Method to improve hydrodynamics and efficient use of an oil and/or gas well's energy to lift fluids through superficial gas velocity maintenance and application of load regulating device(s)

Abstract

A hydrocarbon wellbore production apparatus includes a tailpipe and a control valve connected with the tailpipe. The tailpipe has a fluid inlet receiving well fluids entering the casing from a formation, and a fluid outlet above the fluid inlet to deliver well liquid to a connected pump inlet. The control valve is operable to (i) open when a lower fluid pressure below the flow control valve exceeds an upper fluid pressure above the flow control valve to allow upward flow through the flow control valve, (ii) close when the upper fluid pressure exceeds the lower fluid pressure by an amount which does not exceed a prescribed pressure limit value to hold fluid in the apparatus above the flow control valve, and (iii) open when the upper fluid pressure exceeds the lower fluid pressure by an amount which exceeds the pressure limit value to release excess fluid back down the tailpipe.

Claims

1. An apparatus for production of well fluids, including well liquids and well gases, in an oil and gas well having a casing extending down to an oil and gas formation wherein the casing has an interior and has perforations formed therethrough for receiving oil and gas from the formation and the well having a pump supported from a tubing string with a pump inlet located above the perforations, the apparatus comprising: a tailpipe having a fluid inlet for receiving the formation well fluids that enter the casing through the perforations, and having a fluid outlet located above said tailpipe fluid inlet and communicating with the pump inlet to deliver well liquids thereto; and at least one pressure-regulated flow control valve connected in series with the tailpipe, the at least one pressure-regulated flow control valve being operable between open and closed states and having a pressure limit value associated therewith; the at least one pressure-regulated flow control valve being configured to open and allow upward flow through the pressure-regulated flow control valve in response to a lower fluid pressure below the pressure-regulated flow control valve exceeding an upper fluid pressure above the pressure-regulated flow control valve to; the at least one pressure-regulated flow control valve being configure to close and hold fluid in the apparatus above the pressure-regulated flow control valve in response to the upper fluid pressure exceeding the lower fluid pressure by an amount which does not exceed the pressure limit value; and the at least one pressure-regulated flow control valve being configured to open and release excess fluid back down the tailpipe in response to the upper fluid pressure exceeding the lower fluid pressure by an amount which exceeds the pressure limit value.

2. The apparatus according to claim 1 wherein said at least one pressure-regulated flow control valve comprises two flow control valves at longitudinally spaced locations relative to one another.

3. The apparatus according to claim 1 wherein said at least one pressure-regulated flow control valve includes one flow control valve at a location spaced above a bottom end of the tailpipe.

4. The apparatus according to claim 1 wherein the casing has an upper section which is upright in orientation, a lower section which is oriented at an inclination of greater than 45 degrees from vertical, and a transition section between the upper and lower sections, and wherein said at least one pressure-regulated flow control valve includes one flow control valve within the transition section of the casing.

5. The apparatus according to claim 1 wherein said at least one pressure-regulated flow control valve includes one flow control valve adjacent the pump inlet of the pump.

6. The apparatus according to claim 5 in combination with the pump wherein the pump comprises a plunger lift pump.

7. The apparatus according to claim 1 further comprising a gas separator connected in series between the tailpipe therebelow and the pump inlet thereabove, wherein said at least one pressure-regulated flow control valve is located below the gas separator.

8. The apparatus according to claim 1 wherein the casing has an upper section which is upright in orientation, a lower section which is oriented at an inclination of greater than 45 degrees from vertical, and a transition section between the upper and lower sections, and wherein the tailpipe is located within the transition section.

9. The apparatus according to claim 8 wherein the tailpipe fluid inlet is located in proximity to a bottom of the transition section.

10. The apparatus according to claim 1 wherein the tailpipe has an internal diameter which is less than that of said tubing string along a length of the tailpipe between the tailpipe fluid inlet and the tailpipe fluid outlet and wherein the tailpipe fluid inlet is reduced in diameter relative to the tailpipe fluid outlet.

