US2699730A - Pressure controlled gas lift valve - Google Patents

Description

Jan. 18, 1955 T. E. BRYAN PRESSURE CONTROLLED GAS LIFT VALVE Filed Feb. 18 1950 I F R H 72101445 5 er Au INVENTOR.

BY @qz flwu United States Patent C) PRESSURE CONTROLLED GAS LIFT VALVE Thomas E. Bryan, Fort Worth, Tex.

Application February 18, 1950, Serial No. 145,039

9 Claims. (Cl. 103-433) This invention relates to new and useful improvements in oil well flowing devices and, in part, is a modification and improvement in the device shown and described in my co-pending application, Serial No. 83,536, now abandoned, and it has particular reference to the art of raising oil flowed into the well tubing, under formation pressures, by artificial gas or air pressures introduced from the earths surface, and its principal object resides in the provision of apparatus moving the oil upwardly in the tubing in time cycles, or at predetermined intervals, in accordance with the productivity of the well, and without imposing unnatural gas pressures upon the producing formations to impair their productivity by irretrievably displacing the petroleum products.

An object of the invention resides in the provision of a valve structure embodying a mechanism which is adapted to be installed in the tubing of a well at predetermined elevations or stages, the first of which should be arranged near the bottom of the well, as the tubing is installed therein, and others at spacings which are determined by the depth of the particular well and the productive capabilities thereof, it being desirable to establish the valves along the fluid column at spacings designed to lift the fluid with the minimum of applied pressures and with a view to increasing such pressures progressively downward as the oil column is raised to the surface and the load is lessened.

Other flowing devices have been designed to accomplish the flowing of oil from Wells, including that described in my co-pending application, Serial No. 66,605, now Patent No. 2,681,014. Some of these devices oper ating in some manner controlled by a pressure-controlled bellows structure, and incorporating a method of flow wherein greater pressures are employed to accomplish the lift, or flowing operation, at or near the surfaceand successively decreasing the pressure to cause the devices to operate as greater flowing depths are uncovered in the well. This method of flowing oil has obvious disadvantages in that, at each cycle of operation from devices located lower in the well, less fluid can be lifted to the surface resulting in waste of gas in proportion to the quantity of fluid lifted during each cycle. Another disadvantage in such methods of operation is obvious in that an attempt is made to utilize gas at lower pressures to accomplish a greater lift, where it is obvious that more power is required to raise fluid from a single injection point over a greater distance. A third objectionable result obtains in attempting to utilize gas at lesser pressures, wherein the energy contained in the gas is in proportion to its pressure, according to scientific authority, to accomplish the necessary lift and is contrary to natural laws controlling the energy factor of gas under pressure.

It is an object of the invention, therefore, to supply apparatus capable of operation in accordance with said natural laws, and each of said valves operating as a single injection point without assistance from any other valve device spaced in the Well and to introduce gas at each valve at a pressure in proportion to the operation involved, wherein it becomes greater as each lower valve is uncovered in the casing, and after all the well fluid has been expelled from the casing, the lowest valve in operation will be loaded to operate at a pressure conforming to the increased depth, including the factor of friction developed by the flow, and permit the lifting of the greatest quantity of fluid up the tubing at each cycle.

Another object of the invention is that of providing an especially designed fitting adapted to be connected into the tubing string at the required spacings to support the valve mechanisms and have means thereon by which the valves can be removably attached exteriorly thereof and have communication therethrough with the interior of the 5 tubing, the supporting means being capable of rigidly securing the valve mechanisms in the tubing string in a manner calculated to minimize the hazards of vibrations, and in operating the tubing into and out of the well.

A still further object of the invention is that of providing a pressure chamber for applied gas pressures exteriorly of the tubing in the casing by installing a packer about the tubing near the lower end thereof and expelling or displacing the oil in the casing into the tubing through the lowermost valves and compressing air or gases into the pressure chamber by suitable apparatus, controlling such pressures, and maintaining definite time cycles for introduction thereof, by pressure regulators and time control mechanisms which do not form a part of this invention.

