ABSTRACT

: Hydraulic fracturing of hot and dry rock (HDR) usually produces a single main fracture. However, a single main crack is prone to produce "thermal short-circuit effect" in the heat transfer process, thus reducing the heat transfer efficiency. This will lead to the early abandonment of the HDR wells and restrict the development of the HDR resources. In view of the technical problems faced by the development of HDR resources, the idea of using downhole robots to implement blasting-hydraulic fracturing is put forward. The novel exploitation technology of the HDR resources can avoid the single main fracture caused by the in-situ stress, rock strength and natural fracture, and form a complex fracture network as far as possible, which can improve the thermal interaction area of the HDR and avoiding the "thermal short-circuit effect". Based on the novel exploitation technology of the HDR resources, the working mechanism of the downhole robot is studied. A prototype of the downhole robot and a special experimental bench and system are developed. On this basis, a series of the ground experiments such as static/dynamic experiments and control reliability of the downhole robot have been completed. Finally, the new exploitation technology of the HDR resources is of great scientific significance and engineering application prospects for the economic and efficient development of HDR resources.

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