11. The apparatus according to claim 10 wherein the tailpipe includes a lower section adjacent to the tailpipe fluid inlet having a first internal diameter along a length thereof, and an upper section above the lower section which spans a majority of a length of the tailpipe having a second internal diameter along a length thereof which is greater than the first internal diameter.

12. The apparatus according to claim 1 further comprising an isolating member supported within an annulus between the casing and the tailpipe to block flow in the annulus across the isolating member, the isolating member being located adjacent to the tailpipe fluid inlet.

13. The apparatus according to claim 12 further comprising an auxiliary member supported within the annulus between the casing and the tailpipe to block flow in the annulus across the auxiliary member, the auxiliary member being located in proximity to the fluid outlet of the tailpipe.

14. The apparatus according to claim 1 further comprising: the tailpipe having an internal diameter which is less than that of said tubing string along a length of the tailpipe between the tailpipe fluid inlet and the tailpipe fluid outlet; tailpipe fluid inlet being reduced in diameter relative to the tailpipe fluid outlet; and an isolating member supported within an annulus between the casing and the tailpipe to block flow in the annulus across the isolating member, the isolating member being located adjacent to the tailpipe fluid inlet.

15. An apparatus for production of well fluids, including well liquids and well gases, in an oil and gas well having a casing extending down to an oil and gas formation wherein the casing has an interior and has perforations formed therethrough for receiving oil and gas from the formation and the well having a pump supported from a tubing string with a pump inlet located above the perforations, the apparatus comprising: a tailpipe having a fluid inlet for receiving the formation well fluids that enter the casing through the perforations, and having a fluid outlet located above said tailpipe fluid inlet and communicating with the pump inlet to deliver well liquids thereto; said tailpipe being located within the casing so as to define an annulus passage fully occupying a space between an outer diameter of the tailpipe and an inner diameter of the casing; said tailpipe has an internal diameter less than that of said tubing string to thereby purposefully increase the gas velocity inside which generates a flowing condition possessing a higher gas void fraction (GVF) and thus reduces the pressure gradient of the well fluids flowing in said tailpipe as compared to a pressure gradient that would exist without use of said tailpipe, and thereby correspondingly reduce a minimum required producing bottom hole pressure as well as production rate to lift fluids and correspondingly increase well deliquification and fluid production in the oil and gas well; and said tailpipe fluid inlet being reduced in diameter relative to said tailpipe fluid outlet.

16. The apparatus according to claim 15 wherein the tailpipe includes a lower section adjacent to the tailpipe fluid inlet having a first internal diameter along a length thereof, and an upper section above the lower section which spans a majority of a length of the tailpipe having a second internal diameter along a length thereof which is greater than the first internal diameter.

17. The apparatus according to claim 15 further comprising an isolating member supported within the annulus passage between the casing and the tailpipe to block flow in the annulus passage across the isolating member, the isolating member being located adjacent to the tailpipe fluid inlet.

18. The apparatus according to claim 17 further comprising an auxiliary member supported within the annulus passage between the casing and the tailpipe to block flow in the annulus passage across the auxiliary member, the auxiliary member being located in proximity to the fluid outlet of the tailpipe.

19. An apparatus for production of well fluids, including well liquids and well gases, in an oil and gas well having a casing extending down to an oil and gas formation wherein the casing has an interior and has perforations formed therethrough for receiving oil and gas from the formation and the well having a pump supported from a tubing string with a pump inlet located above the perforations, the apparatus comprising: a tailpipe having a fluid inlet for receiving the formation well fluids that enter the casing through the perforations, and having a fluid outlet located above said tailpipe fluid inlet and communicating with the pump inlet to deliver well liquids thereto; said tailpipe being located within the casing so as to define an annulus passage fully occupying a space between an outer diameter of the tailpipe and an inner diameter of the casing; and an isolating member supported within the annulus passage, to fully span across the annulus passage between the inner diameter of the casing and the outer diameter of the tailpipe to block flow in the annulus passage across the isolating member; the isolating member being located adjacent to the tailpipe fluid inlet.

