Maurice P. Lebourg and Patent No. 3,174,547 granted to Roger Q. Fields. As described in those patents, a perforating-and-injecting tool is positioned adjacent a formation that is believed to be unconsolidated. An extendible wall engaging member is actuated to shift the tool toward one wall of the casing and sealingly engage a sealing member thereon to isolate a portion of the casing from the well control fluids. A perforator, such as a shaped charge, is

then actuated to produce a perforation through this isolated portion into the adjacent earth formation.- Thereafter, a bonding agent is ejected from a cylinder in the tool by a displacing piston and injected through the perforation into the formation. If desired, other treating agents may also be injected into the perforation for other purposes.

It will be realized, of course, that these treating agents must be injected into a formation at a pressure that is at least somewhat higher than the formations natural pressure. Accordingly, various arrangements have been proposed heretofore for developing higher injection pressures. Typical of such arrangements are those employing a slowburning propellant explosive to develop a gas pressure that is calculated to be greater than the natural formation pressure for actuating the displacement piston. Other arrangements, such as those shown in the above-mentioned Lebourg and Fields patents, utilize the hydrostatic pressure of the well control fluids for urging the displacement piston to expel the treating agents from the treating cylinder and inject them into the formation. Where such hydrostatically actuated pistons are employed, however, it will be realized that the injection pressure will only be equal to the hydrostatic pressure of the well control fluids.

Although such arrangements as these have been generally satisfactory, it will be realized that the depth of penetration of the treating agents will be dependent upon the differential between the formation pressure and the injection pressure. Thus, should the hydrostatic pressure of the well control fluids be only slightly greater than the formation pressure, the depth to which the treating agents will penetrate into the formation will be greatly reduced.

It is not too practical to employ conventional hydrostatically actuated piston multipliers, however, since either the quantity of the treating agents must be drastically reduced or the tool must be greatly elongated to accommodate the same volume of agents that can be carried in .a tool such as those in the aforementioned Lebourg and Fields patents. It will also be noted that conventionally arranged piston multipliers will have a reduced-diameter portion that is under high compressive forces. Thus, the reduced-diameter portion must of necessity be held to a diameter and length that will not allow it to buckle under the substantial compressive loads.

Accordingly, it is an object of the present invention to provide new and improved apparatus utilizing the hydrostatic pressure of the well control fluids to develop an injection pressure that is substantially greater than the hydrostatic pressure, but without requiring a treating cylinder that is of an impractical size.

This and other objects of the present invention may be accomplished by closing one end of a cylinder adapted to contain a material to be injected with an annular piston that is slidably and sealingly mounted around a fixed member extending through the cylinder. A second piston secured to the free end of the fixed member is slidably and sealingly disposed within a sealed chamber coupled to the opposite side of the floating piston. By maintaining the pressure in the sealed chamber at a particularly low magnitude, such as atmospheric pressure, and admitting well control fluids into the sealed annular space between the pistons, the material therein will be exhausted from the treating cylinder at a pressure that is substantially twice the hydrostatic pressure.

The novel features of the present invention are set forth with particularity in the appended claims. The present invention, both as to its organization and manner of operation together with further objects and advantages thereof, may best be understood by way of illustration and example of certain embodiments when taken in con junction with the accompanying drawings, in which:

FIG. 1 is a view of a well-completion tool arranged in accordance with the present invention as it appears in position within a well bore;

FIG. 2 is a schematic View illustrating the principles of the present invention;

FIGS. 3A-3B are successive cross-sectional views of a preferred embodiment of the present invention; and

FIGS. 46 are views depicting in sequence the operation of the apparatus of FIG. 1.

Turning now to FIG. 1, a well-completion tool employing the principles of the present invention is shown suspended from a multi-conductor cable 11 in a casing 12 secured within a borehole 13 by a column of cement 14.

The cable 11 is spooled from a Winch (not shown) at the 'earths surface, with some of its conductors being arranged for selective connection to a power source (not shown) 'and others being connected to indicating-and-recording means (not shown) at the surface.

