US1805025A - Deep well pumping system - Google Patents

Description

W. N. SQUIRES Filed Jan. 21, 1929 3 Sheets-Sheet 1 May l2, 1931.

DEEP WELL PUMPING SYSTEM /A m I m J May l2, 1931.. w. N. sQUlREs DEEP WELL PEMPING SYSTEM Filed Jan. 21, l1929 3 Sheets-Sheet 2 May 12, 1931. w. N'` SQUIRES DEEP WELL PUMPING SYSTEM Filed Jan. 2l, 1929 3 Sheets-Sheet 5 Patented May 12, 1931 WILBUR N. SQUIRES, F JOPLIN. MISSOU RI, ASSIGNOR TO HYDRAULIC DEEP WELL PUMP COMPANY, 0F .'J'OIPLIN, MISSOURI, A. CORPORATION 0F MISSOURI DEEP WELL PUMPING- SYSTEM Application led January 21,v 1929. Serial No. 333,869.

My invention relates to hydraulic pumps of the character disclosed in my co-pending application, Serial No. 329,591, led December 31, 1928, and is more p-articularl concerned with the provision of means or diminishing or avoiding the eHect of com'- pressibility of the power column.

By refernce to my co-pending application, above referred to, a full explanation of the detailed mechanism for producing the motion of the power column may be had. It has been found that when pumping from great depth the compressibility of the power column results in a hysteresis which causes a loss of power and capacity of the equipment.

I have conceived the possibility of putting the power column under initial pressure which is not released during the operation of the system and hence the hysteresis loss due to compression and expansion of the powercolumn is greatly reduced.

In the system disclosed in my above referred to application, pressure is applied to the power column to make the discharge stroke of the pump by the downward motion Aof the column y under pressure. -A certain part of the displacement of the power jack is required to bring the power column to av state of compression great enough to actuate the pumpand likewise at the end of the stroke a certain part of th'e return. stroke is occupied in permitting expansion of the power column to bring it back to a condltion where the control valve may be opened to permit the escape of gas if any should b'e evolved in the power column and to permit .P

of the replacement of any liquid which may have escaped from the power column.

The referred means by which I reduce or obviate the effect of compressibility of the power column is to put the same under an initial pressure great enough to take up 1n a large part of its compressibility, which compressibility appears to reside mainly in the gas contained in the liquid of the power column and the spring in the container of the power column. l

This may be done in either of two ways. The preferred method is to isolate the ma] or part of the power column from the jack, as by means of a movable septum or wall, that is, a sliding piston, and place such part'of the ower column under a definite pressure which 1s maintained at all times. An alternative method is to place the volume tank, jack, cylinder and power column all under an initial pressure great enough to take'up a large part of the objectionable compressibility.

The inventive concep[t may be embodied in a' variety of forms. n order to acquaint thoseskilled in the art with the manner of constructing a device embodying my invention, I shall describe in connection with the accompanying drawings several diierent embodiments of the invention.

In the drawings:

Figure 1 is a diagram of a-system embodying my invention and employinga jack hav-v infa cylinder for each liquid column;

igure 2 is a diagram of a similar system in which the jack applies pressure only to the power column;

Figure 3 is a longitudinal section throu h the power column and connected parts of tie system shown in Figure 1;

Figure 4 is a vertical section through the shock alleviator;

Figure 5 shows rod and the pump piston in plan view; and

Figure 6 is a section taken on the line 6-6 of Figure 5 to illustrate the connection of the rod to the pump piston.

Referring now to the embodiments of Figures 1, 3, 5 and 6, the pump 1 is disposed in the well 2 and submerged in the liquid to be umped, the upper level of which is indicated connected to two pipe at 3. The pump 1 is define the inner and strings 4 and 5 which -outer hydraulic columns 6 and 7., The` pump 1 comprises a working cylinder 8 having a working plunger 9, a static cylinder 10 having a staticI plunger 11, and a pumping cylinder 12 having a pumping plunger 13.' The power or working plunger 9 is connected to the static plunger 11 and the pumping plunger 13 through the medium of crossheads 14 and 15 with connecting rods 16.

The pumping plunger .13 is a hollow or tubular plunger having a discharge check the coupling between the valve 17 mounted in a cage 18. The pumping cylinder 12 has the intake check valve 19 t rough which liquid flows from the well into the pumping cylinder.

