US2725014A - System and apparatus for flowing wells - Google Patents

Description

Nov. 29, 1955 R. C. PRYQR SYSTEM AND APPARATUS FOR FLOWING WELLS 5 Sheets-Sheet l Filed Feb. ll 1951 6 I w QW F/G 2 INVENToR.

R. c. PRYoR A 7l TORNE Y Nov. 29, 1955 R. c. PRYOR SYSTEM AND APPARATUS vFOR FLOWING WELLS 5 Sheets-Sheet 2 Filed Feb. l, 1951.

INVENTOR. R. C. PRYOR A TTORNEYS Nov. 29, 1955 R. c. PRYOR SYSTEM AND APPARATUS FOR FLOWING WELLS 5 Sheets-Sheet 3 -Filed Feb. l, 1951 INVENTOR. R. C. PRYOR F/G. 4A

A TTOPNEYS Nov. 29, 1955 R. c. PRYOR SYSTEM AND APPARATUS FOR FLOWING WELLS 5 Sheets-Sheet 4 Filed Feb. l. 1951 "III,"

Nov. 29, 1955 Filed Feb. l 1951 R. C. PRYOR SYSTEM AND APPARATUS FOR FLOWING WELLS 5 Sheets-Sheet 5 INVENTOR. R. c. PRYOR *WMM A TTORNE VS United States Patent O 2,725,014 SYSTEM AND APPARATUS FOR FLOWING WELLS Robert C. Pryor, Keytesville, Mo., assignor to Phillips Petroleum Company, a corporation of Delaware Application February 1, 1951, Serial No. 208,946 7 Claims. (Cl. 10S- 233) This invention relates to a system and apparatus for flowing wells. In one embodiment this invention relates to a system for flowing Wells wherein fluid controlled valves are utilized to regulate the addition of lifting gas to production lluid. In another embodiment this invention relates to a system for owing wells by gas wherein a plurality of uid controlled valves, operating at different controlling fluid pressures and actuated from a single source at the surface of the well, regulate the addition of lifting gas to production fluid.

In producing wells, it is often necessary to produce large volumes of water along with the oil recovered from the well. In such wells, the production lluid usually contains large quantities of suspended sand. It can readily be seen that to produce the large quantity of production fluid with sucker rod pumps, the pumps must be actuated very rapidly. This rapid movement, and the suspended sand acting as an abrasive, increases wear on the moving parts of the pump to such an extent that, in many cases, it is uneconomical to produce the Well with a sucker rod pump. When this diiculty is encountered in producing a well, resort is usually made to producing the well by a gas lift system. f

It has been found that the amount of lifting gas necessary to ow a well at the desired production rate varies over a wide range from well to well and even in the same well over a period of time. For economic reasons it is highly desirable to supply only that amount of lifting gas necessary to give the desired production. Although much time and effort has been expended in attempting to calculate the amount of lifting gas necessary in each case before owing operations are; begun, no satisfactory method has yet been discovered. Even if such a method were discovered the problem of furnishing only that amount of lifting gas necessary to give the desired production at any particular time would not be solved because, as was pointed out above, the amount of lifting gas necessary may vary over a wide range in the same well over a period of time. Therefore it is highly desirable to have a means of regulating the amount of lifting gas supplied to a well at any given time during the well flowing operation so as to utilize only that amount of lifting gas necessary to give the desired production.

ln the past, in continuous gas lift systems utilizing spring or iiuid loaded valves, the operation of the valves has been dependent upon a pressure differential between the casing and the tubing in the well, or upon the pressure differential between the casing or tubing and a fluid or spring loaded valve, the pressure of the fluid or the tension of the spring of which cannot be varied from the surface of the well. Valves of the type mentioned are set to operate at a given pressure differential before being lowered into a well and such a differential cannot be changed from the surface of the well.

As was pointed out above, the amount of lifting gas necessary to flow a well cannot be calculated before flowing operations are begun and even if this were possible, the amount of lifting gas necessary in a well may vary greatly over a period of time. Thus since the fluid or spring loaded valves used in the past in continuous well flowing operations must be preset to a single pressure differential and since the amount of lifting gas necessary may vary over a wide range, it is apparent that arranged'sequence.

