Abstract:
Problems occur when drilling horizontal wells in the tight gas reservoirs in Sulige Gas Field. They include low ROP, contradiction between formation collapse and lost circulation, long drilling cycles, etc. By analyzing the formation drilling challenges, technical research of factory drilling of horizontal wells was conducted to determine the best path forward. The areas studied included drilling mode optimization, “high efficiency PDC bit + high-power PDM” aggressive drilling technology, mode optimization of wellbore trajectory control technology with different offsets and sectional optimization of strongly inhibitive low-density CQSP-4 anti-collapse drilling fluid system. After the study was completed, recommendations were made regarding forming a new optimized fast drilling technology for horizontal wells in the tight gas reservoirs in Sulige Gas Field. In 2019, this technology was applied in 56 wells in Sulige Gas Field, with an average ROP of 12.76 m/h, an average drilling cycle of 39.12 days, and a well construction period of 52.20 days. Compared with those in 2018, in 2019 the ROP increased by 23.16%, the drilling cycle was shortened by 23.71% and the well construction period was reduced by 16.02%. The research and application showed that the key technology for horizontal wells drilling in the tight gas reservoirs in Sulige Gas Field had a remarkable effect on drilling acceleration, which provided technical support and the basis for best practices for the efficient development of the tight gas reservoirs in Sulige Gas Field.