Vertical well negative displacement based horizontal butt-joint type geothermal well borehole trajectory and designing method

Abstract

The invention provides a vertical well negative displacement based horizontal butt-joint type geothermal well borehole trajectory and a designing method. The designing method includes the following steps: a first step, determining positions and coordinates of a mouth A of an inclined well and a mouth B of a horizontal engineering well according to the size and the shape of a construction region, calculating a distance d1 between the mouth A and the mouth B according to the coordinates of the mouth A and the mouth B, and determining a negative displacement offset distance d2 of a borehole trajectory of the inclined well according to the distance d1; a second step, determining a borehole trajectory of the vertical well; and a third step, determining a borehole trajectory of the horizontal engineering well. The negative displacement offset distance d2 is generated through construction of a second S402 section of the horizontal engineering well, the d1+d2>=250 m, a downhole communication butt-joint distance is effectively increased, two-well communication working can be smoothly performed, and a condition is created for city narrow places where a horizontal butt-joint geothermal well technology is adopted to develop deep hydrothermal geothermal resources; the problem that the conventional hydrothermal geothermal resource developments take heat and water can be solved, and an objective that heat is taken but water is not taken can be achieved.

Description

technical field [0001] The invention belongs to the technical field of geothermal energy development, and relates to a geothermal well borehole track and a design method based on vertical well negative displacement horizontal docking. Background technique [0002] At present, there are three methods for the development of hydrothermal geothermal resources in the middle and deep layers of 1500-3000m in China: the first is to drill a vertical well, from which the underground hot water is directly extracted without recharging; the second is to drill a vertical well as a drainage well The first is to drill a number of vertical wells around them as recharge wells, combining drainage and recharge; the third is to drill a vertical well, run concentric pipes into the well, and use the concentric pipes to perform cold and hot water circulation and heat exchange. There are the following problems in these three development forms: ① all take the water-bearing heat reservoir (sandstone l...

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Problems solved by technology

[0003] The purpose of the present invention is to provide a geothermal well track and design method based on negative displacement horizontal docking of vertical wells, which solves the problem of "extracting both heat and water" in the existing hydrothermal geothermal resource development mode, and truly realizes "only The purpose of "taking heat but not water"

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