Accelerated downhole pressure testing

Abstract

The present invention provides a method and apparatus for completing a well by means of a perforating gun attached to the downhole end of a string of production tubing, producing the well until it is clean, shutting-in the well at a point relatively near the perforating gun, and measuring the shut-in pressure.

What is claimed is: 
     
       1. A method for completing and/or testing a hydrocarbon formation of a well having a cased borehole, comprising the steps of: running a string of production tubing into the borehole, said tubing string including a perforating gun on the lower end thereof, a valve above, but relatively near, the perforating gun, a packer apparatus below the valve, and a vent assembly below the packer apparatus;   setting the packer apparatus;   opening the vent assembly;   firing the perforating gun;   shutting-in the well at the valve; and   measuring the shut-in pressure within said tubing string below the valve.   
     
     
       2. A method according to claim 1 further comprising the step of placing a pressure measuring sensor means in communication with said tubing string below the valve prior to said firing. 
     
     
       3. A method according to claim 2 further comprising the steps of: removing a tool string from the borehole; and   stabbing a production string in place of the tool string.   
     
     
       4. Apparatus for completing and/or testing a well having a cased borehole, comprising: a string of production tubing disposed within the cased borehole;   a perforating gun attached to the downhole end of said tubing string; the perforating gun having an impact responsive firing head;   a weighted object adapted to pass through the tubing to impact and actuate the firing head;   means on said tubing string near said perforating gun for closing the interior of said tubing string to the flow of fluids in a first state of operation and in a second state of operation providing an opening therethrough of sufficient size to permit the weighted object to pass therethrough; and   means on said tubing string downhole of said closing means for measuring pressure within said tubing string.   
     
     
       5. Apparatus according to claim 4 wherein said closing means comprises a valve which can be actuated by turning the upper end of said tubing string. 
     
     
       6. Apparatus according to claim 4 wherein said measuring means comprises: a pressure measuring apparatus;   a housing affixed to said tubing string for supporting at least a portion of said measuring apparatus; and   means for communicating fluid pressure within said tubing string to said housing.   
     
     
       7. Apparatus according to claim 6 wherein said measuring apparatus comprises a sensor means disposed within said housing and an indicating means disposed at the surface of the borehole. 
     
     
       8. Apparatus according to claim 6 wherein said measuring apparatus comprises a sensor means and an indicating means both disposed within said housing. 
     
     
       9. Apparatus according to claim 8 further comprising: a packer apparatus disposed between the borehole casing and said tubing string;   means for removing an upper portion of said tubing string including said measuring means, leaving a lower portion of said tubing string supported by said packer;   means for connecting a second string of production tubing to the lower portion of said tubing string; and   means for releasing said perforating gun from the downhole end of said tubing string.   
     
     
       10. Apparatus according to claim 8 further comprising means for retrieving and replacing said measuring apparatus while said tubing string remains disposed within the borehole. 
     
     
       11. Apparatus according to claim 10, wherein said retrieving and replacing means comprises: means for accessing said housing from the interior of said tubing string;   a wireline; and   means on said wireline for gripping said measuring apparatus.   
     
     
       12. Apparatus for completing and/or testing a well having a cased borehole, comprising: a string of production tubing disposed within the cased borehole;   a perforating gun having an impact responsive firing head affixed to the lower end of said tubing string;   a weighted object adapted to pass through the tubing to impact and actuate the firing head;   a housing protruding from the exterior of said tubing string, said housing being in fluid communication with the interior of said tubing string;   a valve within said tubing string .Iadd.near said perforating gun and .Iaddend.above said housing for closing said tubing string in a first state of operation and, in a second state of operation, providing an opening therethrough of sufficient size to permit the weighted object to pass therethrough; and   means for measuring pressure within said tubing string, at least a portion of said measuring means being disposed within said housing.   
     
     
       13. Apparatus according to claim 12 wherein said measuring means comprises a sensor means disposed within said housing and an indicating means disposed at the surface of the borehole. 
     
