System, Program Products, and Methods For Controlling Drilling Fluid Parameters

• US 20110125333A1
• Filed: 01/31/2011
• Published: 05/26/2011
• Est. Priority Date: 07/01/2005
• Status: Active Grant

• Current Assignee: Board of Regents of the University of Texas System (University of Texas System)
• Original Assignee: Board of Regents of the University of Texas System (University of Texas System)
• Inventors: Gray, Kenneth E.
• Granted Patent: US 8,256,532 B2
• Time in Patent Office: Days
• US Class Current: 700/282
• 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

Abstract

Embodiments of systems, program product, and methods for controlling drilling fluid pressures are provided. These embodiments, for example, can provide dynamic density control with highly adaptive, real-time, process-control and are scalable to any rig, large or small, on land or water. Combined static and dynamic stresses and displacements can be determined continuously at strategic locations in and around the wellbore of a well so that insitu and operational induced pressure window limitations at specific weak-points or other locations of interest are controlled.

Claims

1. A method of controlling drilling fluid pressures, the method comprising the steps of:

for each of a plurality of longitudinally separated locations of interest within a drilling system extending within a wellbore;

forming pressure volume and pressure volume time curves for the respective longitudinally separated location of interest responsive to measured fluid pressure data and measured volume data;

determining a change in fluid volume for fluid circulating portions of the drilling system, the change in fluid volume attributable to at least one of the following;

fluid kick and drilling system component breathing and ballooning;

differentiating between fluid kick and drilling system component breathing and ballooning when performing drilling operations responsive to the respective pressure volume and pressure volume time curves and earth formation compressibility data at a respective one of the plurality of locations of interest and at each longitudinally prior one of the plurality of locations of interest; and

responsive to the step of differentiating, controlling drilling system downhole pressure realtime when performing the drilling operations.

2. A method as defined in claim 1, wherein the step of forming pressure volume and pressure volume time curves includes:

filling the fluid circulating portions of the drilling system including at least one casing string being tested with drilling fluid;

sealing each drilling system fluid supply inlet and outlet;

applying pressure to the fluid by pumping additional fluid into the drilling system by a pressure pump to thereby compress the drilling fluid, radially expand wellbore components of the drilling system, and compress an earth formation surrounding the wellbore adjacent the respective location of interest; and

measuring an increase in fluid pressure and volume of fluid pumped into the drilling system at each of a plurality of instances when applying pressure to the fluid.

3. A method as defined in claim 1, wherein the step of forming pressure volume and pressure volume time curves includes:

measuring fluid volume of fluid pumped into the fluid circulating portions of the drilling system, the volume measured in real time at each of a plurality of instances during pressurization of the drilling system; and

measuring fluid pressure at the respective longitudinally separated location of interest within the drilling system, the pressure measured in real time at each of the plurality of instances during pressurization of the drilling system.

4. A method as defined in claim 3, wherein both fluid volume and fluid pressure measurements are made during both pressure induced expansion and contraction of wellbore components and adjacent earth formations surrounding the wellbore at the respective location of interest.

5. A method as defined in claim 1, further comprising the steps of:

analyzing drilling component compressibility data describing expansion and contraction of wellbore components of the drilling system, the wellbore components including riser, casing, drill pipe, and cement components; and

analyzing earth formation compressibility data describing expansion and contraction of earth formations surrounding the wellbore to include subsurface stratae and pore fluids residing within the stratae surrounding the wellbore at each of the plurality of locations of interest.

6. A method as defined in claim 1, further comprising the steps of:

measuring expansion and compressibility of the fluid circulating portions of the drilling system and compressibility of a surrounding earth formation at each of the plurality of areas of interest to formulate a description of a physical behavior of the drilling system components;

performing a cased hole pressure test to determine a volume associated with expansion of pressurized fluid circulating portions of the drilling system during drilling operations; and

performing an integrity and fracture pressure test to determine integrity of cement sealing a casing string to the wellbore and fracture pressure of an adjacent earth formation to thereby determine a dynamic maximum pressure that can exist at a lower end of the casing string without fracturing the associated earth formation or bonding of the cement.

7. A method as defined in claim 1, wherein the step of determining a change in fluid volume for the fluid circulating portions of the drilling system includes determining the change in fluid volume within the entire fluid circulating portion of the drilling system.

