US2622535A - Gas pressure operated oil well pump - Google Patents

Description

Dec. 23, 1952 P. G.'CARPENTER GAS PRESSURE OPERATED on. WELL PUMP INVENTOR. P.G. CARPENTER Filed Jan. 2, 1951 A TI'ORNEVS Patented Dec. 23, 1952 GAS PRESSURE OPERATED OIL WELL PUMP Paul G. Carpenter, Bartlesville, 0kla., assignor to Phillips Petroleum Company, a corporation of Delaware Application January 2, 1951, Serial No. 204,031

4 Claims.

This invention relates; to oil well pumps. In one aspect it relates to an oil well pump employing gas under bottom hole pressure as a means for lifting the oil from the well. In another aspect it relates to an oil well pump employing gas under bottom hole pressure for operating a reciprocating pump for lifting the oil from the well.

The deep well pumping apparatus of my invention has particular utility in pumping an oil well in which there is insufiicient bottom hole gas pressure for continuously producing th well by conventional production methods.

When a well ceases to flow naturally through the casing or tubing it is common to run a string of small diameter tubing with a packer installed near the reservoir so that the energy of the gas may be used. directly in lifting the oil. Deep well pumps heretofore employing the confined gas pressure for lifting the oil to the surface have employed a pump of the rotary type, rotated from the surface of the ground by means of the tubing. Under other conditions, it is necessary to utilize a type of pump which is operated by a fluid, either gas or liquid, introduced from the surface of the ground through one tubing and discharged through an annular space between that tubing and another string of tubing or casing.

The pumping apparatus of my invention is a reciprocating type pump which utilizes the confined bottom hole gas pressure for lifting the oil to the surface of the ground. In this manner, it is not necessary to provide such a pipe or tubing which has sufiicient strength for rotating a valve or a portion of the pumping apparatus at great distances from the source of power. When the pump of my invention is installed with a packer properly set above the pump, operation begins as soon as sufficient gas under pressure has accumulated under the. packer. In this manner, no power need be transmitted from the surface of the ground to the pumping apparatus in the well.

One object of my invention is to devise a deep well pumping apparatus which can operate from bottom hole gas pressure without transmission of power from the surface of the ground.

Another object of my invention is to devise a deep oil well pumping apparatus which is simple to construct and install.

Another object of my invention is to devise such a deep well oil pumping apparatus which is adapted for pumping small quantities of oil with low maintenance and operating costs.

Still other objects and advantages of my invention will be realized'upon reading the following description which taken with the attached drawing forms a part of this specification.

In the drawing, the figure is an elevational view of my pump installed in a well.

Referring now to the drawing, a Well casing I is shown as installed in a bore hole, the walls of which are identified by reference numeral I0. Disposed axially in this casing is a string of tubing l2. A packer I3 is installed at apoint near the bottom of the casing and surrounding the tubing I2. This packer is intended to produce a gas-tight seal between the casing H and the tubing l2. Below this packer formation gas is intended to accumulate as a gas layer l5. Under the layer of gas I5 is the liquid oil It. Disposed on the bottom end of the tubing I2 is the pump assembly M.

This pump assembly is composed of a small diameter cylinder 2| attached directly to the tubing string I 2. At the upper end of this small diameter cylinder 2| is provided a ball valve 22. Just below this ball valve 22 is a side arm ball valve 23. This latter valve is intended to allow oil from the reservoir to flow therethrough into the cylinder 2|. As the cylinder operates in a pumping operation, the oil is then forced upward through the valve 22, and at the end of the piston stroke the ball of the valve 22 seats to prevent oil flowing down from the tubing l2. The cylinder 2| is provided with a correspondingly small diameter piston 24. This small diameter piston may be provided with rings, not shown, if desired. The bottom end of the piston 24 is attached rigidly to a larger diameter piston 21. This piston 21 reciprocates in a cylinder 26 having an upper end wall 25 and a lower end wall 64. Piston 21 is provided with rings 28. Between the upper surface of the piston 21 and the upper end wall 25 is provided a coil spring 29. In like manner, between the lower surface of the piston 21 at the bottom of its stroke and the bottom end wall -64 is provided a coil spring 30. Extending through the upper end wall 25 are some pins 3| and 32. Packing glands 33 and 34 are provided surrounding the pins 3| and 32 so that pressure from within the cylinder 26' cannot leak past these pins. The upper ends of the pins 3| and 32 are pivoted to rocker arms 35 and 36, respectively. These rocker arms are pivoted at pivots 31 and 38 to upper extensions from the cylinder wall 26. At the opposite end of these rocker arms 35 and 36 are pivoted some rods 39 and 40, respectively. These rods 39 and line 50 and line 52 below the piston 21.

