SIMULATED EXPERIMENTAL STUDY OF IMPACT FRACTURING OF HYDRATE-BEARING SEDIMENTS

In the second round of test mining of natural gas hydrates in China, multi-stage perforation injection with horizontal wells was used to improve the extraction efficiency, which reveals the prospect for the application of hydraulic fracturing technology. However, the effect of perforation in hydrate-bearing sediments is still unclear and needs further study. Therefore, experimental studies to simulate impact fracturing in hydrate-bearing sediments have been carried out through two types of experiments: perforation and impact of falling weights. Through these experiments, the transformation law of the energy provided by the impact and the fracture area was analyzed, and it was found that the larger the loading speed of the impact was the more favorable to cracking; the larger the total energy provided and the shorter the time of action were, the more favorable to cracking the strata and generating a larger fracture area, but the efficiency of the energy transformed into fracture in the current experiments was not high, which needs to be further researched.