8. A method as defined in claim 1, wherein the step of determining a change in fluid volume for the fluid circulating portions of the drilling system includes:

measuring fluid volume of fluid pumped into the fluid circulating portions of the drilling system;

measuring fluid volume of returned fluid; and

determining a difference between the volume of fluid pumped into the fluid circulating portions of the drilling system and the volume of fluid returned.

9. A method as defined in claim 1, wherein the step of controlling drilling system downhole pressure comprises:

increasing downhole pressure at the respective location of interest when the difference between the volume of fluid pumped into the drilling system and the volume of fluid returned is attributed to fluid kick.

10. A method as defined in claim 1, wherein the step of controlling drilling system downhole pressure comprises:

maintaining drilling system annulus pressure when the difference between the volume of fluid pumped into the fluid circulating portions of the drilling system and the volume of fluid returned is attributed to breathing and ballooning; and

increasing annulus pressure when the difference between the volume of fluid pumped into the fluid circulating portions of the drilling system and the volume of fluid returned is attributed to fluid kick, the step of increasing annulus pressure including applying fluid to a drilling system annulus fluid outlet.

11. A method as defined in claim 10, wherein the step of controlling drilling system downhole pressure further comprises:

increasing injection pump pressure when the difference between the volume of fluid pumped into the drilling system and the volume of fluid returned is attributed to fluid kick.

12. A method as defined in claim 1, wherein the step of controlling drilling system downhole pressure further comprises:

determining a maximum dynamic bottom hole pressure at a plurality of future depths to be drilled.

13. A method as defined in claim 1, wherein the drilling system includes casing string cement, the method further comprising the step of:

employing a plurality of operational simulators; and

determining an effect of mud channels in the casing string cement responsive to at least one of the operational simulators.

14. A method as defined in claim 1, wherein the step of determining a change in fluid volume for the fluid circulating portions of the drilling system is performed at a first time instance, the method further comprising the steps of:

determining a change in fluid volume for the fluid circulating portions of the drilling system at a second time instance, the change in fluid volume attributable to at least one of the following;

fluid kick and drilling system component breathing and ballooning;

differentiating between fluid kick and drilling system component breathing and ballooning when performing drilling operations responsive to the respective pressure volume and pressure volume time curves and earth formation compressibility data at a respective one of the plurality of locations of interest and at each longitudinally prior one of the plurality of locations of interest; and

increasing downhole pressure at the respective location of interest when the difference between the volume of fluid pumped into the fluid circulating portions of the drilling system and the volume of fluid returned is attributed to fluid kick.

15. A method as defined in claim 1, wherein the step of determining a change in fluid volume for the fluid circulating portions of the drilling system is performed at a first time instance, the method further comprising the steps of:

determining a change in fluid volume for the fluid circulating portions of the drilling system at a second time instance, the change in fluid volume attributable to at least one of the following;

lost circulation due to formation fracture and drilling system component breathing and ballooning;

differentiating between lost circulation due to formation fracture and drilling system component breathing and ballooning when performing drilling operations responsive to the respective pressure volume and pressure volume time curves and earth formation compressibility data at a respective one of the plurality of locations of interest and at each longitudinally prior one of the plurality of locations of interest; and

decreasing downhole pressure at the respective location of interest when the difference between the volume of fluid pumped into the fluid circulating portions of the drilling system and the volume of fluid returned is attributed to formation fracture.

16. A method as defined in claim 1, wherein the step of determining a change in fluid volume for the fluid circulating portions of the drilling system is performed at a first time instance, the method further comprising the steps of:

determining a change in fluid volume for the fluid circulating portions of the drilling system at a second time instance, the change in fluid volume attributable to at least one of the following;

formation leak-off and drilling system component breathing and ballooning;

differentiating between formation leak-off and drilling system component breathing and ballooning when performing drilling operations responsive to the respective pressure volume and pressure volume time curves and earth formation compressibility data at a respective one of the plurality of locations of interest and at each longitudinally prior one of the plurality of locations of interest; and

maintaining downhole pressure at the respective location of interest when the difference between the volume of fluid pumped into the fluid circulating portions of the drilling system and the volume of fluid returned is attributed to formation leak-off.