"ice

4flowing system pulled and the valve settings changed, or

excess lifting gas must be supplied with resulting waste and high lifting costs as the operating pressure of the valves cannot be changed from the surface of the well.

By the practice of my invention, the above noted difculties are eliminated. According to my invention, the operation of uid controlled valves in a continuous well owing system is not dependent upon a pressure differential between the well casing and tubing nor upon a preset pressure differential between a fluid loaded valve and the casing ortubing.

In my invention, uid controlled .valves are utilized in a continuous well flowing system and the valves are controlled from a single source at the surface of the well thereby permitting a variation in the amount of lifting gas supplied to the well necessary to give desired production as conditions in a well change. Thus my invention eliminates the necessity of pulling the gas lift system from the well to reset the valves when conditions change, and yet realizes the'most economic well flowing conditions at any given time.

In a continuous gas lift system, it is often desirable to have a plurality of valves vertically spaced in the well and operating at different pressures. By my inven tion, a plurality of lluid controlled valves, operating at different fluid. pressures, are vertically spaced in a well and controlled through a common source of control fluid from a point at the surface of the well thereby actuating the valves individually from a single control point at the surface of the well.

An object of my invention is to provide a continuous gas lift system for flowing wells wherein fluid controlled valves are utilized and are controlled from the surface of the well.

Another object of my invention is to provide a continuous gas lift vsystem for ilowing well wherein fluid controlled valves, operating at different pressures and controlled from the surface of the well, are utilized.

Another object of my invention is to provide a continuous gas lift system for flowing wells wherein a plurality' of uid controlled valves, vertically spaced in a well, actuated at dilferent pressures by iluid furnished through a common source, and controlled from a point l*at the surface of the well, are utilized.

-rality of uid controlled valves are actuated individually through a common source of controlling fluid and are controlled from'the surface of the well.

Another object of my invention is to provide a continuous gas lift system wherein iluid controlled valves are utilized that can be actuated from the surface of the well so that the amount of lifting gas furnished to said well to obtain desired production may be varied without pulling said gas lift system from said well in order to reset said valves.

Another object of my invention is to provide an irnproved iluid controlled gas lift valve which can be actuated from the surface of a well in a continuous gas lift system.

Another object of my invention is to provide an improved uid controlled gas lift valve which is adapted to be connected with similar valves which are actuatedl at different fluid pressures so as to provide a plurality of such valves vertically spaced in a well so that all the valves can be individually actuated from the surface of the well through a common source of controlling uid in any pre- Other objects will be apparent to one skilled in the art upon reading the discussion and examining the drawings herein set forth.

In one embodiment of my invention for owing wells, a plurality of uid controlled valves forl regulating the amount of lifting gas supplied tothe production fluid of a well are vertically spaced on the tubing in said well. Said valves are actuated. at different pressures through a cornmon source of controlling fluid connecting said valves with a point at the surface of the well.v By varying the pressure of said controlling fluid, said valves may be actuated individually in any preselected sequence, thereby providing the desired amount of lifting gas at any given time in the well in spite of changing conditions in the well. Thus by the practice of my invention, the amount of lifting gas necessary to provide the desired production rate without Wasting lifting gas is obtained in a continuous well flowing system. By surface control of the iiuid controlled valves utilized in said system, the necessity of pulling the gas lift system and resetting the valves therein because of changes in lifting gas requirements of said well iseliminated.

My invention can be more clearly understood by referring to the accompanying drawings wherein:

Figure l is a sectional elevationy of. a well to which one embodiment of my invention has been applied.

Figure 2 is a sectional elevation of a well to which another embodiment of my invention has been applied.

Figure 3a is a vertical section of an embodiment of a valve suitable for the practice of my inventionshowing the valve attached to a Well tubing.

Figure 3b is a vertical section of the valve of Figure 3a taken along line 3b.

Figure 4a is a vertical section of another embodiment of a valve suitable for the practice of my inventiony showing the valve attached to a well tubing.

Figure 4b is a vertical section of the valve of Figure 4a taken along line 4b. l

Figure 5a is a vertical section ofv another embodimen of a valve suitable for the practice of my invention showing the valve attached to a welltubing.

Figure 5b is a Vertical section of the valve of Figure 5a taken along line 5b.