40 are relatively long and extend downward and are pivoted to rocker arms 58 and 59, respectively. These rocker arms 58 and 59 which may for convenience be termed the lower or bottom rocker arms are pivoted at pivot points 60 and GI to some extensions from the lower portion of the cylinder wall 26. The other ends of these rocker arms 58 and 59 are in turn pivoted to some pins 53 and 54, respectively. These latter pins extend through the bottom cylinder wall 64 and leakage is prevented from around the pins by packing glands 55 and 56.

Extending through the cylinder wall 25 are some outlet or inlet tubes 43, 44, 5|, and 52. Tubes 43 and 44 are positioned in the upper portion of the cylinder wall 26 just below the upper end plate 25, while the tubes 5| and 52 are positioned in the cylinder walls 26 at a point just above the bottom end plate 64. The tubes 43 and 44 extend radially into some three-way valves 4| and 42, respectively. Lowertubes 5| and 52 extend upward and into the bottom portion of these three-way valves. A gas inlet tube 50 extends from the gas pressure space just under the packer I3 t the top portion of the three-way valve 42. A gas exhaust tube 49 extends from a point above the packer I3 to the top of the three-way valve 4|. This gas exhaust tube 49 is extended through the packer I3 in a gas-tight manner so that gas will not leak from the space below the packer.

The long rod 39 is provided with a pivot 45 which is attached to a lever arm 41. This lever arm in turn is attached to the three-way valve 4| in such a manner that as rod 39 moves upward or downward the lever arm 41 will rotate the valve for opening tube 43 or tube 5| to the gas exhaust tube 49.

In like manner, the long rod 4| is provided with a pivot 46 which is attached to a valve lever arm 48 for operating the three-way valve 42.

After the tubing I2 has been run in the well with the pumping apparatus on its lower end and the packer I3 positioned above ball valves 22 and 23, but before packer I3 is set in its sealing position, compressed gas is pumped into the annular space between the tubing I2 and the casing I I and oil enters tubing I2 through valves 23 and 22 and is removed from the well until the liquid level in the well is forced down to packer I3.

Packer I3 is set to seal the space between the tubing I2 and easing II. Then, as the pressure is reduced in the annular space between tubing l2 and casing II, and a gas layer I5 forms under packer I3, gas enters the upper and open end of the gas inlet tube 50. As illustrated in the drawing, gas from this gas space I5 passes downward through the tube 59 and through the three-way valve 42 and continues downward on through tube 52 and flows into the bottom end of the large diameter cylinder 26. When high pressure gas is flowing into the cylinder 25 through tube 52, the piston 21 is intended to be rising and under that condition the three-way valve 4| is intended to be open to the flow of exhaust gas through the outlet port 43, through valve 4|, and through the exhaust gas line 49 to a point above the packer I3. Thus, under this condition, high pressure gas is entering the cylinder through The piston is then forced upward and the gas on top of the piston is exhausting through outlets 43, valve 4|, and exhaust gas line 49. Also, under this condition, a small diameter piston 24 is being forced upward and any liquid oil within the 4 cylinder 2| is forced upward through the ball valve 22 into the tubing string I2.

As the piston 21 nears the top end of this stroke, which is determined by the spring 29, this piston contacts the pins 3| and 32. Pin 3| is raised which in turn lowers the long rod 39. As this long rod 39 is lowered the three-way valve lever arm 41 is also lowered which turns the valve 4| so that the exhaust tube 5| is opened through the valve to the exhaust gas tube 49.

At the same time the piston pushes pin 32 to lower the long rod 40. When the rod 40 is lowered, the three-way valve lever arm 48 of valve 42 is lowered and valve 42 is turned in such a manner that gas inlet tube 44 is open to the pressure tube 59 and the gas inlet tube 52 is closed therefrom. When the high pressure gas from the gas space I5 flowing through gas inlet tube 58 is introduced into the cylinder 26 at a point above the piston 21, the piston is forced downward in cylinder 26 and this downward movement of piston 21 also causes the small diameter piston 24 to move downward. When piston 24 moves downward, liquid oil is sucked into the cylinder 2| through the ball valve 23. Pressure of the liquid entering the small cylinder 2| assists in forcing the piston 24 downward.) Ball valve 22 remains in a closed condition under this condition.

