A method for extracting thermal energy from a conventional geothermal reservoir that includes a natural source of pressurized hot water or brine and at least one naturally-occurring fracture, the method comprising:
- drilling or accessing a production well that intersects the conventional geothermal reservoir;
- determining a position of a naturally-occurring fracture from well log data, wherein the naturally-occurring fracture carries a flow of the pressurized hot water or brine into the production well, the naturally-occurring fracture having a major width dimension and a minor height dimension, wherein the major width dimension of the naturally-occurring fracture is larger than the minor height dimension of the naturally-occurring fracture;
- deploying a downhole tool in the production well, wherein the downhole tool has a tool body that supports at least one linear shaped charge having a major length dimension and a minor width dimension, wherein the major length dimension of the at least one linear shaped charge is larger than the minor width dimension of the at least one linear shaped charge, wherein the major length dimension of the at least one linear shaped charge is larger than the minor height dimension of the naturally-occurring fracture and the minor width dimension of the at least one linear shaped charge is smaller than the major width dimension of the naturally-occurring fracture;
- aligning a position of the downhole tool in the production well to the position of the naturally-occurring fracture as determined from the well log data;
- and
- detonating the at least one linear shaped charge supported by the tool body to enlarge or open an aperture of the naturally-occurring fracture at an intersection of the naturally-occurring fracture and the production well, which reduces pressure loss of fluid flow into the production well from the naturally-occurring fracture, wherein the downhole tool is positioned with the major length dimension of the at least one linear shaped charge extending in a direction generally orthogonal to the minor height dimension of the naturally-occurring fracture and the minor width dimension of the at least one linear shaped charge extending parallel to the major width dimension of the naturally-occurring fracture,
- wherein:
- the downhole tool has a central axis, and the at least one linear shaped charge is supported by the tool body of the downhole tool in an orientation generally parallel to the central axis of the downhole tool;
- the at least one linear shaped charge comprises a continuous core of explosive material enclosed in an elongate seamless metal sheath housing having an inverted V-shape;
- the elongate seamless metal sheath housing and the continuous core of explosive material produce a uniform linear cutting action upon detonation;
- and
- the tool body further supports a detonation control module operably coupled to the at least one linear shaped charge and remotely controllable from a surface to activate detonation of the at least one linear shaped charge.