Well completion method and apparatus

Method of perforating a cased borehole adjacent to a hydrocarbon containing formation and gravel packing the perforated zone in a single trip into the borehole comprising the steps of:

• (1) assembling a tool string by attaching a casing perforating gun in series relationship respective to two spaced packer devices having a screen apparatus located therebetween;
• (2) running the tool string downhole into the borehole on the end of a tubing string and positioning the gun adjacent to the hydrocarbon containing formation;
• (3) perforating the casing by firing the gun;
• (4) moving the tool string within the borehole until the spaced packers straddle the perforated zone;
• (5) setting said packers thereby forming an annular area between the screen and casing;
• (6) forming a flow path which extends down through the tubing string, into the annular area between the screen and casing, and from the screen back into the casing annulus located above said tool string;
• (7) flowing a mixture of gravel and fluid along the flow path described in step (6) so that gravel is deposited within said annular area between the casing and the screen while fluid is returned into the casing annulus.

Method of completing a pay zone located downhole in a cased borehole comprising the steps of:

• (1) running a tool string downhole into the borehole wherein the tool string includes a casing perforating device, a packer means, and a screen means;
• (2) positioning the perforating device adjacent to a pay zone;
• (3) actuating the perforating device, thereby communicating the interior of the casing with the pay zone;
• (4) positioning the screen means adjacent to the pay zone by changing the elevation of the tool string respective to the surface of the ground;
• and, using the packer means to form an isolated screen annulus between the screen means and the perforated pay zone wherein the annulus is in flow communication with the perforated pay zone;
• (5) forming a first flow path which extends from the surface of the ground down to the screen annulus, and a second flow path which extends from the screen means back uphole to the surface of the ground;
• (6) flowing a fluid admixed with gravel down the first flow path to cause the gravel to be deposited within the screen annulus, while the separated fluid continues through the screen and up along the second flow path to the surface of the ground;
• (7) producing the pay zone by forming a production flow path which extends from the perforations, through the gravel and screen, and uphole to the surface of the ground.

In a cased borehole having a pay zone located downhole therein and separated from the interior of the borehole by the casing;

• the combination with the cased borehole of a tool string for completing and producing the borehole;
• said tool string includes a packer means, a string of tubing, a main body having a gravel screen formed therein, and a perforating gun means;
• said packer means, gravel screen, and perforating gun means being supported from said string of tubing and positioned in axial aligned series relationship respective to one another;
• said packer means being located above and below said screen means and positioned to pack off an annular area between the screen and the casing;
• a mandrel telescopingly received within said main body;
• means forming a gun firing passageway which extends from said tubing string, through said mandrel, and to said gun means;
• means by which said mandrel can form a gravel flow passageway which extends from said tubing string, through a marginal length of said mandrel, and into said screen annulus;
• means by which said mandrel can form a return fluid passageway from said screen to the annular area between the casing and tubing string;
• and means associated with said tubing string and main body for forming a production flow passageway which extends from said screen annulus into said tubing string.

Method of completing a formation located downhole in a cased borehole, comprising the steps of:

• (1) communicating the formation with the interior of the casing by perforating the casing with a casing perforating means thereby forming a perforated zone;
• and thereafter
• (2) isolating the perforated zone by straddling the perforated area of the interior of the casing with a packer means, and placing a screen means between the packers, thereby providing an annular area between the exterior of the screen means and the interior of the perforated casing;
• and thereafter
• (3) forming a first flow path which extends from the surface of the ground, downhole into the annular area along which gravel can flow;
• and, forming a second flow path which extends through the screen, uphole to the surface of the earth;
• and, flowing gravel admixed with a fluid along the first flow path and returning the fluid along the second flow path;
• and thereafter
• (4) producing the formation by forming a flow path which extends from the formation, through the perforations, gravel, screen, and uphole to the surface of the ground.

Apparatus for perforating and gravel packing a cased borehole on a single trip into the well comprising:

• a pipe string;
• a gravel packing tool suspended on the pipe string, said gravel packing tool including means for conducting gravel flowing down said pipe string into the cased borehole;
• a perforating gun suspended on the pipe string below said gravel packing tool;
• means defining a passageway extending from said perforating gun through said gravel packing tool and pipe string for accomodating means for actuating said perforating gun and for gravel packing the well, and
• means defining a return path from said gravel packing tool to the surface for the return of gravel packing fluids.

A tool string suspended on a single pipe string within a cased borehole for completing a pay zone located downhole in a single trip, comprising:

• a screen means suspended on the pipe string for screening the production from the pay zone;
• perforating means suspended on the pipe string for perforating the cased borehole;
• means for actuating said perforating means;
• means suspended from said pipe string forming a gravel passageway for conducting gravel flowing down said pipe string into the cased borehole surrounding said screen means;
• and
• means suspended from said pipe string forming a return passageway extending from said screen means to the surface.

Method of completing a well, comprising

• lowering into a cased wellbore on a single string of tubing gravel packing means including screen means and perforating means,
• perforating the well by actuating the perforating means,
• flowing gravel down through the tubing string, through the gravel packing means and into the cased wellbore surrounding the screen means, and
• flowing produced fluid from the perforations through the gravel, through the screen, and uphole to the surface of the ground.