US3165071A

US3165071A - Oil well pump

Info

Publication number: US3165071A
Application number: US221134A
Authority: US
Inventors: Horg George
Original assignee: MONARCH ENGINEERING CORP
Current assignee: MONARCH ENGINEERING CORP
Priority date: 1962-09-04
Filing date: 1962-09-04
Publication date: 1965-01-12
Anticipated expiration: 1982-01-12

Description

Jan. 12, 1965 G. HoRG oIL WELL PUMP Filed sept. 4. 1962 ias it tends to bend or buckle.

United States Patentl` OliceA A man' Patented jan 12, lg

3,165,071 H.. WELL PUM? George Horg, Southgate, Calif., assigner to Monarch Engineering Corp., Gardena, Calif., a corporation of California Filed Sept. 4, 1962, Ser, No. 221,134 2 Ciaims. (Cl. 10S-211) The present invention relates generally to pumps and, more particularly, to pumps for pumping viscous fluids such as a heavy crude oil or petroleum and for lifting such liuids from great depths such as from the bottom of oil wells.

When it is desired to pump crude oil or petroleum from an oil well, it is frequently necessary to raise the crude oil several thousand feet. As a consequence, the pump must be placed at the bottom of the well whereby it can lift the crude oil to the surface. The motor for drivingy the pump is normally located at the well head on the surface of the ground and is connec-ted to the pump by a suitable mechanical linkage. Normally, the pump employs a reciprocating plunger which rises during the work or pumping stroke and descends during the intake stroke. The mechanical linkage for connecting the pump to the motor consists of a walking beam and a string of socalled sucker rods. This string of sucker rods forms a very long slender column that can be heavily loaded in tension whereby it can very effectively lift the plunger .during the pumping or work stroke and thereby raise the crude oil. However, since the column of sucker rods is very long and slender, it cannot be loaded in compression As `a consequence, the string of sucker rods cannot force the plunger downwardly and it is necessary for a certain amount of lost motion to be present between the plunger and the walking beam. This, in turn, results in the plunger falling through the crude oil primarily as a result of its own weight. In lightweight crude oil having a low viscosity, the pump plunger can descend during the intake stroke sufciently fast to permit the use of pump strokes of reasonable lengths at reasonable pumping rates.

However, in some of the more desirable grades of petroleum, the crude oil is very heavy and has a high viscosity. Under these circumstances, during the intake stroke the pump plunger has descended at Ia very low velocity. As a consequence, the pump plunger does not descend the full length of the stroke before the follow pump stroke commences. This, in turn, effectively limits the length of the pumping stroke and the rate at which the pump is running. it may thus be seen that although the previous pumps have been effective for pumping crude oil from an oil well, they have not been entirely satisfactory, particularly when pumping the heavier or more viscous forms of crude oil.

It is now proposed to provide pumping means which will overcome the foregoing difficulties. More particu larly, it is proposed to provide pumping means particularly adapted to pump heavy or viscous iluids such as crude oils at higher rates of liow. This is to be accomplished by providing pumping means wherein the effective stroke -of the pump is increased and the pump may be driven at a faster rate. In one embodiment of the present invention, the pumping means includes an elongated hous- 'ing or jacket that is disposed between the lower end of the tubing string and the upper end of the `pump housing so as to interconnect the pump plunger with the sucker frod string. In addition, means are provided in the elon gated housing for biasing the pump plunger downwardly at all times. This will not only maintain the entire string of sucker rods under tension, but will also insure the pump plunger travelling downwardly during the intake stroke at a velocity substantially equal to the rate at which the sucker rods are descending.

These and other ,features and advantages of the present invention will become readily apparent from the following detail description of one embodiment thereof, particularly when taken in connection with the accompanying drawings wherein like reference numerals refer to like parts, and wherein:

FIGURE l is a transverse cross-sectional view of pumping means embodying one form of the present invention; and

FlGURE 2 is a horizontal cross-sectional view taken substantially along the plane of line 2 2 in FIGURE l.