The construction of this pump is shown in detail in my co-pending application, Serial No. 329,591, filedfDecember 31, 1928. The static cylinder l0 is closed at its upper end and is provided with a discharge check valve (not shown) for permitting the escape of any fluid which might leak into the same.

It can be seen that as the pressure is caused to preponder in one vcolumn over the other alternately the moving parts of the pump will make strokes taking liquid into the pumping cylinder 12 and discharging the same through the discharge column 7. The outer casing 20 is an enlargement of the outer pipe string 7 and the space within the same forms a part of the discharge column or may be considered as an extension of the same.

The pump is adapted to be operated by alternate preponderance of pressure in the power column and discharge column caused through the working of the jack 22, which is illustrated here only diagrammatically. By reference to my co-pending application, above referred to, the details of this jack are fully revealed. The jack compris-es essentially a pair of cylinders 23 and 24 and cooperating pistons 25 and 26, preferably the cylinders and pistons being aligned so that the pistons may take the form of plungers in actual alignment operated through a suitable crank (not shown) working through a pitman 27 and. crosshead 28 connected to said plungers 25 and 26. The cross head 28 has a cam plate or table 29 upon which are placed suitable cam strips operating upon pairs of rollers 30, one pair of rollers for each cylinder, to operate push rods such as 32 and through them operate the control'valves 33 and 34 for the cylinders 23 and 24. The control valves 33 and 34 comprise poppet valves seating with the internal pressure in the cylinders 23 and 24 and held normally to their seats as by means of springs 35, 36 and being adapted to be unseated by the bell crank levers 37 and 38, which bell crank levers are connected through the pull rods 39 and 40 with suitable bell cranks 43and 44 connected to the push rods 32.

Beneath the cylinders 23 and 24 I have shown the valve diagrams for the preferred setting of the control valves throughout the. stroke under the influence of the 'cam strips 42 on the cam table 29. The cylinders 23 and 24 are connected by pipes 45 and 46 to the power column 6 and discharge' column 7,`r.espectively,A and the space defined by the cylinders and pipes and columns 6 and 7 is filled with liquid.

The inner pipe string 4 is continued upwardly and connects to a cylinder 47 in which there is disposed a piston 48, said piston 48 being connected by a rod 49 to the working plunger 9 of the pump 1. At the lower end of the cylinder 47 a connection 50 is provided for the introduction of liquid under high pressure into the space between the pistons 48 and 9. This pressure may be applied by a suitable pump and reservoir or by any other preferred means and the pressure is intended to be retained upon so much of the power column as lies between the pistons 48 and 9 at all times while the system is in operation.

The discharge column 7 is connected to a pressure trap 52 connected through a T to the line 46 and this line 46 includes a check valve 54 and a by-pass 53 including a loaded valve 55 and check valve 56.

The values 33 and 34 which control the escape of liquid from the cylinders 23 and 24 have connec'lions to the volume tanks-56 and 57, these tanks preferably being open to atmosphere and the tank 57 having an overow connection at 58 through which the liquid which is pumped by the pump 1 is discharged to a suitable receptacle. .I

The power cylinder 23 isconnected to a shock alleviator 58 which is shown in sec- .tion in Figure 4. Its function is to provide a cushion against any accidental water hammer which might be caused by motion of the liquid or inaccurate setting of the cam strips for the valve 33.

By reference to Figures 3, 5 and 6, it may be seen how the structure may be built up or assembled in the field from sections threaded together. The cylinder 47 is constructed of a length of seamless .tubing suitably machined and ground in securely and provided at its upper and lower ends with threads, and by means of the reducer coupling 60 Vconnects the pipe 45 with the cylinder 47 and at the lower end the T 61 connects the cylinder 47 to the laterally extending pressure pipe 50 and also at the lower end to the pipe string 4.

The head T 62, which is provided with the packing gland 63 for sealing 0H the upper ends of the column 7 where the pipe string 4 emerges, connects at one side with the pipe 46 and at its lower end with the pipe string 5. The T 62 rests upon a suitable supporting plate 64 on the casing head of the well.

