基于双重介质复合气藏模型的潜山储层试井解释方法  

Well test interpretation method for buried hill reservoir based on dual medium composite gas reservoir model

作　　者：许峰 于伟强 李伦 XU Feng;YU Weiqiang;LI Lun(China-France Bohai Geoservices Co.,Ltd.,Tianjin 300452,China;Downhole Technology Service Company,CNPC Bohai Drilling Engineering Company Limited,Tianjin 300283,China)

机构地区：[1]中法渤海地质服务有限公司,天津300452 [2]中国石油集团渤海钻探工程有限公司井下技术服务分公司,天津300283

出　　处：《油气井测试》2019年第3期7-13,共7页Well Testing

摘　　要：渤中凹陷某区块太古界潜山储层存在裂缝发育,气藏在径向和纵向上非均质性强,单纯采用双孔、径向复合等模型存在一定的局限性。通过建立适合本区块潜山储层的双重孔隙介质复合气藏模型,求取模型的Laplace空间解,经过Stehfest数值反演求得井底压力解析解,并对相关影响参数进行敏感性分析。结果表明,内外区储能比主要影响导数曲线过渡段下凹的深度;内外区窜流系数主要影响导数曲线下凹的相对位置,且内区窜流系数足够小时,内区系统拟径向流段和外区流动阶段部分特征会被掩盖。利用该模型对渤中凹陷潜山储层BZ-A1、BZ-A2井试井资料进行解释,得到两井内、外区界面半径分别为79.3m和92.6m,试井解释曲线拟合程度较好,为该区气藏的储层评价和动态开发提供了依据。The reservoirs of the Archean buried hills in a block in the Bozhong sag have the characteristics of fracture development,and the gas reservoirs were characterized by high heterogeneity in the radial and longitudinal directions.Therefore,the use of dual-pore or radial composite models for well test interpretation has certain limitations.In order to solve this problem,a dual-pore composite gas reservoir model suitable for the buried hill reservoir of this block was established and the Laplace spatial solution of the model was obtained.Then the spatial solution can be inversed by Stehfest numerical to obtain the analytical solution of the bottom hole pressure,so as to analyze the sensitivity of the relevant influence parameters.The results showed that the energy storage ratio of the inner and outer zones mainly affected the depth of the concave section of the derivative curve;the turbulence coefficient of the inner and outer zone mainly affected the relative position of the concave curve in the derivative curve.When the inner zone turbulence coefficient is small enough,some features of the inner zone system′s pseudo-radial flow zone and outer zone flow phase would be masked.The well test data of well BZ-A1 and well BZ-A2 in the buried hill reservoir of the Bozhong Sag were interpreted by the model and the result showed that the interface radius of the inner and outer zones of the two wells were 79.3 m and 92.6 m respectively,and the fit degree of well test interpretation curve was better.The new method provided a basis for reservoir evaluation and dynamic development of gas reservoirs in this area.

关 键 词：潜山储层 双重介质 复合模型 试井解释 探测半径 压力动态特征 储能比 窜流系数 

分 类 号：TE353[石油与天然气工程—油气田开发工程]