US2383934A - Oil well pump - Google Patents

Description

Sept. 4, 1945.

w. s. CRAKE OIL WELL PUMP Filed Aug. 1, 1944 Inventor: Wilfred S. Cr akz w. z m H A .5 h UJ RV Fig. I

Patented Sept. 4, 1945 01L WELL PUMP Wilfred S. Crake, Houston, Tex, assignor to Shell Development Company, San Francisco, a corporation of Delaware CaliL,

- Application August 1, 1944, Serial No. 547,621

(or. 103-219) r 4 Claims.

This invention pertains to the art of producing hydrocarbon materials from underground formations, and relates more particularly to an improved oil well pump adapted to be actuated by the reciprocation of the tubing string,

Conventional oil well pumps are usually operated by reciprocating a string of sucker rods within a tubing or flow string which is, in turn, run within the well casing. The pump is installed at the lower end of the tubing string, and is supported thereby, the pump plunger being reciprocated through said sucker rod string by suitable prime-mover means at the surface. The sucker rod string is furthermore used, in well known fashion, to install and to withdraw the plunger and travelling valves of the pump.

A modification of this system is to be found in so-called casing pumps, wherein the pump is anchored directly in the well casing at the desired depth, and the tubing string is eliminated, the sucker rods reciprocating directly within the casing. The casing pump depends for its operativeness on the feature of packing off the c ing above the pump, whereby the casing itself so vesas a tubing string. This type of pump is however not suitable for wells having low fluid levels and producing large or even normal quantities of formation gas, because the gas can be produced to the surface only through the pump, and causes frequent failures of; the pump due to gas lock.

it 'is therefore an object of this invention to provide an improved and simplified pump installation wherein the sucker rod string is eliminated, and the pump is installed, reciprocated during operation, and-removed solely by means of th tubing string.

It is also an object of this invention to provide a pump system wherein the tubing string is used. duringv operation, both as actuatinglmeans for supplying motive power to the pump, and as con-' duit means for conveying the liquid output of the pump to the surface.

It is another object of this invention to provide a pump which is installed in the well casing in such manner that the formation gas can 'pass around the pump and escape through the anreleased by simple vertical movement of the tub ing string. i

It is also an object of this invention to provide a well pump having a precompression chamber which increases the efiiciency of the pump in wells having a relatively high gas-oil ratio.

These and other objects of this invention will be understood from the following description taken with reference to the attached drawing wherein: 5'

Figure l is a vertical view, partly in cross-section, showing the present pump as it is'lowered into the well; 3

Figure 2 is a similar view showing the pump of Figure 1 locked in place within the casing strings;

, Figure 3 is a partial view in cross-section of a modification of the present pump provided with a' precompression chamber.

Referring to Figure l, the present pump is shown as being lowered into a well having a casing I l and a casinghead 9, provided with suitable conduit connections 8 for the removal of gases nular space between the tubing and the casing strings, as in conventional well-pumping systems,

whereby the possibility of gas lock is eliminated or minimized.

Itis also an object of this invention to provide 1 an oil well pump having an outer housing adapted to lock with the well casing against upward or downward movement during operation, and to be entering the casing in the well. The pump is at-' tached to the end of a tubing string 5 which passes into the casing through a suitable lubricator device I. The tubing 5 serves for imparting a reciprocating motion to the pump, as will be described hereinbelow, and is for this purpose connected at3 to a cable or similar means 2 leading to primemover means such as a walking beam, not shown," The tubing 5 also serves as a flow or eduction tube for the oil being pumped, and is connected, through a swivel head 4, to an output conduit l.

One of the coupling joints l5, used to connect together the tubing string 5, serves as a support for a yoke or plate l3. An upper slip bowl 2! is supported from the yok I3 by means such as tubular or linear reins 'or link means H, at-

tached to said bowl and said yoke by hooks and eyelets l4 and It, as shown in thedrawing. The upper slip bowl 2! surrounds the upper pump barrel 23, and is free to move slidingly therealong between an upper flange IQ of said barrel, and a lower coupling 21 connecting the upper pump barzrgl 23 to its lower enlarged portion, shown at Slips 25 ar slidably attached to the slip bowl 2|, and have tapered inner faces 24 adapted to co-act with the outer tapered faces 2 2 of the upper slip bowl, whereby said slips are forced out and into contact with the casing l I by the weight of the bowl 2| when said bowl is lowered relative to barrel 23, as shown in Figure-2.