Referring to the drawings in more detail, the present invention is particularly adapted to be embodied in pump means 19 for use in an oil well 12 for pumping petroleum or crude oil from the bottom of the well v12 to a well head at the surface of the ground. In the present instance, this well 12 includes an outer protective casing 14 that consists of a series -of pipe sections that are installed at the time the well is drilled. These sections are connected end-to-endv and are embedded in the ground to form an unbroken string all the way from the well head down into the oil-bearing strata. Although the casing 14 is normally imperforate for substantially its entire length, the lower end thereof may be perforated to allow the crude oil to flow through the perforations into the casing and accumulate in the bottom thereof.

In order to remove the crude oil as it accumulates in the casing 14, it is usually necessary to provide pump means 1t? that may be connected to the lower end of a tubing string 16 so las to lift the crude oil through the tubing string 16 to the well head. Because of the depth of the well, it is necessary for the pump means 1t) to be disposed in the bottom of the casing 14 and at least partially immersedin the crude oil. Although the pump means'ltl may be of any desired variety, for purposes of illustration in the present instance, it includes la pump housing 18 and a jacket 2t). The upper end of the pump housing 18 is connected to the lower end of the jacket 2t) by a reducer coupling 21 and the upper end of the jacket 2t) is connected to the tubing string 16. Thus, the crude oil discharged from the outlet or discharge end of the pump housing 18 will llow through the reducer coupling 21 and the jacket 20 into the tubing string 16 and vertically upwardly therethrough.

The inside of the pump housing 18 may include a passage of uniform diameter having a smooth surface that forms a cylinder or pumping chamber. A pump plunger Vor piston may be disposed inside of this cylindrical pumping chamber so as to be able to move axially of the chamber. A plunger or piston rod 22 is connected to the plunger so as to extend axially of the pump chamber and project upwardly from the topvof the pump housing 18. The plunger or piston may include suitable valving that will permit the crude oil to flow upwardly through the piston but will prevent itflowing vertically downwardly therethrough. Additional valving means may also be provided at the top and/or bottom of the pump housing 18 for preventing the crude oil flow backwardly through the pumping chamber. As a consequence, it may be seen that. duringthe pumping stroke when the piston rod 22 lifts the plunger or piston upwardly through the pumping chamber, the entire column of crude oil in the pump Basauri typical pump, the piston may have a stroke on the order of 24 to 43 inches and a pumping rate on the order of up to 30 strokes a minute.

in order to drive the pump piston through the pump chamber, a string of so-called sucker rods 24 may extend axially through the center of the tubing string 16. This string of sucker rods 2d consists of a series of sections of solid rods that are secured end-to-end by couplings to form a long slender column. The upper end of the top sucker rod string 2Limay be connected to a motor-driven walking beam located at the well head. As the walking beam oscillates, it will periodically raise and lower the sucker rod string 24 inside of the tubing string 16.

I eretofore, the lower end of the sucker rod string 24 has been connected directly onto the upper end of the piston rod 22. This has permitted the rising sucker rod string 24 to raise the piston and pump the crude oil vertically up through 'the tubing string. In addition, as the sucker rod string 24 descends, the piston has been free to descend through the barrel of the pump 1S and accumulate a fresh charge of crude oil thereabove. However, it has been found that as the viscosity of the crude oil increases, the rate at which the crude oil can flow through the valving on the piston decreases and the piston will not descend las fast as the walking beam lowers fthe sucker rodY string 2d, As a consequence, during the descending stroke, the load on the sucker rod string 24 is released. Moreover, since the sucker rod string 24 is such a long slender column, it cannot withstand any compressive loads without buckling` and/ or bending. As a result, where the crude oil has been very viscous, the pump piston has failed to descend lto the end of its stroke while the sucker rod string 24 has been lowered. Thus, when the sucker rod string 2&5 has been raised, the slack has to have been taken vout of the sys-tem whereby a shock loading of the string has occurred since the piston was not at the bottom of its designed stroke. Moreover, the piston was raised only through the top portion of its stroke. Although this would pump some oil, since the piston only travels a fraction of the available stroke, the quantity was only a fraction of the maximum possible amount. This, in turn, made it necessary to reduce the pumping rate to a Sulliciently low number of strokes per minute to permit the piston to approach its full stroke.

