Search Images Maps Play YouTube News Gmail Drive More »
Sign in
Screen reader users: click this link for accessible mode. Accessible mode has the same essential features but works better with your reader.

Patents

  1. Advanced Patent Search
Publication numberUS3580697 A
Publication typeGrant
Publication dateMay 25, 1971
Filing dateApr 23, 1969
Priority dateApr 23, 1969
Publication numberUS 3580697 A, US 3580697A, US-A-3580697, US3580697 A, US3580697A
InventorsJohn O Youngblood
Original AssigneeJohn O Youngblood
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Pump
US 3580697 A
Images(2)
Previous page
Next page
Description  (OCR text may contain errors)

United States Patent @QC e Primary Examiner-Robert M, Walker Attorney-Dunlay, Laney, Hessin and Dougherty ABSTRACT: A pump for use in oil wells which includes an elongated production tubing, a working barrel positioned within the production tubing, a special oriced sub connected to the lower end of the working barrel, a standing valve cage connected to the special oriced sub, and a holddown shoe connected to the standing valve cage and engaging the production tubing. A plunger carrying a traveling valve is reciprocably mounted in the working barrel and connected at its upper end to a sucker rod string. The special oced sub is positioned immediately above the standing valve of the pump and has a bore therethrough which is radially offset from the axis of the aligned bores through the standing valve and the working barrel. Communicating with the bore through the special orificed sub is an orifice which extends upwardly and inwardly from the outside of the special sub.

PUMP

BACKGROUND OF THE INVENTION l. Field of the Invention This invention relates to sucker rod pumps, and more particularly, to bottom holddown pumps constructed to reduce 'or eliminate gas locking.

2. Brief Description of the Prior Art A problem with which petroleum production engineers are thoroughly familiar is that of gas locking is due to a large accumulation of gas being drawn through the sanding valvc into the working barrel. Here the gas builds up between the standing valve and travelling valve and due to its compressability, the gas is merely compressed during the downstrokc of the plunger, and does not exert enough pressure to cause the traveling valve Vto open against the hydrostatic pressure exerted by the column of production fluid above this valve. The pump is then gas locked.

it has previously been proposed to overcome gas locking by forming openings, or orifices tin the working barrel above the standing valve. These openings are usually at a location in the working barrel where they are traversed by the plunger during its stroke, however, and this arrangement soon results in the opening being worn to an excessive size and thus being more detrimental than advantageous.

BRIEF DESCRIPTION F THE PRESENT INVENTION The present invention is an improved sucker rod pump in which gas locking is substantially eliminated. This improved performance results from the location and geometric configuration of an orificed sub positioned immediately above the standing valve. The orificed sub is a tubular member having a bore therethrough which is radially offsetifrom the axial centerline of the sub. Extending through the wall of the sub at an angle to the bore is a small orifice or capillary bore which extends inwardly and upwardly with respect to the outer wall" of the sub.

-To broadly describe the combination: of the orf'lced sub with other elements of the pump, the pumpincludes the usual production tubing, a working barrel within' the production tubing, and a holddown shoe connectedf tothe lower end of the working barrel and holding it in place within the production tubing. A plunger secured to the lowerfend of a sucker rod string is `reciprocable movable in the working barrel and includes a traveling valve. The oriced sub is secured to the lower end of the working barrel, and to the upper end of va valve cage for the standing valve of the pump. The valve cage is secured to the upper end of the holddown shoe.

From the foregoing description of the invention, it will have become apparent that is it is an important object of the invention to provide a sucker rod pump which is less susceptible to gas locking than previously proposed pumps of this type.

Another object of the invention is to provide a sucker rod pump which minimizes gas locking of the pump, which pump includes structure which permits the working barrel of the pump to have a longer effective operating life.

A further object of the invention is to provide a sucker rod pump having structural incorporated therein for preventing gas locking, which structure can be relatively easily and economically manufactured. 4

An additional object of the invention is to provide a sucker rod pump which will decrease the power requirement usually entailed in operating sucker rod pumps.

Additional objects and advantages of the invention will become apparent as the following detailed description is read in conjunction with the accompanying drawings which illustrate the invention.

BRIEF DESCRIPTION 0F THE DRAWINGS FIG. 1A is a partially sectional, partially elevational view of a portion of the pump of the invention as it appears when located down hole in an oil well casing.

