蜀南地区S井气水产出特征及储量变化研究

蜀南地区茅口组有水气藏储层非均质性强,气水关系复杂,气藏采收率偏低。本文以该地区S井为例,在气藏地质特征及开发动态特征相结合的基础上,对研究区储层地质模型、气水关系等进行细致分析,认为缝洞型储层基质低孔低渗,不具备储渗能力,溶洞和裂缝是主要的储渗空间,储层地质模型可以描述成洞穴系统和裂缝网络的组合;水体自身能量有限,气体驱动是气藏产水的主要驱动力,生产过程中一般存在多个气水空间相互进行能量补充,表现为气井气水产出特征极为复杂;气井生产后期存在压力下降缓慢甚至上升的现象,直接进行储量计算带来较大的误差,根据生产特征划分为多个阶段进行储量计算,后期增加的储量即为被水体分隔的气体空间储量。

The heterogeneity of fracture and cave reservoir are seriously strong in Maokou Group of Shunan region, and the relationship between gas and water layers is very complicated.Based on the combination of reservoir geological characteristics and dynamic characteristics of the development, we took the S well for example,to analyze the reservoir geological model,gas and water relations in this paper,The reservoir of the study area was a typical fractured reservoir,with low matrix porosity and low permeability,and caves and cracks were the main reservoir and flow space.The reservoir geological model can be described as a combination of caves and the crack network.We believed that gas drive was the main driving force of water production in gas reservoir. Direct reserve calculation is bad to truth.So it should be divided into multiple stages.