Directional hydraulic fracturing connected mining method

Abstract

The invention discloses a directional hydraulic fracturing connected mining method, which comprises the following steps of: performing directional well spacing; performing fracturing connection; continuously mining; and designing and arranging a fracturing well group along a cleavage direction by detecting a natural cleavage fracture direction of an ore body so as to produce and extend a horizontal fracture along a designed cleavage direction, wherein the connection direction of hydraulic fracturing can be manually controlled and vertical fractures are avoided so as to prevent disasters such as ground brine emerging and pollution of farmlands and fish ponds due to serious water filling of a cover layer; the recovery ratio of the resource is greater than or equal to 70 percent (including recovery of a second-stage mining project) and is higher than that of any mining method; the safety of a cavern roof is improved and the life of a production well is naturally prolonged by regularly arranging (similar to a room-and-pillar method) pillars of an underground cavern and an ore bed goaf; and the recovery ratio of the resource is improved.

Description

technical field [0001] The invention relates to the hydraulic fracturing mining technology of the halogen deposit ore layer and the oil field, in particular to a directional hydraulic fracturing connected mining method. Background technique [0002] The rock salt hydraulic fracturing method that emerged in China in the 1970s was introduced from oil extraction technology. During the hydraulic fracturing of the ore layer, when the high-pressure pump injects water that greatly exceeds the absorption capacity of the formation into the drilling well, a pressure that exceeds the in-situ stress near the drilling wall and the tensile strength of the ore layer will be generated near the drilling base, that is, a horizontal pressure will be formed in the ore layer. Fractures, but not along the extension direction of the fractures, but set well groups in any direction, arrange well groups, and carry out hydraulic fracturing exploitation of resources. This method has a large increase i...

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Problems solved by technology

This method has a large increase in production, but it is difficult to control the generation direction of horizontal fractures during fracturing, that is, the connection direction of the two wells, and during the fracturing and recovery periods, the phenomenon of ground brine emerges endlessly, making the solution cavity (mining Field) the arrangement of ore pillars in the ground is also disorderly, causing the roof of the solution cavity to collapse in advance, and the life of the production well is short, and the recovery rate of resources is extremely low, only 9%-15%.

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