MULTI-STAGE FRACTURE INJECTION PROCESS FOR ENHANCED RESOURCE PRODUCTION FROM SHALES
First Claim
1. A method of generating an enhanced fracture network in a rock formation, said formation characterized by a network of native fractures and incipient fractures and a minimum hydraulic fracture initiation pressure and rate, said method comprising the sequential stages of:
- i) injecting a non-slurry aqueous solution into a well extending into the formation at a rate and pressure which is slightly above the minimum hydraulic fracture initiation pressure and rate of said formation and under conditions suitable for promoting increased pore pressure, shearing, dilation and hydraulic communication of the native fractures and incipient fractures, wherein said stage i generates an outer zone essentially comprising self-propping fractures forming high permeability paths connecting to the injection well, and wherein said stage i is performed until the maximum possible stimulated volume of the formation has been substantially attained as determined by formation response measurement data;
ii) injecting a first slurry comprising relatively fine grains of proppant into said formation to prop fractures generated in said stage i within an intermediate zone located within and surrounded by the outer zone generated in stage i; and
iii) injecting a second slurry comprising relatively coarse grains of proppant into said formation to generate large fractures within an inner zone surrounded by and within the intermediate zone, in communication with the fractures generated in said stages i and ii.
0 Assignments
0 Petitions
Accused Products
Abstract
The invention relates to a method of generating an enhanced fracture network in a rock formation by the sequential stages of: i) injecting a non-slurry aqueous solution into a well extending into the formation at a rate and pressure which is close to the minimum hydraulic fracture initiation pressure and rate of the formation, until the maximum possible stimulated volume of the formation has been substantially attained to generate an outer zone of self-propping fractures; ii) injecting a first slurry of relatively fine grains of proppant to prop fractures generated in stage i within an intermediate zone located within and surrounded by the outer zone generated in stage i; and iii) injecting a second slurry comprising relatively coarse grains of to generate large fractures within an inner zone surrounded by and within the intermediate zone, in communication with the fractures generated in stages i and ii.
48 Citations
46 Claims
-
1. A method of generating an enhanced fracture network in a rock formation, said formation characterized by a network of native fractures and incipient fractures and a minimum hydraulic fracture initiation pressure and rate, said method comprising the sequential stages of:
-
i) injecting a non-slurry aqueous solution into a well extending into the formation at a rate and pressure which is slightly above the minimum hydraulic fracture initiation pressure and rate of said formation and under conditions suitable for promoting increased pore pressure, shearing, dilation and hydraulic communication of the native fractures and incipient fractures, wherein said stage i generates an outer zone essentially comprising self-propping fractures forming high permeability paths connecting to the injection well, and wherein said stage i is performed until the maximum possible stimulated volume of the formation has been substantially attained as determined by formation response measurement data; ii) injecting a first slurry comprising relatively fine grains of proppant into said formation to prop fractures generated in said stage i within an intermediate zone located within and surrounded by the outer zone generated in stage i; and iii) injecting a second slurry comprising relatively coarse grains of proppant into said formation to generate large fractures within an inner zone surrounded by and within the intermediate zone, in communication with the fractures generated in said stages i and ii. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23)
-
-
24. A method of generating an enhanced fracture network in a rock formation, said formation characterized by a network of native fractures and incipient fractures and a minimum hydraulic fracture initiation pressure and rate, said method comprising the sequential stages of:
-
i) injecting a non-slurry aqueous solution into a well extending into the formation at a rate and pressure which is slightly below or at the minimum hydraulic fracture initiation pressure and rate of said formation and under conditions suitable for promoting increased pore pressure, shearing, dilation and hydraulic communication of the native fractures and incipient fractures, wherein said stage i generates an outer zone essentially comprising self-propping fractures forming high permeability paths connecting to the injection well, and wherein said stage i is performed until the maximum possible stimulated volume of the formation has been substantially attained as determined by formation response measurement data; ii) injecting a first slurry comprising relatively fine grains of proppant into said formation to prop fractures generated in said stage i within an intermediate zone located within and surrounded by the outer zone as generated in stage i; and iii) injecting a second slurry comprising relatively coarse grains of proppant into said formation to generate large fractures within an inner zone surrounded by and within the intermediate zone, in communication with the fractures generated in said stages i and ii. - View Dependent Claims (25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46)
-
Specification