中拐凸起598断块上乌尔禾组气藏低产因素分析

中拐凸起上乌尔禾组储层砂体厚度大,非均质性强,相邻断块间产能差异大。为分析598断块低产因素,应用录井、测井、岩心、岩石薄片、分析化验等资料,对598断块存在明显产能差异的邻井进行储层岩石学、物性、储集空间、孔隙结构特征及含油气性对比研究。研究表明,598断块低产井的储层岩石塑性强,碎屑颗粒间主要呈线接触,压嵌式胶结,储层低孔低渗,孔喉配置关系差。储层物性差、孔隙结构复杂是低产的根本因素;黏土矿物含量高,存在一定水敏性是造成低产的重要因素;孔喉配置差,微细吼道发育,地层能量亏空,近井筒地带存在水锁效应也是不可忽略的因素之一。

Low production factors analysis of gas reservoirs in upper Wuerhe formation in 598 fault-block of Zhongguai uplift

The sand body of upper Wuerhe formation of Zhongguai uplift has the characteristics of big thickness, strong heterogeneity and great productivity difference between adjacent fault blocks. In order to analyze the low production factors in 598 fault-block, the data of mud logging, gamma logging, core, rock thin sections and analytical analysis were applied to conduct a comparative study on petrology, physical properties, reservoir space, pore structure characteristics and oil-gas bearing characteristics of adjacent wells with obvious productivity differences in 598 fault-block. The results show that the reservoir rock of low production wells in 598 fault-block is of strong plasticity, and the clastic particles are mainly in linear contact with each other, low porosity and permeability, and poor relationship between pore throat configuration. Poor reservoir physical properties and complex pore structure are the fundamental factors of low production. The high content of clay minerals and the presence of water sensitivity are important factors for low production. Poor hole throat configuration, micro-roar development, formation energy loss and water lock effect near the wellbore are important factors that cannot be ignored.