The well-completion tool 10 is comprised of an elongated body which, to facilitate manufacture and assembly,

may be arranged to include upper and lower sections 15 and 16 that are tandemly connected above and below an intermediate section 17 having an annular sealing member 18 on one side thereof and extendible wall-engaging means 19 on its opposite side. The upper section 15 encloses a hydraulic system (not shown) for selectively actuating the extendible wall-engaging means 19. This hydraulic system may, for example, be of the type illustrated in Patent No. 3,011,554 granted to Robert Desbrandes which utilizes the hydrostatic pressure of the well control fluids 26 to develop an increased pressure in the system for selectively actuating the wall-engaging means 19. Thus, upon command from the surface, the wall-engaging means 19 will be extended against one side of the casing 12 to shift the tool 10 laterally and sealingly engage the sealing member 18 against the opposite wall of the casing.

The hydraulically actuated wall-engaging means 19 are comprised of one or more extendible pistons 21 supporting a back-up shoe 22 that is normally held in a retracted position against the tool 10 by springs 23. The pistons 21 are 'sealingly received within hydraulic cylinders (not shown) that are connected to the hydraulic system. Thus, whenever the hydraulic system is activated from the surface, the developed hydraulic pressure will urge the pistons 21 outwardly to extend the back-up shoe 22 against the casing 12. Inasmuch as the particular details of the hydraulic system and wall-engaging means 19 are not necessary for a full understanding of the present invention they have been shown only schematically in FIG. 1 to illustrate their .general relationship to the present invention.

The intermediate section 17 houses material-discharge means 24 which include a lateral chamber 25 within the section that is open at one end, with the annular sealing member 18 being mounted around the open end of the chamber .to provide a central opening 26 for discharging materials therefrom. A thin-walled closure member 27 is disposed adjacent to and blocks the central opening 26 through the annular sealing member 18. It should be noted that although an elastomeric annular member such as that shown at 17 in the Lebourg and Fields patents is used for the sealing member 18, an annular reinforcing or back-up member 28 must be provided around the sealing member. Thus, when the tool 10 is shifted against the casing 12, the sealing member 18 will be sealingly engaged and its periphery supported by the back-up member 28 to prevent the outward extrusion of the sealing member Whenever agents are exhausted at a high pressure through the central opening 26.

As described in greater detail in the aforementioned Lebourg patent, a shaped charge 29 is disposed in the rear of the chamber 25 and faces the closure member 27 so that, upon detonation, the perforating jet will puncture the closure member and be directed through the central opening 26. The shaped charge 29 is connected to electrically responsive igniter means (not shown) that are ignitable from the surface of the earth via a conductor in the cable 11. The shaped charge chamber 25 is connected by conduit 30 via a normally-closed, electrically actuated, valve 31, such as that shown in FIG. 3 of the Lebourg patent, to the upper end of a treating agent cylinder 32 in the lower section 16. Accordingly, it will be appreciated that until it is detonated, the shaped charge 29 will be isolated from the materials in the treating agent cylinder 32 by the normallyclosed flow-line valve 31 and the well control fluids 20 are prevented from entering the shaped charge chamber 25 by the expendable closure member 27.

A pressure transducer 33, which may be of the type illustrated in FIG. 9 of the Desbrandes patent, is connected to a branch passage 34 for determining pressures in the conduit 30 and transmiting a characteristic electrical signal via a conductor in the cable 11 to the surface.

The treating agent injector 35 of the present invention is comprised of a slidable, hollow cylinder 36 that has a closed lower end 37 and istelescoped over a piston 38 secured through an elongated coaxial rod 39 to the upper end of the treating agent cylinder 32 and slidably received in the lower end of the treating agent cylinder. An annular piston 48 secured to the upper end of the slidable cylinder 36 is fluidly sealed by O- rings 41 and 42 to the inner wall of the treating agent cylinder 32 and elongated rod 39, respectively, to isolate the treating agents in the cylinder 32 above the annular piston. Au O-ring 43 fluidly seals the fixed piston 38 to the inner wall of the hollow cylinder 3a to provide an enclosed low-pressure or atmospheric chamber 44 therein below the fixed piston. A port 45 is provided in the wall of the hollow cylinder 36 to admit Well control fluids 20 into the space 46 below the annular piston 40 and above the fixed piston 38.

