Method of dynamically controlling bottom hole circulation pressure in a wellbore

• US 6,607,042 B2
• Filed: 05/17/2001
• Issued: 08/19/2003
• Est. Priority Date: 04/18/2001
• Status: Expired due to Term

• Current Assignee: Weatherford Canada Limited (Weatherford International PLC)
• Original Assignee: Precision Drilling Technology Services Group, Inc. (Weatherford International PLC)
• Inventors: Graham, Robert A., Hoyer, Carel W. J., Steiner, Adrian
• Primary Examiner(s): Neuder, William
• Application Number:
  US09/858,954
• Publication Number:
  US 20020170749A1
• Time in Patent Office: 824 Days
• Field of Search: 175/38, 175/48, 175/65, 175/320
• US Class Current: 175/38
• 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 of drilling a well having a first tubular member extending from the surface of the well to a position proximate the bottom of the well. The first tubular member has an inner annulus therethrough. A fluid is pumped into the well through the inner annulus of the first tubular member to flush drilling cuttings out of the well. A fluid is also injected into the well, exterior to the inner annulus, to control the bottom hole circulating pressure in the well.

Claims

1. A method of drilling a well through an underground formation, the method comprising the steps of:

with a drill bit drilling a borehole from a location near the surface into the earth;

using a first string to define an inner annulus within said borehole, said inner annulus running from the surface to a point proximate the bottom of said borehole;

positioning a second string within the borehole about said first string and thereby defining a second annulus between the interior of said second string and the exterior of said first string, thereby also defining an outer annulus exterior to said second string;

providing a connecting passageway between said outer annulus and said second annulus at a point uphole from the bottom of said first string, said outer annulus sealed at a point downhole of said connecting passageway such that fluid entering said outer annulus is prevented from escaping into the bottom of the well and is directed through said connecting passageway;

providing a supply of pressurized drilling fluid to the drill bit by pumping said drilling fluid through said inner annulus, said drilling fluid flushing cuttings produced by said drill bit through said second annulus and exiting out of said well in the form of drilling fluid returns; and

,

providing a supply of pressurized fluid to said second annulus by pumping said fluid into said outer annulus and forcing said fluid into said second annulus through said connecting passageway, said fluid forced into said second annulus increasing the friction of said returns flowing through said second annulus resulting in an increase in friction pressure within said second annulus and thereby increasing the bottom hole circulating pressure in the well.

2. The method as claimed in claim 1 including the further step of maintaining the bottom hole circulating pressure in the well within defined limits through monitoring downhole fluid pressure proximate the bottom of the well and controlling the volume and pressure of fluid pumped into said outer annulus in response to fluctuations in the downhole fluid pressure.

3. The method as claimed in claim 2 wherein said step of maintaining the bottom hole circulating pressure in the well within defined limits includes increasing the friction pressure within said second annulus through increasing the rate of pumping of said fluid into said outer annulus upon a decrease in the pressure of the downhole fluid pressure proximate the bottom of the well, and decreasing the friction pressure within said second annulus through decreasing the rate of pumping of said fluid into said outer annulus upon an increase in the downhole fluid pressure proximate the bottom of the well.

4. The method as claimed in claim 1 including the further step of maintaining the bottom hole circulating pressure in the well within defined limits through monitoring the pressure of said returns within said second annulus and controlling the volume and pressure of fluid pumped into said outer annulus in response to fluctuations in the pressure of said returns in said second annulus.

5. The method as claimed in claim 4 wherein said step of maintaining the bottom hole circulating pressure in the well within defined limits includes increasing the friction pressure within said second annulus through increasing the rate of pumping of said fluid into said outer annulus upon an increase in the pressure of said returns in said second annulus, and decreasing the friction pressure within said second annulus through decreasing the rate of pumping of said fluid into said outer annulus upon a decrease in the pressure of said returns in said second annulus.

6. The method as claimed in claim 5 wherein said pressurized drilling fluid supplied through said inner annulus and said pressurized fluid pumped through said outer annulus are of the same composition.

7. The method as claimed in claim 1 including the step of encasing the borehole and thereby defining said outer annulus between the exterior of said second string and the interior of said casing.

8. The method as claimed in claim 1 wherein said underground formation is a high pressure hydrocarbon formation and including the step of maintaining the well in a controlled pressure state.

9. A method of drilling an encased well into a high pressure underground hydrocarbon formation utilizing a drill bit to drill a borehole from a location near the surface into the underground formation, the method comprising the steps of:

with a first string situated within the borehole, defining an inner annulus running from the surface to a point proximate the bottom of the borehole;

placing a second string within the borehole about said first string thereby defining a second annulus between the interior of said second string and the exterior of said first string, thereby also defining an outer annulus between the exterior of said second string and the interior of the well casing;

providing a connecting passageway between said outer annulus and said second annulus at a point uphole from the bottom of said first string;

providing a supply of pressurized drilling fluid to the drill bit by pumping said drilling fluid through said inner annulus, said drilling fluid flushing cuttings produced by said rotary bit through said second annulus, said drilling fluid and said cuttings in said second annulus comprising drilling fluid returns;

providing a supply of pressurized fluid to said second annulus by pumping said fluid into said outer annulus and forcing said fluid into said second annulus through said connecting passageway; and

,

maintaining the bottom hole circulating pressure in the well within defined limits through monitoring the pressure of said returns within said second annulus and controlling the volume and pressure of fluid pumped into said outer annulus in response to fluctuations in the pressure of said returns in said second annulus.