In order to overcome this difficulty, the pumping means l@ includes the cylindrical jacket Z and the operative elements therein. More particularly, the jacket 20 is a hollow cylindrical member having inside and outside diameters substantially the same as the corresponding diameters of the tubing string 16. The jacket 2l) will thus form a passage 30 that extends axially thereof in substantial alignment with the passage formed by the tubing string le. j

The lower end of the jacket 20 is secured to the upper end of the reducer 21 by means of a collar 32. This collar 32 may be of conventional design in that it includes two internally threaded sections that are separated from each other by means of a radially inwardly-directed flange 34. This flange 3d extends only partially inwardly toward its center to form an enlarged opening or passage 36 and a radial shoulder 38. The upper end of the jacket 20 is secured to the lower end of the tubing string 16 by means of a second collar 4t). This collar 49 may be substantially identical to the lirst collar 32 in that it also includes a pair of thread portions and a radial flange 42 therebetween that forms a passage 44 surrounded by an annular shoulder 46.

A lifting plate 4S may be disposed in the lower end of the jacket Ztl so as to be free to rest on the shoulder 38 formed by the ilange 34. This plate 48 may be essentially a disc of sufficient thickness to be very rigid even when subject to the forces involved. The outside diameter of the plate may be large enough to closely lit in the passage with only a small clearance space Si). This clearance space :Sil will permit the plate 48 to move axially of the passage. ln order to permit the free llow of crude oil upwardly through the jacket 2%, portions of the plate 48 may be relieved to form llow passages or a plurality of perforations 52 may be provided in the plate d8 at circunit'erentially disposed parts. in addition, an opening may be provided in the center of the plate so as to form a passage 54 that extends axially therethrough.

Resilient means may be disposed in the jacket 20 so as to exert a resilient biasing force on the plate d8. Although any desired means may be employed, in the present instance, a coil spring 56 is disposed in the passage 32 extending through the jacket Ztl. referably, the outside diameter of the spring is approximately' equal to the inside diameter of the passage 32 and the inside diameter of the spring $5 is large enough to form an open and unobstructed passage extending axially along the center thereof. The lower end of the spring 56 may be cut oft normal to the axis and seated on the plate 48 so as to react vertically downwardly against the plate 48 and force it toward the shoulder 38. The upper end of the spring 56 may be in engagement with the shoulder 46 on `the lower side of the flange 42. lt will thus be seen that this spring 56 will react betr/'een the collar 49 on the jacket Ztl and forcibly bias the lifting plate 48 downwardly through the passage 32 toward the lower collar 32..

It has been found desirable for the free length of the spring 55 to be greater than the space between the ange l2 and the top of the plate d3. rl`his will maintain the spring 5d under compression at all times and insure a biasing force on the plate l even when it has descended to the bottom of the passage 32 and is seated on the shoulder 3d.

A connecting rod 6G may be disposed inside of the jacket 2t) so Aas to extend axially thereof substantially concentric with the spring 56. The upper end of the connecting rod dll may extend upwardly from the top of the spring S6 so as to be attached to the lower end of the bottom sucker rod in the string 2.4i by means of a suitable coupling 62. rl`he lower end of the connecting rod e0 may extend downwardly through the passage 54 in the center of the plate 48. rl`he outside diameter of the connecting rod dit is preferably only enough smaller than the inside diameter of the passage 54 to permit the rod 6E) to slide freely therethrough. The lower end of the connecting rod 6) is attached to the upper end of the piston rod 22 by means of a coupling 645.

