US2626829A - Method for hydraulically displacing well materials - Google Patents

Description

Jan. 27, 1953 W. A. MAXWELL ET AL METHOD `FOR HYDRAULCALLY DISPLACING WELL. MATERIALS Filed May 5, 1947 geni/ FOM INVENTORS um M HIJ-Mr Patented Jan. 27, 1953 IVIETHGD FR HYDRAULICALLY DISPLAC- ING WELL MATERIALS Wilber A. Maxwell, Houston, Tex., and .lohn A. Engstrand, Los Angeles, Calif., assignors to Grant Oil Tool Company, Los Angeles, Calif., a corporation of California Application May 5, 1947, Serial No. 746,039

(Cl. 29e- 86) Si Claims.

This invention relates to improved methods for-the'displacement or recovery of solid materials and bodies in oil wells, and having as a general mode of operation such displacement or recovery by the creation of a iiuid surge resulting from the Vopening of a low pressure chamber in communication with the displacement zone. The typical apparatus herein described as adapted for carrying out the present process is claimed in our co-pending application Ser. No. 746,038,

Heretofore this same type of operation has been extensively `employed in the use of suctiontype bailers and cleaners in various forms utilizing normally closed chambers lowered within the hydrostatic well uid column to the 1bottom of the well or to the location at which solids are to be displaced, the chambers having closures adapted to be suddenly opened to admit to the chambers hydraulic material displacing surges which occur under pressures corresponding to the hydrostatic head of the well liquid column standing above the displacement zone at which the chamber inlet ordinarily is located. In instances where the extent of the hydrostatic column above the displacement is great, the differential between the hydrostatic and empty charge receiving chamber pressures are correspondingly great, the result being that when the chamber is suddenly opened, the responsive fluid now or surge into the chamber occurs with considerable violence. Now it has been found that the magnitude and violence of such surges are frequently so great as to create seriously undesirable disturbances in the well, such as the displacement of excessive quantities of sand into the Well, collapsing of weak casing s Heretofore. such con- 'l or liners. and like effects. sequences have been unavoidable for the reason that the hydrostatic column-chamber pressure diiierential and the fluid iiow or surge proportionate to that differential have been xed because the displacement zone and the chamber inlet have been under virtually the same hydrostatic pressure, and the chamber constitutes a closed empty zone under atmospheric pressure.

The primary object of the present invention is to avoid the abovementioned consequences of violent pressure surges in the displacement or recovery of solid materials from a well, by providing for the maintenance of any desired differential between the chamber pressure and the hydrostatic displacement zone pressure, and in so doing to diminish to whatever extent desired the violence of the surge that would ordinarily occur at the displacement zone depth employing the conventional methods and equipment.

Specifically the invention contemplates certain novel methods whereby either or both the chargereceiving chamber and hydrostatic head of the well liquid tending to enter the chamber, may be varied to give whatever differential is desired. In accordance with one adaptation of the invention, the chamber may be positioned above the displacement zone a distance sufciently remote therefrom that the effective hydrostatic pressure of the iiuid tending to enter the chamber will be less than the hydrostatic pressure on the displacing zone, to a degree such that when the chamber is opened, the consequent liquid iii-surge will have no greater activity or violence than necessary for movement of solids in the displacement zone, Thus the effective column-chamber pressure differential may be selected or predetermined as desired to create sufficient surge for displacement of the solids, while insuring against a surge violence productive of adverse results.

Instead of, or in addition to such selection or predetermination of the hydrostatic column pressure with relation to the chamber pressure, the pressure inside the chamber may be predetermined or controlled as desired, by subjecting the chamber internally to the pressure of a 'hydrostatic column inside a pipe string carrying the chamber. Thus by placing the chamber in communication with the top of the well through the pipe string, liquid may be put into the string to establish a controllably variable head which in turn establishes the chamber pressure and the differential between that pressure and the effective pressure of the hydrostatic column of the well.

The invention further contemplates the retention and recovery of solid materials carried by the surge in the displacement Zone, all in a manner permitting removal of such solids from the well.