Another object of the invention resides in the specific valve structure described herein to accomplish these beneficial results whereby the controlling medium combination of bellows, pressure chamber and valve elements provided, permit a first opening operation of the valve so that gas under pressure may enter the tubing, when the gas in the casing approximates the loaded pressure of the bellows chamber, then increasing the pressure in the easing annulus, forcing the second closure element of the valve into contact with its seat thereby stopping injection of gas through any valve. A third function sought is to reduce the pressure in the casing annulus after first opening the valve and permit the casing pressure to fall by dissipation through the valve and to cause the valve to return to its first closedposition held there by the pres sure in the bellows chamber. The next function sought is the provision of successively increasing the loading pressure of each bellows chamber whereby it requires a greater pressure in the casing to first open each valve to admit gas to the tubing and then still a greater pressure to cause the second valve closure element to stop passage of gas therethrough, and repeating the process successively downwardly to the lowermost valve, increasing the pressures as the greaterlift is encountered.

It is yet another object of the invention to provide a system of valves, located at predetermined elevations in the well, which can be adjusted or set to function at different applied pressures, each having a pressure chamber capable of being loaded to a specified pressure and having a yieldable bellows element therein amenable to such pressure to maintain one of the closure elements of the assembly against its seat to exclude the applied pressures from the pressure chamber in the well casing until such latter pressures reach a predetermined force, or a force suflicient to be elfective against the closure element, and its impelling force, to move the element from its seat and open the passage into the tubing, and then to close the same either by reducing the pressures to the original amount or by increasing the pressures.

Broadly the invention contemplates the provision of a device for selectively flowing fluid from a deep well in accordance with accepted correct theories of accomplishing the highest efliciency and extraction of all the energy possible from gas under pressure and expending it in to a column of fluid, and lifting the fluid in greater columns as lower levels are encountered in the well, thus resulting in the conservation of gas.

While the foregoing objects are paramount, other and lesser objects will become manifest as the description proceeds, taken in connection with the appended drawings wherein:

Figure 1 is a longitudinal cross-sectional view of the valve structure, showing the supporting fitting fragmentarily, and illustrating the pressure chamber and bellows closure actuating element.

Figure 2 is a plan view of the valve assembly, the supporting fitting being fragmentarily shown.

Figure 3 is a transverse sectional view, on lines 3-3 of Figure l, and also illustrating the supporting fitting fragmentarily.

Figure 4 illustrates, in elevation, the closure elements,

portions being shown in cross-section and fragmentarily,

and

. -.Figure is an inverted plan view of the valve assembly,

cycle control device at the earth s surface.

Figure 7 is a fragmentary view of the assembly shown in Figure 1 at the top of the bellows member 66.

,Accordingly, the apparatus employed in the invention comprises, primarily, a valve assembly which is especially adapted for installation in specially designed fittings 10 arranged at predetermined elevations along the tubing 11 in the casing 12, as shown in Figure 6, a packer 13 being installed about the tubing 11 near the bottom thereof to isolate the annular space 14 within the casing 12 about the tubing 11, only a tail pipe 15 extending below the packer 13into the production area 16 in the well bore.

The casing 12 is closed at the top by a head 17 from which are extended conduits 18 and 19 through which oil is conveyed to storage. Valves 20 and 21 are respectively arranged in the conduits 18 and 19.

Each of the fittings 10 are cylindrical in form and have threaded portions 22 on each end adapting the devices to be connected by collars 23 into the tubing 11. On one side of the fitting 10 is formed an integral lug 24 near its lower end for supporting the valve assembly which will be presently described. A set screw 25 is threaded through the lug 24, in parallel axial alignment with the fitting 10 and has a lock nut 26 thereon, as apparent in Figure 1.

Spaced above the lug 24 is an integral collar 27, also having its axis parallel to that of the fitting 10, and is interiorly threaded to receive the exteriorly threaded portion 28 of a fitting 29 forming a part of the cylindrical housing for the valve assembly. An annular groove 30 is formed within the collar 27 and intersects a port 31 in the wall of the fitting 10 within the collar 27, as shown in Figure 1.

