System and Method for Subterranean Deposit Access

Abstract

According to one embodiment, a system for accessing a subterranean zone from the surface includes a well bore extending from the surface to the subterranean zone, and well bore pattern corrected to the junction and operable to drain fluid from a region of the subterranean zone to the junction.

1 . A system for accessing a subterranean coal seam from the surface, comprising:
 a substantially vertical well bore extending from the surface to the subterranean coal seam;   an articulated well bore extending from the surface to the subterranean coal seam, the articulated well bore horizontally offset from the substantially vertical well bore at the surface;   a substantially horizontal well bore extending from the articulated well bore and intercepting the substantially vertical well bore at a junction proximate to the subterranean coal seam;   a plurality of substantially horizontal drainage well bores coupled to the substantially horizontal well bore and extending into the subterranean coal seam;   wherein the plurality of substantially horizontal well bores extends into the coal seam beyond the substantially vertical well bores; and   wherein gas may be produced from the subterranean coal seam to the surface through either the substantially vertical or articulated well bore.   
     
     
         2 . The system of  claim 1  wherein the plurality of substantially horizontal well bores comprises at least three substantially horizontal drainage well bores extending into the coal seam beyond the substantially vertical well bore. 
     
     
         3 . The system of  claim 1  wherein water is produced through only the substantially vertical well bore. 
     
     
         4 . The system of  claim 1  wherein the substantially vertical well bore is coupled to a dewatering pump. 
     
     
         5 . The system of  claim 1  wherein each of the plurality of substantially horizontal drainage well bores extends to substantially equal distances in the coal seam. 
     
     
         6 . The system of  claim 1  wherein the substantially vertical well bore and articulated, well bore are spaced no further than 1,000 feet apart from one another on the surface. 
     
     
         7 . The system of  claim 1  wherein a cavity is disposed below the intersection of the substantially vertical well bore and the substantially horizontal well bore. 
     
     
         8 . The system of  claim 1  wherein both the substantially vertical well bore and the articulated well bore each intersect the subterranean coal seam at a depth of no more than 1,500 feet. 
     
     
         9 . A method for accessing a subterranean coal seam from the surface, comprising:
 drilling a substantially vertical well bore extending from the surface to the subterranean coal seam;   drilling an articulated well bore extending from the surface to the subterranean coal seam, the articulated well bore horizontally offset from the substantially vertical well bore at the surface;   drilling a substantially horizontal well bore extending from the articulated well bore and intercepting the substantially vertical well bore at a junction proximate to the subterranean coal seam;   drilling a plurality of substantially horizontal drainage well bores coupled to the substantially horizontal well bore and. extending into the subterranean coal seam; and producing gas from the subterranean coal seam to the surface through either the substantially vertical or articulated well bore.   
     
     
         10 . The method of  claim 9  further comprising producing water through the substantially vertical well bore. 
     
     
         11 . The method of  claim 9  further comprising drilling the substantially vertical well bore no more than 1,000 feet away from the articulated well bore on the surface. 
     
     
         12 . The method of  claim 9  further comprising drilling the substantially vertical well bore and the articulated well bore to intercept the subterranean coal seam at a depth of no more than 1,500 feet. 
     
     
         13 . A system for accessing a subterranean coal seam from the surface, comprising:
 a substantially vertical well bore extending from the surface to the subterranean coal seam;   an articulated well bore extending from the surface to the subterranean coal seam, the articulated well bore horizontally offset from the substantially vertical well bore at the surface;   a substantially horizontal well bore extending from the articulated well bore and intercepting the substantially vertical well bore at a junction proximate to the subterranean coal seam;   a substantially horizontal drainage pattern coupled to the substantially horizontal well bore and extending into the subterranean coal seam;   wherein gas may be produced from the subterranean coal seam to the surface through either the substantially vertical or articulated, well bore.   
     
     
         14 . The system of  claim 13  wherein water is produced through only the substantially vertical well bore. 
     
     
         15 . The system, of  claim 13  wherein the substantially vertical well bore is coupled to a dewatering pump. 
     
     
         18 . The system of  claim 13  wherein the substantially vertical well bore and articulated well bore are spaced no further than 1,000 feet apart from one another on the surface. 
     
     
         17 . The system of  claim 13  wherein a cavity is disposed below the intersection of the substantially vertical well bore and the substantially horizontal well bore. 
     
     
         18 . The system, of  claim 13  wherein both the substantially vertical well bore and the articulated well bore each intersect the subterranean coal seam at a depth of no more than 1,500 feet. 
     
     
         19 . A method for accessing a subterranean coal seam from the surface, comprising:
 drilling a substantially vertical well bore extending from the surface to the subterranean coal seam;   drilling an articulated well bore extending from the surface to the subterranean coal seam, the articulated well bore horizontally offset from the substantially vertical well bore at the surface;   drilling a substantially horizontal well bore extending from the articulated well bore and intercepting the substantially vertical well bore at a junction proximate to the subterranean coal seam;   drilling a substantially horizontal drainage pattern coupled to the substantially horizontal well bore and extending into the subterranean coal seam; and   producing gas from the subterranean coal seam to the surface through either the substantially vertical or articulated well bore.   
     
