利用全气藏关井监测资料描述低渗有水气藏动态——以WBT石炭系气藏为例

Application of monitoring data with all gas well shut-in to dynamic description of low permeability and water-bearing gas reservoir: a case of WBT Carboniferous gas reservoir

王容 周源 何琦 李文 李菡韵 吴宜禄

中国石油西南油气田分公司勘探开发研究院，四川 成都 610051

Exploration and Development Research Institute, Southwest Oil & Gas Field Company, PetroChina, Chengdu 610051, China

WBT石炭系气藏属于低渗有水非均质碳酸盐岩气藏，目前已进入开发后期，产量年递减率15.1%。气藏受水侵影响，生产动态特征复杂，给下一步挖潜措施的制定带来了困难。为进一步深化对气藏开发后期动态特征的认识，排除井间干扰的影响，进行全气藏关井测压获得了可靠的动态监测资料。通过对测压资料的综合分析研究，掌握了气藏非均质性及地层压力分布的情况，明确了气藏水侵大小及强度，核实了气藏动态储量。与产量不稳定分析法描述的单井动态储量相比，水驱气藏物质平衡法计算的动态储量，可排除井间干扰的影响；与有水气藏数值模拟结果相比，利用全气藏关井监测资料描述的地层压力分布，能更精细刻画气藏内部的非均匀压力降，为明确气藏潜力及制定合理挖潜措施提供科学依据。

WBT Carboniferous gas reservoir, which belongs to low permeability, water-bearing and heterogeneous carbonate gas reservoir, has entered into the later development stage with the production decline rate 15.1% per year. The production dynamic characteristics of gas reservoir are complex due to water invasion, which makes it difficult in developing measures for remaining gas exploration. In order to further deepen the understanding of dynamic characteristics in the later period of development without well interference, the whole gas reservoir is shut in to obtain reliable dynamic monitoring data. Based on the comprehensive analysis of these dynamic data, the heterogeneity and reservoir pressure distribution is obtained, the water influx and intensity is defined, and the dynamic reserves are verified. Compared with the single well dynamic reserves obtained by rate transient analysis, the dynamic reserves calculated by material balance method of water drive gas reservoir could eliminate the influence of well interference; and compared with the numerical simulation results of water-bearing gas reservoir, the reservoir pressure distribution described by the monitoring data with all gas wells shut-in can depict the non-uniform pressure drop finely, which provides scientific basis for identifying the potential and formulating reasonable measures of remaining gas.

10.6056/dkyqt201906012