In recent years, the development of shale gas has been paid more attention in China. Since the first shale gas well drilled in 2009, the number of shale gas wells is increasing rapidly. In 2015, the yearly gas production reached 210 BCF. As a matter of fact, China is experiencing an era of shale gas boom regardless of the low oil price in the international market.
From 2010, to speed up the development process, four national shale gas demonstration plots were built, including CW plot, JSB plot, ZT plot, and YA plot. After the JSB plot obtained the first breakthrough in 2013, CW plot took its important step in the development of shale gas resources in 2015. Due to the topographic inequality of Sichuan basin, the multi-well pad was used to solve the problem of well deployment difficulty. In 2013, continuous operation including batch drilling, factory fracturing and gas testing for 13 wells has been successfully conducted in tight-gas reservoir, which provides valuable experience for the shale gas operation model.
This paper aims to describe the continuous operation model and its effectiveness in the pad W202H2 of block Weiyuan (CW plot), located in the southwest China. To improve the cost effective production while maintaining a responsibility for health, safety, and the environment is the most important advantage of the model. To improve the operation effectiveness, two rounds of 3-well zipper fracturing are conducted. The cooperation among water supply, fluid mixing, sand supply, and pumping ensures the continuous fracturing. A total fluid and proppant injection of 189023m3 and 6677m3 for 102 stages/299 clusters are completed in 44 days, which makes the best efficiency record in China. Compared with the single well fracturing, the economic benefit is highly improved and about 6 million dollars are saved. Moreover, the continuous operation model shows a large effective stimulated reservoir volume (ESRV), which is in accordance with the micro-seismic monitoring result.the maximum daily production and wellhead pressure reaches to 32×104m3 and 44MPa, respectively.