     
         20 . The method of  claim 19  further comprising producing water through the substantially vertical well bore. 
     
     
         21 . The method of  claim 19  further comprising drilling the substantially vertical well bore no more than 1,000 feet away from the articulated well bore on the surface. 
     
     
         22 . The method of  claim 19  further comprising drilling the substantially vertical well bore and the articulated well bore to intercept the subterranean coal seam at a depth of no more than 1,500 feet. 
     
     
         23 . A system for accessing a subterranean coal seam from the surface, comprising:
 a first, substantially vertical well bore extending from the surface to the subterranean coal seam;   a second well bore extending from the surface and having both a vertical portion and a curved portion, the curved portion being proximate to the subterranean coal seam;   a third, substantially horizontal well bore extending from the second well bore and intercepting the first well bore at a junction proximate to the subterranean coal seam;   a plurality of substantially horizontal drainage well bores coupled to the third well bore and extending into the subterranean coal seam;   wherein the plurality of substantially horizontal well bores extends into the coal seam beyond the first well bore; and   wherein gas may be produced from the subterranean coal seam to the surface through either the first or second well bores.   
     
     
         24 . The system of  claim 23  wherein the plurality of substantially horizontal well bores comprises at least three substantially horizontal drainage well bores extending into the coal seam beyond the first well bore. 
     
     
         25 . The system of  claim 23  wherein water is produced through only the first well bore. 
     
     
         26 . The system of  claim 23  wherein the first well bore is coupled to a dewatering pump. 
     
     
         27 . The system of  claim 23  wherein each of the plurality of substantially horizontal drainage well bores extends to substantially equal distances in the coal seam. 
     
     
         28 . The system of  claim 23  wherein the first and second well bores are spaced no further than 1,000 feet apart from one another on the surface. 
     
     
         29 . The system of  claim 23  wherein a cavity is disposed below the intersection of the first and third well bores. 
     
     
         30 . The system of  claim 23  wherein both the first and second well bores each intersect the subterranean coal seam at a depth of no more than 1,500 feet. 
     
     
         31 . A method for accessing a subterranean coal seam from the surface, comprising:
 drilling a first, substantially vertical well bore extending from the surface to the subterranean coal seam;   drilling a second well bore extending from the surface and having both a vertical portion and a curved portion, the curved portion being proximate to the subterranean coal seam;   drilling a third, substantially horizontal well bore extending from the second well bore and intercepting the first well bore at a junction proximate to the subterranean coal seam;   drilling a plurality of substantially horizontal drainage well bores coupled to the third well bore and extending into the subterranean coal seam; and   producing gas from the subterranean coal seam to the surface through either the first or second well bores.   
     
     
         32 . The method of  claim 31  further comprising producing water through the first well bore. 
     
     
         33 . The method of  claim 31  further comprising drilling the first well bore no more than 1,000 feet away from the second well bore on the surface. 
     
     
         34 . The method of  claim 31  further comprising drilling the first well bore and the second well bore to intercept the subterranean coal seam at a depth of no more than 1,500 feet. 
     
     
         35 . A system for accessing a subterranean coal seam from the surface, comprising:
 a first, substantially vertical well bore extending from the surface to the subterranean coal seam;   a second well bore extending from the surface and having both a vertical portion and a curved portion, the curved portion being proximate to the subterranean coal seam;   a third, substantially horizontal well bore extending from the second well bore and intercepting the first well bore at a junction proximate to the subterranean coal seam;   a substantially horizontal drainage pattern coupled to the third, well bore and extending into the subterranean coal seam;   wherein gas may be produced from the subterranean coal seam to the surface through either the first or second well bores.   
     
     
         36 . The system of  claim 35  wherein water is produced through only the first well bore. 
     
     
         37 . The system of  claim 35  wherein the first well bore is coupled to a dewatering pump. 
     
     
         38 . The system of  claim 35  wherein the first and second well bores are spaced no further than 1,000 feet apart from one another on the surface. 
     
     
         39 . The system of  claim 35  wherein a cavity is disposed below the intersection of the first and third well bores. 
     
     
         40 . The system of  claim 35  wherein both the first and second well bores each intersect the subterranean coal, seam at a depth of no more than 1,500 feet. 
     
     
         41 . A method for accessing a subterranean coal seam from the surface, comprising:
 drilling a first, substantially vertical well bore extending from the surface to the subterranean coal seam;   drilling a second well bore extending from the surface and having both a vertical portion and a curved portion, the curved portion being proximate to the subterranean coal seam;   drilling a third, substantially horizontal well bore extending from the second well bore and intercepting the first well bore at a junction proximate to the subterranean coal seam;   drilling a substantially horizontal drainage pattern coupled to the third well bore and extending into the subterranean coal seam;   producing gas from the subterranean coal seam, to the surface through either the first or second well bores.   
     
     
         42 . The method of  claim 41  further comprising producing water through the first well bore. 
     
     
         43 . The method of  claim 41  further comprising drilling the first well bore no more than 1,000 feet away from the second well bore on the surface. 
     
     
         44 . The method of  claim 41  further comprising drilling the first and second well bores to intercept the subterranean coal seam at a depth of no more than 1,500 feet.