     
       14. Apparatus according to claim 13 wherein said measuring means comprises: a source of fluid, said source providing a generally positive flow of fluid at a substantially constant pressure;   means for transporting a continuous flow of fluid from said source into a borehole;   means for measuring the flow rate of fluid through said transporting means and providing an output indicative thereof;   means for measuring pressure in said transporting means near said source and providing an output indicative thereof; and   means connected to said pressure measuring means for determining pressure in the borehole.   
     
     
       15. Apparatus according to claim 12 wherein said measuring means comprises a sensor means and an indicating means both disposed within said housing. 
     
     
       16. Apparatus according to claim 15 further comprising means for replacing and retrieving said measuring means from the interior of said tubing string without pulling said tubing string. .Iadd. 
     
     
       17.  Apparatus for perforating and testing a hydrocarbon formation in a well having a cased borehole comprising: a string of tubing disposed within the borehole;   perforating means attached to the downhole end of said tubing string for creating one or more perforations through the sides of the borehole and into the formation;   valve means located relatively near said perforating means for closing the interior of said tubing string to the flow of fluids when it is in a first state of operation and for opening the interior of said tubing string to the flow of fluids when it is in a second state of operation;   packer means located proximate said perforating means and said valve means for selectively effecting a seal between the exterior of said tubing string and the interior of the borehole;   means for selectively opening and closing said valve means to open or shut-in the well;   means located below said packer means for providing a fluid communication between the interior of said tubing string and the annulus between said tubing string and the borehole;   pressure sensing means associated with said tubing string and proximate to said valve means for sensing the pressure within said tubing string below said valve means; and   surface indication means at the surface of the well and in communication with said pressure sensing means for providing a surface readout of the sensed pressure while said packer means is sealed and said tubing string and said associated sensing means remains disposed in the borehole..Iaddend. .Iadd.   
     
     
       18.  Apparatus for perforating and testing a hydrocarbon formation in a well having a cased borehole comprising: a string of tubing disposed within the borehole;   perforating means attached to the downhole end of said tubing string for creating one or more perforations through the sides of the borehole and into the formation;   valve means located relatively near said perforating means for closing the interior of said tubing string to the flow of fluids when it is in a first state of operation and for opening the interior of said tubing string to the flow of fluids when it is in a second state of operation;   packer means located proximate said perforating means and said valve means for selectively effecting a seal between the exterior of said tubing string and the interior of the borehole;   means for selectively opening and closing said valve means to open or shut-in the well;   means located below said packer means for providing a fluid communication between the interior of the tubing string and the annulus between said tubing string and the borehole;   a housing incorporated in said tubing string, said housing being located proximate said valve means and above said fluid communication means and being radially displaced from but in fluid communication with the interior bore of said tubing string; and   pressure measuring means disposed at least in part within said housing for measuring the pressure within said tubing string below said valve means while said packer means is sealed and said tubing string remains disposed in the borehole. .Iaddend. .Iadd.   
     