The rod 49 is connected to the plunger 9 by a connection which may be made after the pump has-been lowered into the well, and 1t consists of a T-shaped head 65 on the lower end of the rod 49 and a suitable slot formed in the plunger 9. This slot comprises a portion 66 open at the top into which the head 65 may drop down to a lower position '67 where the head is turned at right angles and is then pulled up into a crosswise notch or slot 68.

The alleviator shownin Figure 4 comprises an upper cylinder 69 and a lower cylinder 70, the lower cylinder being connected to the 'jack c`1inder 23 either directly or through cap 74 the discharge connection 45. A .stepped piston 71 comprising an upper enlarged portion 72 and a lower or reduced portion 73 is arranged to play in these two cylinders. The upper end of the cylinder 69 is closed by a which is connected through a check K valve 75 to atmosphere.4 The check valve permits the entry of air into the upper end of the cylinder 69 but prevents discharge of air therethrough. The cylinders are proyided `with oilers and thelstepped piston provided with oil grooves to maintain ya tight seal. The lower end'of the cylinder 69 is connected through a valve 76 to permit discharge of any leakage which may accumulate in the bottom of the cylinder 69.

The operation of the pistonshown in Figure 1 is as follows: Assume that the cam strips 42 have been pitched so as to cooperate with the rollers 30 and push rods 32 to'produce the valve diagrams shown below the cylinders 23 and 24. Assume that the sroke of the plungers 25 and 26 is now proceeding toward the left withY the valve 33 closed and the valve 34 open. Liquid is being discharged from the cylinder 23 into the pipe 45 and such liquid forces the piston 48 downwardly. v1f the pump 1 is disposed at approximately 3,000 feet, the static head of liquid upon the same will be of the order of 1,000 pounds per square inch pressure. 1

The pressure applied by the jack must be great enough to cause movement of the' columns and to cause a discharge of liquid by the pump into the discharge column 7. Since the two columns are substantially in balance, being balanced against each other through the pump, the pipe string 4 definingcthe inner column is not subjected to the static pressure but the outer string 5 is subjected to the static head of the liquid. Upon applying pressure j ack'cylinder 23 and plunger 25 to the power column, assuming that the plunger 48 and rod 49 were not in place, it will be seen that the pressure imposed by the would tend to compress any gas in the power column and to expand the string of tubing 4.

By introducing a pressure between the pistons 48 and 9 in excess ofany pressure which will bev applied by the jack cylinder 23, it can be seen that this part of the power column may t? kept under a continuous stress ,or pressu e' which will prevent the fluctuations of pressure and hence' the hysteresis loss,

. which would otherwise be occasioned by the breathing or stretching and contracting effect of the pipe string 4.

` I have found it advantageous .at the same time to maintain the discharge column under .a continuous back ressure and while I do this particularly or a different purpose, namely, to steady the dischage ilow'of liquid, it serves at the same time to prevent the hysf y teresis loss above referred/to, that is, the ex- Hence, as pressure 1s applied by the movement of the plunger 25 to the left, the piston 48 is forced downwardly and the body of liquid under pressure between the pistons 48 and 9 act like a solid rod forcing the moving piston of the pump plunglers downwardly to make the discharge stro e of the pump. The liquid displaced by the piston system of the pump is forced up the discharge column 7 and since gas may be evolved in the discharge column as the liquid is forced upwardly toward the head where the hydrostatic pressure becomes less, it tends to flow off rapidly and violently. The pressure trap 52 serves to steady this discharge and so does the pressure retaining valve 55 through which the liquid is compelled to ilow because of the check valve 54. The discharge then proceeds up to the pipe 46 through valve 34 and into the volume tank 57 and overflow 58 to a suitable receptacle.

Due to the compressibility of the` outer 5, because of variations in pressure column and the stretch of the pipe string 5 c the i'low of discharge does not appear promptly at the head of the well upon the beginning of downward motion of the power plunger 9. Also lit is to be noted that after the outward stroke of the plunger 25 is completed the discharge flow at the head of the well continues for some time and the control valve 34 is allowed to remain open until the -plunger 26 has approximately reached the point indicated on the valve diagram near the endlof its stroke where the valve 34 will be allowed to close and pressure be applied to the pipe 46 and to the discharge column. Anyliquid which ilows from the cylinder 24 into the discharge column 7 passes through the check valve 54 which is arranged to permitV the same.