Figure 6a is a vertical section of still another embodiment of a valve suitable for the practice of my invention showing the valve attached to a Well tubing.

Figure 6b is a vertical sectionof the valve of Figure 6a taken along line 6b.

Referring to Figure l, casing 10 surrounds tubing 11 forming annulus 12 with static production fluid level 13 and pumping production fluid level 14. Fluid controlled valves 16, 17, 18, and 19, preferably of the type shown in either Figures 4a, 5a, or 6a, are secured to tubing 11 by clamps or other means not shown and control the flow of gas and production fluid between the interior of tubing 11y and annulus 12. The valvesare controlled by regulating the controlling fluid pressure supplied to the valves from source 21 through common control fluid supply means 22. Lifting gas is introduced into annulus 12 1 through pipe 15- and production uid is withdrawn from tubing 11 through pipe 20. It is within the scope of my invention to secure the valves on the outside and/ or inside of tubing 11, and to pump lifting gas down the wellthrough annulus 12 and up the well through tubing 11 or to pump the lifting gas down the well through tubing 11 and up the Well through annulus 12. y

Referring now to Figure 2, casing lsurrounds-tubing 11 forming annulus 12 with static production iiuid level 13 and pumping production fluid level 14. Fluid controlled valves 23, 24, 25, and 26, preferably of thertype illustrated in `Figure 3a, are secured to tubing 11 byY clamps or other means not shown and control the flow ofI lifting gas and production fluid between the interior ofl tubing 11 and annulus 12. The valves are controlled by regulating the controlling fluid pressure supplied to. the valves from source 21 through common controlling. fluid supply means 22, and are vented through common venting means 27. Again it is within the scope of my invention to pump lifting gas down the well through annulus 12 and up the well through tubing 11 or to pump the lifting gas down the well through tubing 1l and up the well through annulus 12. Also the valves can be secured to the outside and/or inside of tubing 11.

Referring now to Figures 3a and 3b, housing 28 forms chamber 29 with piston 3i) slidably operating therein. O-rings or other sealing means 31 and 32 form a seal be tween piston 3i) and the walls of chamber 29. Housing 28 is provided with a first conduit 33 for supplying controlling uid to the valve and a second conduit 34 for venting chamber 29 between O rings 31 and 32, each of the conduits being longitudinally disposed in the wall of housing 28 and extending the length thereof. Conduit 33 communicates with one end of chamber 29 for supplying controlling fluid thereto. One end of housing 28'is provided with a plug 35 and the other end is provided with a cylindrical valve seat 36. Pack-ing 40 prevents leakage between plug 35 and housing 28, and packing 39 prevents leakage between valve seat 36 and housing 28. O ring 38 forms a seal between piston 3i) and valve seat 36 when the valve is in a closed position. Housing 28 is supplied with nipple 37 which connects the interior of tubing 11 and chamber 29. Conduits 33 and 34 are adapted at each end for connection to similar valves through control fluid supply means 22 and vent 27. The valve is secured to tubing 11 by clamps 41. The position of piston 30 is determined by the balance of pressure forces acting on it, i. e., when the pressure of the controlling fluid times the area of piston 3i)` exposed to the controlling fluid is greater than the sum of the forces due to the pressure of the lifting gas times the area of piston 30 exposed to the lifting gas and the pressure in chamber 29 between O rings 31 and 32 times the area exposed to it, then piston 30 will move to a closed position, conversely, when the pressure of the controlling fluid times the area of piston 30 exposed to the controlling fluid is less than the sum of the forces due to the pressure of the lifting gas times the area of piston 30 exposed to the lifting gas and the pressure in chamber 29 between O rings 31: and 3 2 times the area exposed to it, then piston 3Q will move to an open position.

Referring now to Figures #in and 4b. The elements and operation of this embodiment of my valve are the sarnc as described in reference to Figures 3a and 3b except that conduit 34: for Venting that portion of chamber 29 be tween O rings 31 and 32 has beenv omitted from housing 42. in a valve of this type, the volume of chamber 2*) between O rings 31 and 32 when the valve is in an open position, should be large with respect to the volume swept by the piston when it moves to a closed position in order to avoid excessive build-up of pressure between the G rings.