17. Dynamic density control program product to control drilling pressures, the program product comprising a set of instructions, stored on a tangible computer readable medium, that when executed by a computer, cause the computer to perform the operations of:

for each of a plurality of longitudinally separated locations of interest within a drilling system extending within a wellbore;

forming pressure volume and pressure volume time curves for the respective longitudinally separated location of interest responsive to measured fluid pressure data and measured volume data;

determining a change in fluid volume for fluid circulating portions of the drilling system, the change in fluid volume attributable to at least one of the following;

fluid kick and drilling system component breathing and ballooning;

differentiating between fluid kick and drilling system component breathing and ballooning when performing drilling operations responsive to the respective pressure volume and pressure volume time curves and earth formation compressibility data at a respective one of the plurality of locations of interest and at each longitudinally prior one of the plurality of locations of interest; and

responsive to the operation of differentiating, providing data to control drilling system downhole pressure realtime when performing the drilling operations.

18. Program product as defined in claim 17, wherein the operation of forming pressure volume and pressure volume time curves includes:

filling the fluid circulating portions of the drilling system including at least one casing string being tested with drilling fluid;

sealing each drilling system fluid supply inlet and outlet;

applying pressure to the fluid by pumping additional fluid into the fluid circulating portions of the drilling system by a pressure pump to thereby compress the drilling fluid, radially expand wellbore components of the drilling system, and compress an earth formation surrounding the wellbore adjacent the respective location of interest;

measuring fluid volume of the additional fluid pumped into the fluid circulating portions of the drilling system, the volume measured in real time at each of a plurality of instances during both pressure induced expansion of wellbore components and adjacent earth formations surrounding the wellbore at the respective location of interest;

measuring fluid volume of fluid returned during contraction of the wellbore components and the adjacent earth formations surrounding the wellbore at the respective location of interest; and

measuring fluid pressure at the respective longitudinally separated location of interest within the drilling system, the pressure measured in real time at each of the plurality of instances during both pressure induced expansion and contraction of the wellbore components and the adjacent earth formations surrounding the wellbore at the respective location of interest.

19. Program product as defined in claim 17, wherein the operations further comprise:

analyzing drilling component compressibility data describing expansion and contraction of wellbore components of the drilling system, the wellbore components including riser, casing, drill pipe, and cement components; and

analyzing earth formation compressibility data describing expansion and contraction of earth formations surrounding the wellbore to include subsurface stratae and pore fluids residing within the stratae surrounding the wellbore at each of the plurality of locations of interest.

20. Program product as defined in claim 17, wherein the operations further comprise:

measuring expansion and compressibility of the fluid circulating portions of the drilling system and compressibility of a surrounding earth formation at each of the plurality of areas of interest to formulate a description of a physical behavior of the drilling system components;

performing a cased hole pressure test to determine a volume associated with expansion of pressurized fluid circulating portions of the drilling system during drilling operations; and

performing an integrity and fracture pressure test to determine integrity of cement sealing a casing string to the wellbore and fracture pressure of an adjacent earth formation to thereby determine a dynamic maximum pressure that can exist at a lower end of the casing string without fracturing the associated earth formation or bonding of the cement.

21. Program product as defined in claim 17,

wherein the operation of determining a change in fluid volume for the fluid circulating portions of the drilling system includes determining the change in fluid volume within the entire drilling system;

and

wherein the operations further comprise providing data to one or more drilling system components to perform the operation of;

increasing downhole pressure at the respective location of interest when the difference between the volume of fluid pumped into the drilling system and the volume of fluid returned is attributed to fluid kick.

22. Program product as defined in claim 21, wherein the operation of increasing downhole pressure when the difference between the volume of fluid pumped into the drilling system and the volume of fluid returned is attributed to fluid kick comprises:

increasing injection pump pressure.

23. Program product as defined in claim 17, wherein the operation of providing data to control drilling system downhole pressure comprises providing data to one or more drilling system components to perform the operations of:

maintaining drilling system annulus pressure when the difference between the volume of fluid pumped into the fluid circulating portions of the drilling system and the volume of fluid returned is attributed breathing and ballooning; and

increasing annulus pressure when the difference between the volume of fluid pumped into the fluid circulating portions of the drilling system and the volume of fluid returned is attributed to fluid kick, the operation of increasing annulus pressure including applying fluid to a drilling system annulus fluid outlet.

