TESTING WHILE FRACTURING WHILE DRILLING

• US 20140238668A1
• Filed: 10/08/2012
• Published: 08/28/2014
• Est. Priority Date: 10/06/2011
• Status: Active Grant

• Current Assignee: Schlumberger Technology Corporation (SLB)
• Original Assignee: Schlumberger Technology Corporation (SLB)
• Inventors: Bittleston, Simon, Johnson, Ashley Bernard
• Granted Patent: US 9,677,337 B2
• Time in Patent Office: Days
• US Class Current: 166/250.01
• CPC Class Codes: E21B 21/085 Underbalanced techniques, i.e. where borehole fluid pressure is below formation pressure
• CPC Class Codes: E21B 43/26 by forming crevices or fractures
• CPC Class Codes: E21B 49/08 Obtaining fluid samples or testing fluids, in boreholes or wells
• CPC Class Codes: E21B 49/087 Well testing, e.g. testing for reservoir productivity or formation parameters
• CPC Class Codes: E21B 49/0875 determining specific fluid parameters
• CPC Class Codes: E21B 7/00 Special methods or apparatus for drilling

Abstract

A drilling procedure is operated such that a formation around the wellbore being drilled is fractured and then reservoir fluids from a hydrocarbon reservoir contained in the formation are flowed into the wellbore where the flow of the reservoir fluids is tested. Production predictions for the wellbore are processed from the measurements made on the flow of reservoir fluids and decisions regarding further drilling operations are made based upon the reservoir fluid measurements. By testing reservoir fluids prior to completing the wellbore, drilling operations such as, for example, continuing to drill the wellbore may be made without tripping the drillstring from the wellbore.

Claims

1. A method for performing a drilling procedure to drill a wellbore into a subterranean formation to produce hydrocarbons from a hydrocarbon reservoir therein, comprising:

using a drilling system comprising a drillstring and a drill bit to drill the wellbore into the subterranean formation, wherein the drilling procedure comprises circulating drilling fluids through the wellbore, down the drillstring and up through a drilling annulus;

fracturing a section of the subterranean formation at a location along the wellbore;

flowing formation fluids from the subterranean formation into the wellbore at the location prior to completing the wellbore; and

measuring properties of the flow of formation fluids into the wellbore.

2. The method according to claim 1, wherein at least one of the steps of fracturing the section of the fracturing the section of the subterranean formation and flowing formation fluids into the wellbore are performed with the drillstring in the wellbore.

3. The method according to claim 2, further comprising:

making a drilling decision based upon the measured properties of the flow of the formation fluids into the wellbore, wherein the drilling comprises at least one of continuing drilling the wellbore, completing the wellbore, determining where to induce a further fracture in the subterranean formation and determining a direction in which to continue drilling the wellbore.

4. The method according to claim 1, wherein the measured properties are used to process a production model for the wellbore prior to completing the wellbore.

5. The method according to claim 1, wherein the measured properties of the formation fluids comprise at least one of a flow rate of the formation fluids into the wellbore, a composition of the reservoir fluids, a phase of the reservoir fluids, a phase fraction of the reservoir fluids, a gas cut of the reservoir fluids, a water cut of the reservoir fluids, an oil cut of the reservoir fluids, a conductivity or resistivity of the reservoir fluids, a temperature of the reservoir fluids, a pressure of the reservoir fluids, density of the reservoir fluids, a viscosity of the reservoir fluids and a volume flow rate of the reservoir fluids.

6. The method according to claim 1, wherein the properties of the formation fluids are measured by one or more sensors disposed on the drillstring.

7. The method according to claim 1, wherein the step of fracturing the section of the subterranean formation comprises pumping a high density drilling fluid into the wellbore to increase the bottom hole pressure.

8. The method according to claim 1, wherein the step of flowing formation fluids into the wellbore comprises pumping a low density drilling fluid into the wellbore to decrease the bottom hole pressure below a pressure of the subterranean formation.

9. The method according to claim 1, wherein the step of fracturing the section of the subterranean formation comprises using a choke to choke a flow of the drilling fluid out of the drilling annulus and increase the bottom hole pressure.

10. The method according to claim 1, wherein the step of flowing formation fluids into the wellbore comprises adjusting a choke to reduce an amount of choke applied to a flow of the drilling fluid out of the drilling annulus and increase the bottom hole pressure.

11. The method according to claim 1, wherein the drilling system comprises a managed pressure drilling system.

12. The method according to claim 11, wherein a gas is injected into the drilling fluid to decrease a bottom hole pressure below a pressure of the subterranean formation.

13. The method according to claim 1, further comprising:

continuing drilling of the wellbore after measuring the properties of the flow of formation fluids into the wellbore.

14. The method according to claim 1, wherein the properties of the flow of formation fluids into the wellbore are measured while the drilling fluid is being circulated through the wellbore.

15. The method according to claim 1, wherein the step of measuring properties of the flow of formation fluids into the wellbore comprises using sensors on the drill string to measure the properties of the flow of the formation fluids.

16. A method for performing a drilling procedure to drill a wellbore into a subterranean formation to produce hydrocarbons from a hydrocarbon reservoir therein, comprising:

using a drilling system comprising a drillstring and a drill bit to drill the wellbore into the subterranean formation, wherein the drilling procedure comprises circulating drilling fluids through the wellbore, down the drillstring into a bottom of the wellbore and up through a drilling annulus;

pumping a first drilling fluid into the wellbore;

pumping a second drilling fluid with a density higher than the first drilling fluid into the wellbore to increase a pressure at the bottom of the wellbore;

fracturing the subterranean formation;

pumping a third frilling fluid with a density lower than the second drilling fluid into the wellbore;

lowering the pressure at the bottom of the wellbore below a pressure of the subterranean formation; and

measuring properties of a flow of formation fluids flowing from the subterranean formation into the wellbore.

17. The method according to claim 16, wherein the third drilling fluid comprises the first drilling fluid.

18. The method according to claim 16, wherein the step of fracturing the subterranean formation comprises at least one of choking a flow of the second drilling fluid out of the wellbore and increasing a rate of pumping the second drilling fluid into the wellbore.

19. The method according to claim 16, further comprising:

pumping one a clean fluid and a fluid containing a proppant into the wellbore after the second drilling fluid is pumped into the wellbore.

20. The method according to claim 16, further comprising:

pumping a sealing fluid into the wellbore to seal factures in the subterranean formation.

21. The method according to claim 20, further comprising:

increasing the pressure at the bottom of the wellbore above the pressure of the subterranean formation and continuing drilling the wellbore.

22. The method according to claim 16, wherein the first, second and third drilling fluids are pumped through the wellbore as a fluid train.

23. The method according to claim 16, wherein at least one of the first, second and third drilling fluids are injected into the drilling annulus using coiled tubing.

24. The method according to claim 16, wherein the drillstring comprises wired drillstring and the measurements are communicated to a surface via the wired drillstring.