Referring now to Figures 5a and 5b. The elements and operation of this embodiment of my valve are also the same as described in reference to Figures 3a and 3b except that conduit 34 has been omitted and nipple 44 has been added to housing Li3 for venting that portion of chamber 29 between O rings 31 and 32 into tubing 11.

Referring now to Figures 6a and 6b.` The elements and operation of this embodiment of my valve are again the same asv described in reference to Figures 3a and 3h except that conduit 34 has been omitted from housing 45 and' piston 46 no longer forms a seal with the walls of chamber 29 at the controlling fluid end of the piston and the piston is biased in an open position by spring means 47.

In the practice of a specific embodiment of my invention, a plurality of fluid controlled valves, say four as shown in Figure 2, preferably of the type illustrated in Figures 3a and 3b, is secured to the outside of tubing 11 and connected to a common source of controlling fluid through tube 22 and a common vent 27 such` that the valves are vertically spaced in the well when the tubingis lowered therein. Each valve controls the flow of lifting gas and production fluid between annulus 12 and the inside of tubing 11. The valves are selected so that the ratio of the area of the piston exposed to the controlling fluid to the area of the piston exposed to the lifting gas in each valve decreases from the top to the bottom of the well such that as the pressure of the controlling fluid is increased, valve 23 having the largest ratio referred to above closes first, valve 24 having the next largest ratio closes second, valve 25 having the third largest ratio closes third, and valve 26 having the smallest ratio closes last. Therefore, by the practice of my invention, it is possible to control a plurality of fluid controlled valves in a pre-selected sequence from a common source of control fiuid. It is apparent that the valves can be positioned along tubing 11 so as to close in any pre-selected sequence.

As the pressure of the lifting gas supplied to annulus 12 through pipe 15 is increased, production fluid is forced down annulus 12, through the valves, up tubing 11, and is discharged through pipe 20. When static production fluid level 13 falls below valve 23, the pressure of the controlling fluid supplied to the valves through common tube 22 from source 21 is increased so as to close valve 23 but not close valves 24, 25, and 26. Production fluid level 13 continues to fall until pumping production fluid level 14 is reached. As the static production fluid level is forced down past each of the valves, the pressure of the controlling fluid in tube 22 is increased so as to close that valve such that valves 23, 24, and 25 are closed in sequence, and when pumping level 14 is reached, the lifting gas for flowing the well is supplied through valve 26 only. It is apparent that the sequence of closing of the valves can be chosen so that any of the valves will be either open or closed, as the particular situation demands, when pumping level 14 is reached.

When utilizing the valves illustrated in Figures 4a, 4b, a, 5b, 6a, and 6b in the practice of my invention, the operation is similar to that described above and therefore will not be repeated. Since the fluid controlled valves of my invention are not dependent upon the amount of pressure of the lifting gas or production fluid for operation, the pressure of the lifting gas supplied to the well can be changed to obtain desired production and the valves still operated in the preselected sequence by changing the pressure of the controlling fluid at the surface of the well. Therefore, by the practice of my invention, desired production can be obtained without waste of lifting gas or without pulling the valves from the well in order to reset them as conditions in the well change or as the rate of production is changed.

Since changes in details of construction and arrangement can be made in the examples used to illustrate my invention without departing from the spirit and scope thereof, l do not desire to be unduly limited by the examples but desire to be limited only by the claims herein made.

I claim:

l. A fluid operated gas lift valve which comprises an elongated cylindrical housing having a chamber therein for receiving and discharging lifting gas and controlling fluid, a first conduit longitudinally disposed in the wall of said housing and extending the length of said housing, said first conduit being adapted at each end of said housing forconnection with other gas lift valves so as to form a series of said valves controllable from a single source, said first conduit in each valve communicating withy one end of said chamber therein for supplying controlling fluid thereto, said housing in said valve having a first opening therein at the other end of said chamber for passage of said lifting gas between said chamber and the outer face of said housing, said housing having a second opening therein at a point intermediate said first opening and said one end of said chamber for passage of said lifting gas between said chamber and the outer face of said housing, a piston slidably operating inside said chamber in response to changes in pressure of said controlling fluid so as to form a seal between said first opening and said second opening and prevent passage of said lifting gas through said valve when said controlling fluid pressure is increased to close said valve, a first 0 ring on that end of said piston which is exposed to said controlling fluid for effecting a seal between said piston and the walls of said chamber thereby forming a separate chamber for controlling fluid, a second O ring on said piston intermediate said first O ring and said second opening in said housing for effecting a second seal between said piston and the walls of said chamber, and a second conduit longitudinally disposed in the wall of said housing and communicating with said chamber intermediate said first and said second O rings for venting that portion of said chamber between said O rings, said second conduit being adapted at each end of said housing for connection to like conduits in similar valves so as to form a series of valves vented to a single source.

