典型底水气藏开发特征及适宜开发对策启示

Development characteristics of typical bottom water gas reservoirs and enlightenment of suitable development countermeasures

四川盆地高石梯-磨溪灯二段气藏和太和气区灯二段气藏储层非均质性强,多尺度孔(洞)、缝发育,具有裂缝-孔洞型底水气藏特征,开发过程中面临底水沿缝洞快速侵入风险,开采难度大,缺乏可借鉴的有效开发技术对策。为科学开发这类裂缝性底水气藏,并为其他类型底水气藏提供技术参考,以中外典型底水气藏为研究对象,深入剖析各类型底水气藏的开发现状、地质特征和开发对策,明确影响底水气藏采出程度的主控因素,总结底水气藏控水治水对策,并在此基础上提出针对强非均质裂缝-孔洞型底水气藏的适宜开发对策。研究发现,裂缝发育程度、隔夹层发育程度和水体能量强弱是影响底水气藏开发效果的主要地质因素,深化气藏特征认识是提高底水气藏采出程度的基础,合理的开发技术对策可减缓底水非均匀侵入,均衡开采是实现裂缝-孔洞型底水气藏高效开发的关键。具体开发技术对策启示包括:(1)井震联合精细刻画储层缝、洞分布规律,动静资料结合持续深化气藏地质特征认识;(2)制定合理开发技术界限,加强气藏动态监测管理;(3)建立底水气藏水侵预测模拟体系,形成气藏全生命周期控水治水技术。

The gas reservoirs of the second Member of Dengying Formation both in Gaoshiti-Moxi area and Taihe gas area have strong heterogeneity and multi-scale fractures and pores(caves),showing the characteristics of fracture-cavity gas reservoirs with bottom water. It is difficult to develop such reservoirs due to the rapid intrusion of bottom water along the fractures and caves and no effective technologies for reference. In order to scientifically develop such fractured gas reservoirs with bottom water and provide technical reference for other gas reservoirs with bottom water,this paper takes the development characteristics of typical gas reservoirs bottom with water both in China and abroad as the research object,deeply analyzes the development status,geological characteristics and development technologies of various gas reservoirs with bottom water,clarifies the main controlling factors affecting the the reservoir recovery and summarizes the technologies for controlling water in the reservoirs. In addition,the paper puts forward appropriate strategies for developing fracture-cavity bottom water gas reservoirs with strong heterogeneity. The study found that the the fractures,interlayers and water energy are the main geological factors that affect the development effect of the reservoirs. Furthermore,the reservoir recovery can be improved by deepening the understanding of gas reservoir characteristics. Reasonable technical technologies can slow down non-uniform bottom water intrusion. Balanced production is the key to realizing the efficient development of fracturecavity gas reservoirs with bottom water. Specific technical strategies are as follows.(1)The distribution law of fractures and caves in the reservoirs shall be precisely depicted by a well-seismic combination,and the understanding of the geological characteristics of the reservoirs shall be continuously deepened under dynamic and static conditions.(2) The reasonable technical limits shall be made to strengthen the monitoring and management of the reservoirs.(3)The prediction and simulation systems for the water intrusion in the reservoirs shall be constructed to develop a water control strategy for the whole life cycle of the reservoirs.