Methods for creating multiple hydraulic fractures in oil and gas wells

Patent metadata

Field	Value
Publication number	US-10422207-B2
Application number	US-201715451269-A
Country	US
Kind code	B2
Filing date	Mar 6, 2017
Priority date	Mar 7, 2016
Publication date	Sep 24, 2019
Grant date	Sep 24, 2019

Abstract

Transverse fractures are formed from a borehole using hydraulic fracturing fluid while maintaining the downhole pressure close to a target pressure. The target pressure is selected to be greater than the expected transverse fracture initiation pressure at predetermined weak points, such as notches, and less than the expected longitudinal fracture initiation pressure. The process can be repeated to form multiple transverse fractures by pumping diversion composition(s).

First claim

What is claimed is:

1. A method of creating transverse hydraulic fractures in an earth formation surrounding a wellbore, the method comprising:
selecting a target downhole pressure level that is greater than an initiation pressure for a transverse fracture in the earth formation and less than an initiation pressure for a longitudinal fracture in the earth formation;
injecting a fracturing fluid into the wellbore;
monitoring at least one parameter related to downhole pressure; and
controlling the fluid injection based on the monitored parameter in order to maintain a downhole pressure that is within a predetermined range of the selected target downhole pressure, to facilitate initiation of one or more transverse fractures without initiation of longitudinal fractures in the earth formation.

2. The method according to claim 1 , further comprising:
forming one or more weak points along the wellbore configured to facilitate initiation of the one or more transverse fractures therefrom.

3. The method according to claim 2 , wherein the wellbore is open hole where the one or more transverse fractures are initiated, and the one or more weak points are perforations or notches and are formed using one or more techniques selected from a group consisting of: mechanical scribing, high pressure jetting, cutting with laser tools, and arranging of shaped charges.

4. The method according to claim 2 , wherein the wellbore includes a casing where the one or more transverse fractures are initiated and the weak points are in the form of one or more perforations in the casing.

5. The method according to claim 1 , wherein the at least one monitored parameter is pressure measured using a downhole pressure sensor.

6. The method according to claim 5 , wherein said controlling the fluid injection comprises controlling one or more surface pumps and the measurements from the downhole pressure sensor provide real time feedback to effect closed-loop control of said surface pumps.

7. The method according to claim 6 , wherein said closed loop control is further based in part on pre-job analysis of fracture initiation, fracture opening and fracture orientation with respect to the near wellbore and far-field stresses.

8. The method according to claim 1 , further comprising:
identifying fracture initiation based at least in part on detecting an increase in fluid injection rate.

9. The method according to claim 1 , wherein the initiation pressures for transverse and longitudinal fractures are known from one or more selected from a group consisting of: laboratory studies; information from previous jobs; and theoretical estimates.

10. The method according to claim 1 , wherein the at least one monitored parameter is a surface measurement indicative of downhole pressure.

11. The method according to 10 , wherein said surface measurement is a surface pressure measurement that is related to downhole pressure at least in part by estimating frictional losses.

12. The method according to claim 1 , wherein the at least one parameter is acoustic signals measured using a fiber optic cable and the injected fluid comprises collapsible elements configured to generate an acoustic signature when they collapse under a predetermined pressure.

13. The method according to claim 1 , wherein multiple transverse fractures are sequentially initiated.

14. The method according to claim 13 , further comprising:
injecting a composition configured to temporarily plug one or more fractures such that further transverse fractures may be initiated.

15. The method according to claim 1 further comprising:
in a first phase, injecting the fracturing fluid into the wellbore at a constant flow rate; and
after the downhole pressure is within the predetermined range of the target downhole pressure, in a second phase, injecting the fracturing fluid into the wellbore so as to maintain the downhole pressure within the predetermined range of the target downhole pressure.

16. The method according to claim 15 , wherein at least one of the one or more transverse fractures is initiated during the first phase.

17. The method according to claim 1 , wherein the wellbore where the one or more transverse fractures are initiated is horizontal or nearly horizontal and is formed along a minimal horizontal far-field stress of the earth formation.

Assignees

• Schlumberger Technology Corp

Inventors

• Aidagulov Gallyam
• Brady Dominic Joseph
• Edelman Eric

Classifications

• E21B7/04

  Directional drilling · CPC title

• E21B43/25

  Methods for stimulating production {(by vibrating earth formations E21B43/003)} · CPC title

• E21B43/00

  Methods or apparatus for obtaining oil, gas, water, soluble or meltable materials or a slurry of minerals from wells (applicable only to water E03B) · CPC title

• E21B49/006

  Measuring wall stresses in the borehole · CPC title

• E21B43/255

  including the injection of a gaseous medium as treatment fluid into the formation · CPC title