As pointed out in my co-pending application, there are a number'of forces which ten to make the return stroke, one force being the trapped pressure on the discharge column in the pressure trap 52 and in the gas content of said discharge column 7 L' Likewise, there is the submergent headl of liquid in the well which, acting upon the static plunger 11 against the pressure prevailing in the static cyllnder 10, tends to cause the pump to make the' intake o1; suction stroke.

Now, it is to be observed that while I have 4 -tent of the power column and its connectedVJ parts may be put under an initial pressure great enough to keep the power column pressed. This may be balanced on the other side of the pump either by increasing'the size of the static plunger 11 or by increasing the back pressure on the discharge side `of the pump. In such event, of course, the plunger 48 and rod 49 would be omitted.

' If it were desired to apply such pressure, connections for air, as indicated at 77, and for liquid, as indicated at 78, may be applied to the volume tanlr- 56 to maintain the same under vsuitable pressure.

The top chamber of the alleviator 58 may likewise be maintained under suitable pressure, if so desired.

The advantage of the scheme shown in Figure 1 is that if the pistons 48 and 9 are l. made of the same diameter, and this is the case check valve 54 and so that there is a constant except as will be referred to hereafter, these parts remain in a static balance since the liquid presses equally in each direction. This puts the rod 49 under tension but as the tension is continuous and evenly maintained, there is not the tendency to fatigue and breakage that there is in the ordinary pump rod.

`If desired, the area of thepiston 48 may be made greater than the area of the plunger 9 upward tendency, that is, a -dierential pressureeflect tending to make the return stroke.

In Figure 2 I have illustrated a system in which only a single endedl jack is employed, that is to say, the return stroke of the pump l is made without the necessity offorcing liquid down the discharge column by the jack. Otherwise the construction is the same as shown in Figure 1, the jack cylinder 24 and its connected parts being omitted land since no liquid requires to be forced down the discharge column 7 by the jack plunger, the check valve56 are not required, the pressure retaininfr valve 55 together with the pressure chamber or trap 52 retaining suicient pressure yupon the discharge column 7' that the return stroke may be made. f

The submergent head, as indicated from the level 3 down togthe static cylinder 10, also provides a force for'making the return stroke. Therefore, to whatever extent submergent pressure is available it assists in making the return stroke.v The part of the power column between the pistons 48 and 9 is maintained under a superior pressure, that is a hydraulic pressure greater than the pressure lwhich is applied by the power cylinder 23 and vits plunger 25, so that a reversal of forces in the rod 49 or in the trap portion of the power column 6 does not occur.

As previously explained, the power column may be maintained ,under an initial pressure by maintaining a pressure upon'the volumej tank .5.6 and making provision to balance the vis in excess of the working pressures Lernspa'` and 2 the timing of the valve may be changed.

to reduce the length of stroke of the pump 1 by any desired amount so as to make it correspond to the rate of production of oill in the Well. i i

The same relation between the pistons 48 and 9, which was previously described, prevails in the piston shown in Figure 2. Preferably the two pistons are of the same diameter, although this may be varied, if desired.

It will be seen that by the above arrangements the hysteresis loss due to the expansion and contraction of the inner power column may be greatly reduced by. maintaining said column under a false head orpressure which is continuously maintained while the System is in operation, which false head or pressure or differences in pressure applied to such working column. A

I do not intend to be limited to the details shown and described.

I claim:

1. In a deep well pump, the combination with tween said columns, a second piston at the head of the well and rst piston and held apart therefrom by a pressure permanently maintained on one of said columns, a pump plunger attached to said first piston, and means for applying impulses of pressure alternately to said columns to operate said pistons to cause said plunger to make strokes. l

2. In a deep well pump, the combination with a pair of liquid columns one within the other, a piston located in the well and between saidcolumns, a pump plunger attached to said piston, a second piston at the head of the well, a non-compressible medium connecting said pistons through one of said columns, means for constantly maintaining said medium under hydraulic pressure, and meansfor applying impulses of pressure to said second piston, which `impulses are transferred through said non-compressible medium to said first piston to. move it and thereby cause said pump plunger to make f strokes.

