Gas separator with inlet tail pipe

A method of producing 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 and interior and has perforations formed therethrough for receiving oil and gas from the formation, and having a pump located above the perforations and supported from a tubing string, having a tubing string diameter, with a pump inlet, the method comprising the steps of:

• operating the pump, thereby enabling well liquids to flow into the pump inlet, and inducing 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;
• inducing the well fluids to flow up a tailpipe from a fluid inlet located proximate the oil and gas formation and an outlet located above said fluid inlet, the tailpipe having 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, and
• discharging the well fluids from a fluid outlet of a gas separator, which is coupled to an upper end of the tailpipe, into a separation annulus defined by an exterior of the gas separator and the casing interior, wherein the well gases rise and are separated from the well liquids that fall, entering a liquid inlet of the gas separator, and
• delivering the separated well liquids from the gas separator into the pump inlet, and
• isolating the flow of well fluids up the casing from the oil and gas formation by an isolation means disposed to sealably engage the casing interior at a location below the gas separator liquid inlet.

Apparatus for the production of well fluid, which includes liquids and gas, from a well having therein a casing, having an interior, that extends from the surface down to a formation that is the source of well fluids and a downhole pump, having an inlet, located above the formation for driving the liquids upward through tubing, having a diameter, to the surface, comprising:

• a gas separator having a fluid inlet, a liquid outlet and which defines a separation annulus between an exterior of said gas separator and the casing interior, and wherein gas in the fluid rises and separates from the liquid, said gas separator liquid outlet coupled to the inlet of said pump;
• a tailpipe having a fluid inlet located below said gas separator for receiving said well fluids that have flowed into said casing from said formation and a fluid outlet coupled to said gas separator fluid inlet;
• an isolator disposed within the casing below said separator to provide a pressure seal to isolate a casing interior region above the isolator from a casing interior region below the isolator, and
• said tailpipe having an internal diameter less than the diameter of said tubing to provide a lower pressure gradient of said well fluid passing upward through said tailpipe in comparison to a tailpipe having the same internal diameter as that of said tubing, to thereby correspondingly reduce a minimum required producing bottom hole pressure and correspondingly increase fluid production from the well.

A method for producing fluid, which includes liquid and gas, from a well having therein a casing that has an interior, and which extends from the surface down to a formation that is the source of the fluid and a downhole pump located above the formation within the casing for pushing liquids upward through tubing to the surface, comprising the steps of:

• receiving said fluid from said formation through perforations in said casing into a bottom hole casing annulus region,
• driving fluid in said bottom hole casing annulus region upward through a tailpipe which has an inlet in said casing annulus region, said tailpipe having an internal diameter less than the diameter of said tubing such that the pressure gradient of said fluid in said tailpipe is less than the pressure gradient of a tailpipe similarly located and having the same diameter as that of said tubing, to thereby reduce correspondingly a minimum required producing bottom hole pressure and correspondingly increase fluid production from the well,
• receiving said fluid from said tailpipe at a fluid inlet of a gas separator, which has an exterior,
• directing said fluid received at the fluid inlet of said gas separator to a gas separation zone that is contiguous with said separator, said separation zone defined by the separator exterior and the casing interior, and wherein gas rising in said gas separation zone at least partially separates from said liquid in said fluid, said gas separation zone formed by an isolation member positioned in said casing below said gas separator, said isolation member providing a pressure seal between the gas separation zone and the casing annulus region below said isolation member,
• transferring said liquid, which remains after said gas has been at least partially separated from said liquid, from said gas separation zone into an inlet of said pump, and
• flowing said gas, which has separated from said fluid in said gas separation zone, upward through the casing to the surface.

An apparatus for the production of well fluids, including liquids and gases, from an oil well having a casing that has perforations formed threrethrough for ingress of the well fluids from an oil bearing formation and a pump located above the perforations, and coupled to tubing within the casing for extracting liquids from the well, the apparatus comprising:

• a gas separator, having an exterior, coupled to deliver well liquids to an inlet of the pump, said gas separator defining a separation annulus zone between the exterior of said gas separator and an interior wall of the casing adjacent to said gas separator, said gas separator having a fluid inlet at a lower portion thereof and a fluid outlet at an upper portion thereof for transferring well fluid from said gas separator into said separation annulus zone;
• a tail pipe coupled at an upper end thereof to said gas separator fluid inlet and extending downward in the oil well to receive well fluids in the casing below said gas separator, said tail pipe having a lesser interior diameter than that of said tubing to thereby reduce a pressure gradient for well fluids flow upward through said tail pipe to said gas separator, to thereby correspondingly reduce a minimum required producing bottom hole pressure and correspondingly increase fluid production from the well, and
• a polymeric isolating member mounted to an exterior surface of said tail pipe below said gas separator to provide a pressure seal in a casing annulus.

