US1900588A - Liquid counter-balanced pumping system - Google Patents

Description

March 7, 1933. B. scoTT y LIQUID COUNTER BALANCED PUMPING SYSTEM Filed'June 2, 19:50 2 sheets-sheet l 5er/Zarza? H 6003i;

Hot ne? 3 March 7, 1933. B, SCOTT 1,900,588

LIQUID COUNTER BALANCED PUMPING SYSTEM Filed June 2, 1930 2 Sheets-Sheet 2 '5er/20722 z5. 600%; @NZM www Patented Mar. 7, 1933 PATENT OFFICE BERNARD E. SCOTT, F GLENDALE, CALIFORNIA LIQUID COUNTER-BALANCE PUMPING SYSTEM Application led .Tune 2, 1930. Serial No. 458,973.

This 'invention relates to liquid counterbalanced pumping systems or, in other words, to pumps in which a liquid column is employed against a shoulder on the plun er to counter-balance the column of liquid ing raised by the plunger.

The commonly employed deep well pump in the oil fields has its plunger` connected with a string of sucker rods which extends 4 1 downwardly from the top of the well. It

will be obvious that the well may attain such depth that the strain on the sucker rods ma reach a value in excess of the tensile strengt of the rods, thereby entailing parting or rupture of the rods.

In the pumpin cycle of the commonly employed type of eep well pump, the sucker rods and ump plunger are started from a position ci) rest and moved upwardly by the power equi ment at the surface of the earth. To accom ish this, it is necessary that the weight o pump tubing above the plunger, plus the weight of the string of sucker rods, be started 2? from a state of rest and moved upwardly a distance equivalent to the stroke of the pump. The amount of energy required to accomplish this is approximately 50% of the entire power consumption necessary to operate the plunger on its fluid lifting stroke. On the down stroke of the plunger the liquid in the tubing rests on the standing valve and the weight of the sucker rods aids the prime mover and,'accordingly on the down stroke very little power is required. This difference in power requirements on the two strokes of the pump is due to the unbalanced load.-

In order to overcome the unbalanced load condition, it is common to employ at the earths surface some form of counterweight that is connected with the prime mover in such manner that the weight is raised when the plunger is on its down stroke and the weight descends when the plunger is on its up stroke. While counter-balancing is achieved by this arrangement, it does not relieve the sucker rodsfrom that very severe stress which they undergo on the up stroke of the pump.

Accordingly, the expense involved in rethe entire column of oil in the above the pump plunger.

placing broken sucker rods and the monetary loss due to the stopping of production, are not materiall affected by the counter-balancing done at t e surface of the earth.

At the present time oil wells are bei drilled, on an average, to much greater depths than was formerly the case. Production now is often obtained from depths ranging between 6,000 to 8,500 feet and it is Iimpossible with pumps commonly used at the presenty tlme to pump such deep wells after they cease flowing. The usually emplo ed type of pump `can only be used in wells below no greater depth than ap roximately 5,500 feet.

A very important o ject of this invention 05 4is to reduce the strain on the string of sucker rods so as to minimize breakage thereof.

Another important object is to pump wells of greater depths than those which can be pumped with the pumps commonly in use in the oil fields.

I achieve the foregoing, objects by applying the pressure of a counter-balancing liquid column near the base of the string of sucker rods so as to not stress the rods beyond their ultimate breaking strain. In an installation of this character, a reservoir must be provided outside of the pump tubing reaching from the surface of the earth down to the level Where the pressure of the counter-balance fluid is to be applied to the moving parts of the pump. This reservoir may be formed by a portion of the well casing, which portion is separated from another portion by a suitable packer. In other words, the upper portion of the well casing constitutes the reservoir while the lower portion serves to convey the oil to the working-barrel of the pump inthe usual manner. The packer serves to seal off the producing zone of the well from the upper portion of the casing. Since gas present in the well, when the ordinary pump is employed, is permitted to escape through the casing, it is necessary, because of the presence of the packer, to make provision for the gas to escape from beneath the packer out of the well, and a very important object of the invention is to utilize such gas to aid in lifting the column of liquid Another very important object of the invention is the prevention of a gas lock, a condition often present in the commonly employed pumps and resulting when an accumulation of gas occurs between the pump plunger and the standing valve, said gas slipplng downwardly by the plunger on the up stroke of the plunger.

Another very important object is to prevent sanding up of the pump. 'In the ordinary type of deep well pump, the lower end of the pump barrel screws into a seat melnber in which the standing valve seats and the sand accumulates around the barrel, making it very difficult to pull the pump.