FIG. 1B is a partially sectional, partially elevational view of that portion of the pump of the invention which is disposed immediately below, and is connected to, the portion of the pump shown in FIG. 1A.

FIG. 2 is an enlarged sectional view of a portion of the pump of the invention which is located at the lower end of the production tubing.

FIG. 3 is a sectional view taken along line 3-3 of FIG. 2.

FIG. 4 is a sectional view ofa special orificed sub forming a part of the present invention.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE INVENTION Referring initially to FIGS. 1A and 1B of the drawings, there is there illustrated a casing l0 of an oil well which extends into an oil producing formation in the earth l2. Positioned concentrically within the casing I0 is a production tubing storing I4 which extends to the surface and functions to convey to the surface, oilproduced by the production formation at the lower end of the borehole 16. For the purpose of pumping the oil into the production tubing 14 and through the this tubing to the surface, a sucker rod pump designated generally by reference number 18 is positioned within the production tubing 14 and includes an elongated sucker rod string 20, the lower end of which is connected to the upper end of a pull rod 21. i

The lower end of the pull rod 21 is connected through a suitable coupling 22 to the upper end of a pump plunger designated generally: be reference numeral 24. The pump plunger. 24 is reciprocably mounted in an elongated tubularworking barrel 26.v The lower end of the working barrel 26 is threadedlyconnected to a special orificed sub 28, and its upper end is connected. through a fitting 30 to a slotted or ported rod guide 32. A suitable bearing sleeve or journal 34 is threaded in the slotted rod guide 32 and slidingly surrounds the sucker rod string.v It will be perceived in referring to FIG. 1A that the plunger 24 includes a ported or slotted adapter 36 which isthreadedly engaged with a tubular body portion 38. The tubular body portion 38 carries a plurality of annularsealing rings 30 around the outer periphery thereof, and slidingly and sealingly engages the internal wall of the working barrel 26. The body portion 38 of the plunger 24 threadedly engages a valve cage 42' which is secured to its lower end. A spider structure 44 extends across the lower end of the boys portion to prevent the spherical member or ball 45, constituting a traveling valve, form rising past the spider in the plunger. The ball 46 seats upon an annular seat 47 formed internally within a standing valve seat element 48 threaded into the lower end of the traveling valve cage 42.

The lower end of the special orificed sub 28 is threadedly connected to a tubular-standing valve section 50 which has a spider or valve-retaining element 52 located therein, and which hasan annular-standing valve seat 54 pressed into a counterbore formed.f in the lower end thereof. The annularstanding valveseat 54 supports a spherical member or ball 55 and is retained in position against the shoulder formed by the counterbore by a bottom holddown 55 which is threaded into the counterbore and carries at the outer periphery thereof intermediate its length, a plurality of seating cups 58 which are spaced from each othe'r and placed in compression by means of a plurality of spacer cups 60 which are concentrically mounted on the bottom holddown 56. The seating cups 58 bear against a tubular-seating nipple 62 which is threaded into the lower end ofthe production tubing 14. The seating nipple 62 threadedly engages the upper end of a mud anchor 63 which has a plurality of apertures or openings 64 formed therein at a location below the end of the casing l0 andop.- positc the producing formation.

As will understood in sucker rod technology, the bottom holddown 56, with its associated seating cups 58', functions to secure the pump 18'in a stationary position relative to the production tubing 14 and prevent the working barrel 26 of the pump from being pulled upwardly during the reciprocating stroke of the sucker rod string. Threaded into the lower cnd of the bottom holddown'56 is a gas anchor 66. The gas anchor 66 has a plurality of perforations or openings 68 formed in the lower end thereof.

