Creation of multi-azimuth permeable hydraulic fractures

• US 4,834,181 A
• Filed: 12/29/1987
• Issued: 05/30/1989
• Est. Priority Date: 12/29/1987
• Status: Expired due to Term

• Current Assignee: Mobil Oil Corporation (Exxon Mobil Corporation)
• Original Assignee: Mobil Oil Corporation (Exxon Mobil Corporation)
• Inventors: Uhri, Duane C., Jennings, Alfred R. Jr.
• Primary Examiner(s): Neuder, William P.
• Application Number:
  US07/139,216
• Time in Patent Office: 518 Days
• Field of Search: 166/281, 166/308
• US Class Current: 166/281
• CPC Class Codes: E21B 43/26 by forming crevices or fractures
• CPC Class Codes: E21B 43/261 Separate steps of (1) cementing, plugging or consolidating and (2) fracturing or attacking the formation

Abstract

A process for creating multi-azimuth fractures by hydraulically fracturing a formation via a single wellbore where a special polymer is used as the fracturing fluid. An induced fracture is formed and a solidifiable gel material is injected into the fracture which is allowed to solidify. Thereafter, hydraulic fracturing with the special polymer is repeated causing the fracture trajectory to form contrary to the far-field in-situ stresses.

Claims

1. A process for creating multi-azimuth fractures via hydraulic fracturing in a subterranean formation containing at least one wellbore comprising:

(a) applying a hydraulic fracturing pressure into the formation through a liquid in said wellbore which pressure is sufficient to fracture said formation thereby forming at least one vertical fracture;

(b) releasing said pressure and directing into said wellbore a solidifiable gel material sufficient to form a temporary plug within a desired time and distance within said formation;

(c) allowing said solidifiable gel material to form a plug within said vertically created fracture; and

(d) applying thereafter into said formation through a liquid in said wellbore a pressure sufficient to propagate at least one dendritic fracture from the existing vertical fracture because of the temporary plug in said fracture which dendritic fracture intersects a natural fracture system.

2. The process as recited in claim 1 where in step (b) said plugging material comprises a solidifiable gel material which gel material breaks within about 0.5 to 24 hours.

3. The process as recited in claim 1 where steps (b), (c) and (d) are repeated until multi-azimuth fractures are created in said formation.

4. The process as recited in claim 1 where said formation contains a subterranean resource such as iron, copper ore, uranium ore, geothermal heat, coal, oil shale, or hydrocarbonaceous fluids.