I avoid this difculty by placing the seat member above the level of the standing valve so that at least that portion of the working barrel is suspended from the seat member.

Other objects and advantages will appear in the subjoined detailed description.

The accompanying drawings illustrate the invention: 'j

Figure 1 is a broken elevation, partly in section, of a liquid counter-balanced pumping system constructed in accordance with the provisions of this invention.

Fig. 2 is an enlarged broken longitudinal section of the upper portion of the pumping system.'

Fig. 3 is an enlarged broken longitudinal section of the lower portion of the pumping system.

Fig. 4 is an enlarged sectional detail of some of the parts illustrated in Fig. 3, constituting the lock for the working barrel.

Fig. 5 is a horizontal. section on the line indicated by 5 5, Fig. 4.

Fig. 6 is an enlarged sectional detail of those parts of Fig. 3 that constitute the means for releasing gas from beneath the packer into the column' of liquid being pumped.

Referring to the drawings, a well casing is indicated at 11 and is divided by a packer 12 into an upper chamber or reservoir 13 and a lower chamber 14. The casing 11 is provided with the usual perforations 15, through which fluid from the producing area may flow into the pump. It is to be particularly noted that the perforations 15 communicate only with the chamber 14 that is below the packer 12.

Positioned within the chamber 14 is a working barrel 16 in which operates the hollow head 17 of a plunger which is indicated in general by the character 18, and the lower end of the working barrel is provided with a suitable standing valve 19. In this instance, the standing valve 19 is of the poppet type. The valve body 20 is threaded into the lower end of the working barrel 16. The plunger head 17 is hollow and is provided at its lower end with an inlet valve 21. Thus, upon up stroke of the plunger head 17 the valve 19 opens, while the valve 21 remains closed, thus permitting liquid to flow from the chamber 14 into the working barrel below the ascending plunger. On the down stroke of the plunger head 17, the valve 19 closes and the valve 21 opens, thus permitting the fluid in the working barrel beneath the plunger to How into the 'plunger head 17 and upwardly through a reduced tubuar portion 22 of-the plunger, said portion 22 being screwed or otherwise secured to the upper end of the head 17. The upper end of the plunger portion 22 is provided with a port or vports 23 through which the fluid flows from the plunger portion 22 into a tubular member 24, the bore of which is sealed by a tubular member 25 from the bore of the working barrel 16. The plunger portion 22 has a sliding fit in the member 25.

From the bore of the member 24, the fluid flows through a port or ports 26 into another reduced tubular portion 27 of the plunger, said portion 27 being connected with the portion 22 by a rod 28. The fluid Hows upwardly through the tubular portion 27 into the lower end of the upper hollow head 29 of the plunger 18, said head 29 being provided at its upper end with an outlet valve 30 of any approved type. In this instance the upper end of the tubular portion 27 is screwed into the lower end of the plunger head 29. The cage of the valve 30 is indicated at 31 and to it is connected, in the usual manner, a string 32 of sucker rods which extend to the surface of the earth for connection with suitable pump operating mechanism, not shown.

The plunger head 29 operates ina cylinder 33 and the upper end of said cylinder connects with pump tubing 34 which extends to the surface of the earth as is customary in this art. Accordingly, the fluid dischar es from the plunger head 29 through the va ve 30 into the cylinder 33 above said valve and thence into the pump tubing through which it flows to the surface of the earth in a manner well understood in this art.

It will be readily understood that reciprocation of the pump plunger is effected by operation o the string of sucker rods, in a manner well understood in this art and the construction for counter-balancing the liquid being raised by the pump plunger will now be described: The underface 35 of the lower end of the plunger head 29 constitutes an annular shoulder on the plunger and against this annular shoulder comes the pressure of the liquid column that occupies the reservoir 13. For example, if oil is the liquid being pumped,- the reservoir 13 will be filled with oil to the surface of the earth. This oil in the reservoir has access to the cylinder 33 beneath the plunger head 29 through ports 36 in a member 37 that, in this instance, constitutes a coupling that connects a tubular jacket section 38 with another jacket section 39. The section 38 surrounds the cylinder 33 and the section 39 constitutes a packing expanding meming. Accordingly,

ber. The outer face of the member 39 is of conical form to lit the tapered inner face 41 of a. resilient tubular packing member 12. The tapered faces taper inwardly and downwardly so that the weight of the pump expands the packer member 12 against the inner face of the well casing 11. The members 39, 12 together constitute the packer hereinbefore referred to as dividing the casing into the chambers 13, 14.

