At present, relatively few drilling surveys have been conducted on coral reefs, and comprehensive geological info on coral reefs is difficult to obtain. However, research of coral reef is of great importance to our development and exploitation of maritime resources. The survey of South China Sea some Islands saw China’s first usage of digital borehole camera technology, which resulted in a large amount of first-hand geological data. Because the coral reef, special rock mass, integrity evaluation is very difficult, we proposed the RMDI and coring rate comparative analysis method. The evaluation method is applied to the South China Sea some Islands, and the evaluation results prove generally consistent with actual cores. The results indicate that: (1) high-resolution borehole images can provide reliable results for evaluation of coral reef integrity; (2) The RMDI and coring rate comparative analysis method is a feasible approach for the evaluation of coral reef integrity along the full or partial depth of a borehole.
Risk analysis of extended reach wells in the Liuhua Oilfield, South China Sea, based on comprehensive fuzzy evaluation method
