MULTI-SECTION STAGED PRESSURE-REDUCTION WATER INJECTION APPARATUS BASED ON FRACTURE OBSERVATION AND OBSERVATION METHOD THEREOF

摘要

A multi-section staged pressure-reduction water injection apparatus based on fracture observation and an observation method thereof. The apparatus comprises a testing probe, a propulsion system, and a control system, the testing probe comprising plugging devices, a partial pressure assembly (49), and a connecting pipe (28), a water injection cavity being formed between the plugging devices and the borehole, the partial pressure assembly (49) being mounted at the tail end of a front part plugging device (35) and a middle part plugging device (36), and being formed of a primary converter (6) and a secondary converter (39) for converting in stages the high-pressure water source in the connecting pipe (28) into a low-pressure water source to flow into the water injection cavity for detection; the plugging device comprises a water leakage pipe (3), a rubber bladder (5), and a joint, the rubber bladder (5) being wrapped around the outside of the water leakage pipe (3) and being fixed at two ends of the joint by means of a fastening ring (24), forming a plugging cavity (30) with the water leakage pipe (3). The present apparatus uses the same external water source to implement a plugging process and a detection process and operate under the respective pressures thereof, stabilises pressure conversion, and integrates plugging and side leakage systems, solving the problem of the winding of the drill rod and hose during the propulsion process, and also implementing multi-section measurement for each propulsion and improving measurement efficiency.