The member 39 is unsea-ted from the member 12 by pulling the pump tubing and the member 39 is provided beneath the member 12 with an annular shoulder 42 that, when the member 12 is expanded, is spaced from the lower end of the member 12. Thus, when the member 39 Ais raised to release it from the member 41, said member 12 is engaged by the shoulder 42 and is withdrawn from the well when the pump is pulled.

When the pump is installed in a well producing gas, as is the case in an oil well, gas that separates from the oil within the chamber 14 cannot flow to the surface of the earth through the casing because ofthe presence of the packer 12, but it is necessary to relieve the gas pressure within the casing for, otherwise, the pressure would increase to such an extent as to hold back the fluids in the producing stratum. In this instance, not only is the gas pressure relieved in the chamber 14, but provision is made for utilizing said gas to aid in lifting the column of oil in the pump tubthere is provided a ported means to permit of the flow of gas from the chamber 14 into the tubular member 24 and, in this instance, said ported means is constructedv as follows: A tubular member 43 is screwed into a reducing coupling 44 that in turn is screwed into the lower end of the jacket section 39, and said member 43 is screwed into the upper end of the tubular member 24.

The member 43 is provided with a port 45 that communicates at one end with the chamber 14 and at its other end with the bore of the member 43. Within the port 45 is a valve seat 46 for a ball check valve 47 that opens when the pressure within the chamber 14 exceeds that in the tubular member 24. This difference in pressure is caused by reason of the plunger portion 22, tubular portion 27 and rod 28 together constituting one form of lost motion connection between the plunger heads 17, 29. In this instance, the lost 'motion is due to the fact that the combined lengths of the plunger portion 22, tubular portion 27 and rod 28 are sulcient so that there is a material stretching thereof, thus insuring that the upper plunger head will move upwardly a material distance before the lower plunger head begins its up stroke.

en, as above explained, the upper plunger head moves upwardly while the lower plunger head remains stationary, a lowered cordingly, the valve 47 will open and gas j from within the chamber 14 will pass through the port 45 into the bore of the member 43,

thence through the ports 26 into the tubular lportion 27, thence into the upper plunger On the next succeeding down stroke of the plunger head 29, when the valve 30 opens, the gas thathas flowed into the plunger head 29 will pass said valve and ow up through the pump tubing, expanding as it ascends and thus aiding in raising of the liquid column in the pump tubing in the manner of the, sotermed, gas lift. It is noted that the gas that passes throughthe port 45 cannot pass connected by a reducing coupling 49 to the lower end of the pump tubing 34.

,The working barrel 16 is screwed on, or otherwise connected with the sealing member 25 which is provided with an external tapered face 50 removably fitting a tapered seat 51 in a seat member 52. The member 25 is releasably held against upward movement by a spring arm or a1ms 53 which are riveted or otherwise secured at 54 in the seat member' 52. The arms 53 normally spring inwardly so that their lower ends overhang the upper end of the member 25 and recesses 55 are provided inthe seat. lmember 52 to accommodate the arms 53 when said arms are retracted outwardly to permit the member 25 passing upwardly. 1

To effect retraction of the spring arms 53, the upper end of the member 25, as clearly shown in Fig. '5, is lprovided with radially extending shoulders or projections 56 which may be caused to engage and retract the spring arms 53 by rotation of the member 25 into a position where the projections 56 are in alinement with the spring arms 53. It isto be noted that sanding-up of this pump cannot occur because the pump barrel 16 is suspended from the seat member 52. In the ordinary pump, the seat member isat the lower end of the working barrel.

The. construction and operation of the invention will be understood from the foregoing description and, briefly stated, theoper-v ation is as follows: The pump having been installed in a producing well, with the packer 12 in place, the reservoir v13 will be filled with oil and the operating mechanism at the e the surface of the earth will be connected As the lower into the workin barrel below the plunger through the stan ing valve. Any slippage of gas past the plunger from the base o the liquid column above the plunger, will travel downwardly under high velocity, but instead of said gas flowing into the suction chamber of the working barrel and thus retarding inflow of liquid from the well, the gas that has passed along the plunger and that enters the working barrel above the lower plunger head 17, flows outwardly throu h a port or ports 57 in the upper portion o? the working barrel into the chamber 14. The same thing occurs on the down stroke of the plunger.