' The enlarged pump barrel 29 has outwardly and fixedly mounted thereon a lower tapered slip bowl 33. Slips 35 are slidably attached to bowl 33, and are connected by actuating arms 31 to a latch ring or collar 39, slidably mounted around the pump barrel '29. The latch ring 38 is connectedby guide or friction springs 45 to a second ring 41, likewise slidably mounted around the pump barrel 29. The latch ring 39 has formed therein a J-slot 43, adapted to receive a pin 4| fixedly carried on th periphery of the pump barrel, the slips 35 being maintained in retracted position, as shown in Figure 1, when the pin 4| is within the slot 43. A portion of tubing 5 forming the upper polished plunger 5a extends through the upper barrel 23 into the enlarged pump barrel 29, an annular chamber 3|. being formed thercbetween, as shown in Figure 2. Attached to the lower end of tubing 5, as shown at 63, is a hollow plunger.

51, having an outside diameter larger than that of tubing 5 and adapted for a sliding fit within the pump barrel 29. The plunger is provided with a passage or orifice 65, opening to the space within the pump barrel below the plunger and' forming a valve seat for an upwardly opening ball valve 6|,- held in place by a bafile plate 59. The plunger has also ports 55 in communication with the space within the pump barrel above the plunger.

'I'he tubing 5 is provided, at a suitable distance above the plunger, with lateral ports 44 in communication with the chamber 3|. Mounted within the tubing 5 above these ports is a valve structure comprising an orifice 42, a valve seat 40, an upwardly opening ball valve 38, and a bafiie Pin 3'.

The pump barrel 29-is closed at the lower end by a transverse member or plate El, having there through an oriflce 68 in register with a downwardly extending tube 68 depending from said plate. Ports H are formed in the walls of the pump barrel above the lower end of the tube 69 to permit the inflow of the fluid from the well, and the pump barrel or housing 2! is closed at the bottom by a bull plug 13, andarrangement 61--69'|| forming in efiect a pump anchor.

The operation of the present tubing-actuated pump is as follows:

The pump is lowered into the well as shown the casing II, as shown in Figure 2. The pump barrel 29 together with barrel 23 and flange 21 being thus anchored within the casing against downward movement, a further lowering of the tubing 8 will result in applying the weight of the suspended .upper slip bowl 2| to the tapered faces of slips 25, forcing these slips out into engagement with the casing. and thus anchoring the pump against upward movement, as likewise shown in Figure 2.

The pump is now installed and anchored within the casing ll against either downward or upward motion, and is ready for operation by the reciprocation of the tubing 5, the dimensions of the barrels 23 and 28, plunger 51 and tubing 6 below the coupling I! being selected so that the plunger 51 and coupling I! do not strike plate 61 and flange I8, respectively, at the end of the lower stroke, and coupling I5 does not strike yoke 12 at the end of the upper stroke of the p mp- As the plunger 51 is reciprocated within the pump barrel by means of tubing 5 and suspending elements 2 and 3 from a prime-mover element such as a walking-beam, the flow of the well liquid proceeds to the surface as follows:

During the downward stroke, valve 38 is closed by the column of fluid in tubing 5 and the well fluid entering the pump barrel through ports II and tube 68 passes into the plunger 51. valve 6| being open, and hence intochamber 3| through ports 55 due to the vacuum created in chamber 3| above the plunger 51' by the downward displacement of said plunger. On the upward stroke, the valve 6| is closed, and the fluid displaced from chamber 8| by the rising plunger is forced through ports 44 and upwards into the tubing 5, opening the valve II.

ball valve '9 installed in a fltting 81, which may be used instead of the transverse member or plate 61 of Figures 1 and 2. Theuseoi thisball valve converts the space within the pump barrel below the plan er into a second enclosed chamber 84 similar chamber 3|, which chamber 84 is fllled to its full volume on the upstroke.

, 0n the downstroke, valve 89 being closed, fluid in Figure 1, the pump barrel comprising the elements 23 and 29 being supported by the abutment of flange l9 against the upper face or slip bowl 2|, suspended on links I! from the yoke.

II which is in turn supported on the coupling It or thetubing s. p

When the pump has been lowered to the desired level in the well, the supporting tubing 5 is rotated from the surface. Since the key I8, forming a part of thepump barrel is at this time engaged within the keyway 2B of the slip bowl 2|, and a key H on the yoke I3 is engaged within the keyway H on the coupling joint IS.

the rotation oithe tubing caiimes the whole pump to rotate. Guide springs 45 are however in frictional engagement with the casing, and the rotation of the latch ring 39 is therefore Drevented or retarded until the pins 4|, rotating with the pump, are free or the J-siot 43. A further downward movement of the tubing Ii with the springs 45 still in frictional engagement with the casing will result in the slips 3! being moved upwardly with regard to the slip bowl I3 and along its tapered faces into engagement with is sucked upwards through valve 89 in a volume equal to the inner volume 01- the pump barrel minus the volume of the tubing 5. This leaves said last volume of fluid to be disposed of during said downward stroke, which is accomplished by relieving said fluid from said chamber by means of relief valves 23, actuated by springs 85 to close lateral ports 2| in said chamber. Springs 85 may be set to give a desirable precompression in said chamber, for example about 20 lbs. per square inch, which reduces the volume of any gas which may have been sucked together with the liquid into chamber 04 during the upstroke, and increases the volumetric ef-' ilciency of the pump in wells making considerable quantities of gas.