Furtherobjects and details of the invention will be understood from the following description of the method as carried out by use of the typical forms of apparatus shown by the accompanying drawing, in which:

Fig. l is a View showing the apparatus in elevation within a well;

Figs. 2 and 3 are enlarged vertical sections tal:- en respectively on lines 2-2 and 3 3 `of Fig. 1; and

Fig. 4 is a cross-section on line 4;-4 of Fig. 2.

The apparatus comprises a pipe string run into the well bore l0 and including a lower section l I and a relatively vertically movable upper section I 2 extending openly to the ground surface. As will appear, the upper section of the pipe string, or at least the lower portion thereof, may constitute a closed low pressure chamber communicable with a lower zone at which the displacement of material is to be effected. According to one method of operation, the chamber may be so positioned in the well that the eifective pressure of the hydrostatic well iiuid column tending to enter the chamber upon its opening, may be any amount less than the hydrostatic column pressure at the displacement zone, depending upon the depth at which the chamber opening, i. e. the bottom portion of the pipe string section I2, is positioned in the well. Thus it will be understood that the well bore may contain a hydrostatic column extending above the bottom portion of the pipe string section I2, and that the length of the latter may be varied as desired, to give any predetermined or selected pressure differential inside and outside the low pressure chamber I3 when the latter is opened. The displacement zone I4 is shown to be at the bottom of the well, and may be assumed to contain displaceable solids of any character, and particularly metallic or other objects retrievable in a so-called junk basket type of fishing tool, for removal to the ground surface.

The pipe string sections Il and I2 are shown to be interconnected by a telescopic joint assembly, generally indicated at I5, including a closure for the bottom of the chamber I3, and means operable by relative vertical movements of the sections to open the closure. Referring to Fig. 2, section I2 is connected by tubular coupling I6 and the threaded joint at I1 witha sleeve I 8, the latter having a counterbore I9 forming an annular shoulder 29. In the broad contemplation of the invention, the chamber I3 may have any suitable type of bottom closure 2I capable of being opened by manipulation of the pipe string to admit well fiuid to the chamber. As illustrative, the closure is shown to consist of a frangible disc 22 confined between gaskets 23 by a bushing 24 screwed into the lower threaded end of the coupling I6, the bushing having a frustro-conical surface 25.

Sleeve I8 is connected with the top coupling end 26 of the lower pipe string section II by a tubular mandrel 21 threaded at 28 into the coupling and having splines 29 extending through ways 30 in the sleeve, see Fig. 4, the splines permitting transmission of rotation from the upper to the lower string section, as for turning the fishing tool into the bottom sand. The mandrel 21 has an enlarged diameter disc breaker head 3| engageable against shoulder 20 to suspend the string section below, and containing one or more lateral openings 32 through which fiuid may pass upwardly from section II into the space 33. Head 3I may carry the O type seal rings SII to prevent fluid leakage along the head. Upon downward movement of the upper section I2 relative to the lower section II, the disc 22 is fractured by impact against the pointed breaker head 3Ia, relative movement of the breaker toward the disc being limited by engagement of the lower end of the coupling with tool joint 26. Full opening of the chamber inlet may be effected by raising the seat 25 from the breaker after the disc is ruptured. In order to assure quick and complete rupturing of the disc, impacting of the latter against the breaker may bc caused to occur under substantial load from above, as by using a shear pin 35 projecting into and engageable with the end of the mandrel recess 36 until the superposed load is sufficiently great to shear the pin, at which point the disc is suddenly dropped against the breaker.

The lower string section II may carry any suitable form of tool adapted to receive and retain solids displaced from the zone I4, as a result of an upward fluid surge created by opening the chamber I3. Typically the tool 36 is shown to comprise a tubular body 31 connected by coupling 38 to the pipe string and having a bottom coring edge 39 capable of penetrating the sand in the bottom of the well. The body may contain one or more sets of retainers, such as the circular arrangement of radially deilectible ngers 40 shown in Fig. 3, past which the solids are carried upwardly by the fluid surge to thereafter be retained by the finger assembly.

Suitable provision may be made for venting gas or air from the top of the lower pipe string section II as the latter is run down through the hydrostatic column, as by means of a valvular gas release preventingr in-flow to the string when the low pressure chamber is opened. Referring to Fig. 2, coupling 26 may contain a pressure release, generally indicated at 40 comprising a ball valve 4I contained in bore 42 and seating against shoulder 43 to control the gas escape from the string section II through passages 44 and 45. Opening of the valve is resisted by coil spring 45, the compressive force of which is adjustable by plug 41 to maintain any desired seating thrust against the valve. As illustrative, the pressure release may be set to permit opening of the valve at a gas pressure of around lbs. per

sq. 1n.

