Well flow control system and method

Claim 2

A well installation comprising: a well casing extending from the surface to the producing formation of the well and having an inlet for well fluids from the producing formation into said casing; a tubing string in said casing extending from the surface of the well downwardly to a packer disposed in the bore of the casing above the producing formation and sealing between the tubing string and the casing to direct well fluids flowing upwardly in the casing into the tubing string for flowing to the surface; a fluid pressure responsive surface controlled subsurface safety valve mounted in the tubing string above the packer, said safety valve being normally biased closed and movable to open position by control fluid pressure directed thereto from the surface; bypass landing nipple means connected in the tubing string below the safety valve and having a lateral flow passage between the interior thereof and the annular space exteriorly thereof; flow regulating valve means disposed in said landing nipple means for controlling admission of fluids through the lateral flow passage of said landing nipple means into the flow tubing string; said flow regulating means having means preventing back flow of fluids through said flow regulating means to the annular space exteriorly of the landing nipple; control fluid pressure means at the surface; control fluid conductor means from the control fluid pressure source at the surface to the safety valve; back pressure conduit conductor means from the back pressure means at the surface to the safety valve for conducting back pressure from the back pressure means to the valve to bias the valve to closed position; injector means at the surface having flow communication with the annular space between the tubing and casing at the surface for injecting chemical treating fluids into the annular space to enter through the lateral port in the landing nipple and through the flow regulating valve means into the tubing string for treating the well pipe or well fluids; said injector means at the surface also providing means for injecting loading fluid into the well through the annular space, the landing nipple, the regulating device, and the tubing string to load the well when desired.

Claim 3

A well installation of the character described in claim 1 wherein the subsurface surface controlled safety valve is insertable into and removable from the tubing string while the tubing is in plaCe in the well.

Claim 4

A well installation of the character set forth in claim 1, wherein the flow regulating device in the bypass landing nipple means is movable through the tubing string, through the safety valve into and out of the landing nipple means while the tubing string and safety valve are in place in the well to permit servicing the regulating valve device.

Claim 5

A well installation of the character set forth in claim 1 wherein: valve means is provided in the bypass landing nipple means for closing the lateral flow passage therein when said flow regulating valve means is removed therefrom.

Claim 8

The method of claim 5 including the additional steps of: injecting treating fluid into the annular space at the surface of the well, and controlling the admission of such treating fluid in the tubing string through the lateral passage.

Claim 9

The method of claim 5 and the additional step of: injecting loading fluid into the annular space between the tubing and casing at the surface and through the lateral flow passage into the tubing string below the safety valve to load the producing formation with loading fluid to prevent uncontrolled flow of fluids from the formation.

Claim 10

The method of claim 5 wherein the packer and safety valve are located in the upper portion of the well below the surface and the well is produced through the casing to the packer and safety valve then through the tubing from the packer and safety valve to the surface.

Claim 11

The method of claim 5 including the step of: supporting the tubing string below the safety valve at a point in the well casing below the surface.

Claim 12

The method of claim 5 including the additional step of: closing the lateral passage into the tubing string below the safety valve to prevent flow therethrough in either direction.

Claim 13

A well system for a well having a string of casing extending downwardly therein from the surface to the producing formation and having an inlet for well fluids from said formation and a well head closure assembly thereon at the surface, said system including: an elongate tubing string; means for supporting said tubing string in the casing at a location below the surface of the well and above the producing formation, said tubing string extending downwardly from the supporting means to a point adjacent the producing formation; a packer sealing between the tubing and casing below the supporting means and above the producing formation; a flow conductor extending upwardly from the supporting means through the well head closure assembly; a receptacle in said flow conductor above said supporting means and above said packer; a removable fluid pressure responsive subsurface safety valve mounted in the receptacle, said safety valve having means normally resiliently biasing it closed; a back pressure fluid control conduit extending from the surface to the receptacle and the safety valve for conducting back pressure fluids from the surface to the safety valve for closing the same in addition to said biasing means; control fluid conduit means extending from a source of control fluid pressUre at the surface to the receptacle and the safety valve for conducting control fluid pressure to said safety valve to move said safety valve to open position against the back pressure fluid acting thereon and the resilient biasing means; bypass landing nipple means connected with the tubing string below the safety valve receptacle and above the packer between the casing and tubing, said bypass landing nipple means comprising a housing having an internal landing nipple therein and a longitudinal flow passage through said housing exteriorly of the internal landing nipple, and having a lateral flow passage connecting the bore of the internal landing nipple with the exterior of the housing and the annular space between the tubing and casing above the packer; flow regulating valve means removably disposed in the landing nipple of said bypass landing nipple means and having valve means biased toward closed position regulating flow of fluid inwardly through the lateral passage of said bypass landing nipple means into the bore of the internal landing nipple and to the tubing string in communication therewith and preventing back flow of fluids from said tubing string outwardly through said passage to said annular space; means for injecting fluid into the annular space at the surface to be admitted through the lateral passage and flow regulating means into the tubing string; said safety valve being operable to close off flow from the well through the flow conductor thereabove and said flow regulating means being operable to prevent flow of fluids from the well producing formation through the lateral passage to the annulus.