     
       19.  The apparatus according to claim 17 or 18 wherein said perforating means includes a perforating gun and a means for selectively firing said perforating gun. .Iaddend. .Iadd.20. The apparatus according to claim 19 wherein said firing means includes an impact responsive firing head on said perforating gun and a weighted object adapted to pass through the tubing string to impact and actuate said firing head. .Iaddend. .Iadd.21. The apparatus according to claim 20 wherein said valve means when open provides an opening of sufficient size in said tubing string to permit said weighted object to pass therethrough. .Iaddend. .Iadd.22. The apparatus according to claim 17 or 18 wherein said valve means when open provides an opening of sufficient size in said tubing string to permit the introduction of tools therethrough. .Iaddend. .Iadd.23. The apparatus according to claim 22 wherein said valve means is a ball valve which is opened by the rotation of the tubing string above said valve. .Iaddend. .Iadd.24. The apparatus according to claim 17 or 18 wherein said perforating means is within 110 feet of said valve means. .Iaddend. .Iadd.25. The apparatus according to claim 17 or 18 wherein the volume of said tubing string below said valve means is negligible in comparison to the volume of said tubing string above said valve means. .Iaddend. .Iadd.26. The apparatus according to claim 17 or 18 wherein said means for selectively opening and closing said valve means is operated by manipulation of the upper end of said tubing string at the surface of the well. .Iaddend. .Iadd.27. The apparatus according to claim 17 or 18 wherein said means for providing a fluid communication includes a vent assembly having ports which can be selectively opened and closed. .Iaddend. .Iadd.28. The apparatus according to claim 17 further comprising a housing incorporated in said tubing string at a location below said valve, said housing being radially displaced from but in fluid communication with the interior bore of said tubing string and said pressure sensing means being disposed within said housing. .Iaddend. .Iadd.29. The apparatus according to claim 18 wherein said pressure measuring means includes a self-contained pressure sensing and recording means which is completely disposed within said housing. .Iaddend. .Iadd.30. The apparatus according to claim 29 further comprising means for retrieving the self-contained pressure sensing and recording means while said tubing remains disposed within the borehole. .Iaddend. .Iadd.31. The apparatus according to claim 30 wherein said retrieving means comprises: means for accessing said housing from the interior of said tubing;   a wireline; and   means on said wireline for gripping said self-contained pressure sensing   
     
     
        and recording means. .Iaddend. .Iadd.32.  The apparatus according to claim 18 wherein said pressure measuring means includes a pressure sensing means proximate said valve means and a surface indication means at the surface of the well and in communication with said pressure sensing means for providing a surface readout of the sensed pressure while said packer means is sealed and the tubing string remains disposed in the borehole. .Iaddend. .Iadd.33. The apparatus according to claim 17 or 32 further comprising a secondary pressure measuring means in the form of a self-contained pressure sensing and recording means associated with said tubing string, radially displaced from but in communication with the interior bore of said tubing string, and proximate to said valve means for simultaneously sensing and recording the pressure within said tubing string below said valve means. .Iaddend. .Iadd.34. The apparatus according to claim 17 or 18 further comprising means for releasing said perforating gun from said tubing string. .Iaddend. .Iadd.35. The apparatus according to claim 17 or 18 further comprising a blanking plug sub means located above said packer means for accepting a blanking plug to blank off said tubing string below said blanking plug sub means. .Iaddend. .Iadd.36. The apparatus according to claim 17 or 18 further comprising an on/off sub means located above said packer means for permitting the removal of the portion of said tubing above said on/off means while leaving the lower portion of said tubing string supported by said packer means. .Iaddend. 
     
     
        .Iadd.37.  The apparatus according to claim 18 wherein said pressure measuring means is a self-contained pressure sensing and recording means and further comprising a pressure sensing means proximate said valve means for sensing the pressure within said tubing string below said valve means and a surface indication means at the surface of said well and in communication with said pressure sensing means for providing a surface readout of the sensed pressure while said packer means is sealed and said tubing string and said associated sensing means remains disposed in the borehole. .Iaddend. .Iadd.38. The apparatus according to claim 18 wherein said housing protrudes from the exterior of said tubing string. .Iaddend. .Iadd.39. A method for perforating and testing a hydrocarbon formation in a well having a cased borehole comprising the steps of: running a string of tubing into the borehole, said tubing string including a perforating gun on the lower end thereof, a shut-in valve above, but relatively near, the perforating gun, a packer apparatus proximate the perforating gun and the valve, and means for admitting well fluids into the tubing string at a location below the packer;   setting the packer apparatus to effect a seal between the exterior of the tubing string and the borehole;   firing the perforating gun to create a plurality of perforations and channels through the sides of the borehole and into the formation;   shutting the valve to shut-in the well while the packer is sealed and the tubing string is in place;   measuring the shut-in pressure within said tubing string below the valve while the packer apparatus is sealed, the shut-in valve is closed, and the tubing string remains disposed in the borehole and for at least the period of time required for the shut-in pressure to build up to the ultimate shut-in pressure; and   simultaneously providing a surface readout of the measured shut-in   
     