The outside diameter of this coupling d4 is preferably much greater than the inside diameter of the passage 54. As a consequence, the upper end of the coupling 64 will form a shoulder e6 that will engage the bottom side of the lifting plate 48 when the lower end of the connecting rod 60 attempts to pass through the passage 54. As a consequence, upward travel of the connecting rod 6l) will lift the plate 48 clear of the shoulder 38 on the llange 34 and cause the spring 56 to be compressed.

In order to employ the present pumping means in an oil well, the collar 32 may be threaded onto the lower end of the jacket 20. The lifting plate 48 may then be inserted through the open end ot the jacket Ztl and positioned on the shoulder 3S formed by the radial flange 34 on the collar 32. Once the lifting plate 4S is properly seated, the spring 56 may be inserted through -the open end or" the jacket 20 so as to be disposed inside of the jacket 20 with the lower end bearing against the lifting plate 48. The upper collar 4i) is then threaded onto the upper end of the jacket Ztl.

It has been found desirable for the natural or free length of the spring to exceed the distance between the top of the lift plate 48 and the shoulder 46. Thus, when the spring 56 is retained in position by Vthe collar dll, it will be maintained under compression and the plate 48 will be biased toward the shoulder 3S at all times. Although the amount of this force may vary from application to application, by way of example, it may be on the order of 50 to 100 pounds. As the lifting plate 48 rises, it will compress the spring 56 and shorten its length. It is desirable for the length of the spring 56 to be so long that at its normally fully compressed position there will still be a substantial clearance between the convulsions of the spring 56. That is, the spring will never bottom and act as a vsolid member. The connecting rod 60 may then be attached to the piston rod 22 by means of the coupling 62. The piston rod and connecting rod may then be fed through the jacket 20 and the collar thread 32 onto the reducer 21. Following this, the tubing string 16 and the sucker rod string 24 may be Iattached respectively to the collar 40 and the connecting rod 60 and lowered into the well in the conventional manner.

After the entire tubing string 16- and the sucker rod string 24 have been completely assembled and the pump means properly positioned in the bottom of the well 12, the upper end of the sucker rod string 24 may be secured to the walking beam. The upper and lower ends of the stroke of the pump plunger may then be adjusted. At the bottom of the stroke, the plunger may be positioned such that the coupling 62 will always retain the lifting plate 48 above the shoulder 38 substantially as shown in FIGURE 3. This will insure that the spring 56 will be effective to exert a downwardlydirected force on coupling 62 even at the bottom of the stroke. This, in turn, will insure the sucker rod string 24 being maintained in tension at all times. At the top of the stroke, the plunger is positioned such that the spring 56 will not be completely compressed or bottomed That is, there will be some space between the turns such that the spring can be compressed further and does not act like a solid. Following this, the pumping operation may be commenced.

When the pumping operation is in progress during the lift or pump stroke, the sucker rod 24 will be raised and the pump piston lifted. This will cause the crude oil to be discharged from the upper end of the pump housing 18 and through the reducer 21. The oil ilow may continue upwardly through the collar 32 and the jacket 20 and tubing string 16. The shoulder 66 on the upper end of the coupling 62 will be in engagement with the lift plate 48 so that the lift plate will rise with the connecting rod 60 `and cause the spring 56 to be compressed.

At the top or upper end of the pump stroke, the sucker rods 24 will commence their downward travel. The compressed spring 56 will react between the shoulder 46 on the ange 42 and the lift plate 48. Since this will be effective to bias the plate against the coupling 62, it will insure the piston rod 22 and the pump plunger descending into the pump chamber approximately as fast as the sucker rod string 24 is being lowered by the walking beam, even though the crude oil may be very viscous and present substantial resistance to the flow of crude oil therethrough. Consequently, when the sticker rod string 24 has been lowered to the bottom of its stroke, the pump plunger or piston will substantially simultaneously therewith reach the bottom of its stroke. Thus, at the beginning of the following pump stroke, the piston will have accumulated a full charge of fresh crude oil and the sucker rod string 24 will also be loaded in tension.

