Methods and apparatus for completing production wells

Claim 3

The method of claim 1 wherein at least the last of the latter two steps is not performed until shortly before production is to be commenced from the well.

Claim 4

The method of claim 1 wherein said valve is opened by increasing the pressure in said production string above said fluid barrier.

Claim 5

The method of claim 1 wherein said fluid barrier is removed by lowering a grappling device into said production string to secure said grappling device to said fluid barrier; and, thereafter, retrieving said grappling device to bring said fluid barrier to the surface.

Claim 6

The method of claim 4 wherein said valve is opened by increasing the pressure in said production string above said fluid barrier.

Claim 7

The method of claim 4 wherein said upper pressure-actuated valve is not opened until production is about to be commenced from the well.

Claim 8

The method of claim 1 wherein said fluid barrier is positioned before said production string is lowered into said well bore.

Claim 9

The method of claim 1 furtHer including the step of: opening said closed end of said tubular member after said fluid barrier has been removed to provide increased fluid communication between said wellhead and said perforated interval.

Claim 10

Apparatus adapted for producing connate fluids from earth formations traversed by a well bore and comprising: a production string positioned in said well bore between the surface and a perforated interval of said well bore having one or more perforations directed into earth formations adjacent thereto; means adapted for supporting said production string in said well bore and including a wellhead coupled to the upper end of said production string and operatively arranged for selectively controlling communication therewith; a well packer coupled in said production string and operatively arranged for packing-off said well bore to isolate said perforated interval; means adapted for defining an enclosed chamber in said production string including means closing the lower portion of said production string, and a fluid barrier releasably secured therein above said closed lower portion and operatively arranged for selective retrieval to the surface by way of said production string and said wellhead; normally-closed valve means operatively arranged in said production string below said fluid barrier and adapted, upon actuation, for selectively establishing fluid communication between said isolated perforated interval and said enclosed chamber; and pressure actuated means operatively arranged in said production string and adapted for opening said valve means in response to the application of fluid pressure in said production string above said fluid barrier.

Claim 11

Apparatus adapted for producing connate fluids from earth formations traversed by a well bore and comprising: a production string positioned in said well bore between the surface and a perforated interval of said well bore having one or more perforations directed into earth formations adjacent thereto; means adapted for supporting said production string in said well bore and including a wellhead coupled to the upper end of said production string and operatively arranged for selectively controlling communication therewith; a well packer coupled in said production string and operatively arranged for packing-off said well bore to isolate said perforated interval; means adapted for defining an enclosed chamber in said production string including means closing the lower portion of said production string, and a fluid barrier releasably secured therein above said closed lower portion and operatively arranged for selective retrieval to the surface by way of said production string and said wellhead; normally-closed valve means operatively arranged in said production string below said fluid barrier and adapted, upon actuation, for selectively establishing fluid communication between said isolated perforated interval and said enclosed chamber; and pressure actuated means operatively arranged in said production string and adapted for opening said valve means in response to the application of fluid pressure in said production string above said fluid barrier.

Claim 12

The apparatus of claim 9 wherein said valve means include a tubular body coupled in said production string and having a fluid passage adapted for providing fluid communication between said isolated perforated interval and said enclosed chamber, and a valve member movably disposed on said tubular body and operatively associated with said valve-actuating means for movement thereby from a first position blocking said fluid passage to a second position opening said fluid passage.

Claim 13

The apparatus of claim 9 wherein said valve means include a tubular body coupled in said production string and including an internal seat therein adapted for receiving said fluid barrier, first passage means in said tubular body below said internal seat and adapted for providing fluid communication between said isolated perforated interval and said enclosed chamber, and a tubular valve member movably arranged around said tubular body and operatively associated with said valve-actuating means for movement thereby from a first position blocking said first passage means to a second position opening said first passage means.

Claim 14

The apparatus of claim 11 wherein said pressure actuated means include a piston chamber arranged on said tubular body, a piston member movably arranged on said tubular body and fluidly sealed within said piston chamber, second passage means in said tubular body and adapted for providing pressure communication between said piston chamber and said production string above said internal seat, and means operable upon movement of said piston member for moving said valve member from its said first position to its said second position.

Claim 15

The apparatus of claim 11 wherein said pressure actuated means include an annular piston chamber arranged around said tubular body above and facing said valve member, an annular piston member movably arranged around said tubular body and fluidly sealed within said piston chamber, second passage means in said tubular body and adapted for providing pressure communication between said piston chamber and said production string above said internal seat, and means coupling said valve member and said piston member and adapted, upon downward movement of said piston member, for moving said valve member downwardly from its said first position to its said second position.

