System and Method for the Access of Subterranean Deposits

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 a well bore pattern connected to the junction and operable to drain fluid from a region of the subterranean zone to the junction.

1 . A system for accessing one or more subterranean zones, the system comprising:
 a limited surface area, which is land;   a first well, located on the limited surface area, comprising a first substantially vertical wellbore extending at least 6,000 feet and proximate to a subterranean zone, which is shale, and a first drainage wellbore with a horizontal portion that extends at least 6,000 feet from the first substantially vertical wellbore;   a second well, located on the limited surface area, comprising a second substantially vertical wellbore extending at least 6,000 feet and proximate to the subterranean zone, and a second drainage wellbore with a horizontal portion that extends at least 6,000 feet from the second substantially vertical wellbore.   a third well, located on the limited surface area, comprising a third substantially vertical wellbore extending at least 6,000 feet and proximate to the subterranean zone, and third drainage wellbore with a horizontal portion that extends at least 6,000 feet from the third substantially vertical wellbore;   a fourth well, located on the limited surface area, comprising a fourth substantially vertical wellbore extending at least 6,000 feet and proximate to the subterranean zone, and a fourth drainage wellbore with a horizontal portion that extends at least 6,000 feet from the fourth vertical wellbore; and   wherein each of the four wells is located on the limited surface area and offset from each other 2-250 feet, and each well produces oil to the surface.   
     
     
         2 . The system of  claim 1  wherein the four drainage wellbores comprise a quadrilateral drainage pattern, and wherein the four wells are in-line with each other at the surface. 
     
     
         3 . The system of  claim 1  wherein another horizontal drainage wellbore is connected to the fourth horizontal wellbore at a junction and wherein the other drainage wellbore extends into a second subterranean zone. 
     
     
         4 . The system of  claim 1  wherein the first and second drainage wellbores each extend horizontally more than 8,000 feet. 
     
     
         5 . The system of  claim 1  wherein the first and second drainage wellbores each extend horizontally more than 9,000 feet. 
     
     
         6 . The system of  claim 1  wherein the first, second, third, and fourth wells are cased at least in the substantially vertical wellbores and wherein each drainage wellbore has a 10 or more cavities caused by fracing. 
     
     
         7 . The system of  claim 1  wherein the four drainage wellbores are adjacent to another drilling pad with at least two wells at the surface, which have substantially vertical wellbores extending proximate a subterranean zone, and wherein each well from the other drilling pad has a horizontal drainage wellbore that extends at least 5,000 feet and have a plurality of cavities caused by fracing. 
     
     
         8 . The system of  claim 1  wherein the first, second, third, and fourth drainage wellbores extend horizontally into a coal seam. 
     
     
         9 . A system for accessing one or more subterranean zones, the system comprising:
 a drilling pad at a surface, which is land with a limited surface area,   three or more wells, each well located on the drilling pad, comprising a substantially vertical wellbore extending at least 6,000 feet proximate to a subterranean zone, and a horizontal drainage wellbore extending from the substantially vertical wellbore used for production of fluid to the surface;   wherein each horizontal drainage wellbore extends at least 5,000 feet horizontally;   wherein each well is offset from the other wells between 2-300 feet at the surface at the drilling pad;   wherein each of the wells is configured to produce oil to the surface through the substantially vertical wellbore; and,   wherein the subterranean zone comprises shale.   
     
     
         10 . The system of  claim 9  wherein each horizontal drainage wellbore has 10 or more cavities caused by fracing and is operable to produce water to the surface through the corresponding substantially vertical wellbore. 
     
     
         11 . The system of  claim 9  wherein water and other additives are injected into the horizontal drainage wellbores of at least two wells, and wherein the water and other additives injected into these horizontal drainage wellbores exceeds 1,000,000 gallons; and,
 wherein the horizontal drainage wellbores of these two wells have 10 or more cavities caused by fracing. 
 
     
     
         12 . The system of  claim 9  wherein at least one horizontal drainage wellbore comprises 10 or more cavities caused by fracing, and wherein more than 700,000 gallons of water and other additives are injected into the horizontal drainage wellbore. 
     
     
         13 . The system of  claim 9  wherein the horizontal drainage wellbores of two wells each extend 7,000 feet or more. 
     
