Inclusion propagation by casing expansion giving rise to formation dilation and extension

Abstract

The present invention is a method and apparatus for enhanced recovery of petroleum fluids from the subsurface by initiating and propagating vertical permeable inclusions in a plane substantially orthogonal to the borehole axis. These inclusions containing proppant are thus highly permeable and enhance drainage of heavy oil from the formation, and also by steam injection into these planes, enhance oil recovery by heating the oil sand formation, the heavy oil and bitumen, which will drain under gravity and be produced. Multiple propped vertical inclusions are constructed at various locations along a substantially horizontal wellbore by dilation of the formation in the plane of the intended inclusion by radial expansion and axial extension of the formation by an expanding packer system that expands both radially and axially. In another embodiment of the invention, the expansion device is part of a casing string or liner and is in contact with the formation by a swellable elastomer, or by a cement or polymer based grout. The expansion device is expanded by an inflatable packer and the device expands both radially outward and extensionally in the axial direction, giving rise to a dilated extensional plane in the formation which is substantially orthogonal to the well bore axis. Injected fluid propagates preferentially in this dilated and extensional plane within the formation.

1 . A method of forming at least one inclusion in a subterranean formation, the method comprising the steps of: installing an expansion control device in a wellbore with a well casing; expanding the device both radially outward and axially in extension in the wellbore, and inject fluid into the formation. 
     
     
         2 . The method of  claim 1 , wherein the expansion control device includes dual inflation packers placed in an open wellbore. 
     
     
         3 . The method of  claim 1 , wherein the expansion control device includes an expansion casing segment interconnected to the well casing, with the expansion casing segment in contact with the formation. 
     
     
         4 . The method of  claim 3 , wherein the expansion casing segment is in contact with the formation by placing an infill material between the casing segment and the formation before the expansion step. 
     
     
         5 . The method of  claim 4 , wherein the infill material is a swellable elastomer. 
     
     
         6 . The method of  claim 4 , wherein the infill material is a cement based grout. 
     
     
         7 . The method of  claim 4 , wherein the infill material is a polymer based grout. 
     
     
         8 . The method of  claim 3 , wherein the expansion casing segment is expanded by an inflatable packer. 
     
     
         9 . The method of  claim 3 , wherein the expansion step of the casing segment includes widening of at least one axially aligned opening in a sidewall of the casing section, and widening at least one circumferentially aligned opening in the sidewall of the casing section, displacing latch members in circumferential and axial directions respectively, the widening being a first direction; and preventing a narrowing of the openings after the expansion step, the latch members resisting displacement thereof in a second narrowing direction opposite to the first widening direction. 
     
     
         10 . (canceled) 
     
     
         11 . The method of  claim 9 , wherein the expansion step further comprises limiting a width of the axial and circumferential openings. 
     
     
         12 . The method of  claim 11 , wherein the width limiting step includes engaging a stop member with a shoulder, and further comprising the step of integrally forming the stop member and latch member. 
     
     
         13 . The method of  claim 11 , wherein the width limiting step includes yielding a strain hardening latch member. 
     
     
         14 . The method of  claim 9 , wherein the latch member is attached to the casing section on a first side of the opening, and wherein at least one shoulder is attached to the casing section on a second side of the opening opposite from the first side of the opening. 
     
     
         15 . The method of  claim 11 , wherein the resisting displacement step further comprises the latch member engaging the shoulder. 
     
     
         16 . The method of  claim 15 , wherein the shoulder is formed adjacent at least one aperture in the expansion control device for each opening, and wherein the-expansion step further comprises drawing the latch member through the aperture. 
     
     
         17 . The method of  claim 15 , wherein the shoulder is formed on an abutment structure of the expansion control device attached to the casing section. 
     
     
         18 . The method of  claim 17 , wherein the abutment structure includes multiple shoulders and apertures extending longitudinally along and circumferentially around the casing section. 
     
     
         19 . The method of  claim 18 , wherein the expansion control device includes multiple latch members configured for engagement with the multiple shoulders. 
     
     
         20 . The method of  claim 9 , wherein the expansion step further comprises forming the openings by parting the casing section sidewall along at least one axial and one circumferential slot formed in the sidewall, and wherein the slot extends only partially through the casing section sidewall. 
     
     
         21 . The method of  claim 9 , wherein the expansion step further comprises forming the openings by parting the casing section sidewall along at least one axial and one circumferential slot formed in the sidewall, and wherein the slot extends completely through the casing section sidewall. 
     
     
         22 . The method of  claim 21 , further comprising a separate strip of material extending across the slot, and wherein the expansion step further comprises parting the strip.