Method and apparatus for programmable pressure drilling and programmable gradient drilling, and completion

• US 7,775,299 B2
• Filed: 12/31/2007
• Issued: 08/17/2010
• Est. Priority Date: 04/26/2007
• Status: Expired due to Fees

• Current Assignee: Schlumberger Technology Corporation (Schlumberger NV)
• Original Assignee: Schlumberger Technology Corporation (Schlumberger NV)
• Inventors: Downton, Geoff, Khan, Waqar
• Primary Examiner(s): BOMAR, THOMAS S
• Application Number:
  US11/968,010
• Publication Number:
  US 20080264690A1
• Time in Patent Office: 960 Days
• Field of Search: 175/25, 175/48, 175/57, 166/250.07
• US Class Current: 175/57
• CPC Class Codes: E21B 21/00 Methods or apparatus for flushing boreholes, e.g. by use of exhaust air from motor freeing objects stuck in boreholes by flushing E21B31/03
• CPC Class Codes: E21B 21/08 Controlling or monitoring pressure or flow of drilling fluid, e.g. automatic filling of boreholes, automatic control of bottom pressure valve arrangements therefor E21B21/10
• CPC Class Codes: E21B 21/085 Underbalanced techniques, i.e. where borehole fluid pressure is below formation pressure

Abstract

A method for creating a programmable pressure zone adjacent a drill bit bottom hole assembly by sealing near a drilling assembly, adjusting the pressure to approximately or slightly below the pore pressure of the well bore face to permit flow out of the formation, and, while drilling, adjusting by pumping out of, or choking fluid flow into, the drilling assembly between the programmable pressure zone and the well bore annulus to avoid overpressuring the programmable pressure zone unless required to control the well.

Claims

1. A method for programmable pressure drilling comprising:

forming an annular seal at a distal end of a drill string to create a first pressure zone and a second pressure zone in a well bore;

sensing pressure in both the first pressure zone and the second pressure zone;

adjusting pressure between the first pressure zone and the second pressure zone to achieve a specific pressure gradient; and

drilling within the first pressure zone in the well bore while dynamically adjusting pressure in the first pressure zone, and while maintaining the annular seal.

2. The method of claim 1 further comprising strengthening the first pressure zone in the well bore.

3. The method of claim 1 further comprising equalizing pressure in the first pressure zone with the pressure in the second pressure zone.

4. The method of claim 3 further comprising advancing the drilling in the first pressure zone, after equalizing, and sealing at a different point in a well bore.

5. The method of claim 2 further comprising hydraulically isolating the first pressure zone.

6. The method of claim 2 wherein the step of strengthening comprises one of the following selected methods for stabilizing the first pressure zone:

coating the well bore with a sealant;

deploying a sleeve, cementing a casing in place, expanding an expandable tubular, inserting and deploying an interlocking continuous strip, or gravel packing.

7. The method of claim 1 further comprising continuously monitoring formation pressure and depth within the first pressure zone thereby providing a streaming potential profile of the drilled well.

8. The method of claim 7 further comprising modulating pressure in the first pressure zone and measuring the streaming potential to determine formation pressure and permeability.

9. The method of claim 1 further comprising continuously exciting the formation with sonic energy and measuring sonic velocity in the formation while modulating pressure in the first pressure zone thereby detecting formation characteristics without fracturing the first pressure zone.

10. The method of claim 1 further comprising transmitting well information dynamically while drilling from the first pressure zone to the surface and receiving control signals back from the surface.

11. The method of claim 10 wherein the well information is transmitted through wired drill pipe.

12. The method of claim 1 further comprising determining productivity potential of each pressure zone in the well as it is being drilled in the first pressure zone.

13. The method of claim 1 further comprising steering a drill bit within the first pressure zone utilizing information determined by a control unit communicating with one or more sensors located within the first pressure zone.

14. A method for programmable pressure drilling of a well bore comprising:

disposing an annular seal proximal to a distal end of a drill pipe equipped with a bottom hole assembly, said annular seal allowing continuous movement of the drill pipe;

engaging the annular seal with the well bore to form an alterable annular pressure in an annulus adjacent the bottom hole assembly below the seal in said well bore;

drilling the well bore utilizing the bottom hole assembly while maintaining the annular seal; and

maintaining the well bore pressure on a distal side of the seal during the drilling of the bore at a pressure different from a pressure on a proximal side of the seal.

15. The method of claim 14 further comprising removing drilling fluid and cuttings through said seal without releasing said seal.

16. The method of claim 14 wherein the pressure in the well bore is lower than the pressure in an annulus on an opposing side of the annular seal.