致密砂岩气藏动态水锁定量评价新方法

致密砂岩气藏开发过程中普遍存在水锁现象，其严重影响气相渗透率及采收率，极大制约了气藏的高效开发，因此水锁程度的准确评价对于气藏精细开发尤为重要。本文通过致密砂岩储层微观孔喉结构分析及基本渗流原理，结合动态生产参数，建立了孔隙度、生产压力梯度与水锁效应之间的数学联系，创新性的提出了动态水锁指数的概念，从而对生产中的水锁程度进行定量化的表征。进而将微观下的表征结论推广到宏观，从微观尺度到宏观尺度对水锁状况进行定量化的分析，明确了不同生产压力梯度与孔隙度对水锁效应的影响程度，建立了一套动态水锁程度定量评价新方法。通过对研究区实际生产资料进行对比分析，进一步验证了该评价方法的准确性与可行性，运用该方法能够对致密砂岩气藏中的水锁程度进行定量化的分析和监测，从而为剩余气分布状况的明确及下一步增产工艺措施的设计提供指导。

New quantitative evaluation method of dynamic water lock in tight sandstone gas reservoir

Water lock is a common phenomenon in the development of tight sandstone gas reservoirs, which seriously affects gas permeability and recovery, and greatly restricts the efficient development of gas reservoirs. Therefore, the accurate evaluation of water lock degree is particularly important for the fine development of gas reservoirs. In this paper, through the analysis of microscopic pore throat structure and basic seepage principle of tight sandstone reservoir, combined with dynamic production parameters, the mathematical relationship between porosity, production pressure gradient and water lock effect is established, and the concept of dynamic water lock index is innovatively proposed, so as to quantitatively characterize the degree of water lock in production.Furthermore, the microscopic characterization conclusion is extended to the macroscopic, and the water lock condition is quantitatively analyzed from the microscopic scale to the macroscopic scale. The influence of different production pressure gradients and porosity on the water lock effect is clarified, and a new method for quantitative evaluation of dynamic water lock degree is established.Through the comparative analysis of the actual production data in the study area, the accuracy and feasibility of the evaluation method are further verified. The method can be used to quantitatively analyze and monitor the degree of water lock in tight sandstone gas reservoirs, so as to provide guidance for the determination of the distribution of remaining gas and the design of the next stimulation process measures.