中国致密砂岩气藏勘探开发关键工程技术现状与展望

Current status and prospect of key techniques for exploration and production of tight sandstone gas reservoirs in China

中国致密砂岩气藏具有低孔低渗、裂缝发育、局部超低含水饱和度、高毛管压力、地层压力异常、高损害潜力等工程地质特征。经过10多年持续攻关,已经形成了裂缝性致密砂岩气藏保护屏蔽暂堵技术系列、气体钻井及全过程欠平衡完井保护技术系列,成功试验了CO2泡沫压裂液体系、N2增能压裂液体系和低摩阻高黏度瓜胶有机硼冻胶压裂液大排量套管注入的大型压裂工艺。实践证明,贯彻储集层保护与改造并举的方针,实现全过程储集层保护是致密砂岩气藏及时发现、准确评价和经济开发的重要保证。建议加强致密砂岩岩石物理学基础研究,重视水平井及特殊工艺井的钻井及完井储集层保护配套技术应用,大力提高增产改造技术的适应性,形成针对不同类型致密砂岩气藏的配套技术系列。

Tight sandstone gas （TSG） reservoirs in China display such characteristics as low porosity and permeability, naturally fractured, partially ultra-low water saturation, high capillary pressure, abnormal formation pressure and high damage potential. Over 10 years, a set of protection technology of temporary shielding, gas drilling, and under balanced completion during entire well operation have been formed for fractured TSG reservoirs. The fracturing fluids include CO2 foam, Ne energized water-based fluid, and guar organoborated gelling fluid with low frictional resistance and high viscosity.Massive hydraulic fracturing by high injection rate thraugh casing has been applicd in fields,Employing both darmange control and stimulation and realizing protection technology are the important guarantee for pay zone detection, precise evaluation and economic development. sandstones, improve reservoir protection and complex wells, enhance applicability of TSG reservoirs. It is proposed to strengthen fundamental research on petrophysics of tight matching technology during drilling and completion, propagate horizontal wells of fracturing stimulation, and establish integrated technologies for different types of TSG reservoirs.