The construction of the special orificed -sub 28 and its location with respect to other elements of structure of the invention may best be perceived by referring to FlGS. 2-4 of the drawings. As here illustrated, the special orificed sub 28 includes a central body portion 70 which has a bore 72 extending therethrough in an axial direction. The bore 72 may be perceived co be radially offset form the central axis of the sub 28 as best depictedl in FIGS. 3 and 4 and in FIG. 2, it will be noted that the diameter of this bore does not exceed one-half the diameters of the bores through the working barrel and tubing section 50 which contains the standing valve. Extending radially inwardly and upwardly at an acute angle to the vertical from one side ofthe sub 28 is a threaded plug-receivingv port 74. The threaded plug-receiving port 74 receives an externally threaded, generally cylindrical plug` 75 which has formed in one end thereof a wrench receiving hexagonally cross-sectioned counterbore 76. A small orifice 78 extend from the counter bore 76 to the end of the plug 75 so that the bore 72 through the sub 28 is place in communication with the outer peripheral surface thereof through thevbore 74, the orifice 78 and the c'ounterbore 76. The orifice 78 and counterbore 76 preferably extend at an angle of between about 20 and about 70 with respect to the vertical. lt will be noted in referring to FIG. 2 that the special orificed sub 28 is located immediately above the standing valve 50 of the pump which includes the ball 55, the annular-standing valve seat 54 and the spider 52. lt will further be noted in referring to FIG. lA that the radially inwardly and upwardly extending bore 74 formed through the side of the orificed sub 28 communicates at its outer end with an annulus 80 located between the production tubing string 14 and the working barrel 26. Any fluid which may be located in this annulus is free to communicate through the orficed plug 75 which with the bore 72 through this special orificed sub 28. This fluid may flow into the inner chamber of the working barrel 26 as well as the inner chamber of the standing'valve section 50.

OPERATION During the upstroke of thepump plunger 2A, suction or lower pressure is created beneath the plunger and oil is drawn from the producing formation through the mud anchor 63 and gas anchor 66 into the tubular bottom holddown 56. From this point, the 'production fluid passes through the annular-standing valve seat 54 since-the ball 55 is, at this time, lifted o' the seat to permit passage of the fluid. The production fluid conv tinues upwardly through the bore 72 in the orificed sub 28. The working barrel 26 below the plunger 24 is then substantially filled with the `production fluid at at the end of the upward motion of the plunger 24.

During the downstroke of the pump plunger 24, the production fluid below this plunger with the result that the traveling valve is opened by lifting of the ball 46 off the annular seat 47. This permits the production fluid to pass into the hollow interior chamber of the plunger 24, and to fill the space within and above the plunger, and around the lower end of the pull rod 2l. Then, upon the following upstroke of the pump plunger 24, he the traveling valve is closed by seating of the ball 45 so that the production fluid above the traveling valve is lifted upwardly and forced out of the ports or slots in the rod guide 32. Eventually, by the repeated reciprocation of the pump plunger 24 within the working level barrel 26, the annulus 80 which surrounds the working barrel 26 becomes filled with production fluid and the production fluid is ultimately lifted to the surface.

ln previously proposed sucker rod pumps of the general type here under consideration, a substantial amount of hydrocarbon gas is generally entrained with the liquid crude petroleum, and results n gas locking of the pump. This occurs as a result of the accumulation of gas in the space between the standing valve and the traveling valve. With such gas accumulation, the downstroke of the plunger results in compression of this gas, and the compressibility of the gas located beneath the traveling valve permits this valve to remain closed under the hydrostatic headimparted to the ball of the traveling valve by the column of liquid production fluid located above the traveling valve. Thus, the pump is rendered substantially inoperative by this gas locked condition .which prevents the traveling valve from opening.

ln the present invention, gas locking of the type described and the many attendant disadvantages or difficulties associated with this phenomenaare obviated or substantially reduced. This avoidance of gas locking is achieved by the inclusion in the pump of a special orificed sub 28. During the upstroke of the plunger 24 within the working barrel 26, oil located in-the annulus between the working barrel 26.and the production tubing l'4 moves through the orifice 78 in the threaded plug 75 under the force imparted thereto by he the hydrostatic head of the column of liquid within the annulus, and under the reduction in pressure effected by the upward movement of the plunger 24 when the traveling valve therein is closed. There is thus delivered to the bore 72 through the sub 28, a jet or small stream of oil which produces several desirable effects.

