致密气藏开发过程水相圈闭损害机理及防治研究进展

在致密气藏开发过程中，随气藏压力下降，边底水侵入会导致水相圈闭损害的发生；水相圈闭损害不仅导致气藏采收率下降，且增加开采成本，延缓开发进程，严重制约气藏的开发效果。分析了水驱气藏开发过程中水相圈闭损害机理，水相圈闭损害发生的影响因素、过程机理、预防措施、治理技术，指出致密气藏的非均质性、水湿性、超低含水饱和度、高毛管压力、裂缝发育和压降等是诱发水相圈闭损害的主要因素，和裂缝一孔隙间水相渗吸、水相圈闭气的形成、水相圈闭动力学模型和水相圈闭损害防治研究等方面的主要进展，认为在含水致密气藏开发过程中，应采取早期预测、主动防御、优选开发方式、合理安排排水采气井及其产量、适时调整压力场分布及整体控制均衡开发等措施，以便有效地预防和治理水相圈闭损害。

ADVANCES ON DAMAGE MECHANISM AND ITS CONTROL OF AQUEOUS PHASE TRAPPING DURING EXPLOITING TIGHT GAS RESERVOIRS

As the pressure decreases, the encroachment of edge water and bottom water can induce the damage of water phase trapping in the exploitation of tight gas reservoirs. It seriously restraint the development, and may decrease the recovery by more than 50%. At the same time, it will increase the cost of production and retard the development progress. This paper analyzes the influential factors, process and mechanism of the aqueous phase trapping damage in water-drived reservoirs, and points out that the heterogeneity, wettability, ultra low initial water saturation, high capillary pressure, fractures and pressure drawdown are the dominant factors of the damage. Then, the paper discusses the new progress of the imbibition between fractures and matrixes, the formation of trapping gas, dynamic models, and the prevention and treatment to water phase trapping. The measurements, such as early predication, initiative precaution, optimized development means, rational well location and output of drainage gas recovery, timely adjusting the distribution of pressure field, and equilibrium exploitation, should be adopted for the prevention and treatment of the damage. Finally, the further research suggestions are pointed out.