20. The apparatus according to claim 19 further comprising an auxiliary member supported within the annulus passage between the casing and the tailpipe to block flow in the annulus passage across the auxiliary member, the auxiliary member being located in proximity to the fluid outlet of the tailpipe.

21. An apparatus for production of well fluids, including well liquids and well gases, in an oil and gas well having a casing extending down to an oil and gas formation wherein the casing has an interior and has perforations formed therethrough for receiving oil and gas from the formation and the well having a pump supported from a tubing string with a pump inlet located above the perforations, the apparatus comprising: a tailpipe having a fluid inlet for receiving the formation well fluids that enter the casing through the perforations, and having a fluid outlet located above said tailpipe fluid inlet and communicating with the pump inlet to deliver well liquids thereto; and at least one flow control valve connected in series with the tailpipe being operable between open and closed states and having a pressure limit value associated therewith, the at least one flow control valve being operable to (i) open when a lower fluid pressure below the flow control valve exceeds an upper fluid pressure above the flow control valve to allow upward flow through the flow control valve (ii), close when the upper fluid pressure exceeds the lower fluid pressure by an amount which does not exceed the pressure limit value to hold fluid in the apparatus above the flow control valve, and (iii) open when the upper fluid pressure exceeds the lower fluid pressure by an amount which exceeds the pressure limit value to release excess fluid back down the tailpipe; wherein the casing has an upper section which is upright in orientation, a lower section which is oriented at an inclination of greater than 45 degrees from vertical, and a transition section between the upper and lower sections, and wherein said at least one flow control valve includes one flow control valve within the transition section of the casing.

22. An apparatus for production of well fluids, including well liquids and well gases, in an oil and gas well having a casing extending down to an oil and gas formation wherein the casing has an interior and has perforations formed therethrough for receiving oil and gas from the formation and the well having a pump supported from a tubing string with a pump inlet located above the perforations, the apparatus comprising: a tailpipe having a fluid inlet for receiving the formation well fluids that enter the casing through the perforations, and having a fluid outlet located above said tailpipe fluid inlet and communicating with the pump inlet to deliver well liquids thereto; and at least one flow control valve connected in series with the tailpipe being operable between open and closed states and having a pressure limit value associated therewith, the at least one flow control valve being operable to (i) open when a lower fluid pressure below the flow control valve exceeds an upper fluid pressure above the flow control valve to allow upward flow through the flow control valve (ii), close when the upper fluid pressure exceeds the lower fluid pressure by an amount which does not exceed the pressure limit value to hold fluid in the apparatus above the flow control valve, and (iii) open when the upper fluid pressure exceeds the lower fluid pressure by an amount which exceeds the pressure limit value to release excess fluid back down the tailpipe; wherein the casing has an upper section which is upright in orientation, a lower section which is oriented at an inclination of greater than 45 degrees from vertical, and a transition section between the upper and lower sections, and wherein the tailpipe is located within the transition section.

23. An apparatus for production of well fluids, including well liquids and well gases, in an oil and gas well having a casing extending down to an oil and gas formation wherein the casing has an interior and has perforations formed therethrough for receiving oil and gas from the formation and the well having a pump supported from a tubing string with a pump inlet located above the perforations, the apparatus comprising: a tailpipe having a fluid inlet for receiving the formation well fluids that enter the casing through the perforations, and having a fluid outlet located above said tailpipe fluid inlet and communicating with the pump inlet to deliver well liquids thereto; and at least one flow control valve connected in series with the tailpipe being operable between open and closed states and having a pressure limit value associated therewith, the at least one flow control valve being operable to (i) open when a lower fluid pressure below the flow control valve exceeds an upper fluid pressure above the flow control valve to allow upward flow through the flow control valve (ii), close when the upper fluid pressure exceeds the lower fluid pressure by an amount which does not exceed the pressure limit value to hold fluid in the apparatus above the flow control valve, and (iii) open when the upper fluid pressure exceeds the lower fluid pressure by an amount which exceeds the pressure limit value to release excess fluid back down the tailpipe; wherein the tailpipe has an internal diameter which is less than that of said tubing string along a length of the tailpipe between the tailpipe fluid inlet and the tailpipe fluid outlet and wherein the tailpipe fluid inlet is reduced in diameter relative to the tailpipe fluid outlet.