It should be noted that, as shown in FIG. 2, the well control fluids 2!; could also be admitted into the space .6 between the pistons 38 and 40 by providing a transverse passage 45' in the section 16 above the upper end of the elongated rod 39 that would continue through the elongated rod and terminate in a lateral port opening into the space 46. This, of course, would replace the port 45. The treating agent cylinder 32 is divided into separate fluid- tight chambers 47, 48 and 49 by spaced floating pistons 56 and 51 that are each fluidly sealed between the elongated rod 39 and inner wall of the cylinder 32. As will be subsequently explained in greater detail, valves 52 and 53 in the annular floating pistons 50and 51 remain closed to segregate the treating agents in the chambers 47-49 until each piston has reached its upper limit of travel. Where the procedure of the completion operation so requires it, a flow restrictor 54 is placed in series with the valve 52 to regulate the flow of treating agents from the 'two lower chambers 48 and 49.

Turning now to FIG. 2, a schematic representation is injector 35 of the present invention with the spaced floating pistons 50 and 51 being omitted for purposes of greater clarity. Assuming that the cylinder 32 is filled with a treating agent 55, it will be realized that the hollow cylinder 36 and annular piston 40 will remain in the position illustrated until the flow-line valve 31 in the discharge conduit 30 is opened. Thus, until the flow-line valve 31 is opened, the forces tending to move the hollow cylinder 36 and piston 49 upwardly must equal the forces acting downwardly thereon.

Accordingly, by reference to FIG. 2, the summation of these forces can be expressed by the equation:

F1= 2+F3 (Eq- 1) Since each of these forces is equal to the product of a pressure multiplied by the effective cross-sectional area that it acts upon, the forces in Equation 1 can be expressed as:

This equation in turn resolves into:

It will be appreciated that (A A will be very nearly equal to A and that P will be practically negligible. Thus, it will be realized that the pressure developed (P in the treating cylinder 32 will be very nearly double the hydrostatic pressure (P of the well control fluids 20. Accordingly, if, for example, the ratio of the developed and hydrostatic pressures is in the order of 18:1 and the hydrostatic pressure is 10,000-p.s.i.g., it will be appreciated that the injection pressure will be l8,000-p.s.i.g. Thus, if the natural formation pressure is 9-,000-p.s.i.g., the treating agent 55 will be injected at an effective differential of 9,000p.s.i. rather than only 1,000 p.s.i. as would have been the case with a well-completion tool such as that shown in the Lebourg and Fields patents.

It is particularly significant that in the present invention, the elongated rod 39 is maintained in tension whenever there is pressure in the treating fluid cylinder 32. Thus, there are no compressive forces tending to buckle the rod 39 and its cross-sectional area may be reduced to a minimum. It will be appreciated also that by maintaining the rod 39 in tension, a much longer rod of a relatively small diameter can be employed than would be possible if the rod was in compression.

Turning now to FIGS. 3A-3B, successive cross-sectional views are shown of a preferred embodiment of the treating agent injector 35, with the reference numerals used in conjunction with FIGS. 1 and 2 identifying the corresponding elements. The upper end of treating agent cylinder 32 is sealingly closed by a removable closure 56 that is threadedly coupled to a sub 57 in which the flow-line valve 31 (FIG. 1) is mounted. A longitudinal passage 58 through the closure member 56 that opens into a recess 59 in the sub 57 and a passage 60 leading therefrom together form the lower portion of the conduit leading to the flow-line valve 31.

The upper end of the elongated rod 39 extends through an axial bore 61 in the closure member 56 and is supported therein by threaded cap 62 sealingly received within a counterbore 63 in the closure member. The fixed piston 38 is likewise threadedly connected to the lower free end of the elongated rod 39 to permit the annular piston to be removed from the treating agent cylinder 32 after the hollow cylinder 36 has been disengaged.