The valve assembly is encased in a housing which consists of a body portion 32 upon the upper end of which the fitting 29 is threaded, the lower end being closed by a flanged nipple 33 secured into the lower end thereof, the nipple 33 being formed with a depending portion 34 having interior and exterior threads, a cap 35 being threaded thereon, as shown in Figure l. A recess 36 is formed in the bottom surface of the cap 35 to receive the upper end of the set screw 25 by which the assembly is secured.

The member 29 has a reduced portion 37 on its upper end, above the threaded portion 28, which extends through the collar 27 and projects upwardly thereabove, its upper end being exteriorly threaded for the attachment of a cap 38 having a plurality of ports 39 therein. The member 29 has a plurality of ports 40 which also open the port 31. Immediately above the ports 40, internally of the portion 37 of the member 29, is formed a pair of opposingly arranged seats 41 and 42 having a passage 43 therethrough connecting at each end with chambers 44 and 45 above and below the seats 41 and 42, respectively.

The seats 41 and 42 are engageable by closure members 46 and 47, respectively, coupled by a stem 48, as shown in Figures 1 and 4. The stem 48 has a reduced portion 49 at its upper end defining a shoulder 50 at the base of the reduced portion 49 and a threaded portion 51 on the upper end of the reduced portion. A circumferential groove 52 is formed in the portion 49 in which is arranged a packing ring 53, the upper member 46 being arranged upon the portion 49, about the ring 53 and against the shoulder 50. Nuts 54 and 55 are threaded upon the portion 51 to secure the upper closure member 46, as illustrated particularly in Figure 4.

The lower closure element 47 is integral with the stem 48 and has a threaded bore 56 by which it is attached to the threaded spindle 57 formed on the upper end of a second stem 58 which will be presently described. The stem 48 is arranged through the passage 43 between the seats 41 and 42, as shown in Figure 1, retaining the closure members 46 and 47 in proper position to engage the seats 41 and 42.

Below the lower closure 47 is a washer 59 which is arranged about the spindle 57 on the stem 58 and rests of the valve, and SllOWll'lg the pressure regulator and time into the groove 30 and consequently communicates with 55 upon the shoulder 60 defined at the base of the spindle 57.

The closure member 47* is threaded against the washer 59. A groove 61 is formed about the stem 58 below the shoulder 60 and a packing ring 62 is arranged'therein, the function of which will presently become apparent.

In Figure l is shown a structure in which a sleeve 63 is pressed into the fitting 29 above the upper end of the housing member 32 and surrounds the stem 58, its internal diameter being sufficiently greater than the diameter of the stem 58 to provide an annular passage 64 therearound capable of being closed by the packing ring 62 on the stem 58 when the upper closure element 46 engages the seat 41. In the position of the elements shown in Figure 1 the lower end of the stem 58 extends into the bellows member 66 and is attached thereto at its lower end, the passage 64 continues internally of the bellows 66 surrounding the member'58 and affords fluid communication with the interior of the bellows. The upper end of the member 66 ends in a ring 65 forming an integral part thereof, and this member is securely welded or silversoldered to the interior upper end of the member 32 thereby preventing communication between the chamber 66 and the fitting 29 through the passage 64. At the lower end of the member 66 a cap 67 is attached thereto forming a guide to maintain the bellows 66 and the stem 58 secured therein in vertical alignment to enable the member 6766 and 58 to move freely longitudinally in the chamber 66. Figure 4 shows a modification of this assembly with respect to attachment of the ring 65 to the member 70, and clearly shows the passage 64, shown in Figure 1, in fluid communication with the interior of the ing member 32, a depending flange 71 affording means for attaching the upper end of the bellows member 66 to the sleeve 68, the bellows 66 being secured to the flange 71 by any suitable means, such as by silver solder. The lower end of the bellows 66 is attached to the stem 58 as by the arrangement shown in Figure 1.