Claim 16

APparatus adapted to be used in a well bore having at least one perforated interval traversing earth formations from which connate fluids are to be produced and transported to the surface through a string of production piping having a production packer dependently coupled thereto and supported in the well bore by a wellhead operatively arranged at the surface for selectively controlling communication with the production piping, said apparatus comprising: an elongated body adapted for dependent coupling to a production packer suspended thereabove from a string of production piping and having a longitudinal bore therein adapted to be in communication with such a piping string; means adapted for isolating at least a portion of said longitudinal bore to define a fluid-receiving chamber therein and including closure means normally closing the lower portion of said longitudinal bore, and a seat operatively arranged around the upper portion of said longitudinal bore for releasably receiving a fluid barrier adapted for selective retrieval to the surface by way of such a piping string and wellhead; and valve means adapted for selectively controlling fluid communication between a perforated interval isolated by such a production packer and said fluid-receiving chamber when a fluid barrier is positioned in said seat, said valve means including a tubular valve member coaxially mounted around said elongated body and adapted for movement thereon between first and second longitudinally-spaced positions, an annular piston chamber on said elongated body and cooperatively arranged around the upper portion of said valve member, piston means on said upper portion of said valve member within said piston chamber, first passage means normally blocked when said valve member is in its said first position and adapted for providing such fluid communication into said fluid-receiving chamber upon movement of said valve member toward its said second position, and second passage means adapted for providing pressure communication between said piston chamber and said longitudinal bore above said seat for operating said piston means to move said valve member to its said second position for admitting well fluids through said first passage means into said fluid-receiving chamber while a fluid barrier is positioned in said seat.

Claim 17

APparatus adapted to be used in a well bore having at least one perforated interval traversing earth formations from which connate fluids are to be produced and transported to the surface through a string of production piping having a production packer dependently coupled thereto and supported in the well bore by a wellhead operatively arranged at the surface for selectively controlling communication with the production piping, said apparatus comprising: an elongated body adapted for dependent coupling to a production packer suspended thereabove from a string of production piping and having a longitudinal bore therein adapted to be in communication with such a piping string; means adapted for isolating at least a portion of said longitudinal bore to define a fluid-receiving chamber therein and including closure means normally closing the lower portion of said longitudinal bore, and a seat operatively arranged around the upper portion of said longitudinal bore for releasably receiving a fluid barrier adapted for selective retrieval to the surface by way of such a piping string and wellhead; and valve means adapted for selectively controlling fluid communication between a perforated interval isolated by such a production packer and said fluid-receiving chamber when a fluid barrier is positioned in said seat, said valve means including a tubular valve member coaxially mounted around said elongated body and adapted for movement thereon between first and second longitudinally-spaced positions, an annular piston chamber on said elongated body and cooperatively arranged around the upper portion of said valve member, piston means on said upper portion of said valve member within said piston chamber, first passage means normally blocked when said valve member is in its said first position and adapted for providing such fluid communication into said fluid-receiving chamber upon movement of said valve member toward its said second position, and second passage means adapted for providing pressure communication between said piston chamber and said longitudinal bore above said seat for operating said piston means to move said valve member to its said second position for admitting well fluids through said first passage means into said fluid-receiving chamber while a fluid barrier is positioned in said seat.

Claim 18

The apparatus of claim 14 further including means releasably securing said closure means to said elongated body and adapted for releasing said closure means therefrom only upon application of force to said closure means after removal of a fluid barrier from said seat.

Claim 19

The apparatus of claim 15 wherein said closure means include a plug adapted to be sealingly disposed within said elongated body, said plug being fabricated of a material selected to be corroded by well fluids.

Claim 20

The apparatus of claim 14 further including a fluid barrier positioned in said seat, a means cooperatively arranged between said fluid barrier and said elongated body and adapted for releasably securing said fluid barrier in said elongated body.

Claim 21

The apparatus of claim 17 wherein said means releasably securing said fluid barrier in said elongated body are adapted for releasing said fluid barrier upon application of force thereto.

Claim 22

The apparatus of claim 18 wherein said fluid barrier includes means thereon adapted for coupling said fluid barrier to a cable tool lowered from the surface through a piping string supporting said elongated body.

Claim 23

The apparatus of claim 14 further including means releasably retaining said valve member in its said first position on said elongated body and adapted for releasing said valve member for movement toward its said second position only upon an increase of pressure in said piston chamber.