德惠断陷致密气藏直井高密度完井体积压裂技术

High-density completion volume fracturing technology for vertical wells in tight gas reservoirs in Dehui fault depression

德惠断陷致密气储集层致密,物性差,自然产能低,常规直井压裂技术难以实现区块效益开发。为增大改造体积和提高单井产能,明确储集层体积压裂可行性,利用水平井细切割体积压裂思想,针对纵向跨度大的直井开展精细分层、多簇射孔、多级暂堵转向和缝网压裂于一体的高密度完井体积压裂技术攻关和现场试验,形成了致密气直井高密度完井体积压裂技术,实现全井段改造;配合新型纳米微乳助排压裂液体系造复杂缝网和多粒径组合支撑缝网,极大限度提高致密气储集层纵向及横向改造体积。2018-2019年现场试验5口气井,均获工业气流,平均日产天然气10.8×10^4 m^3,最大无阻流量28.6×10^4 m^3/d,实现单井产气量的突破,为致密气藏增产改造提供了技术支撑。

The tight gas reservoir in Dehui fault depression is characterized by tight reservoir, poor physical properties and low natural productivity, so it is difficult to realize beneficial development of the block by conventional vertical well fracturing technology. In order to increase the reconstruction volume, improve the productivity of single well and clarify the feasibility of reservoir volume fracturing, the high-density completion volume fracturing technology and field test are carried out for vertical wells with large longitudinal span, including fine stratification, multi cluster perforation, multi-stage temporary plugging diversion and fracture network fracturing, forming the high-density completion volume fracturing technology for tight gas vertical wells and realizing the fracturing of the whole well section. The new nano microemulsion cleanup additive fracturing fluid system is combined to create the complex fracture network and multi particle size combined support fracture network is made, which greatly improves the vertical and horizontal fracturing volume of tight gas reservoir. From 2018 to 2019, 5 gas wells were tested, and all of them produced industrial gas flow. The average daily natural gas output is 10.8×10^4 m^3, and the maximum open flow rate is 28.6×10^4 m^3/d, which achieved a breakthrough in single well gas production and provided technical support for stimulation and fracturing of tight gas reservoirs.