Method and system for accessing subterranean deposits from the surface
Improved method and system for accessing subterranean deposits from the surface that substantially eliminates or reduces the disadvantages and problems associated with previous systems and methods. In particular, the present invention provides an articulated well with a drainage pattern that intersects a horizontal cavity well. The drainage patterns provide access to a large subterranean area from the surface while the vertical cavity well allows entrained water, hydrocarbons, and other deposits to be efficiently removed and/or produced.
1. A method for surface production of gas from a coal seam, comprising:
forming a first well bore;
forming an articulated well bore intersecting the first well bore, the articulated well bore at least partially in a coal seam and operable to conduct water and gas from the coal seam to a well bore junction;
conducting water and gas from the coal seam through the articulated well bore to the well bore junction, the well bore junction coupled to a portion of the first well bore at least partially disposed below at least a portion of the articulated well bore;
collecting water from a substantially horizontal well bore for production to the surface;
pumping water from the well bore junction to the surface; and
producing gas from the well bore junction to the surface.
2. The method of claim 1 , further comprising drilling the substantially horizontal well bore through the articulated well bore.
3. The method of claim 1 , further comprising drilling the substantially horizontal well bore underbalanced.
4. The method of claim 1 , further comprising drilling the substantially horizontal well bore underbalanced using foam.
5. The method of claim 1 , further comprising drilling the substantially horizontal well bore at a slope in the coal seam.
6. The method of claim 1 , further comprising:
conducting water and gas from a plurality of lateral well bores extending from the substantially horizontal well bore; and
collecting water from the substantially horizontal well bore and the plurality of lateral well bores at the well bore junction for production to the surface.
7. The method of claim 6 , further comprising drilling the substantially horizontal well bore and the plurality of lateral well bores underbalanced.
8. The method of claim 6 , further comprising drilling the substantially horizontal well bore and the plurality of lateral well bores underbalanced using foam.
9. The method of claim 1 , wherein forming the articulated well bore comprises forming the articulated well bore such that a radiused portion of the articulated well bore has at least a 100 foot radius.
10. The method of claim 1 , wherein forming the substantially horizontal well bore in the coal seam comprises forming the substantially horizontal well bore in a coal seam that comprises an ultra low pressure reservoir having a pressure below 150 pounds per square inch (psi).
11. The method of claim 1 , further comprising forming an enlarged cavity in the first well bore proximate to the coal seam.
12. The method of claim 11 , wherein forming the articulated well bore comprises:
forming a substantially vertical portion extending downwardly;
forming a radiused portion extending from the substantially vertical portion; and
forming a substantially horizontal portion extending from the radiused portion to the well bore junction.
13. The method of claim 12 , wherein forming the radiused portion extending from the substantially vertical portion comprises forming the radiused portion such that the radiused portion has a radius of between 100 to 150 feet.
14. The method of claim 13 , wherein the first well bore is offset approximately three hundred feet from the articulated well bore at the surface.
15. The method of claim 13 , wherein forming the substantially horizontal well bore comprises forming the substantially horizontal well bore disposed substantially within a horizontal plane of the subterranean zone.
16. The method of claim 13 , further comprising forming an enlarged cavity formed in the first well bore proximate to the subterranean zone to intersect the first well bore at the well bore junction, and wherein the first well bore extends below the enlarged cavity to form a sump for the enlarged cavity.