. 2. A fluid operated gas lift valve which comprises an elongated cylindrical housing having a chamber therein for receiving and discharging lifting gas and controlling fluid, a conduit longitudinally disposed in the wall of said housing and extending the length of said housing, said conduit being adapted at each end of said housing for connection with other gas lift valves so as to form a series of said valves controllable from a single source, said conduit in said valve communicating with one end of said chamber therein for supplying controlling fluid thereto, said housing in said valve having a first opening therein at the other end of said chamber for passage of said lifting gas between said chamber and the outer face of said housing, said housing having a second opening therein at a point intermediate said first opening and said one end of said chamber for passage of said lifting gas between said chamber and the outer face of said housing, a piston slidably operating inside said chamber in response to changes in pressure of said controlling fluid so as to form a seal between said first opening and said second opening and preventing passage of said lifting gas through said valve when said controlling fluid pressure is increased to close said valve, sealing means disposed around said piston forming separate chambers so that said piston is actuated by the action of controlling fluid tending to seat said piston against the action of lifting gas, the first of said separate chamber being exposed to said controlling fluid, and the volume of the second of said separate chambers, when said piston is in the open position, being large with respect to the volume swept by the piston when the piston moves to a closed position.

3. A fluid operated gas lift valve which comprises an elongated cylindrical housing having a chamber therein for receiving and discharging lifting gas and controlling uid, a conduit longitudinally disposed in the wall of said housing and extending the length of said housing, said conduit being adapted at each end of said housing for connection with other gas lift valves so as to form a series of said valves controllable from a single source, said conduit in said valve communicating with one end of said chamber therein for supplying controlling fluid thereto, said housing in said valve having a first opening therein at the other end of said chamber for passage of said lifting gas between said chamber and the outer face of said housing, said housing having alsecond opening therein at a point intermediate said first opening and said one end of said chamber for passage of said lifting gas between said chamber and the outer face of said housing, a piston slidably operating inside said chamber in re sponse to changes in pressure of said controlling fluid so as to form a seal between said first opening and said second opening and preventing passage of said lifting gas through said valve when said controlling fluid pressure is increased to close said valve, sealing means disposed around said piston forming separate chambers so that said piston is actuated by the action of controlling fluid tending to seat said piston against the action of lifting gas, the first of said separate chambers beingV exposed to said `controlling fluid and a conduit in the second of said separate chambers establishing communication Ibetween said second chamber and the outer face of said housing.

4. A fluid operated gas lift valve which comprises an elongated cylindrical housing having a chamber therein for receiving and discharging lifting gas and controlling fluid, a .conduit longitudinally disposed in the wall of said housing and extending the length of said housing, said conduit being adapted at each end of said housing for connection with other gas lift valves so as to form a series of said valves controllable from a single source, said conduit in said valve communicating with one end of said chamber therein for supplying controlling fluid thereto, said housing in said valve having a first opening therein at the other end of said chamber for passage of said lifting gas between said chamber and the outer face of said housing, said housing having a second opening therein at a point intermediate said first opening and said one end of said chamber for passage of said lifting gas between said chamber and the outer face of said housing, a piston slidably operating inside said chamber in response to changes in pressure of said controlling fluid so as to form a seal between said first opening and said second opening and prevent passage of said lifting gas through said valve when said controlling fluid pressure is increased to close said valve, and a resilient means for normally holding said piston in an open position.

