Drilling and stimulation of subterranean formation

Abstract

Apparatus and methods for drilling and stimulating a subterranean formation. The method may comprise drilling a wellbore comprising a deviated wellbore portion extending through a subterranean formation, forming a plurality of lateral tunnels extending from the deviated wellbore portion through the subterranean formation such that at least a portion of each of the plurality of lateral tunnels extends along a plane of maximum horizontal stress of the subterranean formation, and performing stimulation operations of the subterranean formation via the plurality of lateral tunnels.

What is claimed is: 
     
         1 . A method comprising:
 drilling a wellbore comprising a deviated wellbore portion extending through a subterranean formation;   forming a plurality of lateral tunnels extending from the deviated wellbore portion through the subterranean formation such that at least a portion of each of the plurality of lateral tunnels extends along a plane of maximum horizontal stress of the subterranean formation; and   performing stimulation operations of the subterranean formation via the plurality of lateral tunnels.   
     
     
         2 . The method of  claim 1  wherein at least a portion of each of the plurality of lateral tunnels extends at an angle ranging between zero degrees and about 45 degrees with respect to true vertical. 
     
     
         3 . The method of  claim 1  wherein at least a portion of each of the plurality of lateral tunnels extends at an angle ranging between about 45 degrees and about 90 degrees with respect to true vertical. 
     
     
         4 . The method of  claim 1  wherein forming the plurality of lateral tunnels is performed with a drilling tool comprising a rotating drill bit. 
     
     
         5 . The method of  claim 1  wherein forming the plurality of lateral tunnels is performed with a hydraulic jetting tool. 
     
     
         6 . The method of  claim 1  wherein forming the plurality of lateral tunnels is performed with a laser cutting tool. 
     
     
         7 . The method of  claim 1  wherein the deviated wellbore portion extends substantially horizontally. 
     
     
         8 . The method of  claim 1  wherein the deviated wellbore portion extends at an angle ranging between zero degrees and about 45 degrees with respect to true horizontal. 
     
     
         9 . The method of  claim 1  further comprising, before performing stimulation operations, completing the deviated wellbore portion with a casing string and isolation material between the casing string and a sidewall of the deviated wellbore portion, wherein the isolation material fluidly isolates portions of annular space extending between the casing string and the sidewall of the deviated wellbore portion to fluidly isolate ones of the plurality of lateral tunnels from each other. 
     
     
         10 . The method of  claim 9  wherein completing the deviated wellbore portion with a casing string is performed before forming the plurality of lateral tunnels. 
     
     
         11 . The method of  claim 9  wherein the isolation material comprises at least one of a plurality of packers and cement. 
     
     
         12 . The method of  claim 9  wherein the casing string comprises fracturing sleeves. 
     
     
         13 . The method of  claim 1  wherein performing the stimulation operations of the subterranean formation comprises pumping a fracturing fluid into the plurality of lateral tunnels to hydraulically fracture the subterranean formation. 
     
     
         14 . The method of  claim 1  further comprising:
 before forming the plurality of lateral tunnels, completing the deviated wellbore portion with a first casing string; 
 after forming the plurality of lateral tunnels, installing a second casing string within the first casing string; 
 expanding packers located between the first and second casing strings to fluidly isolate one or more of the plurality of lateral tunnels from each other; and 
 forming a fluid passage extending through a wall of the second casing string to fluidly connect the second casing string with a selected one or more of the plurality of lateral tunnels, wherein performing stimulation operations of the subterranean formation comprises stimulating the selected one or more of the plurality of lateral tunnels via the fluid passage. 
 
     
     
         15 . The method of  claim 14  further comprising, before forming each of the plurality of lateral tunnels, drilling a corresponding hole through a wall of the first casing string. 
     
     
         16 . The method of  claim 14  wherein forming the plurality of fluid passages comprises at least one of:
 shifting a fracturing sleeve of the second casing string to an open position; and 
 perforating the second casing string with a perforating tool. 
 
     
     
         17 . The method of  claim 14  wherein:
 the fluid passage is a first fluid passage; 
 the selected one or more of the plurality of lateral tunnels is a selected first one or more of the plurality of lateral tunnels; and 
 performing stimulation operations comprises:
 stimulating the selected first one or more of the plurality of lateral tunnels via the first fluid passage; 
 forming a second fluid passage extending through the wall of the second casing string to fluidly connect the second casing string with a selected second one or more of the plurality of lateral tunnels; 
 fluidly isolating the first fluid passage from the second fluid passage; and 
 stimulating the selected second set of one or more of the plurality of lateral tunnels via the second fluid passage. 
 