An external shoulder 64 around the annular piston 40 normally rests on a mating surface 65 around the inner wall of the cylinder 32 to support the piston 40 and hollow cylinder 36 in their normal extended positions as shown in FIG. 3. Ports 66 and 67 through the cylinders 32 and 36, respectively, form the port to admit the well control fluids 20 into the annular space 46 between the pistons 38 and 40.

The upper floating piston is fluidly sealed within the treating agent cylinder 32 and around the support rod 39 by O- rings 68 and 69, respectively. An annular valve member 70, that is loosely fitted around the support rod 39, is slidably received within an axial counterbore 71 in the upper face 72 of the piston 50 and fluidly sealed therein by spaced O- rings 73 and 74. A spring 75 engaged between the bottom of the counterbore 71 and the valve member 70 lifts the valve member relative to the piston 50 and urges it against an annular stop 76 fixed to the upper face of the piston. A longitudinal passage 77 extending from the lower face 78 of the piston 50 is terminated at a transverse port 79 opening into the counterbore 71 at a point that is straddled by the spaced O- rings 73 and 74 whenever the valve member 70 is in its elevated position.

The upper portion 80 of the valve member 70 is reduced in diameter and extended a short distance above the upper face 72 of the piston 50. Lateral ports 81 through the reduced-diameter valve portion 8 0 and above the O- rings 73 and 74 ensure that treating agents in the cylinder space 47 above the piston 50 are free to pass through the annular clearance 82 between the rod 39 and valve member 70 into the counterbore 71 to prevent premature opening of the valve member.

The flow restrictor 54, which may be comprised of a plurality of serially arranged orifices (not shown) is fluidly sealed within an enlarged-diameter portion 83 of the longitudinal passage 77 for reasons that will become apparent. A filter screen 74 is received in a complementary recess 85 in the lower face 78 of the piston 50 and secured in place by some suitable means such as an apertured retainer 86.

The annular piston 51 and valve 53 below the piston 50 are similar in most respects to the piston 50 and valve 52 already described. This lower piston 51, however, has only an unrestricted longitudinal passage 87 extending from the lower face 88 to a transverse port 89 that is normally closed by spaced O- rings 90 and 91 around the valve member 92.

To fill the treating agent cylinder 32, the upper closure member 56, cap 62 and floating pistons 50 and 51 are removed. After the first agent has been deposited in the cylinder space 49, the lower piston 51 is threadedly coupled to a tubular tool (not shown) and slipped over the elongated rod 39 into position. Then, after pulling upwardly to ensure that the valve 53 is closed, the tubular tool is unthreaded and removed. The second agent is then deposited within the cylinder space 48 and the upper piston 50 and valve 52 positioned in the same manner before the last agent is finally deposited into the cylinder space 47. After replacing the upper closure member 56 and cap 62, the injector 35 is then coupled to the sub 57 and the remainder of the tool 10.

The adjacent ends of a pair of longitudinal passages 93 and 94 at the lower end 37 of the hollow cylinder 36 are connected by a transverse bore 95 to provide fluid communication into the enclosed space 44. A valve member 96 is threaded into the transverse bore 95 and normally seated on a valve seat 97 therein to close fluid communication into the hollow space 44. A threaded plug 98 in a counterbore 99 in the outer end of the passage 9 4 normally seats in the bottom of the counterbore and closes a transverse passage 100' leading therefrom to the exterior of the hollow cylinder 36.

Before transporting the treating agent injector 35, lowpressure air is injected through the ports 66 and 67 into the space 46 between the pistons 38 and 40 to telescope the annular piston 40 and hollow cylinder 36 upwardly into the empty treating agent cylinder 72. An O-ring 101 around the lower end of the outer cylinder 32 prevents leakage of air through the clearance between the cylinders 32 and 36. When it is desired to fill the treating agent cylinder 32, the valve member 96 and threaded plug 98 are unscrewed and low-pressure .air is admitted into the enclosed space 44 to return the piston 40 and hollow cylinder 36 to their extended position. Then, whatever air pressure that may be trapped in the hollow cylinder 36 is allowed to bleed off before the threaded plug 98 and valve member 96 are reseated in the positions shown in FIG. 3.