10. A method of drilling an encased well into a high pressure underground hydrocarbon formation utilizing a drill bit to drill a borehole from a location near the surface into the underground formation, the method comprising the steps of:

with a first string situated within the borehole, defining an inner annulus running from the surface to a point proximate the bottom of the borehole;

placing a second string within the borehole about said first string thereby defining a second annulus between the interior of said second string and the exterior of said first string, thereby also defining an outer annulus between the exterior of said second string and the interior of the well casing;

providing a connecting passageway between said outer annulus and said second annulus at a point uphole from the bottom of said first string;

providing a supply of pressurized drilling fluid to the drill bit by pumping said drilling fluid through said inner annulus, said drilling fluid flushing cuttings produced by said drill bit through said second annulus, said drilling fluid and said cuttings in said second annulus comprising drilling fluid returns;

providing a supply of pressurized fluid to said second annulus by pumping said fluid into said outer annulus and forcing said fluid into said second annulus through said connecting passageway; and

,

maintaining the bottom hole circulating pressure in the well within defined limits through monitoring the downhole fluid pressure proximate the bottom of the well and controlling the volume and pressure of fluid pumped into said outer annulus in response to fluctuations in the downhole fluid pressure.

11. A method of drilling a well having a first tubular member extending from the surface of said well to a position proximate the bottom of said well, said first tubular member having an inner annulus, said well also having a second tubular member extending from the surface of said well to a position proximate the bottom of said well, said first and second tubular members forming a second annulus therebetween, said second tubular member and said well forming an outer annulus therebetween, said method comprising:

pumping a first fluid through said inner annulus; and

,

pumping an additional volume of said first fluid through said outer annulus and into said second annulus to control the circulating pressure while drilling said well.

12. The method as claimed in claim 11 including the further step of maintaining the circulating pressure within defined limits through monitoring downhole fluid pressure proximate the bottom of said well and controlling the volume of fluid pumped into said outer annulus in response to fluctuations in said downhole fluid pressure.

13. The method as claimed in claim 12 including the step of providing a connecting passageway between said outer annulus and said second annulus at a point uphole from the bottom of said first tubular member such that fluid pumped through said outer annulus is directed through said connecting passageway into said second annulus.

14. A method of controlling the bottom hole circulating pressure when drilling a well having first and second tubular members extending from the surface into said well, said well having an inner annulus defined by the interior of said first tubular member, said well having a second annulus defined by the outer surfaces of said first and said second tubular members and the inner surface of said well, said well having an outer annulus defined by the interior of said second tubular member, the method comprising the steps of:

pumping a first fluid through said inner annulus in said first tubular member; and

,

pumping an additional volume of said first fluid through said outer annulus in said second tubular member and into said second annulus to control the circulating pressure while drilling said well.

15. The method as claimed in claim 14 including the further step of maintaining said bottom hole circulating pressure within defined limits through monitoring downhole fluid pressure proximate the bottom of said well and controlling the volume of fluid pumped into said outer annulus in response to fluctuations in said downhole fluid pressure.

16. The method as claimed in claim 14 including the further step of maintaining said bottom hole circulating pressure within defined limits through monitoring the pressure of drilling returns within said second annulus and controlling the volume of fluid pumped into said outer annulus in response to fluctuations in the pressure of said returns in said second annulus.

17. A method of controlling the bottom hole circulating pressure when drilling a well having first and second tubular members extending from the surface into said well, said second tubular member comprising a double walled pipe, said well having an inner annulus defined by the interior of said first tubular member, said well having a second annulus defined by the outer surfaces of said first and said second tubular members and the inner surface of said well, said well having an outer annulus defined by the interior of said second tubular member, the method comprising the steps of:

pumping a fluid through said inner annulus in said first tubular member; and

,

pumping a fluid through said outer annulus in said second tubular member and into said second annulus to control the circulating pressure while drilling said well.

18. The method as claimed in claim 17 including the further step of maintaining the circulating pressure within defined limits through monitoring downhole fluid pressure proximate the bottom of said well and controlling the volume of fluid pumped into said outer annulus in response to fluctuations in said downhole fluid pressure.

19. A method of controlling the bottom hole circulating pressure when drilling an encased well having a first tubular member extending from the surface into said well, said well having an inner annulus defined by the interior of said first tubular member, said well having a second annulus defined by the outer surface of said first tubular member and the inner surface of said well, said well having an outer annulus defined by the interior of a second tubular member extending from the surface along the exterior surface of the well casing, said second tubular member intersecting said well casing at a defined position along the length of said well casing and said outer annulus in communication with said second annulus adjacent said point of intersection, the method comprising the steps of:

pumping a fluid through said inner annulus in said first tubular member; and

,

pumping a fluid through said outer annulus in said second tubular member and into said second annulus to increase friction pressure within said second annulus and to increase bottom hole circulating pressure while drilling said well.

20. A method of controlling the bottom hole circulating pressure when drilling an encased well having a first tubular member extending from the surface into said well, said well having an inner annulus defined by the interior of said first tubular member, said well having a second annulus defined by the outer surface of said first tubular member and the inner surface of said well, said well having an outer annulus defined by the interior of a second tubular member extending from the surface along the exterior surface of the well casing, said second tubular member intersecting said well casing at a defined position along the length of said well casing and said outer annulus in communication with said second annulus adjacent said point of intersection, the method comprising the steps of:

pumping a fluid through said inner annulus in said first tubular member;

pumping a fluid through said outer annulus in said second tubular member and into said second annulus to increase friction pressure within said second annulus and to increase bottom hole circulating pressure while drilling said well; and

,

maintaining the circulating pressure within defined limits through monitoring downhole fluid pressure proximate the bottom of said well and controlling the volume of fluid pumped through said outer annulus in said second tubular member.