According to one mode of operation, the apparatus is run into the well in the condition illustrated in Figs. l and 2, with the connection I5 located at a remote elevation above the displacement zone I4. As illustrative, depending upon the desired pressure differential conditions, the low pressure chamber inlet 48 may be located in excess of 500 to 1000 feet above the displacement zone. As the equipment is lowered down through the hydrostatic column of well fluid, the latter may be permitted to rise Within the lower string section II to the height of the disc 22 (when the latter is lowered below the top of the hydrostatic column) because of the capacity of the pressure release 40 to open and vent gas or air from the lower string section. Assuming the tool 36 to be bottomed in the sand, downward movement of the upper string section I2 causes the disc to be impacted and ruptured against the breaker head, as described, whereupon the chamber I3 is opened to admit a high velocity surge of well fluid from the displacement zone I 4 upwardly through the lower string section. As will be understood, however, the effective pressure differential under which the fluid enters the chamber, is the difierence between the normal internal pressure of the chamber and the hydrostatic pressure of the well fluid column standing above the chamber inlet. Thus, though directly communicated to the displacement zone IA, the action or magnitude of the surge will be far less than that which ordinarily results from the opening of a chamber at the depth of the displacement zone and with consequent excessive disturbances in the well.

In accordance with a variational method, the pressure differential causing flow into the pressure chamber, vmay be varied as desired, and within wide limits, by controlling the chamber pressure, with or'without variation from the vdisplacement zone pressure of the hydrostatic fluid pressure tending to enter the chamber. For this purpose iiuid may be introduced to the upper pipe string section to maintain whatever chamber pressure desired at the time the chamber is opened. Thus circulating mud or other liquid may be lled into the upper section l2 to a depth imposing the desired pressure at the chamber side of the disc. Since by this method the difierential flow creating pressure is controllable independently of the hydrostatic well pressure at the chamber inlet, the latter, including the joint assembly I5, may be placed at any depth in the well, including that of the displacement zone le in which event the chamber closure may be directly above the tool 3S. In general, the desired pressure diiierential may be established by relating any selected chamber pressure to the effec tive outside hydrostatic pressure as determined by the depth at which the chamber inlet is positioned.

We claim:

1. The method of displacing material at a bottom location in a well containing a hydrostatic column, that includes lowering in the well and said column a low pressure chamber comprising a vertical string of pipe stands closed against reception of the column liquidl and communicable through a passage with the top of the well, in-

troducing liquid to said passage to form a liquid column in the chamber extending vertically through a large number of said pipe stands and of a height to maintain inside and outside of the chamber unbalanced hydrostatic column pressures the differential of which is substantially less than the pressure of the hydrostatic well column pressure at said location, and then suddenly admitting well fluid to the chamber to create a liquid surge from said location.

2. The method of displacing material at a bottom location in a well containing a hydrostatic column, that includes lowering in the well and said column a low pressure chamber comprising a vertical string of pipe stands closed against reception -oi the column liquid and communicable through a passage with the top of the well, introducing liquid to said passage to form a liquid column in the chamber extending vertically through a large number of said pipe stands and of a height to maintain inside and outside of the chamber unbalanced hydrostatic column pressures the diierential of which is substantially less than the pressure of the hydrostatic well column pressure at said location, then suddenly admitting well fluid to the chamber to create a liquid surge from said location, and entrapping and recovering for removal from the well solids displaced by the liquid surge.

3. rlhe method yof displacing material at a location in a well containing a hydrostatic column, that includes lowering into the well an extended tubular string comprising a vertical series of pipe stands communicating at a lower portion of the string with said location and containing a closure acting to prevent fluid flow upwardly from said location beyond a predetermined point in the string, maintaining a column of liquid in said string of a height substantial as compared with but less than the height of the well column and extending vertically through a large number of said pipe stands so that the diiierential between the well column pressure and the pressure at the inside of the string is substantially less than the hydrostatic pressure of the well column at said location, and then opening said closure to create a liquid surge from said location upwardly within the string.