The housing member 32 is loaded by air pressure through a loading valve 72 threaded into the member 34 and enclosed by the cap 35, as shown in Figure l, the effect of the pressures within the member 32 being that of acting upon the bellows member 66 to actuate the stem 58 to move the lower seat 47 against the seat 42 and close the passage 43 therethrough and the ports 40 and 31, shutting ofi passage of gas pressures from the annular chamber 14 in the casing 12 to the tubing 11 until the pressures in the casing 12 reach a sufficient differential to move the closure 47 from its seat 42.

It is desirable to space the valve assemblies along the tubing 11 in a manner calculated to suit the particular conditions, as the productivity of the well, or flow rate thereof, and the oil-gas-water ratio, the first consideration being that of determining, the common static fluid level under favorable conditions. The spacing of the valve assemblies are then spaced to meet the particular requirements.

For best results the bellows chamber 66' is loaded at pressures ranging, for example, from 500 pounds in the lowermost valve to 250 pounds in the uppermost valve, a differential of 50 pounds from one valve to another being a desirable practice. Thus, the greater applied pressures can be utilized at the bottom of the fluid column where such pressures can accomplish the greater effect thereon although such an arrangement can obviously be reversed, if desirable, so that the uppermost valve can carry the greater pressure load.

Automatic operation of the system is accomplished by setting the time cycle device 73, shown in Figure 6, to inject pressures into the casing 12 at intervals determined by the time required to establish a selected level for the fluid column in the tubing 11. The control assembly comprises the time cycle element 73 which is afforded by a bypass tube 74 connected between the conduit 75 and the element 73, a cut-off valve 76 and reduction valves 77 and 78 being installed in the tube 74 whereby the pressure in the casing 12 can be controlled to properly actuate the cycle device 73. As an example, if the casing pressure is approximately-1000 pounds, the first reduction valve77 will reduce the pressure to approximately 250 pounds while the next valve 100 further reduces such pressure approximately 30 pounds at which the cycle device 73 is actuated. Pressure in the cycle device is bled therefrom through an outlet 79 on one side of the device.

The valve assemblies are operated, upon the occurrence of a suitable liquid level in the tubing, by gas pressures from the casing 12 entering through the ports 39 in the cap 38 and through the passage 43 in the seat member 37 to bear against the lower closure 47 impelling this member from its seat 42. The initial pressures admitted through the passage 43 will pass downwardly about the member 47 and the Washer 59 to enter and extend the bellows 66 but such operation is instantaneous, and before excessive pressures enter the bellows 66, which might tend to rupture the same, the member 59, with the sealing ring 62, Will have closed the passage 64 into the bellows 66 and the applied pressures are passed directly into the tubing 11 through the ports 40 and 31, respectively, to lift the fluid column and as the casing pressures are increased above the loaded pressures of the bellows chamber 66' the latter will force the upper closure element 46 to its seat and shut ofl the pressures to the tubing. Each of the valves will function in succession downwardly until the fluid in the casing has been expelled whereupon all of the valves will be closed by the element 46 contacting its seat 41.

When the lowermost valve in the tubing string has been uncovered by the fluid column, gas in the casing is substantially reduced in pressure to equal the loaded pressure of the chamber 66 to enable the upper element 46 to rise off its seat while the lower element 47 will be urged against its seat, or to the original closed position, and the valve will be at rest until the fluid rises into the tubing to form another column. Thereafter the valve is operated at regular intervals to inject gas to the tubing by action of the time cycle device 73 to raise the pressure in the casing to equal the loaded pressure of the valve thereby causing the member 47 to again be forced from its seat to admit gas to the tubing.

This operation is maintained until all fluid is lifted to the surface, and when the time cycle device and regulator 79 are actuated to stop injection of gas to the casing, the pressures therein will decrease by dissipation through the valve and the latter will close automatically when the pressure falls to equal the loaded pressure of the valve, which is the primary opening pressure of the valve, and this cycle may be repeated as often as the fluid flow of the well is required.