24. Program product as defined in claim 17, wherein the drilling system includes casing string cement, and wherein the operations further comprise:

employing a plurality of operational simulators;

determining an effect of mud channels in the casing string cement responsive to at least one of the operational simulators; and

determining a maximum dynamic bottom hole pressure at a plurality of future depths to be drilled.

25. Program product as defined in claim 17, wherein the operation of determining a change in fluid volume for the fluid circulating portions of the drilling system is performed at a first time instance, and wherein the operations further comprise:

determining a change in fluid volume for the fluid circulating portions of the drilling system at a second time instance, the change in fluid volume attributable to at least one of the following;

lost circulation due to formation fracture and drilling system component breathing and ballooning;

differentiating between lost circulation due to formation fracture and drilling system component breathing and ballooning when performing drilling operations responsive to the respective pressure volume and pressure volume time curves and earth formation compressibility data at a respective one of the plurality of locations of interest and at each longitudinally prior one of the plurality of locations of interest; and

decreasing downhole pressure at the respective location of interest when the difference between the volume of fluid pumped into the drilling system and the volume of fluid returned is attributed to formation fracture.

26. Program product as defined in claim 17, wherein the operation of determining a change in fluid volume for the fluid circulating portions of the drilling system is performed at a first time instance, and wherein the operations further comprise:

determining a change in fluid volume for the fluid circulating portions of the drilling system at a second time instance, the change in fluid volume attributable to at least one of the following;

formation leak-off and drilling system component breathing and ballooning;

differentiating between formation leak-off and drilling system component breathing and ballooning when performing drilling operations responsive to the respective pressure volume and pressure volume time curves and earth formation compressibility data at a respective one of the plurality of locations of interest and at each longitudinally prior one of the plurality of locations of interest; and

maintaining downhole pressure at the respective location of interest when the difference between the volume of fluid pumped into the drilling system and the volume of fluid returned is attributed to formation leak-off.

27. A system for controlling drilling fluid pressures, the system comprising:

a dynamic density control computer including a processor and memory associated with the processor; and

dynamic density control program product stored in the memory of the dynamic density control computer and including instructions that when executed by the processor of the dynamic density control computer, cause the computer to perform the operations of;

for each of a plurality of longitudinally separated locations of interest within a drilling system extending within a wellbore;

forming pressure volume and pressure volume time curves for the respective longitudinally separated location of interest responsive to measured fluid pressure data and measured volume data,

determining a change in fluid volume for fluid circulating portions of the drilling system, the change in fluid volume attributable to at least one of the following;

fluid kick and drilling system component breathing and ballooning,

differentiating between fluid kick and drilling system component breathing and ballooning when performing drilling operations responsive to the respective pressure volume and pressure volume time curves and earth formation compressibility data at a respective one of the plurality of locations of interest and at each longitudinally prior one of the plurality of locations of interest, and

responsive to the operation of differentiating, providing data to control drilling system downhole pressure realtime when performing the drilling operations.

28. A system as defined in claim 27, wherein the operation of forming pressure volume and pressure volume time curves includes:

filling the fluid circulating portions of the drilling system including at least one casing string being tested with drilling fluid;

sealing each drilling system fluid supply inlet and outlet;

applying pressure to the fluid by pumping additional fluid into the fluid circulating portions of the drilling system by a pressure pump to thereby compress the drilling fluid, radially expand wellbore components of the drilling system, and compress an earth formation surrounding the wellbore adjacent the respective location of interest;

measuring fluid volume of the additional fluid pumped into the fluid circulating portions of the drilling system, the volume measured in real time at each of a plurality of instances during both pressure induced expansion of wellbore components and adjacent earth formations surrounding the wellbore at the respective location of interest;

measuring fluid volume of fluid returned during contraction of the wellbore components and the adjacent earth formations surrounding the wellbore at the respective location of interest; and

measuring fluid pressure at the respective longitudinally separated location of interest within the drilling system, the pressure measured in real time at each of the plurality of instances during both pressure induced expansion and contraction of the wellbore components and the adjacent earth formations surrounding the wellbore at the respective location of interest.