As the ordinary rod o eratedipump is so designed that the seal o the pump plunger is at `all times subjected to the hydrostatic pressure of the column of liquid in the pump tubing, there is no way to avoid gas lock resulting from gas released by agitation of fthe fluid, for it is impossible to deslgn a practical pump with a working clearance suliciently small to avoid sli page of the gas past the plunger. Thereibre, in order to minimize and practically prevent slippage of gas past the plunger into the suction cham ber of the working barrel, I provide a differential releasing chamber between the suction chamber and the liuid column in the pump tubing. It will be seen that the gas that passes out of the working barrel through the ports 57 passes with other gas in the chamber 14 through the port 45 when there is a pressure differential favorable to the pas- -sage of gases from the chamber 14 into the tubular member 24, and this is when the upper plunger head 29 has moved upwardly;

before upward movement of the lower plunger head 17 occurs. As soon as the pressure of gas within the chamber 14 falls below the pressure within the tubular member 24, the xcheck valve 47 closes, thus preventing backflow of oil fromthe pump tubing into the casing. Y

The up stroke of the pump plunger is assisted by pressure of the oil in the reservoir against the shoulder 35, the head of oil in the reservoir being the same as that in the pump tubing-provided the dischar of the oil in the pump tubing is at the sur ace of the earth or, in other words, at approximately the level of the upper end of the reservoir 13. If the effective area of the shoulder 35 is the same as the effective areas of the valve 30 and the the surface of the earth to increase the head of the counter-balancing liquid in the reservoir.

I claim:

1. A liquid-balanced pumping system comprising a working barrel, a standing valve for the working barrel, a valved plunger having a hollow head in the working barrel, 'a means forming a reservoir in a well for liquid, a means to apply the hydrostatic head of the liquid the reservoir to the plunger in the direction of motion of the plunger on its pumping stroke, and a string of sucker rods mechanically connected with the plunger for actuating the latter.

2. A liquid-balanced pumping system comprising a casing, a packer in the casing to provide a reservoir or liquid in the casing thereabove, a working barrel in the casing, a standing valve for the working barrel, a cylinder in the casing provided with a port near its lower end opening into the casing above the packer, a valved lunger having a hollow head in the working arrel and provided with a shoulder in the cylinder,and mechanical connecting means extending from said plunger up through said casing to positively reciprocate the plunger.

3. A liquid-balanced pumping system comprising a casing, a packer in the casing to provide a reservoir for liquid in the casing thereabove, a working barrel in the casing, a standing valve for the working barrel, a cylinder in the casing provided with a port near its lower end opening into the casing above the packer, a valved plunger having a hollow head in the working barrel and provided with a shoulder in the cylinder, and a string of sucker rods mechanically connected with the plunger for actuating the latter.

4. A liquid-balanced pumping system comprising a casing, a packer in the casingv to provide a reservoir for liquid inthe casing thereabove, a working barrel in the casing, a standing valve for the working barrel, a cylinder in the casing having a port near its lower end opening into the casing above the 5. A liquid-balanced pumping system comprising a casing, a packer in the casing to provide a reservoir for liquid in the casingthereabove, a working barrel in the casing, 'a standing valve for the working barrel, a cylinder in the casing, valved heads in the working barrel and cylinder, a ported tubular member connected with the heads, a tubular member connected with the working .barrel and' the cylinder and sealed from the cylinder, and ported measn to discharge gas from the casing below the packer into the last mentioned tubular member.

' 6. A liquid-balanced pumping system comcylinder in the casing having a port near its l prisin a casing, a acker in the casing to tween the heads including a ported tubular member, a tubular member connected with the working barrel and cylinder and sealed from the cylinder, and orted means to discharge gas from the casm below the packer into the last mentioned 'tu ular member.

.7 A liquid-balanced pumping system comprisme' a casing, a packer in the casing to provide a reservoir for liquid in the casing thereabove, a working barrel in the casing, a standlng valve for the lworking barrel, a valved plunger having a hollow head in the working barrel, a cylinder in the casing provlded with a port near its lower end opening 1nto the casing above the packer, the plunger provlded with a shoulder in the cylinder, means other than said standing valve to discharge gas from the casing below the packer into the plunger, and means to reciprocate the plunger.

liquid-balanced pumping system comprlsmg a casing, a packer in the casing to provide a reservoir for liquid in the casing thereabove, a working barrel in the casing, a standing valve for the working barrel, a cylinder in the casing, valved heads working in the cylinder and working barrel,.ported tubular members connected and communicating with the valved heads, a rod connecting the ported tubular members, a tubular member connected with the working -barrel and cylinder and sealed from the cylinder and communicating with the working barrel, ported means to discharge gas from the casmg below the packer into the last mentioned tu ular member, and means to reciprocate the plunger.

