Offset barrier wells in subsurface formations
First Claim
1. A method of positioning wellbores for forming a double barrier for at least a portion of a treatment area, comprising:
- forming a plurality of first barrier wells in the formation for a first barrier, wherein a substantially constant spacing separates adjacent first barrier wells;
analyzing the formation to determine the principal direction of water flow in at least one layer of the formation;
determining an offset distance of the second barrier wells relative to the first barrier wells based on the principal direction of water flow in at least one layer to limit a maximum separation distance between a closest barrier well and a theoretical breach extending from the first barrier to the second barrier along the principal direction of water flow to a distance of less than one half of the spacing that separates adjacent first barrier wells; and
forming a plurality of second barrier wells in the formation for a second barrier to a side of the first barrier wells by a substantially constant separation distance, wherein the second barrier wells are offset from the first barrier wells by a distance that is at least substantially the same as the offset distance.
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Accused Products
Abstract
A plurality of first barrier wells are formed in a formation for a first barrier. A substantially constant spacing separates adjacent first barrier wells. The formation is analyzed to determine the principal fracture direction of at least one layer of the formation. An offset distance of second barrier wells relative to first barrier wells is determined based on the principal fracture direction to limit a maximum separation distance between a closest barrier well and a theoretical fracture extending between the first barrier and the second barrier along the principal fracture direction to a distance of less than one half of the spacing that separates adjacent first barrier wells. The second barrier wells are offset from the first barrier wells by a distance that is at least substantially the same as the offset distance.
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Citations
20 Claims
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1. A method of positioning wellbores for forming a double barrier for at least a portion of a treatment area, comprising:
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forming a plurality of first barrier wells in the formation for a first barrier, wherein a substantially constant spacing separates adjacent first barrier wells; analyzing the formation to determine the principal direction of water flow in at least one layer of the formation; determining an offset distance of the second barrier wells relative to the first barrier wells based on the principal direction of water flow in at least one layer to limit a maximum separation distance between a closest barrier well and a theoretical breach extending from the first barrier to the second barrier along the principal direction of water flow to a distance of less than one half of the spacing that separates adjacent first barrier wells; and forming a plurality of second barrier wells in the formation for a second barrier to a side of the first barrier wells by a substantially constant separation distance, wherein the second barrier wells are offset from the first barrier wells by a distance that is at least substantially the same as the offset distance. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A method of positioning wellbores for forming a double barrier for at least a portion of a treatment area and treating a hydrocarbon containing formation, comprising:
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forming a plurality of first barrier wells in the formation for a first barrier, wherein a substantially constant spacing separates adjacent first barrier wells; analyzing the formation to determine the principal direction of water flow in at least one layer of the formation; determining an offset distance of the second barrier wells relative to the first barrier wells based on the principal direction of water flow in at least one layer to limit a maximum separation distance between a closest barrier well and a theoretical breach extending from the first barrier to the second barrier along the principal direction of water flow to a distance of less than one half of the spacing that separates adjacent first barrier wells; forming a plurality of second barrier wells in the formation for a second barrier to a side of the first barrier wells by a substantially constant separation distance, wherein the second barrier wells are offset from the first barrier wells by a distance that is at least substantially the same as the offset distance, and wherein the first and second barrier wells at least partially surrounds a treatment area in the formation; providing heat to at least part of formation from one or more heat sources located in the treatment area; and mobilizing at least some hydrocarbons located in the treatment area with the provided heat. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20)
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Specification