As piston 21 nears the bottom end of this stroke, spring 35) prevents metal-to-metal contact of piston 21 and end wall '64. When piston 21 pushes pin 54 downward, the long rod 40 is raised upward. As rod 49 is raised, the lever arm 48 of the three-way valve 42 is raised to such an extent that this valve closes off the flow of gas from tube 50 to tube 44 and opens the gas inlet tube 52. In this manner, gas under pressure from the gas space I5 begins to flow through tube 50, valve 42, tube 52, into the space below the piston 21. At the same time, as pin 54 is pushed downward the pin 53 is also lowered and the long rod 39 is raised. As the long rod 39 is raised, the three-way valve 4| is turnedin such a manner that the tube 43 is opened to the exhaust gas line 49 and the lower exhaust tube 5| is closed therefrom. As the high pressure gas from the gas space flows through tubes 58 and 52 into the space below the piston 21, the piston is raised and at the same time the gas previously introduced into the space above the piston 21 is exhausted through the exhaust outlet 43 and out tube 49 to the low pressure space above the packer I3. Under these conditions the piston 21 raises and forces piston 24 upward and at the same time displacing the oil from cylinder 2| through ball valve 22 into the tubing I2.

Thus, the piston 21 moves downward and again upward, oil from the well hole is sucked in through the ball valve 23 into the cylinder 2| and thence forced upward through the ball valve 22 into the tubing string I2.

The ratio of the diameter of the piston 21 to the diameter of the piston 24 is a critical point of my invention. This ratio is determined by the available gas pressure under the packer I3. If a relatively large pressure is available under the packer I3, the ratio of the diameter of the piston 21 to that of piston 24 need not be especially large. For example, if the gas pressure available from space I6 is of the order from 450 pounds per square'inch, the ratio of the diameter of piston 21 to piston 24 may be about 1.5 to 1 when the oil is to be lifted 2000 feet. If the pressure available from the gas space I6 is of the order of, for example, 100 pounds per square inch, and the height through which the oil is to be lifted is, for example, 2000 feet, the ratio of the diameter of piston 21 to the diameter of piston 24 must be considerably larger, as, for example 3.5 to 1. Ihus, the ratios of the diameters of pistons 27 and 2:; will be dependent upon the conditions encountered in the well, that is, the available gas pressure and the height to which the oil is to be pumped.

When the occasion arises for removal of my pumping apparatus from a well, it is merely necessary to raise the packer 13 from its sealing position and remove it with the tubing string [2 and the attached pumping apparatus from the well.

The apparatus of my invention may be constructed from materials generally available in the industry taking into consideration, of course, the corrosive nature of the oil and the gas to be produced.

While the connections at the ends of the rocker arms 35, 36, 5B, and 59 are shown and described as pivot points, it is preferable that these movable joints be slotted for obvious mechanical reasons. Valve lever arms 4! and it are also preferably slotted at pivots 45 and 48, respectively. The lever arms 47 and 48 are also preferably adjustable so as to throttle inlet gas to the cylinder ends in order to conserve gas.

The drawing and the above description is merely given as an example or the construction and operation of the pump embodying the principles of my invention. This illustration is not intended to limit my invention but merely to be illustrative. The invention is intended to be limited only by the following claims.

I claim:

1. In an oil well pumping assembly of the character described, a casing disposed in an oil well, a stationary oil flow tubing disposed axially within said casing, a gas sealing packer within and near the bottom end of said casing and surrounding said tubing, a first cylinder operatively attached at its head end to the lower end of said tubing, a single acting first piston in said first cylinder, a second cylinder of diameter greater than the first cylinder and attached at one end to the other end of said first cylinder, a double acting second piston operatively fittin said sec- 0nd cylinder and operatively attached to said first piston, means for admitting formation gas to said second cylinder and means for exhausting said gas from said second cylinder to a point above said packer, a fiuid inlet valve attached to the head end of said first cylinder and a discharge valve in operative communication between the head of said first cylinder and said oil fiow tubing.

2. In an oil well pumping assembly of the character described wherein formation gas pressure is utilized for pumping a well, a casing disposed in an oil well, a stationary oil fiow tubing disposed axially within said casing, a gas sealing packer within and near the bottom end of said casing and surrounding said tubing in such a manner as to permit accumulation of gas under said packer, a first cylinder operatively attached at its head end by means of a discharge valve assembly to said oil flow tubing, an inlet valve attached in operative communication to the head end of said cylinder, a single acting first piston in said first cylinder, a second cylinder of diameter greater than the first cylinder and attached at one end to the other end of said first cylinder, a double acting second piston operatively fitting said second cylinder and rigidly attached to said first piston, a tube and valve means for admitting formation gas from the gas space under the packer to either end of said second cylinder, a tube valve means for exhausting said gas from said second cylinder to a point above said packer.

3. In the oil well pumping assembly of claim 2 wherein the ratio of the diameter of the second piston to the diameter of the first piston is greater than 2.

l. In the oil well pumping assembly of claim 2 wherein the ratio of the diameter of the second piston to the diameter of the first piston is greater than 5.

PAUL G. CARPENTER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 245,191 Thayer et a1 Aug. 2, 1881 372397 Wells Oct, 25, 1887

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