Method of fracturing multiple zones within a well using propellant pre-fracturing

Patent metadata

Field	Value
Publication number	US-9915137-B2
Application number	US-201514708822-A
Country	US
Kind code	B2
Filing date	May 11, 2015
Priority date	Aug 5, 2011
Publication date	Mar 13, 2018
Grant date	Mar 13, 2018

Abstract

A method of fracturing multiple zones within a wellbore formed in a subterranean formation is carried out by forming flow-through passages in two or more zones within the wellbore that are spaced apart from each other along the wellbore. The flow-through passages are arranged into clusters, where the directions of all flow-through passages, which belong to the same cluster, are aligned within a single plane (cluster plane). At least one cluster of flow-through passages is formed in each zone. The clusters within each zone have characteristics different from those of other zones provided by orienting the cluster planes at different angles relative to principal in-situ stresses and by placing them into different locations along the wellbore in each of the two or more zones. A propellant pre-fracturing treatment is then performed in the two or more zones to create initial fractures (pre-fractures) in each of the two or more zones. The fracturing fluid in the fracturing treatment is provided at a pressure that is above the pre-fracture propagation pressure of one of the two or more zones to facilitate fracturing of said one of the two or more zones. The pressure of the fracturing fluid is below the pre-fracture propagation pressure of any other non-treated zones of the two or more zones. The isolating of the treated zone is then performed. The fracturing process is then repeated for at least one or more non-treated zones of the two or more zones.

First claim

We claim:

1. A method of fracturing a zone within a subterranean formation traversed by a wellbore, comprising:
(a) forming a flow-through passage in two or more zones wherein the flow-through passage is aligned within a single plane, and wherein stresses perpendicular to the planes are different for each of the two or more zones;
(b) generating a pressure pulse to form pre-fractures in each of the two or more zones;
(c) introducing a fracturing fluid into the wellbore in a fracturing treatment;
wherein a pressure of the fracturing fluid in the fracturing treatment forms a fracture and wherein the pressure is above that of the pre-fracture propagation pressure of a pre-fracture within non-treated zones and the pressure of fracturing fluid is lower than the pressure of fracture propagation resumption in all treated zones;
(d) isolating all the fractures within the zone being treated if there is at least one non-treated zone;
(e) repeating (c) and (d) for each pre-fracture within non-treated zones.

2. The method of claim 1 , wherein the fracturing fluid contains a proppant.

3. The method of claim 2 , wherein the concentration of proppant in the fracturing fluid is increased towards the end the fracturing treatment performed in (c) for at least one of the two or more zones.

4. The method of claim 1 , wherein isolation is realized as an incremental pressure buildup (a stress cage) provided by fracture closure on a proppant placed inside the fracture, during the fracturing treatment, the pressure buildup on the proppant occurring during subsequent interruption of pumping or reduction of pumping rate.

5. The method of claim 1 , wherein isolating is achieved by the use of mechanical tools, ball sealers, packers, bridge plugs, flow-through bridge plugs, sand plugs, fibers, particulate material, viscous fluid, foams, or combinations of these.

6. The method of claim 1 , wherein a degradable material is used for isolating the fractured zone.

7. The method of claim 1 , wherein a single plane is parallel to a wellbore axis direction in the area of perforation cluster location.

8. The method of claim 7 , wherein the flow-through passages are formed using 0° of 180° phasing with a-density of 4 shots per foot or more.

9. The method of claim 1 , wherein the single plane is directed at an angle between 0° and 90° relative to a wellbore axis direction in the area of perforation cluster location.

10. The method of claim 9 , wherein the flow-through passages are formed using phasing with the angle more than 0° and less than 30°.

11. The method of claim 1 , wherein the flow-through passages are formed by at least one of a perforating gun, by jetting or by forming holes in a casing of the wellbore.

12. The method of claim 1 , wherein the two or more zones are located in a portion of the wellbore that is substantially vertical.

13. The method of claim 1 , wherein the two or more zones are located in a portion of the wellbore that is curved.

14. The method of claim 1 , wherein the two or more zones are located in a portion of the wellbore that is deviated from vertical.

15. The method of claim 1 , wherein the two or more zones are located in a portion of the wellbore that is substantially horizontal.

16. The method of claim 1 , wherein the stress that acts perpendicular to a cluster plane is different by 100 psi or more from the stress that acts perpendicular to cluster of flow-through passages of any other of the two or more zones.

17. The method of claim 16 , wherein the difference of stresses that act perpendicular to cluster planes is provided by orienting the planes of clusters at different angles relative to a selected direction.

18. The method of claim 17 , wherein the selected direction is a direction of maximum principal stress of the formation surrounding the wellbore.

19. The method of claim 1 , wherein the stress that acts perpendicular to cluster planes within the fractured zone of (e) is less than the stress that acts perpendicular to the planes of clusters of any other non-fractured zones of the two or more zones.

20. The method of claim 1 , wherein the zone fractured according to (c) is located towards a toe position of the wellbore and the zone fractured according to (d) is located towards a hell position of the wellbore.

Assignees

• Schlumberger Technology Corp

Inventors

• Alekseenko Olga Petrovna
• Zazovsky Alexander F
• Potapenko Dmitriy Ivanovich
• Fredd Christopher N

Classifications

• E21B43/267

  reinforcing fractures by propping · CPC title

• E21B33/124

  Units with longitudinally-spaced plugs for isolating the intermediate space · CPC title

• E21B43/14

  Obtaining from a multiple-zone well · CPC title

• E21B43/116

  Gun or shaped-charge perforators · CPC title

• E21B43/26 Primary

  by forming crevices or fractures · CPC title