应用毛管压力与相渗曲线研究复杂碳酸盐岩储层生产能力——以土库曼阿姆河右岸M区块气田为例

Study on production capacity of complex carbonate reservoir by capillary pressure curve and relative permeability curve

土库曼阿姆河右岸M区块气田储层非均质性强、气水过渡带长、气水关系复杂,常规测井解释对识别流体界面、气水过渡带难度较大且具有较大的不确定性。针对这些困难,通过毛管压力曲线形态及退汞效率对不同孔隙级别下的储层进行评价分类和有效性分析,得出储层有效孔隙度下限为3.5%,与实际测试结果匹配良好。综合毛管压力曲线、相渗曲线研究了气藏高度和气水分布特征,确定纯气产层的最低闭合高度应达到75 m,气藏气水过渡带较厚约为50 m,结合相渗曲线等渗点得出气水过渡带上部26 m左右为经济效益产层。

The gas reservoirs in the M block of Amu River are characterized by strong reservoir heterogeneity,wide gas-water tran-sition zone and complex gas-water relationship.It is difficult and inaccurate for conventional logging interpretation to identify the fluid interface and gas-water transition zone.Considering these problems,we evaluate and classify reservoirs of different porosity and analyze the effciency of them by analyzing the shape of capillary pressure curve and efficiency of mercury withdrawal.Our conclusion is that,the lower limit of porosity is 3.5%,which matches well with the actual test data.We also study the height of the gas reservoir and distribution characteristic of gas and water by capillary pressure curve and relative permeability curve.And,we draw conclusions that the minimum close-height is up to 75 m,the gas-water transition zone is about 50 m,and the economic beneficial layer is within the upper part of 26 m in the gas-water transition zone according to the intersection point of relative per-meability curve,which can provide reference of avoidance of water in gas well production.