 
     
     
         18 . The method of  claim 1  wherein performing stimulation operations comprises performing multi-stage stimulation operations comprising:
 stimulating a first zone of the subterranean formation via a first set of one or more of the plurality of lateral tunnels; 
 fluidly isolating the first set of one or more of the plurality of lateral tunnels from a second set of one or more of the plurality of lateral tunnels; and 
 stimulating a second zone of the subterranean formation via the second set of one or more of the plurality of lateral tunnels. 
 
     
     
         19 . A method comprising:
 drilling a wellbore comprising a deviated wellbore portion extending through a subterranean formation;   forming a plurality of lateral tunnels extending from the deviated wellbore portion through the subterranean formation such that at least a portion of each of the plurality of lateral tunnels extends at an angle ranging between zero degrees and about 90 degrees with respect to true vertical; and   performing stimulation operations of the subterranean formation via the plurality of lateral tunnels.   
     
     
         20 . The method of  claim 19  wherein at least a portion of each of the plurality of lateral tunnels is substantially aligned with a plane of maximum horizontal stress of the subterranean formation. 
     
     
         21 . The method of  claim 19  wherein at least a portion of each of the plurality of lateral tunnels extends at an angle ranging between about zero degrees and about 45 degrees with respect to the true vertical. 
     
     
         22 . The method of  claim 19  wherein forming the plurality of lateral tunnels is performed with a drilling tool comprising a rotating drill bit. 
     
     
         23 . The method of  claim 19  wherein forming the plurality of lateral tunnels is performed with a hydraulic jetting tool. 
     
     
         24 . The method of  claim 19  wherein forming the plurality of lateral tunnels is performed with a laser cutting tool. 
     
     
         25 . The method of  claim 19  wherein the deviated wellbore portion extends substantially horizontally. 
     
     
         26 . The method of  claim 19  wherein the deviated wellbore portion extends at an angle ranging between zero degrees and about 45 degrees with respect to true horizontal. 
     
     
         27 . The method of  claim 19  further comprising, before performing stimulation operations, completing the deviated wellbore portion with a casing string and isolation material between the casing string and a sidewall of the deviated wellbore portion, wherein the isolation material fluidly isolates portions of annular space extending between the casing string and the sidewall of the deviated wellbore portion to fluidly isolate ones of the plurality of lateral tunnels from each other. 
     
     
         28 . The method of  claim 27  wherein completing the deviated wellbore portion with a casing string is performed before forming the plurality of lateral tunnels. 
     
     
         29 . The method of  claim 27  wherein the isolation material comprises at least one of a plurality of packers and cement. 
     
     
         30 . The method of  claim 27  wherein the casing string comprises fracturing sleeves. 
     
     
         31 . The method of  claim 19  wherein performing the stimulation operations of the subterranean formation comprises pumping a fracturing fluid into the plurality of lateral tunnels to hydraulically fracture the subterranean formation. 
     
     
         32 . The method of  claim 19  further comprising:
 before forming the plurality of lateral tunnels, completing the deviated wellbore portion with a first casing string; 
 after forming the plurality of lateral tunnels, installing a second casing string within the first casing string; 
 expanding packers located between the first and second casing strings to fluidly isolate one or more of the plurality of lateral tunnels from each other; and 
 forming a fluid passage extending through a wall of the second casing string to fluidly connect the second casing string with a selected one or more of the plurality of lateral tunnels, wherein performing stimulation operations of the subterranean formation comprises stimulating the selected one or more of the plurality of lateral tunnels via the fluid passage. 
 
     
     
         33 . The method of  claim 32  further comprising, before forming each of the plurality of lateral tunnels, drilling a corresponding hole through a wall of the first casing string. 
     
     
         34 . The method of  claim 32  wherein forming the plurality of fluid passages comprises at least one of:
 shifting a fracturing sleeve of the second casing string to an open position; and 
 perforating the second casing string with a perforating tool. 
 
     
     
         35 . The method of  claim 32  wherein:
 the fluid passage is a first fluid passage; 
 the selected one or more of the plurality of lateral tunnels is a selected first one or more of the plurality of lateral tunnels; and 
 performing stimulation operations comprises:
 stimulating the selected first one or more of the plurality of lateral tunnels via the first fluid passage; 
 forming a second fluid passage extending through the wall of the second casing string to fluidly connect the second casing string with a selected second one or more of the plurality of lateral tunnels; 
 fluidly isolating the first fluid passage from the second fluid passage; and 
 stimulating the selected second set of one or more of the plurality of lateral tunnels via the second fluid passage. 
 