Accordingly, it may be seen that means have been provided for increasing the effective pump stroke and the pumping rate of an oil well. Although only a single embodiment has been illustrated, it will be readily apparent to persons skilled in the art that numerous changes and modifications may be made thereto without departing from the invention. Accordingly, the foregoing disclosure and drawings are merely for illustrative purposes and do not limit the invention which is deined only by the claims which follow.

What is claimed is:

l. An oil well accessory for use in an oil well having a casing extending from the well head to an underground pool of crude oil, a pump disposed in the casing near the bottom of the casing and having a reciprocating piston and piston rod for forcing the crude oil from a discharge end and pumping the crude oil from the bottom lto the well head, a plurality of sections of tubes interconnecting with each other to form a tubing string extending from the bottom of the casing to the Well head so that said crude oil may ow through said tubing to the well head, a sucker rod string extending axially of the tubing string and through the discharge end, said' sucker rod string being drivinglyl connected to the piston rod in the pump, said accessory including the combination of: I

a section of tubing having an inside diameter that is substantially the same as the inside diameters of said tubing sections,

fastening means on the upper end ,of said last tubing section, said fastening means being elfective to be interconnected with the lower end of the tubing string for securing the last tubing section to the string,

a flange on the inside of the coupling, said flange having an opening that is large enough'for the sucker rod string to pass therethrough but is smaller than the inside diameter of the tubing string,

fastening means on the lower end of the last section for communicating the lower end of the last section with the discharge end of the pump for receiving the crude oil pumped therefrom,

a flange on the inside of the coupling, said flange having an opening that is large enough for the sucker rod string to pass therethrough but is smaller than the inside diameter of the tubing string,

a plate reciprocally disposed in the last tubing section, said plate having an outside diameter that is greater than the opening formed by the second flange, and

a spring disposed in the last section, one end of the spring bearing against the rst flange so as to be retained in the section, the other end of the spring bearing against the plate for biasing the plate against the second ange.

2. -In an oil Well having a casing extending from the well head to an underground pool of crude oil, an oil well pump including the combination of:

a pump positioned in the casing adjacent the bottom thereof and immersed in the pool of crude oil,

a reciprocating plunger in the pump for pumping the crude oil land discharging the crude oil through a discharge end,

a piston rod extending through the discharge end and attached to the plunger for alternately raising and lowering the plunger, said plunger being effective when raised to raise the crude oil and cause crude oil to be discharged axially from the discharge end of said pump,

a jacket secured to the discharge end of said pump so that the crude oil discharged from the pump may flow through said jacket,

a section of tubing having the lower end disposed adjacent said jacket,

fastening means interconnecting the lower end of the section with said jacket to receive the crude oil,

a radially inwardly directed flange on said fastening means, said flange having -an opening in the center thereof that has a diameter that is less than the inside diameters of the section of tubing,

a plate reciprocally disposed in said tubing section adjacent the fastening means, said plate having an outside diameter that is less than the inside diameter of the tubing section but is greater than the diameter of the opening in the ange,

a tubing string inside of the casing extending from the well head to the tubing section,

a connecting rod disposed in said jacket with one end extending through an opening in the plate,

a coupling connecting the lower end of the connecting rod to the piston rod, said coupling being too large to pass through the opening in the plate,

fastening means interconnecting the lower end of the tubing string to the upper end of the tubing section to allow the crude oil to tlow through the tubing string tothe well head,

Y a flange onv the second fastening means extending radially inwardly, said section iange having an opening with a diameter that is smaller than the inside diameter of the Vtubing section, and