4. The method of displacing material at a location in a well containing a hydrostatic column, that includes lowering into the weil an extended tubular string comprising a vertical series of pipe stands communicating at a lower portion of the string with said location and containing a closure acting to prevent fluid iiow upwardly from said location beyond a predetermined point in the string, maintaining a column of liquid in said string or" a height less than the well column but at least about 500 feet and extending vertically through a large number of said pipe stands, so that the differential between the well column pressure and the pressure at the inside of the string is substantially less than the hydrostatic pressure of the well column at said location, and then opening said closure to create a liquid surge from said location upwardly within the string.

5. The method of displacing material at a location in a well containing a hydrostatic column, that includes lowering into the well an extended tubular string comprising a vertical series of pipe stands communicating at a lower portion of the string with said location and containing a closure remotely above said location preventing upward fluid flow within the string beyond a predetermined point, maintaining a column of liquid in said string beneath said closure of a height substantial as compared with but less than the height of the well column and extending vertically through a large number of said pipe stands so that the diilerential between the well column pressure and the pressure at the inside of the string is substantially less than the hydrostatic pressure of the well column at said location, and then opening said closure to create a liquid surge from said location upwardly with the string.

6. The method of displacing material at a location in a well containing a hydrostatic column, that includes lowering into the well an extended tubular string comprising a Vertical series of pipe stands communicating at a lower portion of the string with said location and containing a closure near said location acting to prevent iiuid flow upwardly within the string from said location, maintaining a column of liquid in said string beneath said closure of a height substantial as compared with but less than the height of the well column and extending vertically through a large number of said pipe stands so that the differential between the well column pressure and the pressure at the inside of the string is substantially less than the hydrostatic pressure of the well column at said location, and then opening said closure to create a liquid surge from said location upwardly within the string.

7. The method or" displacing material at a location in a well containing a hydrostatic column, that includes lowering into the well an extended tubular string comprising a vertical series of pipe stands communicating at a lower portion of the string with said location and containing a closure acting to prevent fluid iiow upwardly from said location beyond a predetermined point in the string, maintaining a column of liquid in said string of a height substantial as compared with but less than the height of the well column and extending vertically through a large number of said pipe stands so that the differential between the well column pressure and the pressure at the inside of the string is substantially less than the hydrostatic pressure of the well column at said location, then opening said closure to create a liquid surge from said location upwardly within the string, and recovering for removal from the well solids displaced at said location by the surge.

8. The method of displacing material at a location in a Well containing a hydrostatic column, that includes lowering into the Well an extended tubular string comprising a vertical series of pipe stands communicating at a lower portion of the string with said location and containing a closure acting to prevent fluid flow upwardly from said location beyond a predetermined point in the string, maintaining a column of liquid in said string of a height substantial as compared with but less than the height of the well column and extending vertically through a large number of said pipe stands so that the diierential between the well column pressure and the pressure at the inside of the string is substantially less than the hydrostatic pressure of the Well column at said location, then opening said closure to create a liquid surge from said location upwardly within the string, entrapping in said string solid material carried thereinto by the fluid surge, and draining the fluid from the string downwardly about said solid materials.

9. The method of displacing material at a location in a well containing a hydrostatic column, that includes lowering into the well an extended tubular string comprising a vertical series of pipe stands communicating at a lower portion of the string with said location and containing a rupturable closure acting to prevent fluid flow upwardly from said location beyond a predetermined point in the string, maintaining a column of liquid in said string of a height substantial as compared with but less than the height of the well column and extending vertically through a large number of said pipe stands so that the differential between the well column pressure and the pressure at the inside of the string is substantially less than the hydrostatic pressure of the well column at said location, and then rupturing said closure to create a sudden liquid surge from said location upwardly within the string.

WILBER A. MAXWELL.

JOHN A. ENGSTRAND.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,777,581 Salveson Oct. 7, 1930 1,968,282 Cavins July 31, 1934 2,090,616 Erwin Aug. 24, 1937 2,118,458 Cavins May 24, 1938 2,169,922 Notley Aug. 15, 1939 2,384,090 Hartsell Sept. 4, 1945

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