Turning now to the operation of the injector 35 of the present invention, after the treating agents have been deposited into their separate chambers 47, 48 and 49, the tool 10 is assembled and positioned in a well bore 13 adjacent a selected formation 102. By activating the hydraulic system, the wall-engaging means 19 is extended to shift the tool 10 laterally and sealingly engage the sealing member 18 against the casing 12. Once the sealing member 18 has been firmly seated, it will be appreciated that the space in the central opening 26 forward of the thin-walled closure member 27 will be isolated from the weH control fluids 20 in the well bore 13. Then, by detonating the shaped charge 29, the closure member 7 27 will be punctured and a perforation 103 (FIG. 4) will be produced through the casing 12 and cement 14 into the formation 102.

Once the shaped charge 29 has been detonated, the 'floW-line valve 31 is opened upon command from the Surface to allow the treating agent in the upper chamber 47 to be expelled therefrom and injected into the perforation 103. As this first treating agent is exhausted from the upper chamber 47, it will be realized that the full pressure developed in the treating cylinder 32 will be available to inject this agent at a high flow rate into the formation 192. Thus, by injecting the first agent into the formation 102 at this elevated pressure, the agent will be able to break through any residue left in the perforation 103 by the shaped charge 29 and enter the formation.

When all of the first agent has been expelled from the upper chamber 47, the upper piston 50 will have reached the position shown in FIG. 4. By this time, the upper portion 80 of the valve member 70 in the upper piston 50 will have engaged the upper closure member 56 (FIG. 3) of the cylinder 32 to shift the valve member downwardly into an open position. Thus, with the piston 50 positioned as illustrated in FIG. 4, the second and third agents will pass through the flow restrictor 54 and be injected into the formation 102.

It has been found that by injecting the first treating agent (such as a preflush fluid) at a high flow rate and pressure, loose sand can not flow back into the tool 10 and the perforation 193 will be prevented from collapsing. It has been found advantageous, however, to inject the sand consolidating agents more slowly and with only suflicient pressure to overcome the formation pressure so that the agents will not channel but Will instead permeate and uniformly fill the voids between the individual sand particles. It will be understood, however, that the full developed pressure of the injector 35 is always available and where a greater pressure is needed, the flow rate will be reduced by the restrictor 54 as the pressure downstream thereof increases. It will be realized, moreover, that other well completion operation may not necessarily require the restrictor 54.

It will be seen from FIG. that when the second piston 51 has reached the position shown there, the valve member 32 in the piston will be opened to enable the treating agent in the lower fluid chamber 49 to be expelled through the flow restrictor 54 and into the perforation 103-. Whenever the treating agents have all been expelled from the treating cylinder, the hollow cylinder 36 will be fully telescoped into the treating cylinder 32 as shown in FIG. 5. Subsequently, whenever the pressure in the hydraulic system is relieved, the wall-engaging means 19 will be retracted to enable the tool to be retrieved.

Accordingly, it will be appreciated that the apparatus of the present invention is capable of developing injection pressures that are substantially double that of the hydrostatic pressure of the well control fluids. Moreover, the cooperative arrangement of the new and improved injector permits large quantities of one or more materials to be transported therein without requiring that its overall length be impractical. It should be noted that although the foregoing description is directed to the application of the injector in sand consolidation operations, it will be equally successful either with or without the spaced floating pistons in other completion operations such as hydraulic fracturing, cementing, acidizing and other operations involving a flowable substance. Moreover, since the developed pressure is substantially greater than the hydrostatic pressure, it is not essential to isolate the discharge opening from the well control fluids should it be desired to discharge a material into the well bore itself.

While particular embodiments of the present invention have been shown and described, it is apparent that changes and modifications may be made Without departing from this invention in its broader aspects; and, therefore, the aim in the appended claims is to cover all such changes and modifications as fall Within the true spirit and scope of this invention.

