Single entry fracturing process

Abstract

A method is provided to provide fractures in a subterranean formation that utilizes set of first wire line controllable valves (108) to open communication between the inside of a casing (107) and an outside of a casing that has been cemented into a wellbore (101). A wire line controllable valve associated with each of the first valves isolates the inside of the casing downstream of the first valve. The two valves are operated by a wire line actuator. After each successive fracture is formed, the wire line actuator is moved past the next set of valve, changing their positions, and then the next fracture is formed. The valve isolating the downstream portions of the casing are either opened, milled out, or made of degradable material after the operation is complete to enable production from the formation through the fractures into the well bore.

1 . A method to provide a fractured subterranean formation comprising:
 providing a wellbore from a surface location to the subterranean formation and within the subterranean formation from a heal end to a toe end;   providing a casing within the wellbore wherein the casing comprises a plurality of first wire-line controllable valves effective to provide communication between an inside of the wellbore and an outside of the wellbore, and a plurality of second wire-line actuated valves, wherein each second wire-line actuated valve is associated with a first wire-line actuated valve, and each second wire-line activated valve is effective to isolate a portion of the inside of the wellbore upstream from the first valves from a portion of the inside of the wellbore down-stream of the first valve wherein initially all first wire-line controllable valves are closed, and all second wireline controllable valves are open;   providing a fracture from the wellbore near the toe end of the wellbore between the toe of the wellbore and the first wire-line controllable valve closest to the toe end of the wellbore;   opening the first wire-line controllable valve and closing the second wire-line controllable valve closest to the toe end of the wellbore;   providing a fracture into the subterranean formation through the open first wire-line controllable valve;   opening a first wire-line controllable valve that is second closest to the toe end and closing a second wire-line controllable valve that is second closest to the toe end; and   providing a fracture into the subterranean formation through the open first wire-line activated valve that is second closet to the toe end.   
     
     
         2 . The method of  claim 1  wherein further comprising the step of continuing to open first wire-line controllable valves, closing second wire-line controllable valves, and providing fractures for each sequential set of first and second wire-line controllable valves until fractures have been provided through each of the first wire-line controllable valves. 
     
     
         3 . The method of  claim 1  wherein the wire-line controllable valves are operated by a wire-line kick-over tool. 
     
     
         4 . The method of claim wherein the second wire-line controlled valves are check valves that allow flow to pass from the toe end to the heal end of the well but, when closed, prevent flow from the heal end to the toe end of the well. 
     
     
         5 . The method of  claim 1  wherein the second wire-line controllable valves are flapper valves which when closed, seal a cross-section of the wellbore. 
     
     
         6 . The method of  claim 1  wherein the second wire-line controlled valve comprises materials that degrade at wellbore conditions. 
     
     
         7 . The method of  claim 1  wherein the first wire-line controllable valves are sliding valves that cover ports situated in the circumference of the valve. 
     
     
         8 . The method of  claim 1  wherein the number of sets of first wire-line controllable valves and second wire-line controllable valves is between ten and one hundred. 
     
     
         9 . The method of  claim 3  wherein the wire-line stroker tool is placed in the wellbore with a cement plug behind cement being pumped down the casing and up an annulus between the casing and wellbore to provide zonal isolation along the wellbore. 
     
     
         10 . The method of  claim 9  wherein the fracture near the toe end of the wellbore is provided through a wire-line controllable sleeve valve which is opened by the wire-line stroker tool. 
     
     
         11 . The method of  claim 1  wherein the fracture near the toe end of the well is formed at the end of the casing from an open hole portion of the wellbore. 
     
     
         12 . The method of  claim 3  wherein the wire-line stroker tool is moved past each set of first wire-line controllable valve and second wire-line controllable valve, changing position of each valve, between provision of each fracture, and remains in the wellbore between a most recently moves set of wire-line controllable valves and the next set of wire-line controllable valves while a next fracture is provided. 
     
     
         13 . A method to provide a fractured subterranean formation comprising:
 providing a wellbore from a surface location to the subterranean formation within the subterranean formation from a heal end to a toe end;   providing a casing within the wellbore wherein the casing comprises a plurality of first wire-line controllable valves effective to provide communication between an inside of the wellbore and an outside of the wellbore, and a plurality of second wire-line actuated valves, wherein each second wire-line actuated valve is associated with a first wire-line actuated valve, and each second wire-line activated valve is effective to isolate a portion of the inside of the wellbore upstream from the first valves from a portion of the inside of the wellbore down-stream of the first valve wherein initially all first wire-line controllable valves are closed, and all second wireline controllable valves are open;   providing a fracture from the wellbore near the toe end of the wellbore between the toe end of the wellbore and the first wire-line controllable valve closest to the toe end of the wellbore;   opening the first wire-line controllable valve and closing the second wire-line controllable valve closest to the toe of the wellbore;   providing a fracture into the subterranean formation through the open first wire-line controllable valve by placing a mortar cement slurry having a specific gravity of at least two in the wellbore and permitting the hydrostatic head of the mortar slurry propagate a fracture;   opening a first wire-line controllable valve that is second closest to the toe and closing a second wire-line controllable valve that is second closest to the toe; and   providing a fracture into the subterranean formation through the open first wire-line activated valve that is second closet to the toe end.   
     
     
         14 . The method of  claim 13  wherein further comprising the step of continuing to open first wire-line controllable valves, closing second wire-line controllable valves, and providing fractures for each sequential set of first and second wire-line controllable valves until fractures have been provided through each of the first wire-line controllable valves. 
     
     
         15 . The method of  claim 13  wherein the wire-line controllable valves are operated by a wire-line kick-over tool. 
     
     
         16 . The method of  claim 13  wherein the second wire-line controlled valves are check valves whey allow flow to pass from the toe end to the heal end of the well but, when closed, prevent flow from the heal end to the toe end of the well. 
     
     
         17 . The method of  claim 13  wherein the wire-line controllable valves are operated by a wire-line kick-over tool. 
     
     
         18 . The method of  claim 13  wherein the second wire-line controlled valves are check valves that allow flow to pass from the toe end to the heal end of the well but, when closed, prevent flow from the heal end to the toe end of the well. 
     
     
         19 . The method of  claim 13  wherein the second wire-line controllable valves are flapper valves which when closed, seal a cross-section of the wellbore. 
     
     
         20 . The method of  claim 13  wherein the second wire-line controlled valve comprises materials that degrade at wellbore conditions.