First, the angled inclination of the orifice 78 with respect to the bore 72 accentuates a Venturi effect with respect to the standing valve located immediately below-,the special sub 28. Thus, the reduced pressure due to the Venturi effect aids in opening the standing valve to permit oil to flow freely therethrough. The entry of the oil via the orifice 78 into the special sub 28, and into the working barrel 26 connected thereabove, also assures that a substantial portion of the space below the traveling valve will be filled with a liquid rather than this space being almost entirely filled with gas. ln effect, this fluid so entering the working barrel 26 through the orifice 78 causes the accumulated gas in the working barrel to be compressed sufficiently that the higher compression of the gas under the traveling valve during the downstroke of the plunger 24 will force the gas up through the traveling valve ahead of the fluid entering this space through the orifice 78. This compression is effected a a result of the hydrostatic pressure of the liquid standing in the annulus 80. ln fact, it has been found that the provision of the orifice i n sub 28 in the described location causes the traveling valve to open on every downward pump stroke, and thus gas locking in is substantially entirely obviated. Moreover, the oil jetted through the orifice 78 and moving upwardly into the working barrel 26 lubricates the internal walls of the working barrel at all times, thus avoiding the dryness and associated wear usually occurring during a gas lock condition. 0n the downstroke of the plunger, the fluid in the working barrel and below the traveling valve cannot be forced back through the small orifice 78 as fast as the compressing action will force the liquid and gas up through the traveling valve.

The presence of the orifice 78 at the described location also has the advantage of reducing the occurrence of fluid pounding and its sudden shock impact on the pumping equipment. Thus, the reduction in fluid pounding reduces the wear on the boom hole pump parts, sucker rods, tubing and also the wear on the gearing, bearings, clutch belts and sheaves in the pumping unit at the surface. lt also functions to decrease the total amount of horsepower input which is required to operatethe pumping unit.

Not the least important aspect of the present invention is the locating of the special orificed sub 28 in the pump. By locating this sub at a point below the lowest point of travel of the plunger 24 in the working barrel 26, a difficulty which has been encountered in prior attempts to circumvent gas locking is, in fact, avoided. Thus, though it has previously been proposed to provide very small holes or orifices in the side of the working barrel in order to relieve gas locking, these orifices have usually been straight through apertures formed in the working barrel at a location in the working barrel which is traversed by the plunger during its reciprocation, As a result of this location, such orifices or apertures have quickly become worn to a substantially larger size, with the result that the pump becomes inefficient and ultimately totally inoperative as a result of essentially equal volumes of production fluid moving back and forth through a relatively larger opening formed in the side ofthe working barrel during each stroke.

Although certain preferred embodiments of the present invention have been herein described in order to provide an understanding ofthe general principles of the invention, it will be appreciated that various changes and innovations can be effected in the described pump without departure from these basic principles. All modifications and changes of this type are therefore deemed to be circumscribed by the spirit and scope of the invention except as the same may be necessarily limited by the appended claims or reasonable equivalents thereof.

What l claim is:

l. A pump comprising:

an elongated, vertically extending production tubing;

a working barrel positioned within the production tubing and defining an annulus therewith;

means retaining the working barrel at a fixed location within the production tubing;

a plunger reciprocable mounted in the working barrel for reciprocation to and away from a lowermost position within the working barrel;

a traveling valve in the plunger and movable therewith;

an orificed subconnected to the working barrel below the lowest point of reciprocating travel of the plunger therein, said sub having a bore therethrough and an orifice extending from said bore through one side thereof to said annulus, said orifice extending inwardly and upwardly form a point on the outer periphery of said sub; and

a standing valve connected to the orificed sub on the opposite side of said orificed sub from the working barrel.

2. A pump comprising;

an elongated, vertically extending production tubing;

a working barrel positioned within the production tubing and defining an annulus therewith, said working barrel having an elongated bore therethrough;

means retaining the working barrel at a fixed location within the production tubing;

a plunger reciprocably'mounted in the working barrel for reciprocation to and away from a lowermost position within the working barrel;

a traveling valve in the plunger and movable therewith;

an orificed sub connected to the working barrel below the lowest point of reciprocating travel of the plunger therein, said sub having a bore therethrough communicating with the bore through said working barrel, with the bore through said sub having an axis radially offset from the axis of said working barrel bore, said sub further having an orifice extending from the bore therethrough through one side of said sub to said annulus; and

a standing valve connected to the orificed sub on the opposite side of said orificed sub from the working barrel and having an opening therethrough offset from the axis of the bore of said orificed sub.

3. A pump as defined in claim 2 wherein the orifice in said sub extends from said bore to the side of said sub furthest removed from the bore through said sub and is inclined downwardly with respect to the axis of said bore through said sub at an angle of from about to abut 70.