9. A liquid-balanced pumping system comprising a casing, a acker in the casing to provide a reservoir or liquid in the casing thereabove, a working barrel inthe casing, e

a standing valve for the working barrel, a cylinder in the casing, valved heads in the cylinder and working barrel, ported tubular members connected and communicating with the valved heads, a rod connecting the tubu-I lar members, a means to reciprocate the plunger, and a means to apply the hydrostatic head of liquid in the casing above the packer to the lunger in the direction of motion of the p unger on the pumping stroke.

10. A liquid-balanced umpmg system comprising a casing, a pac er 1n the casing to provide a reservoir for liquid 1n the casing thereabove, a working barrel in the casing, a standing valve for the working barrel, a

lower end opening into the casing above the packer, valved heads in the cylinder and working barrel, ported tubular members connected and communicating with the valved heads, a rod connecting the tubular members, a tubular member connected with the working barrel and'cylinder and sealed from the cylinder and communicating with the working barrel, a shoulder on theplunger in the cylinder, ported means to discharge gas from the casing below the packer into the last mentioned tubular member, and means to reciprocate the plunger.

11. A liquid-balanced pumping system comprising a casing, a packer in the casing to provide a reservoir for liquid in the casing thereabove, a working barrel in the casing provided with a port near its upper end communicating with the casing below the packer, a standing valve for the* working barrel, a plunger having a hollow valved head in the working barrel, a sealing means at the upper end of the working barrel, the plunger provided above said head with a reduced tubular portion slidably iitting in said sealing means, means to discharge gas from the casing below the packer into said reduced tubular'portion of said hollow plunger at a point above said sealing means, and means to reciprocate said reduced tubular portion.

12. A liquid-balanced pumping system comprising a casing, a packer in the casing to provide a reservoir for liquid in the casing thereabove, a working barrel 1n the casing provided with a port near its upper end, a standing valve for the working barrel,

a cylinder in the casing having a port near working barrel and cylinder and sealed from the cylinder, ported means to discharge gas from the casing below the packer into the last mentioned tubular member, and means to reciprocate the reduced tubular portion of the plunger.

13. A liquid-balanced pumping system comprising a casing, a packer in the casing4 to provide a reservoir for liquid in the casing thereabove, a working barrel in the casing provided with a port near its upper end opening into said casing below the packer, a standing valve for the working barrel, a cylinder in the casing having a port in its lower portion communicating with said reservoir, valved heads in the c linder and working barrel, ported tubu ar members connected and communicating with the valved heads, a rod connecting the tubular members, a tubular member between thfe working barrel and cylinderv and sealed from the cylinder, a sealing means at the upper end of the working barrel, one of the ported tubular members having a portion of less diameter than the lower head slidably fitting in said sealing means, and means to reciprocate the upper head.

14. A deep well ump comprising pump tubing, a seat mem er provided with a tapered seat, a means connecting the seat member with the pump tubing, a sealing member provided with a tapered face itting the tapered seat, a working barrel provided with a port near its upper end and connected at its upper end with the sealing member, the sealing member provided with -a shoulder,an arm carried by the seat member and yieldingly held in position to overhang said shoulder,

means operable byrelative rotation between the sealing member and seat member to retract the arm out of the vertical path of movement of the shoulder, and a plunger having a hollow valved head in the-working barrel, the plunger provided with a reduced tubular portion slidably fitting in and sealing with said sealing member.

l5. A deep well pump comprising. pump tubing, va ,seat member provided with a tapered seat, a means connecting the seat member with the pump tubing, a sealing member provided with a tapered face fitting the tapered seat, a working barrel provided with a port near-its upper end and connected at its upper end with the sealing member, the sealing member providedwith a shoulder, an arm carried by the seat member and yieldingly held in position to overhang said shoulder, means operable by relative rotation between the sealing member and seat member to retract the arm out of the vertical path of movement of the shoulder, a plunger having a hollow valved head in the working barrel, the

plunger provided with a reduced tubular portionhslidably fitting in and sealing with said sealing member, and a radially extending shoulder on the sealing member engageable with the arm by relative rotation between the sealing member and seat member to move the arm outwardly from the vertical path of movement of the shoulder.

Signed at Los Angeles,California,this 26th day of May, 1930.

. BERNARD- H. SCOTT.

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