24. An apparatus for production of well fluids, including well liquids and well gases, in an oil and gas well having a casing extending down to an oil and gas formation wherein the casing has an interior and has perforations formed therethrough for receiving oil and gas from the formation and the well having a pump supported from a tubing string with a pump inlet located above the perforations, the apparatus comprising: a tailpipe having a fluid inlet for receiving the formation well fluids that enter the casing through the perforations, and having a fluid outlet located above said tailpipe fluid inlet and communicating with the pump inlet to deliver well liquids thereto; at least one flow control valve connected in series with the tailpipe being operable between open and closed states and having a pressure limit value associated therewith, the at least one flow control valve being operable to (i) open when a lower fluid pressure below the flow control valve exceeds an upper fluid pressure above the flow control valve to allow upward flow through the flow control valve (ii), close when the upper fluid pressure exceeds the lower fluid pressure by an amount which does not exceed the pressure limit value to hold fluid in the apparatus above the flow control valve, and (iii) open when the upper fluid pressure exceeds the lower fluid pressure by an amount which exceeds the pressure limit value to release excess fluid back down the tailpipe; an lower isolating member supported within an annulus between the casing and the tailpipe to block flow in the annulus across the lower isolating member, the lower isolating member being located adjacent to the fluid inlet of the tailpipe; and an upper isolating member supported within the annulus between the casing and the tailpipe to block flow in the annulus across the upper auxiliary member, the upper isolating member being located in proximity to the fluid outlet of the tailpipe.

25. An apparatus for production of well fluids, including well liquids and well gases, in an oil and gas well having a casing extending down to an oil and gas formation wherein the casing has an interior and has perforations formed therethrough for receiving oil and gas from the formation and the well having a pump supported from a tubing string with a pump inlet located above the perforations, the apparatus comprising: a tailpipe having a fluid inlet for receiving the formation well fluids that enter the casing through the perforations, and having a fluid outlet located above said tailpipe fluid inlet and communicating with the pump inlet to deliver well liquids thereto; said tailpipe has an internal diameter less than that of said tubing string to thereby purposefully increase the gas velocity inside which generates a flowing condition possessing a higher gas void fraction (GVF) and thus reduces the pressure gradient of the well fluids flowing in said tailpipe as compared to a pressure gradient that would exist without use of said tailpipe, and thereby correspondingly reduce a minimum required producing bottom hole pressure as well as production rate to lift fluids and correspondingly increase well deliquification and fluid production in the oil and gas well; said tailpipe fluid inlet being reduced in diameter relative to said tailpipe fluid outlet; and said tailpipe including a lower section adjacent to the tailpipe fluid inlet having a first internal diameter along a length thereof and an upper section above the lower section which spans a majority of a length of the tailpipe having a second internal diameter along a length thereof which is greater than the first internal diameter.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) One embodiment of the invention will now be described in conjunction with the accompanying drawings in which:

(2) FIG. 1 is partly sectional schematic view of the apparatus within a wellbore casing according to a first embodiment of the invention;

(3) FIG. 2 is partly sectional schematic view of the apparatus within a wellbore casing according to a second embodiment of the invention; and

(4) FIG. 3 is partly sectional schematic view of the apparatus within a wellbore casing according to a third embodiment of the invention.