3. In combination with a pair of liquid columns, a piston between said columns, a pump plunger attached to said piston, aI second piston, a non-compressible medium connecting said pistons through one of said columns, means for constantly maintaining the medium under pressure, means for applying impulses of pressure to said second pis- -ton,.which impulses are transferred through said non-compressible medium to said first a pair of liquid columns one within the other, a piston located in the Well and be-l rigidly attached to saidl piston -to move it and thereby cause said pump plunger to make strokes, and means comprising the combined force of the other of said Vliquid columns and of said non-compressible medium for moving said second piston to cause said plunger to make opposite strokes.

4. ln combination with a pair of liquid columns one within the other, a piston between said columns, a second piston rigidly attached to said first piston and held apart therefrom by a pressure permanently maintained on one of said columns, a pump plunger attached to said irst piston, and a hydraulic jack. for applying impulses of pressure alternately to said columns tooperate said pistons to cause said pump plunger to make strokes.

5. In combination with a deep well pump having a motor piston and a plunger attached thereto, a pipe column extending upward Jfrom the upper face of said piston to the surface, a cylinder disposed in said column atthe surface, a power piston in said cylinder, a rod extending between said pisi tons, said rod being fastened to said motor piston by a bayonet joint and being threaded into said power piston, a liquid column be- .tween said pistons, means for applying a steady high pressure to said liquid, a ldischarge column containing liquid communieating with the under face of saidfmotor piston, a power column containing liquid com-` municating with the upper face of said power piston, and means for applying impulses of pressure alternately to said discharge and power columns to operate said piston toV thereby operate said pump.

6. ln combination with a deep well pump having a motor piston at the bottom of the well, a discharge column communicating with the under side of said piston, a power column communica-ting with the upper face of said piston, one of said columns being within the other, a power piston closing said power column adjacent the top of the well, said pistons being rigidly fastened together by a rod running between them, means for steadily applying a high pressure to said power column between said pistons, means 'for intermittently applying pressure to said discharge column and the upper face of said power piston, and means for preventing the application of said intermittent pressure from transmitting shocks to saidpiston.

7. ln combinationwith a deep well pump having a4 motor piston and a plunger attached thereto, a pipe column extending upward from the upper face ot said piston to the surface, a cylinder disposed in said column at the surface, a power piston in said cylinder, a rod extending between and rigidly attached to said pistons, a liquid column be.

tween said pistons, a closed tank connected to said pipe column, means including air pressure in said tank for maintaining a steady igh pressure on said liquid column, a discharge column containing liquid communicating with the under face of said motor piston, a power column containing liquid communicating with the upper face of said power piston, and a jack for applying impulses of pressure alternately to said discharge and power columns to operate said pistons to thereby operate said pump.

8. In combination with a deep well pump having a motor piston and a plunger attached thereto, a pipe column extending upward from the upper face of said piston to the surface, a cylinder disposed in said column at the surface, a power piston in said cylinder, arod extending between and rigidly attached to said pistons, a liquid column between said pistons, a closed tank connected tosaid pipe column, means including air pressure in said tank for maintaining a steady high pressure on said liquid column, a discharge column containing liquid communicating with the under face of said motor piston, a power column containing liquid communicating with the upper face of said power piston, and an alleviator disposed 1n said power column lto prevent the transmission of shocks thereto by said jack.

9. ln a deep well pump having a liquid power column and a liquid discharge column and of the type wherein operation is obtained by reciprocating the two columns and imparting an upward drift to the discharge column, the method of preventing the liberation ot gases in the power column, which comprises closing off the two ends, of the power column, constantly maintaining the liquid between the two closed ends of the power column under pressure, and reciprocating the power column including the two closed ends thereof.

l0. ln a deep well pump having a liquid power column and a liquid discharge column and of the type wherein operation is obtained by reciprocating the two columns and impartin an upward drift to the discharge column,t emethod ot reciprocating the ower column which comprises closing o the top and the bottom ot the power column, alternately applying a preponderance of pressure .to the top of the column for lowering it and to the bottom of the power column for raising it, and constantly maintaining the liquid between the closed ends ot"l the power column-under compression lto reduce the gas discharge from the li uid in that column.

lin witness whereo l hereunto subscribe my name this 15th day of January, A. D.

WlLBUR N. SQURES.

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