     
         14 . A system for accessing one or more subterranean zones, the system comprising:
 a drilling pad at a surface, which is land with a limited surface area,   a first substantially vertical wellbore extending at least 7,000 feet from the surface proximate a subterranean zone, and a horizontal drainage wellbore extending from the first substantially vertical wellbore that extends 5,000 feet or more horizontally;   a second substantially vertical wellbore extending at least 7,000 feet from the surface proximate to a subterranean zone, and a horizontal drainage wellbore extending from the second substantially vertical wellbore that extends 5,000 feet or more horizontally;   a third substantially vertical wellbore extending at least 7,000 feet from the surface proximate to a subterranean zone and a horizontal drainage wellbore extending from the third substantially vertical wellbore that extends 5,000 feet or more horizontally;   wherein each horizontal drainage wellbore extends horizontally into one or more horizontal planes;   wherein each substantially vertical wellbore is spaced apart from the other substantially vertical wellbores by 2-100 feet at the surface;   wherein each substantially vertical wellbore produces oil to the surface; and   wherein each substantially vertical wellbore has a first casing, which is a first size, and a second casing, which is a second size.   
     
     
         15 . The system of  claim 14  wherein each substantially vertical wellbore is connected to each horizontal drainage wellbore at a junction, and wherein the junction is cased. 
     
     
         16 . The system of  claim 14  wherein each of the 3 wellbores at the surface is formed by the same drilling rig. 
     
     
         17 . The system of  claim 14  wherein at least one horizontal wellbore intersects an additional horizontal drainage wellbore at a junction proximate the subterranean zone. 
     
     
         18 . The system of  claim 14  wherein the three horizontal drainage wellbores extend into a horizontal plane, which is shale, and form a quadrilateral drainage pattern; and,
 wherein the substantially vertical wellbores are in-line with each other at the surface. 
 
     
     
         19 . The system of  claim 14  wherein the substantially vertical wellbores comprise a linear surface pattern, where the surface locations are in an area that is generally less than 500 square feet, thereby minimizing the footprint at the surface by combining underground equipment and activities at the drilling pad, which is a limited surface area. 
     
     
         20 . The system of  claim 14  wherein at least two horizontal drainage wellbores have 20 or more cavities in a portion of the horizontal wellbores caused by fracing, and wherein the horizontal plane is shale; and,
 wherein more than 500,000 gallons of water and other additives are injected into each of the two horizontal drainage wellbores for fracing. 
 
     
     
         21 . The system of  claim 14  wherein an electrical submersible pump is disposed in at least one horizontal drainage wellbore. 
     
     
         22 . The system of  claim 14  wherein a progressing cavity pump is disposed in at least one horizontal drainage wellbore. 
     
     
         23 . The system of  claim 14  wherein the horizontal plane is the same for each horizontal drainage wellbore. 
     
     
         24 . A system for accessing one or more subterranean zones, the system comprising:
 a drilling pad at a land limited area surface;   a first well, located on the drilling pad, comprising a substantially vertical wellbore extending at least 6,000 feet from the surface and coupled to a first junction proximate a subterranean zone, a first horizontal drainage wellbore extending from the first junction with a horizontal portion that extends at least 6,000 feet;   a second well, located on the drilling pad, comprising a substantially vertical wellbore extending at least 6,000 feet from the surface and coupled to a second junction proximate the subterranean zone, a second drainage wellbore extending from the second junction with a horizontal portion that extends at least 6,000 feet;   wherein the wells are offset from each other by 2-100 feet at the surface;   wherein the first well horizontally extends into the subterranean zone in a first direction;   wherein the second well horizontally extends into the subterranean zone in a second direction;   wherein the drilling pad surface area is smaller than an area containing the first and second horizontal drainage wellbores;   wherein the subterranean zone is shale;   wherein both the first and second wells are cased at least in in the substantially vertical wellbores and are configured to produce oil to the surface; and,   wherein each horizontal drainage well bore comprises 10 or more cavities caused by fracing.   
     
     
         25 . The system of  claim 24  wherein a third well is located on the drilling pad and comprises a substantially vertical wellbore extending at least 8,000 feet from the surface, and a horizontal drainage wellbore extending from the substantially vertical wellbore, wherein the horizontal drainage wellbore extends at least 9,000 feet horizontally. 
     
     
         26 . The system of  claim 24  wherein the first and second wells form a drainage pattern that is substantially quadrilateral, and where the length of the horizontal drainage wellbores of each well is at least 9,000 feet. 
     
     
         27 . The system of  claim 24  wherein there are 20 or more cavities caused by fracing in the first and second horizontal drainage wellbores, and wherein the first and second horizontal drainage wellbores are configured to produce oil, gas, and water to the surface; and,
 wherein 800,000 gallons or more of water and other additives are injected into the first and second horizontal drainage bores from the surface for fracing. 
 
     
     
         28 . The system of  claim 24  wherein a pump, selected from a group consisting of an electrical submersible pump and a progressing cavity pump, is disposed within one of the horizontal drainage wellbores, and wherein the first and second wells are cased. 
     
     
         29 . The system of  claim 24  wherein the first drainage wellbore and second drainage wellbore are adjacent to one another, and wherein fractures are formed in both wellbores in an alternating manner to increase production of oil or gas.