Manifestly, the apparatus herein shown and described is capable of certain changes and modifications, from time to time, by persons skilled in the art without departing from the spirit and intent of the invention or the scope of the appended claims.

What is claimed is:

l. A flow valve structure for oil wells comprising; a valve body, said body having a flow passage therethrough terminating in an inlet port at one end and an outlet port at the other end, a valve member in said body movable from a first position wherein it interrupts said flow passage adjacent the outlet port through an intermediate position where the passage is open to connect said ports to a third position wherein the valve member interrupts the flow passage adjacent the inlet port, means normally biasing said valve member toward its said first position, means responsive to fluid pressure at the inlet port for urging said valve member toward its said third position, fluid pressure responsive means normally connected with said outlet port responsive to fluid pressure for urging said valve member toward its said third position, and means responsive to movement of said valve member from its first position toward its third position, and before the valve reaches its third position, for interrupting the communication of said last mentioned fluid operable means with said outlet port.

2. A flow valve structure for oil wells comprising; a valve body, said body having a flow passage therethrough terminating in an inlet port at one end and an outlet port at the other end, a valve member in said body movabie from a first position wherein it interrupts said flow passage adjacent the outlet port through an intermediate position where the passage is open to connect said ports to a third position wherein the valve member interrupts the flow passage adjacent the inlet port, means normally biasing said valve member toward its said first position, means responsive to fluid pressure at the inlet port for urging said valve member toward its said third position, fluid pressure responsive means normally connected with said outlet port responsive to fluid pressure for urging said valve member toward its said third position, and means responsive to movement of said valve member from its first position toward its third position, and before the valve reaches its third position, for interrupting the communication of said last mentioned fluid operable means with said outlet port, the said means interrupting communication between said outlet port and said fluid operable means also being operable to prevent the said communication during further movement of said valve member toward its said third position.

3. A flow valve structure for an oil well comprising; a valve body having a flow passage therethrough with an inlet port at one end and an outlet port at the other end, a valve seat in said flow passage, a valve member having seat engaging elements spaced thereon, one on each side of said seat whereby said valve member has a first position where the passage is closed adjacent the outlet port, an intermediate position where the passage is open to connect said port, and a third position where the passage is closed adjacent said inlet port, an expansible bellows open at one end and closed at the other end, said expansible bellows having one end connected to the body and its other end connected with said valve member and biasing said valve member toward its first position, said body being formed with a cavity surrounding said bellows whereby the bellows divide the cavity into two chambers, passage means communicating one of said chambers with said outlet port, means for supplying a compressible fluid under pressure to the other of said chambers and entrapping it therein, means responsive to fluid pressure at said inlet port for urging said valve member from its first position toward its third position, and means responsive to a predetermined amount of travel of said valve member away from its first position for interrupting said pas sage means.

4. A well flowing arrangement including a flow string, a series of valves carried by the flow string at different points therealong for controlling communication between the interior of the string at various levels and the space surrounding the said string, the space: surrounding the said string being in communication with a source of gas under pressure, each said valve having a flow passage therethrough with one end opening externally of said valve and the other end opening to the interior of said string, a valve member in each said valve having one position where the flow passage therethrough is interrupted adjacent the string, an intermediate position where the said passage is open, and a third position where the said flow passage is interrupted adjacent the end thereof opened externally of the valve, a bellows having its open end connected with the valve body and its closed end connected with said valve member, means for supplying a compressible fluid under pressure to the side of said bellows opposite its connection with said valve member and for entrapping the fluid therein to move said valve member toward its said first position, means responsive to fluid pressure in the space surrounding said string for moving said valve member toward its said third position, means communicating the other side of said bellows with the interior of said string while the valve is in its said first position, and means for interrupting said communication in response to a predetermined amount of movement of said valve member away from its said first position.

5. A well flowing arrangement as claimed in claim 4, with said valves responsive to increased pressures as said valves are located farther downwardly on the flow string.

