Crossover valve system and method for gas production

Abstract

A crossover valve assembly for insertion into production tubing, or integral with production tubing, includes an outer housing, an inner production tube, a pilot section responsive to external pressure to open an activation passage above a pre-determined pressure, a power section responsive to pressure in the activation passage to open an injection opening; and a crossover valve responsive to pressure in the injection opening to open a crossover port, allowing fluid communication from outside the outer housing to within the inner production tube. The crossover valve assembly may be used in a method of producing a vertical, deviated or horizontal gas well having an annular space defined by a well casing and a concentrically disposed production tubing, wherein an annulus exists above a packer isolating the annulus, includes the steps of (a) opening a communication path through the tubing into the annulus, and if necessary, removing any fluid in the annulus, (b) landing a crossover valve assembly within the production tubing above the packer and exposed to the annulus; and (c) injecting gas into the annular space to open the crossover valve and enter the production tubing, wherein the injected gas lifts liquids in the production tubing to the surface.

What is claimed is: 
     
         1 . A method of producing a vertical, deviated or horizontal gas well having an annular space defined by a well casing and a concentrically disposed production tubing, said well having an annulus and a lower producing zone open to the production tubing, wherein the annulus is isolated from the lower producing zone by a packer, comprising the steps of:
 (a) opening a communication path through the production tubing into the annulus, and if necessary, removing any liquid in the annulus;   (b) landing at least one crossover valve within the production tubing exposed to the annulus through the communication path, wherein the crossover valve has a pilot section having a predetermined closing pressure, a power section and a crossover fluid passage; and   (c) injecting gas into the annulus to at least the closing pressure to activate the pilot section, thereby exposing the power section to the annulus, thereby opening the crossover fluid passage and allowing injected gas to enter the production tubing, wherein the injected gas lifts liquids in the production tubing to the surface.   
     
     
         2 . The method of  claim 1  wherein the at least one crossover valve is deployed on a continuous or jointed tubing string or by wireline, within the production tubing. 
     
     
         3 . The method of  claim 1  wherein the gas is injected continuously or the gas is injected periodically. 
     
     
         4 . The method of  claim 3  wherein the gas is injected in response to pre-determined conditions in the wellbore, including the position of a plunger, pressure in the annulus, pressure or gas flow in the production tubing, tubing fluid levels or pressure differential between the tubing and annulus. 
     
     
         5 . The method of  claim 1  wherein the injected gas comprises instrumentation sweet gas. 
     
     
         6 . A system for producing a vertical, deviated or horizontal gas well having an annular space defined by a well casing and a concentrically disposed production tubing, said well having an annulus and a lower producing zone open to the production tubing, wherein the annulus is isolated from the lower producing zone by a packer, comprising:
 (a) a communication path through the tubing into the annulus;   (b) at least one crossover valve within the production tubing exposed to the annulus through the communication path;   (c) a surface gas injector and a gas supply for injecting gas into the annular space to open the crossover valve and enter the production tubing;   (d) a plunger for reciprocating within the production tubing; and   (e) a surface controller for controlling the gas injector, wherein the controller is responsive to a signal indicative of one or more of the following: the position of the plunger, pressure in the annulus, pressure or gas flow in the production tubing, tubing fluid level or pressure differential between the tubing and annulus.   
     
     
         7 . The system of claim  16  wherein the gas supply comprises sweet instrumentation gas.