 
     
     
         36 . The method of  claim 19  wherein performing stimulation operations comprises performing multi-stage stimulation operations comprising:
 stimulating a first zone of the subterranean formation via a first set of one or more of the plurality of lateral tunnels; 
 fluidly isolating the first set of one or more of the plurality of lateral tunnels from a second set of one or more of the plurality of lateral tunnels; and 
 stimulating a second zone of the subterranean formation via the second set of one or more of the plurality of lateral tunnels. 
 
     
     
         37 . A method comprising:
 drilling a wellbore comprising a deviated wellbore portion extending through a subterranean formation;   operating a hydraulic jetting tool to form a plurality of lateral tunnels extending from the deviated wellbore portion through the subterranean formation; and   performing stimulation operations of the subterranean formation via the plurality of lateral tunnels.   
     
     
         38 . The method of  claim 37  wherein at least a portion of each of the plurality of lateral tunnels is substantially aligned with a plane of maximum horizontal stress of the subterranean formation. 
     
     
         39 . The method of  claim 37  wherein at least a portion of each of the plurality of lateral tunnels extends at an angle ranging between zero degrees and about 90 degrees with respect to true vertical. 
     
     
         40 . The method of  claim 39  wherein at least a portion of each of the plurality of lateral tunnels extends at an angle ranging between about zero degrees and about 45 degrees with respect to the true vertical. 
     
     
         41 . The method of  claim 37  wherein the deviated wellbore portion extends substantially horizontally. 
     
     
         42 . The method of  claim 37  wherein the deviated wellbore portion extends at an angle ranging between zero degrees and about 45 degrees with respect to true horizontal. 
     
     
         43 . The method of  claim 37  further comprising, before performing stimulation operations, completing the deviated wellbore portion with a casing string and isolation material between the casing string and a sidewall of the deviated wellbore portion, wherein the isolation material fluidly isolates portions of annular space extending between the casing string and the sidewall of the deviated wellbore portion to fluidly isolate ones of the plurality of lateral tunnels from each other. 
     
     
         44 . The method of  claim 43  wherein completing the deviated wellbore portion with a casing string is performed before forming the plurality of lateral tunnels. 
     
     
         45 . The method of  claim 43  wherein the isolation material comprises at least one of a plurality of packers and cement. 
     
     
         46 . The method of  claim 43  wherein the casing string comprises fracturing sleeves. 
     
     
         47 . The method of  claim 37  wherein performing the stimulation operations of the subterranean formation comprises pumping a fracturing fluid into the plurality of lateral tunnels to hydraulically fracture the subterranean formation. 
     
     
         48 . The method of  claim 37  further comprising:
 before forming the plurality of lateral tunnels, completing the deviated wellbore portion with a first casing string; 
 after forming the plurality of lateral tunnels, installing a second casing string within the first casing string; 
 expanding packers located between the first and second casing strings to fluidly isolate one or more of the plurality of lateral tunnels from each other; and 
 forming a fluid passage extending through a wall of the second casing string to fluidly connect the second casing string with a selected one or more of the plurality of lateral tunnels, wherein performing stimulation operations of the subterranean formation comprises stimulating the selected one or more of the plurality of lateral tunnels via the fluid passage. 
 
     
     
         49 . The method of  claim 48  further comprising, before forming each of the plurality of lateral tunnels, drilling a corresponding hole through a wall of the first casing string. 
     
     
         50 . The method of  claim 48  wherein forming the plurality of fluid passages comprises at least one of:
 shifting a fracturing sleeve of the second casing string to an open position; and 
 perforating the second casing string with a perforating tool. 
 
     
     
         51 . The method of  claim 48  wherein:
 the fluid passage is a first fluid passage; 
 the selected one or more of the plurality of lateral tunnels is a selected first one or more of the plurality of lateral tunnels; and 
 performing stimulation operations comprises:
 stimulating the selected first one or more of the plurality of lateral tunnels via the first fluid passage; 
 forming a second fluid passage extending through the wall of the second casing string to fluidly connect the second casing string with a selected second one or more of the plurality of lateral tunnels; 
 fluidly isolating the first fluid passage from the second fluid passage; and 
 stimulating the selected second set of one or more of the plurality of lateral tunnels via the second fluid passage. 
 
 
     
     
         52 . The method of  claim 37  wherein performing stimulation operations comprises performing multi-stage stimulation operations comprising:
 stimulating a first zone of the subterranean formation via a first set of one or more of the plurality of lateral tunnels; 
 fluidly isolating the first set of one or more of the plurality of lateral tunnels from a second set of one or more of the plurality of lateral tunnels; and 
 stimulating a second zone of the subterranean formation via the second set of one or more of the plurality of lateral tunnels.