5. A well flow system in cluding a well c asing and tubing, a plurality of fluid controlled piston operated lifting gas valves vertically spaced on said tubing in said well for regulating flow of a lifting gas between the exterior and interior of said tubing, each valve comprising a cylindrical valve housing having an inlet at the bottom and an outlet in the side thereof, a nipple connecting said outlet to the interior of said tubing thereby establishing communication between the interior of said housing and said tubing, a valve seat disposed in the inlet end of said housing, a piston slideably operating in said housing to seat in said valve seat to prevent the ow of lifting gas through said valve, a sealing member disposed around said piston adjacent its end opposite said valve seat thereby forming an upper separate chamber at the piston end opposite the valve seat, a second sealing means disposed around said piston between said sealing member and the valve outlet thereby forming a separate middle chamber, a conduit longitudinally disposed in the wall of said housing extending the length of said housing to permit the flow of a valve controlling uid therethrough from a source at the surface to a succeeding valve and to communicate with said upper chamber for supplying a valve controlling Huid thereto tending to seat said piston against the force due to lifting gas on the opposite end of said piston, the ratio of the area of the piston exposed to controlling fluid to the area of the piston exposed to lifting gas in each valve being such that the valves can be actuated in a pre-selected sequence, a second conduit longitudinally disposed in Athe wall of said housingr extending the length of said housing to communicate with the middle chamber for venting `said charnber and to form with preceding and succeeding valves a common vent, common means for connecting said first conduits of said valves for supplying said controlling fluid for actuating said pistons in said valves, common means for connecting said second conduits of said valves for venting the chambers of said valves, means accessible at the surface of said well for varying the pressure of said controlling fluid supplied to said pistons in said valves through said connecting means and said rst conduits.

6. A gas lift well flowing system comprising a well tubing; a plurality of fluid controlled piston operated valves secured to and vertically spaced along said tubing to regulate ow of lifting gas between the exterior and interior of said tubing, each of said valves comprising a housing having a ow 'passage therethrough which includes a valveseat, means connecting the A'outlet of said ow passage to the interior of said' tubing, said housing having first and second connected piston chambers therein, said first piston chamber being of larger cross-sectional area than said second chamber, said second chamber being in communication with said ow passage adjacent to said valve seat, a piston positioned for movement through said second chamber, said piston being of substantially the same cross-sectional area as said second chamber, one end of said piston forming a valve head engageable with said valve seat, a piston head secured to the other end of said piston within said first chamber, said piston head being of substantially the same cross-sectional area as said first chamber, said piston being positioned so that said piston (head moves through said first chamber away from said second chamber when said valve head moves away from said Valve seat, sealing means disposed between said piston and the walls of said second chamber; and a conduit communicating with the first chambers of each of said valves on the sides of said piston head opposite said respective second kchambers to supply operating fluid to each of said valves, the inlets of each of said flow passages being in communication with regions exterior of said housings so that pressures of lifting gas in said regions tend to move said valve heads awayfrom the valve seats associated therewith, the pressure of the operating fluid tending to move said pistons toward said valve seats, the ratio of the areas of said piston heads and said valve heads in each of said valves being so preselected that said valves are actuated at preselected pressure ratios between said operating liuid and said lifting gas, said valves being actuated at different pressures of said operating fluid.

7. A fluid operated gas lift valve comprising a housing having a flow passage therethrough which includes a valve seat, said housing having first and second connected piston chambers therein, said first piston chamber being of larger cross-sectional area than said second chamber, said second chamber being in communication with said flow passage adjacent said valve seat, a piston positioned for movement through said second chamber, said piston being of substantially the same cross-sectional area as said second chamber, one end of said piston forming a valve head engageable with said valve seat, a piston head secured to the other end of said piston within said first chamber, said piston head being of substantially the same cross-sectional area as said first chamber, said piston being positioned so that said piston head moves through said first chamber away from said second chamber when said valve head moves away from said valve seat, sealing means disposed between said piston and the walls of said second chamber, and a conduit communicating with said first chamber 0n the side of said piston head opposite said second chamber to supply operating fluid, the inlet of said flow passage being iu communication with a region exterior of said housing so that the pressure in said region tends to move said valve head away from said valve seat, the pressure of said operating uid tending to move said piston toward said valve seat, the ratio of the areas of said piston head and said valve head being so preselected that said valve is actuated at a preselected pressure ratio between said controlling uid and said pressure exterior of said housing.

References Cited in the file of this patent UNITED STATES PATENTS 1,677,781 Joyner July 17, 1928 2,278,532 Crickmer Apr. 7, 1942 2,446,680 Walton Aug. 10, 1948

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