Claim 14

A well system for a well having a string of casing extending downwardly therein from the surface to the producing formation and having an inlet for well fluids from said formation and a well head closure assembly thereon at the surface, said system including: an elongate tubing string; means for supporting said tubing string in the casing at a location below the surface of the well and above the producing formation, said tubing string extending downwardly from the supporting means to a point adjacent the producing formation; a packer sealing between the tubing and casing below the supporting means and above the producing formation; a flow conductor extending upwardly from the supporting means through the well head closure assembly; a receptacle in said flow conductor above said supporting means and above said packer; a removable fluid pressure responsive subsurface safety valve mounted in the receptacle, said safety valve having means normally resiliently biasing it closed; a back pressure fluid control conduit extending from the surface to the receptacle and the safety valve for conducting back pressure fluids from the surface to the safety valve for closing the same in addition to said biasing means; control fluid conduit means extending from a source of control fluid pressUre at the surface to the receptacle and the safety valve for conducting control fluid pressure to said safety valve to move said safety valve to open position against the back pressure fluid acting thereon and the resilient biasing means; bypass landing nipple means connected with the tubing string below the safety valve receptacle and above the packer between the casing and tubing, said bypass landing nipple means comprising a housing having an internal landing nipple therein and a longitudinal flow passage through said housing exteriorly of the internal landing nipple, and having a lateral flow passage connecting the bore of the internal landing nipple with the exterior of the housing and the annular space between the tubing and casing above the packer; flow regulating valve means removably disposed in the landing nipple of said bypass landing nipple means and having valve means biased toward closed position regulating flow of fluid inwardly through the lateral passage of said bypass landing nipple means into the bore of the internal landing nipple and to the tubing string in communication therewith and preventing back flow of fluids from said tubing string outwardly through said passage to said annular space; means for injecting fluid into the annular space at the surface to be admitted through the lateral passage and flow regulating means into the tubing string; said safety valve being operable to close off flow from the well through the flow conductor thereabove and said flow regulating means being operable to prevent flow of fluids from the well producing formation through the lateral passage to the annulus.

Claim 15

A well system of the character set forth in claim 11 wherein the subsurface safety valve is insertable into and removable from the receptacle while the flow conductor is in place in the well.

Claim 16

A well system of the character set forth in claim 11 wherein the flow regulating means of the bypass landing nipple means is movable into and out of the internal landing nipple of the bypass landing nipple means through the safety valve thereabove while the safety valve is in place.

Claim 17

A well system of the character set forth in claim 11 wherein the means at the well surface for injecting fluid into the annular space comprises: means for introducing lifting gas under pressure into the annulus to flow through the lateral passage of the bypass landing nipple means through the flow regulating valve means into the tubing to aerate well liquids in the tubing and casing to cause said well fluids to be lifted to the surface of the well.

Claim 18

A well system of the character set forth in claim 11 wherein: means is provided in said system for closing off the means for conducting fluids into the tubing string above the producing formation.

Claim 19

A well system of the character set forth in claim 11 wherein: valve means is provided in the bypass landing nipple means movable to close the lateral flow passage therein to prevent fluids flowing in either direction through said flow passage when said flow regulating valve means is removed from the landing nipple.