29. A system as defined in claim 27, wherein the operations further comprise:

analyzing drilling component compressibility data describing expansion and contraction of wellbore components of the drilling system, the wellbore components including riser, casing, drill pipe, and cement components; and

analyzing earth formation compressibility data describing expansion and contraction of earth formations surrounding the wellbore to include subsurface stratae and pore fluids residing within the stratae surrounding the wellbore at each of the plurality of locations of interest.

30. A system as defined in claim 27, wherein the operations further comprise:

measuring expansion and compressibility of the fluid circulating portions of the drilling system and compressibility of a surrounding earth formation at each of the plurality of areas of interest to formulate a description of a physical behavior of the drilling system components;

performing a cased hole pressure test to determine a volume associated with expansion of pressurized fluid circulating portions of the drilling system during drilling operations; and

performing an integrity and fracture pressure test to determine integrity of cement sealing a casing string to the wellbore and fracture pressure of an adjacent earth formation to thereby determine a dynamic maximum pressure that can exist at a lower end of the casing string without fracturing the associated earth formation or bonding of the cement.

31. A system as defined in claim 27,

wherein the operation of determining a change in fluid volume for the fluid circulating portions of the drilling system includes determining the change in fluid volume within the entire drilling system;

and

wherein the operations further comprise providing data to one or more drilling system components to perform the operation of;

increasing downhole pressure at the respective location of interest when the difference between the volume of fluid pumped into the drilling system and the volume of fluid returned is attributed to fluid kick.

32. A system as defined in claim 31, wherein the operation of increasing downhole pressure when the difference between the volume of fluid pumped into the drilling system and the volume of fluid returned is attributed to fluid kick comprises:

increasing injection pump pressure.

33. A system as defined in claim 27, wherein the operation of providing data to control drilling system downhole pressure comprises providing data to one or more drilling system components to perform the operations of:

maintaining drilling system annulus pressure when the difference between the volume of fluid pumped into the fluid circulating portions of the drilling system and the volume of fluid returned is attributed breathing and ballooning; and

increasing annulus pressure when the difference between the volume of fluid pumped into the fluid circulating portions of the drilling system and the volume of fluid returned is attributed to fluid kick, the operation of increasing annulus pressure including applying fluid to a drilling system annulus fluid outlet.

34. A system as defined in claim 27, wherein the drilling system includes casing string cement, and wherein the operations further comprise:

employing a plurality of operational simulators;

determining an effect of mud channels in the casing string cement responsive to at least one of the operational simulators; and

determining a maximum dynamic bottom hole pressure at a plurality of future depths to be drilled.

35. A system as defined in claim 27, wherein the operation of determining a change in fluid volume for the fluid circulating portions of the drilling system is performed at a first time instance, and wherein the operations further comprise:

determining a change in fluid volume for the fluid circulating portions of the drilling system at a second time instance, the change in fluid volume attributable to at least one of the following;

lost circulation due to formation fracture and drilling system component breathing and ballooning;

differentiating between lost circulation due to formation fracture and drilling system component breathing and ballooning when performing drilling operations responsive to the respective pressure volume and pressure volume time curves and earth formation compressibility data at a respective one of the plurality of locations of interest and at each longitudinally prior one of the plurality of locations of interest; and

decreasing downhole pressure at the respective location of interest when the difference between the volume of fluid pumped into the drilling system and the volume of fluid returned is attributed to formation fracture.

36. A system as defined in claim 27, wherein the operation of determining a change in fluid volume for the fluid circulating portions of the drilling system is performed at a first time instance, and wherein the operations further comprise:

determining a change in fluid volume for the fluid circulating portions of the drilling system at a second time instance, the change in fluid volume attributable to at least one of the following;

formation leak-off and drilling system component breathing and ballooning;

differentiating between formation leak-off and drilling system component breathing and ballooning when performing drilling operations responsive to the respective pressure volume and pressure volume time curves and earth formation compressibility data at a respective one of the plurality of locations of interest and at each longitudinally prior one of the plurality of locations of interest; and

maintaining downhole pressure at the respective location of interest when the difference between the volume of fluid pumped into the drilling system and the volume of fluid returned is attributed to formation leak-off.