     
        pressure. .Iaddend. .Iadd.40.  A method for perforating and testing a hydrocarbon formation in a well having a cased borehole comprising the steps of: running a string of tubing into the borehole, said tubing string including a perforating gun on the lower end thereof, a shut-in valve above, but relatively near, the perforating gun, a packer apparatus proximate the perforating gun and the valve, means for admitting well fluids into the tubing string at a location below the packer, and a pressure sensing means above the admitting means and proximate the valve;   setting the packer apparatus to effect a seal between the exterior of the tubing string and the borehole;   firing the perforating gun to create a plurality of perforations and channels through the sides of the borehole and into the formation;   shutting the valve to shut-in the well while the packer is sealed and the tubing string is in place;   measuring with the pressure sensing means the shut-in pressure within said tubing string below the valve while the packer apparatus is sealed, the shut-in valve is closed and the tubing string remains disposed in the borehole and for at least the period of time required for the shut-in pressure to build up to the ultimate shut-in pressure; and   simultaneously providing a surface readout of the measured shut-in   
     
     
        pressure. .Iaddend. .Iadd.41.  The method according to claim 39 or 40 wherein the step of simultaneously providing a surface readout includes the step of providing a surface readout of both the measured shut-in pressure as a function of time and the absolute measured shut-in pressure at any point in time. .Iaddend. .Iadd.42. The method according to claim 39 or 40 further comprising the step of permitting the well to produce until the perforations and channels are cleaned of debris before initiating the step of shutting the valve. .Iaddend. .Iadd.43. The method according to claim 39 or 40 wherein the valve is within 110 feet of the perforating gun. .Iaddend. .Iadd.44. The method according to claim 39 or 40 wherein the volume of the tubing string below said packer is negligible as compared to the volume of tubing string above said packer. .Iaddend. .Iadd.45. The method according to claim 39 or 40 wherein the step of running the string of tubing into the borehole further includes running an on/off sub and a blanking plug sub into the borehole on said string of tubing, said on/off sub being located between said valve and said packer, and said blanking plug sub being located between said on/off sub and said packer. .Iaddend. .Iadd.46. The method according to claim 45 further comprising the step of positioning a blanking plug within the blanking plug sub, disengaging the tool string at the on/off sub, and retrieving the tubing string above said on/off sub. .Iaddend. .Iadd.47. The method according to claim 39 or 40 wherein the step of firing the perforating gun includes passing a weighted object through the tubing string to impact and actuate the perforating gun. .Iaddend. .Iadd.48. The method according to claim 39 further comprising the step of placing a pressure sensing means in communication with said tubing string below the shut-in valve prior to the step of firing the perforating gun. .Iaddend. .Iadd.49. The method according to claim 39 or 40 further comprising the step of selectively opening and closing the shut-in valve to respectively flow and shut-in the well while the packer is sealed and the tubing string is in place. .Iaddend. .Iadd.50. The method according to claim 40 further comprising the step of retrieving the pressure sensing means while the tubing string remains in the well. .Iaddend. .Iadd.51. The method according to claim 39 or 40 further comprising the step of recording the measured pressure at the surface of the well as a function of time. .Iaddend. .Iadd.52. The method according to claim 39 or 40 further comprising the step of recording the measured pressure at both the surface of the well and 
     
     
        downhole. .Iaddend. .Iadd.53.  The method according to claim 39 or 40 wherein the tubing string is run into the borehole while the tubing string is substantially dry. .Iaddend. .Iadd.54. The method according to claim 39 or 40 wherein said means for admitting well fluids is a vent assembly and further comprising the steps of running the vent assembly into the borehole in a closed position and opening the vent assembly after setting the packer apparatus. .Iaddend.