(5) In the drawings like characters of reference indicate corresponding parts in the different figures.

DETAILED DESCRIPTION

(6) Referring to the accompanying figures there is provided an apparatus generally indicated by reference numeral 10 for the production of well fluids including well liquids and well gases. Although various embodiments of the apparatus 10 are described and illustrated herein, the features in common with the various embodiments will first be described.

(7) The apparatus 10 is suited for use in an oil and gas well of the type having a casing 12 extending downwardly from a wellhead at surface to an oil and gas formation 13 below ground. The casing 12 defines a tubular passage extending longitudinally within the interior thereof. Perforations 14 are provided within the casing to extend through the wall of the casing in alignment with the oil and gas formation 13 for receiving oil and gas from the formation.

(8) The casing typically includes an upper section 16 which is generally upright in orientation so as to be substantially vertical or less than 45° inclination from vertical to extend downwardly from the wellhead into the ground. The casing further includes a lower section 18 which may be horizontal or inclined at a slope of greater than 45° from vertical to extend through the oil and gas formation. The casing can also include a transition section 20 located at an intermediate location connected between the upper section 16 thereabove and the lower section 18 therebelow. The transition section 20 may be a curved section in which the orientation of the casing transitions gradually from the upright orientation of the upper section to the lateral orientation of the lower section.

(9) The well receives a tubing string 22 therein which extends longitudinally through the tubular passage within the interior of the casing. An outer diameter of the tubing string is undersized relative to the interior diameter of the casing to define a well annulus 24 between the tubing string and the surrounding casing. The tubing string defines a tubular passage extending longitudinally along the string within the interior of the tubing string for communicating produced fluids therethrough from the formation up to the wellhead.

(10) A pump 26 is connected in series with the tubing string. The pump may be of various types, typically mounted at the bottom end of the tubing string 22 such as a plunger lift type pump or a submersible pump which is a hydraulically or electrically driven for example. The pump is typically cycled or reciprocated for lifting fluid in stages from the inlet at the bottom of the pump to an outlet of the pump connected to the tubing string thereabove.

(11) A tailpipe 28 is provided as a section of tubing connected in series below the pump 26. The tailpipe communicates between an inlet opening 30 at the bottom end thereof and an outlet at the top end thereof which communicates with the pump inlet. The tailpipe has an internal diameter that is less than the tubing string diameter to thereby reduce a pressure gradient of the well fluids therein, as compared to a pressure gradient that would exist without use of the tailpipe, as a result of the smaller diameter thereof, and thereby correspondingly reduce a minimum required producing bottom hole pressure and correspondingly increase well fluid production from the oil and gas well.

(12) The tailpipe is typically located such that the inlet at the bottom end thereof is in close proximity to or spaced slightly above the perforations in communication with the oil and gas formation. More particularly the tailpipe section is preferably located so as to be mostly or entirely within the transition section 20 of the casing with the inlet at the bottom end being in proximity to the bottom of the transition section 20.

(13) The tailpipe 28 may include a lower section that is adjacent to the tailpipe fluid inlet and that has a first internal diameter which is constant along the length thereof. An upper section of the tailpipe continues above the lower section up to the outlet at the top end of the tailpipe in which the upper section spans a majority of the overall length of the tailpipe. The upper section has a second internal diameter which is constant along the length of thereof which is greater than the first internal diameter of the lower section such that the overall tailpipe 28 is tapered and reduced in cross-sectional flow area at the inlet end thereof relative to the remainder of the tailpipe.

(14) In further embodiments, the tailpipe may comprise three or more sections in which each section is reduced in internal diameter relative to the section therebelow to more gradually taper the cross sectional flow area of the tailpipe from the top to the bottom thereof.

