The Marine Shale Gas-rich Zones Geophysical Prediction and Evaluation Techniques in South China

Abstract

The marine shale gas exploration and development region in South China is in the steep mountains with many well developed faults. The occurrence state of the Silurian and Cambrian shale formation changes dramatically, their exploration and development activities have only started recently, and the drilling cost is very high. Therefore, it is the key for the success of the marine shale gas exploration and development to search for and predict the “sweet spots” or shale gas-rich zones within the shale gas reservoir, to select the location of shale gas exploration and production wells and to design the horizontal wells trajectory. This article introduced the integrated workflow of rock physics analysis, mineral composition prediction, wide azimuth 3D pre-stack and post-stack seismic date to map fracture distribution, pre-stack elastic parameter sensitivity analysis, and the integrated inversion of TOC and brittleness parameters of shale gas formation. It summarized and formed the geophysical prediction and evaluation techniques for marine shale gas exploration and development in south China. These techniques have been applied to the shale gas “sweet spot” prediction and evaluation, exploration well deployment, and horizontal well design and optimization in the national shale gas exploration and development demonstration blocks in MA area of South China.