' a sucker rod string extending axially of the tubing string, the lower end of the sucker rod string being interconnected with the connecting rod to lift the plunger .axially of the pump to raise a column of crude oil axially of the tubing string, said coupling being positioned to engage the plate and S lift the plate axially of the tubing section when the Sucker rod String raises the connecting rod and plunger,

a spring disposed in said jacket concentrically about References Cited in the tile of this patent UNTTED STATES PATENTS 929,164 Paine July 27, 1999 940,347 McCarthy et al Nov. 16, 1909 2,589,420 Mong et al Mar. 18, 1952 2,632,401 Mong Mar. 24, i953

Claims

1. AN OIL WELL ACCESSORY FOR USE IN AN OIL WELL HAVING A CASING EXTENDING FROM THE WELL HEAD TO AN UNDERGROUND POOL OF CRUDE OIL, A PUMP DISPOSED IN THE CASING NEAR THE BOTTOM OF THE CASING AND HAVING A RECIPROCATING PISTON AND PISTON ROD FOR FORCING THE CRUDE OIL FROM A DISCHARGE END AND PUMPING THE CRUDE OIL FROM THE BOTTOM TO THE WELL HEAD, A PLURALITY OF SECTION OF TUBES INTERCONNECTING WITH EACH OTHER TO FORM A TUBING STRING EXTENDING FROM THE BOTTOM OF THE CASING TO THE WELL HEAD SO THAT SAID CRUDE OIL MAY FLOW THROUGH SAID TUBING TO THE WELL HEAD, A SUCKER ROD STRING EXTENDING AXIALLY OF THE TUBING STRING AND THROUGH THE DISCHARGE END, SAID SUCKER ROD STRING BEING DRIVINGLY CONNECTED TO THE PISTON ROD IN THE PUMP, SAID ACCESSORY INCLUDING THE COMBINATION OF: A SECTION OF TUBING HAVING AN INSIDE DIAMETER THAT IS SUBSTANTIALLY THE SAME AS THE INSIDE DIAMETER OF SAID TUBING SECTIONS, FASTENING MEANS ON THE UPPER END OF SAID LAST TUBING SECTION, SAID FASTENING MEANS BEING EFFECTIVE TO BE INTERCONNECTED WITH THE LOWER END OF THE TUBING STRING FOR SECURING THE LAST TUBING SECTION TO THE STRING, A FLANGE ON THE INSIDE OF THE COUPLING, SAID FLANGE HAVING AN OPENING THAT IS LARGE ENOUGH FOR THE SUCKER ROD STRING TO PASS THERETHROUGH BUT IN SMALLER THAN THE INSIDE DIAMETER OF THE TUBING STRING, FASTENING MEANS ON THE LOWER END OF THE LAST SECTION FOR COMMUNICATING THE LOWER END OF THE LAST SECTION WITH THE DISCHARGE END OF THE PUMP FOR RECEIVING THE CRUDE OIL PUMPED THEREFROM, A FLANGE ON THE INSIDE OF THE COUPLING, SAID FLANGE HAVING ON OPENING THAT IS LARGER ENOUGH FOR THE SUCKER ROD STRING TO PASS THERETHROUGH BUT IS SMALLER THAN THE INSIDE DIAMETER OF THE TUBING STRING, A PLATE RECIPROCALLY DISPOSED IN THE LAST TUBING SECTION, SAID PLATE HAVING AN OUTSIDE DIAMETER THAT IS GREATER THAN THE OPENING FORMED BY THE SECOND FLANGE, AND A SPRING DISPOSED IN THE LAST SECTION, ONE END OF THE SPRING BEARING AGAINST THE FIRST FLANGE SO AS TO BE RETAINED IN THE SECTION, THE OTHER END OF THE SPRING BEARING AGAINST THE PLATE FOR BIASING THE PLATE AGAINST THE SECOND SECOND FLANGE.