4. A pump comprising:

an elongated, vertically extending production tubing;

a working barrel positioned within the production tubing and defining an annulus therewith; means retain the working barrel at a fixed location within the production tubing;

a plunger reciprocably mounted in the working barrel for reciprocation to and away from a lowermost position within the working barrel;

a traveling valve in the plunger and movable therewith;

an orificed sub connected to the working barrel below the lowest point of reciprocating travel of the plunger therein, said orificed sub comprising:

a cylindrical body portion having threaded upper and lower ends and having a bore extending through said cylindrical body portion between the upper and lower ends thereof and radially spaced from the central axis of said cylindrical body portion;

a threaded port extending from said bore downwardly and radially outwardly in said body portion to the outside of said body portion; and

a plug threaded into said port and having an orifice extending therethrough along an axis intersecting at an acute angle, the axis of said bore; and

a standing valve connected to the orified sub on the opposite side of said orificed sub from the working barrel.

5. A pump comprising:

an elongated, vertically extending production tubing;

a working barrel positioned within the production tubing and defining an annulus therewith;

means retaining the working barrel at a fixed location within the production tubing;

a plunger reciprocably mounted in the working barrel for reciprocation to and away from a lowermost position within the working barrel;

a traveling valve in the plunger and movable therewith;

an orifice sub connected to the working barrel below the lowest point of reciprocating travel of the plunger therein, said sub comprising:

a cylindrical body portion having threaded upper and lower ends, and having a bore extending through said cylindrical body portion between the upper and lower ends thereof;

a threaded port extending from said bore radially outwardly in said boys portion to the outside of said body portion; and

a plug threaded into said port and having an orifice extending therethrough along an axis intersecting the axis of the bore through said body portion.

6. A pump comprising:

an elongated, vertically extended production tubing;

a tubular-working barrel positioned within the production tubing and defining an annulus therewith;

means retaining the working barrel at a fixed location within the production tubing;

a plunger reciprocably mounted in the working barrel for reciprocation to and away form a lowermost position within the working barrel;

a traveling valve in the plunger and movable therewith;

a tubing section spaced below said working barrel;

a standing valve in said tubing section; and

an orificed sub connected to the lower end of the working barrel and the upper end of said tubing section and located below the lowest point of reciprocating travel of said plunger in said working barrel, said sub having a bore extending therethrough placing said working barrel in communication with said tubing section, said bore through said orificed sub having a diameter not exceeding one-half the diameter of the bore through said tubing section and the bore through said tubular-working barrel and said orificed sub having an orifice extending from the bore therethrough through one side thereof to said annulus to place said annulus in communication with the bore therethrough.

P04050 UNITED STATES PATENT OFFICE (S/GS) CERTIFICATE OF CORRECTION Patent No. 3 580 597 Dated May 25, 1971 Inventods) John 0. Youngblood It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

In Column l, lines ll and 12, after the words "gas locking" insert the following: occurring in sucker rod pumps. The occurrence of gas locking In Column 1, line 46, "reciprocable" should be --reciprocably.

In Column 1,. line 60, "structural" should be -structure.

In Column 2 line 22 "the" should be deleted after the word "through.

In Column 2, line 24, "number" should be -numeral.

In Column 2, line 43, "30" should be 40.

In Column 2, line 46, "boys" should be --body.

In Column 2, line 59, "55" should be -56.

In Column 2, line 72, after the word "As", insert the word --is.

In Column 3, line 62, after the word "plunger" insert --is subjected to compression by the plunger.

In Column 3, line 68, after "24, delete the word -he.

Page 2 Pf3-050 UNITED STATES PATENT OFFICE 5 9 CERTIFICATE 0F CORRECTION Patent No. 3,589,697 Dated May 25, 1971 h b d Invented@ Jo n O Young loo It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

In Column 3, line 69, "45" should be -46.

In Column 4, line 66, "boom" should be bottom.

In Column 4, line 72, "locating" should be location.

In Column 6,' line 42, "boys" should be --body.

Signed and sealed this 2nd day of November l9'fl.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK Attestng Officer Acting Commissioner of Patents

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US1246543 *Jan 29, 1917Nov 13, 1917Robert E CarmichaelMeans for preventing clogging of the working barrels of pumps.
US1730297 *Feb 12, 1927Oct 1, 1929Albert F RuthvenReciprocating pump
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US5915478 *Jan 28, 1998Jun 29, 1999Brown; Henry F.Hydrostatic standing valve
Classifications
U.S. Classification417/557
International ClassificationF04B47/00
Cooperative ClassificationF04B47/00
European ClassificationF04B47/00