(15) The apparatus further includes one or more flow control valves 32 connected in series with the tailpipe. In the preferred embodiments, a first one of the flow control valves is located at an intermediate location along the tailpipe 28 so as to be within the upper section of the tailpipe at a location spaced above the inlet and the lower section of the tailpipe. A second flow control valve 32 is typically located in series between the tailpipe 28 therebelow and the pump 26 thereabove at a location above the top end of the tailpipe.

(16) Each flow control valve 32 is a hydrostatic pressure regulated valve, for example an auto dump valve, which functions to retain fluid in the tubing thereabove below a hydrostatic rating or pressure limit value associated with the valve while permitting excess fluid above the rating or pressure limit value to be released back into the tubing below the valve. The hydrostatic rating or pressure limit value of the valve is adjustable or settable value which is designated by the operator according to the conditions of the well.

(17) The flow control valve 32 operates somewhat like a check valve in that the valve will open when the fluid pressure below the flow control valve exceeds the fluid pressure above the flow control valve to allow upward flow through the valve. Typically, the valve will automatically close when the fluid pressure above the valve exceeds the fluid pressure below the valve but on the condition that the amount that the upper fluid pressure exceeds the lower fluid pressure does not exceed the pressure limit value so as to hold fluid within the apparatus above the flow control valve. When the upper fluid pressure exceeds the lower fluid pressure by an amount which exceeds the pressure limit value, the flow control valve functions to release the excess fluid back down the tailpipe until the pressure differential falls back below the pressure limit value.

(18) In this instance, as the pump is cycled in operation, fluid is lifted above the flow control valve with each positive cycle of the pump with at least part of the upwardly pumped fluid being retained above the valve on the subsequent negative portion of the pumping cycle. In this instance, less work is required to pump the fluid upwardly on the next positive portion of the pumping cycle due to a portion of the fluid already being retained above each flow control valve.

(19) Turning now more particularly to the embodiment of FIG. 1, in this instance the pump comprises a driven pump, for example a submersible pump which is hydraulically or electrically driven, or a reciprocating pump driven by a rod string. The apparatus in this instance further includes a gas separator 34 connected in series below the pump such that an outlet of the gas separator communicates produced fluids into the inlet of the pump thereabove. More particularly the gas separator has a fluid inlet for receiving well fluids into an upper region of the separator for discharge into a separation annulus zone defined between an exterior of the separator and the interior wall of the casing adjacent to the separator and a liquid inlet at a lower region of the separator for receiving liquid from said separation annular zone for transfer upward to an inlet of the pump thereabove.

(20) A solid collector 36 is supported below the gas separator 34 including a tubular section having an interior passage connected in series with the gas separator thereabove and the tailpipe therebelow. A plurality of baffles 38 surround the tubular section of the solid collector to span the annulus between the tubular section and the surrounding casing such that the baffles serve to collect any solids accumulating in the annulus as flow is directed through a portion of the annulus by the gas separator thereabove.

(21) The apparatus further includes an upper isolating member 40 comprising an inner pipe 42 connected in series with the pump inlet thereabove and the outlet of the tailpipe therebelow. More particularly the inner pipe 42 is connected in series directly below the tubular section of the solid collector 36 which is in turn located directly below the gas separator 34. The upper isolating member 40 comprises an annular member 44 surrounding the inner pipe 42 and fully spanning the annular space between the inner pipe 42 and the surrounding casing so as to block flow in the annulus across the isolating member and isolate pressure between the annulus above and the annulus below.

(22) The tailpipe 28 in this instance is connected directly below the inner pipe 42 of the upper isolating member 40. The apparatus may further include a lower isolating member 46 which is mounted at an intermediate location along the tailpipe 28 such that flow through the tailpipe is uninhibited, however, the lower isolating member 46, like the upper isolating member 44 comprises an annular member fully spanning across the annulus passage that fully occupies the space between the outer diameter of the tailpipe and the inner diameter of the surrounding casing to block flow and isolate pressure in the annulus similarly to the upper isolating member 40. The lower isolating member 46 is mounted about the tailpipe adjacent to the inlet at the bottom end thereof.