An apparatus for the production of well fluids, including liquids and gases, from an oil well having a casing with perforations formed therethrough for ingress of the well fluids from an oil bearing formation and a pump located above the perforations, and coupled to tubing within the casing for extracting liquids from the oil well, the apparatus comprising:

• a gas separator coupled to deliver well liquids to an inlet of the pump, said gas separator defining a separation annulus zone between an exterior of said gas separator and an interior wall of the casing adjacent to said gas separator, said gas separator having a fluid inlet at a lower portion thereof and a fluid outlet at an upper portion thereof for transferring well fluids from said gas separator into said separation annulus zone;
• a tail pipe coupled at an upper end thereof to said gas separator fluid inlet and extending downward in the oil well to receive well fluids in the casing below said gas separator, said tail pipe for transferring well fluids to said gas separator at a reduced pressure gradient and thereby correspondingly reduce a minimum required producing bottom hole pressure and correspondingly increase fluid production from the oil well, and
• a polymeric pressure isolating member having a center opening with a cylindrical surface wall and an outer periphery edge, said center opening having said tail pipe therein and having said cylindrical surface wall joined to an exterior wall of said tail pipe, said outer periphery edge of said isolating member in sliding relation with the interior wall of the casing , and said isolating member providing a pressure seal between said separation annulus zone and a casing annulus below said isolating member.

An apparatus for the production of well fluids, including liquids and gases, from an oil well having a casing with perforations formed therethrough for ingress of the well fluids from an oil bearing formation and a pump located above the perforations and coupled to tubing within the casing for extracting liquids from the oil well, the apparatus comprising:

• a gas separator having a fluid inlet for receiving said well fluids to an upper region of said separator for discharge into a separation annulus zone defined between an exterior of said separator and an interior wall of the casing adjacent to said gas separator and a liquid inlet at a lower region of said separator for receiving liquid from said separation annulus zone for transfer upward to an inlet of said pump;
• a tail pipe coupled at an upper end thereof to said gas separator fluid inlet and extending downward in the oil well to intake well fluids from within the casing below said gas separator, said tail pipe for transferring well fluids to said gas separator at a reduced pressure gradient compared to a larger diameter conduit, and thereby correspondingly reduce a minimum required producing bottom hole pressure and correspondingly increase well fluids production from the oil well, and
• a polymeric pressure isolating member mounted to an exterior surface of said tail pipe below said gas separator to provide a pressure seal in a casing annulus.

A method of producing well fluids, including well liquids and well gases, in an oil and gas well having a casing, with an interior, extending down to an oil and gas formation, wherein the casing has perforations formed therethrough for receiving oil and gas from the formation, and having a pump with a pump inlet supported from a tubing string above the oil and gas formation, the method comprising the steps of:

• operating the pump, thereby enabling well liquids to flow into the pump inlet, and inducing 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;
• inducing the well fluids to flow up a tailpipe from a fluid inlet located proximate the oil and gas formation, the tailpipe having an internal diameter that is less than the diameter of the adjacent casing to thereby reduce a pressure gradient, as compared to a pressure gradient that would exist without use of said tailpipe, of the well fluids therein as a result of the smaller diameter thereof, to thereby correspondingly reduce a minimum required producing bottom hole pressure and correspondingly increase well fluid production from the oil and gas well, and
• separating the well liquids from the well gases by discharging the well fluids from a fluid outlet of a gas separator coupled to an upper end of the tailpipe, and into a separation annulus defined by an exterior of the gas separator and the casing interior, wherein the well gases rise and are separated from the well liquids that fall, entering a liquid inlet of the gas separator, and
• delivering the separated well liquids from the gas separator into the pump inlet, and
• isolating the flow of well fluids up the casing from the oil and gas formation by an isolation means disposed to sealably engage the casing at a location below the gas separator liquid inlet.

A method of producing well fluids, including well liquids and well gases, in an oil and gas well having a casing, with a casing interior, extending down to an oil and gas formation, and having a pump with a pump inlet supported from a tubing string, wherein the casing has perforations formed therethrough for receiving oil and gas from the formation, the perforations located below the pump inlet, the method comprising the steps of:

• operating the pump, thereby enabling well liquids to flow into the pump inlet, and inducing 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;
• inducing the well fluids to flow up a tailpipe from a fluid inlet located proximate the oil and gas formation, the tailpipe having an internal diameter that is less than a tubing string internal diameter to thereby reduce a pressure gradient, as compared to a pressure gradient that would exist without use of the tailpipe, of the well fluids therein and thereby correspondingly reduce a minimum required producing bottom hole pressure and correspondingly increase well fluid production from the oil and gas formation, as a result of the smaller diameter thereof, and
• separating the well liquids from the well gases by discharging the well fluids from a fluid outlet of a gas separator coupled to an upper end of the tailpipe, and into a separation annulus defined by the gas separator exterior and the casing interior, wherein the well gases rise and are separated from the well liquids that fall, entering a liquid inlet of the gas separator, and
• delivering the separated well liquids from the gas separator into the pump inlet, and
• isolating a flow of well fluids up the casing from the oil and gas formation by an isolation means disposed to sealably engage the casing at a location below the gas separator liquid inlet.