I claim:

1. In a well tool adapted for use in a well bore. material-discharge means including a support having a cylinder therein adapted to receive a flowable material and normally-closed first passage means connected thereto; means for ejecting materials from said cylinder including an annular first piston member forming a first crosssectional area slidably and sealingly received in said cylinder; and pressure-multiplying means including a member fixed to said support and having a free portion extending into said cylinder and through said first piston member, a tubular member fluidly sealed to said first piston member and having a portion extending beyond the free end of said fixed member, means closing said portion of said tubular member and forming a second cross-sectional area, a second piston member connected to said fixed member and sealingly and slidably received within said tubular member for enclosing a compressible fluid between said closing means and second piston member, means fluidly sealing said first piston member to said fixed member for providing a sealed space between said piston members, and means for applying fluid pressure to said cross-sectional areas including second passage means for admitting fluids into said sealed space.

2. The apparatus of claim 1 wherein said second passage means extend from said support through a portion of said fixed member to said sealed space.

3. The apparatus of claim 2 wherein said second passage means include a port through the wall of said tubular member opening into said sealed space.

4. In a well tool adapted for use in a well bore containing a column of fluids: material-discharge means including a support having a cylinder therein with one end open and being adapted to receive a flowable material, and normally-closed first passage means connected thereto; means for ejecting materials from said cylinder including an annular first piston member forming a first cross-sectional area slidably and sealingly received in said open end of said cylinder; and pressure-multiplying means including a member fixed to said support and having a free portion extending along the axis of said cylinder and through said first piston member, a tubular member having one end fluidly sealed to said first piston member and having its other end extending beyond the free end of said fixed member and closed to form a second cross-sectional area, a second piston member secured to said fixed member and sealingly and slidably received within said tubular member for enclosing a compressible fluid at a pressure lower than that of the column of fluids between said closed end and second piston member, means fluidly sealing said first piston member to said fixed member for providing a sealed space between said piston members, and means for applying the pressure of the column of fluids to said cross-sec- .tional areas including second passage means for admitting well fluids into said sealed space.

References Cited UNITED STATES PATENTS 3,115,932 12/1963 Reynolds 166-400 X 3,174,547 3/1965 Fields 166-400 X 3,269,462 8/ 1966 Voetter 166-100 3,273,647 9/1966 Briggs et al. l6 6l00 CHARLES E. OCO-NNELL, Primary Examiner.

D. H. BROWN, Assistant Examiner.

Claims (1)

1. IN A WELL TOOL ADAPTED FOR USE IN A WELL BORE: MATERIAL-DISCHARGE MEANS INCLUDING A SUPPORT HAVING A CYLINDER THEREIN ADAPTED TO RECEIVE A FLOWABLE MATERIAL AND NORMALLY-CLOSED FIRST PASSAGE MEANS CONNECTED THERETO; MEANS FOR EJECTING MATERIALS FROM SAID CYLINDER INCLUDING AN ANNULAR FIRST PISTON MEMBER FORMING A FIRST CROSSSECTIONAL AREA SLIDABLY AND SEALINGLY RECEIVED IN SAID CYLINDER; AND PRESSURE-MULTIPLYING MEANS INCLUDING A MEMBER FIXED TO SAID SUPPORT AND HAVING A FREE PORTION EXTENDING INTO SAID CYLINDER AND THROUGH SAID FIRST PISTON MEMBER, A TUBULAR MEMBER FLUIDLY SEALED TO SAID FIRST PISTON MEMBER AND HAVING A PORTION EXTENDING BEYOND THE FREE END OF SAID FIXED MEMBER, MEANS CLOSING SAID PORTION OF SAID TUBULAR MEMBER AND FORMING A SECOND CROSS-SECTIONAL AREA, A SECOND PISTON MEMBER CONNECTED TO SAID FIXED MEMBER AND SEALINGLY AND SLIDABLY RECEIVED WITHIN SAID

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