6. A well flowing apparatus including a tubing having a well fluid inlet and a port for admitting a pressure fluid, a valve including a housing attached to the said tubing for controlling the admission of the pressure fluid through the port into the tubing, said valve housing having a ported passage therethrough connected to said port for conducting the pressure fluid into the tubing, 21 valve stem operating within the passage having dual seating surfaces controlling flow through said passage, one of said surfaces being exposed to the pressure fluid and actuated thereby to move said stem to open the passage, the other of said seating surfaces movable to close said passage upon a predetermined movement of said stem, a bellows in said housing surrounding a portion of said stem and attached thereto at one end and anchored to the housing at the opposite end, a pressure fluid confined within the -valvehousing and surrounding said bellows and urging said stern in a direction to oppose the pressure fluid, passage means formed between the stem and the interior of the said housing providing an open fluid communication between the interior of the bellows with the tubing through the port when the passage through the valve is normally closed, and means on said stem for closing the fluid communication between the interior of the bellows and the tubing when the said passage is open and excluding the pressure from the interior of the bellows.

7. A flow valve structure for oil wells including a body adapted to be connected to a port in the well tubing and lowered therewith in the well casing and having a passage therethrough connected to the port for establishing communication between the tubing and the casing, a double valve seat within the passage, a movable valve stem operating within the passage, and through said double seat, dual valves on said stem and spaced apart thereon, one on either side of said seat for controlling flow through said passage, a flexible bellows positioned within said body and sealed thereto at one end, said stern extending into said bellows and attached thereto at its lower end, means to confine a pressure fluid within said section of said body and surrounding said bellows whereby said bellows isv compressed urging said stem in a direction to close said passage by one of said dual valves, passage means formed between said stem and the interior of the body providing open communication between the interior of the bellows and the interior of the tubing through the port when the passage through the valve is closed and means fixed on the stem to close the communication between the interior of the bellows and the casing when the passage is opened.

8. A flow valve structure for oil wells in combination with the tubing and easing of the well including a body adapted to be connected into said tubing and lowered therewith in the well casing, a flow passage through said valve body having fluid communication with said casing at one end and communicating with the said tubing adjacent its other end, a double valve seat within said passage, a movable valve stem extending through said seat having spaced valve closure elements thereon, one on either side of said seat, said stern and valve elements being movable to close said passage in either direction upon the application of a predetermined pressure at either end, a bellows connected to said valve body, one end of said stem extending into said bellows and attached thereto, means to confine a pressure fluid within said valve body surrounding the bellows whereby said bellows and stem are urged in a direction to normally maintain said passage closed, means formed between the stem and the interior of the tubular.v body providing an open fluid communication between the interior of the bellows and the flow passage below the valve seat hence to the tubing when the passage is closed by said valve closure elements and means onsaid stemtor closing said last mentioned communication to the interior of said bellows when the passage is opened.

9. A flow valve structure for ,oil wells adapted to be connected to the well tubing and lowered therewith into the well casing, said valve structure having a jointed sectional tubular body, a passage through one of said sections open to the casing at one end and communicating with the tubing at the other, valve closure elements in said passage for controlling flow therethrough acted upon by pressures in the casing, spaced valve seats in the passage engageable by said valve closure elements, a movable valve stem carrying said valve closure elements spaced thereon, a bellows having its open end connected to another section of said body and extending therein,.a portion of said valve extending through said open end into said bellows and connected thereto at the closed end of the bellows, means to confine a pressure fluid in said tubular body surrounding said bellows urging said bellows and said valve in a direction to close said passage, means formed between thestem and the interior of the tubular body providing an open fluid communication between the interior of the bellows and the flow passage below the valve seats hence to the tubing when the passage is closed by said valve closure elements, and means on said stem for closing said last mentioned communication to the interior of said bellows when the passage is opened.

References Cited in the file of this patent UNITED STATES PATENTS 2,137,441 Bryan Nov. 22, 1938 2,236,864 Worthington Apr. 1, 1941 2,241,656 Crickmer May 13, 1941 2,339,487 King Jan. 18, 1944 2,465,060 Carlisle Mar. 22, 1949 2,519,242 Garrett Aug. 15, 1950

Images