Optimization and practice of the technologies for the green development of Nanchuan Shale Gas Field

Shale gas development and utilization provides an important support for the optimization of energy structure and the improvement of atmospheric environment quality in China. However, the key technologies for the green development of shale gas (e.g. harmless and resource treatment of oil based cuttings, produced water treatment to the standard, high noise, greenhouse gas emission and land occupation) haven’t been solved thoroughly. Moreover, China’s shale gas development is still in the initial stage and ecologic environment protection norms and technologies need improving. In order to provide the reference for the development of shale gas in a larger scope in the future, this paper analyzed the ecologic environment problems in the development process of Nanchuan Shale Gas Field which is sensitive to surface environment and has complex geohydrologic geological conditions. Then, based on existing technologies, a series of optimization studies were carried out on the pollution process prevention and control technologies (such as pollution source reduction technology of intensive land use and electric power drilling and fracturing, full-hole gas tightness detection technology, inflow process testing technology and double-throttle and wet gas metering and production technology) and the comprehensive waste utilization and produced water standard treatment technologies (such as large-scale cement kiln collaborative treatment of oil based cuttings and produced water fracturing fluid recycling). The field practice effects show that this series of technologies reach the goal of “energy saving, consumption reduction, pollution diminish and efficiency improvement”, realizing good field application achievements, and they can be used as the reference for the green development of shale gas in the other blocks in China.