(23) In the embodiment of FIG. 1, one of the flow control valves 32 is located at an intermediate location along the tailpipe spaced above the lower isolating member 46 and below the upper isolating member 40, while a second flow control valve 32 is located in series between the solid collector 36 therebelow and the gas separator 34 thereabove.

(24) Turning now to a second embodiment shown in FIG. 2, in this instance the pump 26 comprises a plunger lift type pump using a rod to reciprocate the plunger of the pump connected to a driver thereabove or relying on wellbore pressure being cyclically released to drive the pump. In this instance, the apparatus is similar to the configuration of the first embodiment of FIG. 1 with the exception of the absence of the lower isolating member 46 and the replacement of the separator 34 with an assembly comprising two diverter pipe sections 48 with a plug 50 connected therebetween. More particularly, the diverter pipe sections include an upper diverter pipe section having an outlet at the top end connected in series to the inlet of the pump thereabove. A plurality of fluid ports 52 communicate through the wall of the pipe section 48 so that fluid from the surrounding annulus may enter through the ports into the hollow interior of the upper diverter pipe section which then communicates through the outlet at the top end thereof to the pump. The plug 50 blocks direct communication with the hollow interior of the upper diverter pipe section 48 through the bottom end thereof. A lower diverter pipe section 48 is connected directly below the plug 50 with similar ports 52 formed in the outer wall thereof such that fluid entering the hollow interior of the lower diverter pipe section through the open bottom end thereof into the hollow interior of the diverter pipe section can then be diverted through the ports into the surrounding annulus by the plug 50 which blocks the top end of the lower diverter pipe section. The upper flow control valve 32 in this instance is connected between the solid collector 36 in series therebelow and the open bottom end of the lower diverter pipe section 48 thereabove. The solid collector 36 is similar in configuration to the previous embodiment for collecting solids accumulating in the annulus as a result of the flow being diverted upwardly and outwardly through the annulus from the lower diverter pipe section to the upper diverter pipe section.

(25) The upper isolating member 40 and the tailpipe 28 remain configured as in the previous embodiment with the exception of the lower isolating member 46 being absent.

(26) Turning now to a further embodiment shown in FIG. 3, in this instance the tailpipe 28 is provided directly below the pump 26 such that the outlet at the top of the tailpipe is coupled to the pump inlet at the bottom end thereof. The pump may comprise a plunger type lift pump as in the previous embodiment. The flow control valves 32 are again provided as a first valve at an intermediate location within the tailpipe and as a second valve at the top end of the tailpipe in communication with the pump inlet thereabove.

(27) In further embodiments, the configuration of the tailpipe 28 having a lower section which is tapered relative to an upper section thereof may be used independently of the flow control valves 32 or the isolating members 40 and/or 46. Similarly the flow control valves 32 may be used independently of the configuration of the tailpipe or the other components described herein. The lower isolating member at the bottom end of the tailpipe may also have benefits independently of the configuration of the tailpipe or the incorporation of the flow control valve therein. Any combination of these features may have some benefits in assisting in the lifting of well liquids and well gasses in a well having a lower section which is inclined or substantially horizontal.

(28) In all embodiments, a similar method of producing well fluids including well liquids and well gases can be accomplished using one of the embodiments described above. In each instance the pump is operated to enable well liquids to flow into the pump inlet which induces flow of the well fluids below the pump including enabling well fluids to flow from the oil and gas formation through the perforations and into the casing and inducing the well fluid to flow up the tailpipe from the tailpipe fluid inlet in proximity to the oil and gas formation to the tailpipe fluid outlet located above the fluid inlet.

(29) Since various modifications can be made in my invention as herein above described, and many apparently widely different embodiments of same made, it is intended that all matter contained in the accompanying specification shall be interpreted as illustrative only and not in a limiting sense.