Indirect hydraulic fracturing method and system

Abstract

A method and system for indirectly fracturing one or a series of two or more wellbore intervals wherein (i) one or more sections of the interacting zone of each indirectly fractured wellbore interval will preferably be isolated by positioning isolation devices therein, (ii) each indirectly fractured wellbore interval will preferably be isolated from the wellhead assembly associated with the wellbore interval, and/or (iii) a directly fractured interval and an indirectly fractured interval can be different portions of the same well, such as a horseshoe well, a deviated or horizontal well, or other well.

What is claimed is: 
     
         1 . A method of indirect hydraulic fracturing comprising steps of:
 a) providing at least a first wellbore interval and a second wellbore interval, different from the first wellbore interval, in a subterranean formation, wherein
 the first wellbore interval has a casing or liner therein and one or more clusters of openings are provided through the casing or liner and 
 the second wellbore interval is positioned and oriented with respect to the first wellbore interval so that hydraulic fractures initiated through at least some of the openings of the one or more clusters of openings of the first wellbore interval will propagate toward and will at least reach the second wellbore interval, the hydraulic fractures which reach the second wellbore interval being interacting hydraulic fractures; 
   b) isolating one or more longitudinal sections of a predicted interaction zone of the second wellbore interval in which it is predicted that the interacting hydraulic fractures initiated from the first wellbore interval will interact with the second wellbore interval, the one or more longitudinal sections being isolated by positioning a series of two or more isolation devices in the second wellbore interval; and   c) pumping a fracturing fluid into the first wellbore interval to produce the interacting hydraulic fractures and propagate the interacting hydraulic fractures at least as far as the second wellbore interval.   
     
     
         2 . The method of  claim 1  further comprising:
 the first wellbore interval being a wellbore interval of a first well and 
 the second wellbore interval being a wellbore interval of a second well which is different from the first well. 
 
     
     
         3 . The method of  claim 2  further comprising:
 the first wellbore interval being at least a portion of a lateral wellbore of the first well and 
 the second wellbore interval being at least a portion of a lateral wellbore of the second well. 
 
     
     
         4 . The method of  claim 1  further comprising a single well which includes both the first wellbore interval and the second wellbore interval. 
     
     
         5 . The method of  claim 4  further comprising:
 the first wellbore interval being at least a portion of a first lateral of the single well and 
 the second wellbore interval being at least a portion of a second lateral of the single well different from the first lateral. 
 
     
     
         6 . The method of  claim 5  further comprising the first wellbore interval and the second wellbore interval being located in opposite laterals of a horseshoe well. 
     
     
         7 . The method of  claim 6  further comprising the first wellbore interval and the second wellbore interval being positioned together in a plain of symmetry. 
     
     
         8 . The method of  claim 1  further comprising:
 the second wellbore interval being a wellbore interval of a well; 
 the well having a wellhead for production from the well; and 
 at least one of the isolation devices positioned in the second wellbore interval in step (b) being positioned in the well between (i) the predicted interaction zone of the second wellbore interval and (ii) the wellhead to prevent the fracturing fluid pumped into the first wellbore interval in step (c) from flowing from the second wellbore interval to the wellhead. 
 
     
     
         9 . The method of  claim 1  further comprising:
 the one or more clusters of openings provided through the casing or liner of the first wellbore interval being a longitudinal series of two or more of the clusters of openings; 
 there being a cluster spacing distance between each adjacent pair of the clusters of openings in the longitudinal series of two or more clusters of openings in the first wellbore interval; 
 at least one said cluster spacing distance between an adjacent pair of the clusters of openings being a maximum cluster spacing distance; 
 the series of two or more isolation devices positioned in the second wellbore interval in step (b) being a series of at least three of the isolation devices; and 
 no adjacent ones of the isolation devices in the series of at least three of the isolation devices being spaced a distance apart which is more than the maximum cluster spacing distance. 
 
     
     
         10 . The method of  claim 9  further comprising the isolation devices being hard plugs. 
     
     
         11 . The method of  claim 1  further comprising:
 the second wellbore interval being an open wellbore interval with no casing or liner therein or 
 the second wellbore interval having a casing or liner therein with perforations, slots, or other openings provided through a wall of the casing or liner. 
 
     
     
         12 . The method of  claim 1  further comprising:
 the second wellbore interval having a liner therein; 
 the liner of the second wellbore interval having one or more sections of slots or other openings provide through a wall of the liner of the second wellbore interval; 
 positioning a first swell-packer (i) between an exterior of the liner of the second wellbore interval and a borehole wall of the second wellbore interval and (ii) at or beyond a first longitudinal end of the one or more sections of slots or other openings provided through the wall of the liner of the second wellbore interval; and 
 positioning a second swell-packer (i) between the exterior of the liner of the second wellbore interval and the borehole wall of the second wellbore interval and (ii) at or beyond a second longitudinal end, opposite the first longitudinal end, of the one or more sections of slots or other openings provided through the wall of the liner of the second wellbore interval. 
 
     
     
         13 . The method of  claim 1  further comprising the fracturing fluid including a proppant material during at least a portion of step (c). 
     
     
         14 . The method of  claim 1  further comprising pumping an amount of the fracturing fluid into the first wellbore interval in step (c) sufficient to propagate hydraulic fractures from and beyond the second wellbore interval. 
     
     
         15 . The method of  claim 14  further comprising the fracturing fluid including a proppant material during at least a portion of step (c). 
     
     
         16 . The method of  claim 14  further comprising:
 providing a proppant material in one or more of the one or more longitudinal sections of the second wellbore interval which are isolated in step (b) and 
 the proppant material provided in the one or more sections of the second wellbore being carried by the fracturing fluid into the hydraulic fractures which are propagated from and beyond the second wellbore interval. 
 
     
     
         17 . The method of  claim 14  further comprising;
 providing a third wellbore interval, different from the first wellbore interval and the second wellbore interval, in the subterranean formation and the third wellbore interval being positioned and oriented with respect to the second wellbore interval so that at least some of the hydraulic fractures propagated from and beyond the second wellbore interval propagate toward and at least reach the third wellbore interval, the hydraulic fractures which reach the third wellbore interval being secondary interacting hydraulic fractures. 
 
     
     
         18 . The method of  claim 17  further comprising, prior to the propagation of hydraulic fractures from and beyond the second wellbore interval, isolating one or more longitudinal sections of a predicted interaction zone of the third wellbore interval in which it is predicted that the secondary interacting hydraulic fractures from the second wellbore interval will interact with the third wellbore interval, the one or more longitudinal sections of the predicted interaction zone of the third wellbore interval being isolated by positioning a series of two or more isolation devices in the third wellbore interval. 
     
     
         19 . The method of  claim 18  further comprising:
 the third wellbore interval being a wellbore interval of a well; 
 the well having a wellhead for production from the well; and 
 at least one of the isolation devices positioned in the third wellbore interval being positioned in the well between the predicted interaction zone of the third wellbore interval and the wellhead to prevent the fracturing fluid pumped into the first wellbore interval in step (c) from flowing from the third wellbore interval to the wellhead. 
 
     
     
         20 . The method of  claim 17  further comprising the amount of the fracturing fluid pumped into the first wellbore interval in step (c) also being sufficient to propagate hydraulic fractures from and beyond the third wellbore interval.