基于水侵预警的边水气藏动态预测模型

Dynamic Prediction Model of Edge-water Gas Reservoir Based on Water Invasion Early Warning

对于水驱气藏,水侵可以起到维持地层压力、保持气井产量的正面作用。但当水锥突破至井底后,受气水两相渗流的影响,气相渗透率急剧降低,严重影响气井生产。如何准确预测边水推进距离,做到水侵的提早预警,对于气藏开发技术对策调整具有重要的意义。基于体积平衡原理、以边水气藏水侵圆环为研究对象,建立的边水气藏水侵预警方程能预测气藏的可能见水井及其见水时间,可实现水侵气藏的早预警、早调整;并结合产量预测、压力预测和水侵量预测模型,建立了一种新的基于水侵预警的边水气藏动态预测模型,应用于PG气田水侵气藏的见水井、见水时间和相关开发指标的动态预测,与实际生产对比表明,该模型预测结果基本吻合,能够指导气藏的水侵预警与及时调整。

Water invasion can maintain the reservoir pressure and keep the production of gas wells for water-drive gas reservoir. The gas well production performance will be affected by the sharp decreasing of gas permeability when the water breaks into the well-bottom. It is very important significance for development technical adjustment to accurately predict the distance of edge water advancing and to early warn for the water invasion. Based on the principle of volume balance of water invasion circle of edge water gas reservoir,the formula of water invasion proximity warning was firstly proposed,then the prediction models of production rate,pressure and water invasion volume were considered in this article,and a new prediction model of edge-water gas reservoir production performance considering water invasion proximity warning was proposed,and a real case study on Puguang Gas Reservoir was conducted finally.