W en it is desired to raise the pump from the well, this may be accomplished by simply pulling the tubing 5; which results first in retracting the upper slips 2!, as soon as the upper slip-bowl is raised by the action of the coupling l5 lifting the yoke l3, and second in retracting the lower slips 3| as soon as the lower slip-bowl is raised, togetber with the body of the pump, by the lifting action of the upper bowl applied against the Figure 3 illustrates the use of an additional cifically the upper Slips anchoring the pump against upward motion, is that the force pushing the fluid into the tubing and up to the surface through valve 38 during the upward stroke tends to' move the pump barrel upwards, said force being caused by the fluid head in tubing plus the friction losses.

Alth'ough the present pump system may be installed in any oil well and in combination with casing and tubing 01' any diameter, its use is especially advantageous in wells producing small volumes of oil, such as stripper wells giving up to 50 barrels of fluid daily, wherein it may be operated in combination with small diameter tubing such for example as one inch. one and one quarter inch, or one and a half inch tubing.

I claim as my invention:

1. In well pumping apparatus, a string of tubing extending into the well, said tubing being adapted for reciprocation from the surface, .a plunger affixed to the lower end of said tubing, a pump barrel slidingly fitting around said plunger, port means for admitting well fluid to aid pump barrel below said plunger, passage means in said plunger for admitting fluid from the under to the upper side thereof within said pump barrel, said tubing being open to said pump barrel above said plunger, valve means adapted to close said passage during the'upward stroke of the plunger,. lower slip means outwardly carried by said pump barrel adapted to anchor said pump barrel against downward motion in the well, and upper slip means adapted to anchor said pump barrel against upward motion in the well. said upper slip means comprising a slip-bowl slidingly surrounding saidpump barrel, stop memberson said pump barrel to limit the upward and the down ward motion of said slip-bowl with regard to said pump barrel, a yoke slidingly surrounding said tubing, a stop member on said tubing adapted to limit the downward motion of said yoke with regard to said tubing, and link means connecting said yoke to said upper bowl, whereby said upper slip means can be set to anchor said pump barrel against upward motion by lowering the tubing after the pump has been anchored by said lower slip means against downward motion.

2. In well'pumping apparatus, a string of tub ing adapted to extend into a, well, a pump barrel enclosing the lowerv end of said tubing, a stop member carried by the tubing above said pump barrel, a yoke memberslidably mounted around the tubing andadapted to rest on said stop member, a bowl member slidably mounted about .the pump barrel, stop members. on the pump barrel adapted to limit the axial movement of said bowl member with regard to the pump barrel, link means connecting said bowl member to said yoke member, first anchoring means mounted around the pum barrel, latching means actuated by tubing manipulation from the surface for setting said anchoring means in the well, second anchoring means mounted on said bowl, said mean being adapted to be set by a downward motion of said tubing with regard to the pump barrel when the pump barrel is anchored in the well by said first anchoring means, and means for conveying Well fluid to the surface through the tubing by reciprocating the tubing with regard to the pump barrel anchored in the well,'said means comprising a-f'valved plunger aflixed to the end of the tubing and slidingly fitting within the pump barrel.

3. A well pump adapted to be positioned in a well at the end of a string of tubing and to be actuated by the reciprocation of said tubing, said pump comprising a valved plunger adapted to be aifixed to the end of the tubing, a pump barrel slidably surrounding said plunger, first anchoring means mounted on said barrel, said first anch'oring means. being adapted to beset in the well in response to a rotational motion of said pump barrel, second anchoring means mounted on said barrel, said second anchoring means being adapted to be set in the well in response to an axial motion of tubing with respect to the pump barrel after the'pump barrel has been anchored in the well by said first anchoring means.

4. A well pump adapted to be positioned in a well at the end of a string of tubing, said pump comprising a pump barrel, 8, valved plunger fitting for a limited stroke within said pump barrel,

said plunger being adapted to be connected to said tubing, first anchoring means carried on said pump barrel in a normally retracted position, latching means for said anchoring means in frictional contact with the walls of the well,

said latching means being adapted to release said anchoring means against the walls of the well in response to a rotational motion of the pump barrel, second anchoring means carried on said pump in a normally retracted position, and actuating means for said second anchoring means supported on said tubing, said actuating means being adapted to force said second anchoring means against the walls of the well in response to an axial motion of the pump barrel with regard to the-pump barrel after the pump barrel has been anchored in the web by said first anchoring means.

WILFRED S. CRAKE.

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