句容地区SK1井盖层封闭性研究

A Study of the Cap Formation Sealing Capability of SK1 Well in Jurong Region

王小群

WANG Xiao-qun

中石化集团 江苏油田分公司 地质科学研究院, 江苏 扬州 225009

Geological Research Institute of Jiangsu Branch of SINOPEC, Yangzhou 225009, China

SK1井是句容断陷中央隆起带上的一口科学探索井,全井共发现油斑、油迹、荧光显示118m/24层,从油气显示丰富但显示级别普遍较低、全井未见油气层来看,该井油气运移十分活跃但在保存条件上存在不足。该井钻遇白垩系浦口组、三叠系青龙组、二叠系龙潭组和志留系高家边组四套泥岩、含膏泥岩盖层。文章系统地分析了各套盖层的宏观、微观及电性特征,较全面地评价了各套盖层的封闭性能,并加以分类。通过对影响盖层封闭有效性的地质因素的分析,认为多期构造运动和上覆陆相地层厚度薄是造成本井盖层封闭条件不佳的主要因素。

SK1 well was a scientific exploration well on central mole track of Jurong fault depression. The 118m shows including oil flecked, oil trace and fluorescence in 24 layers in this well. Abundance shows with low show level and no hydrocarbon reservoirs indicated that hydrocarbon migration in this well was active, but preserve condition was insufficiency. Four cap formations of mudstone and mudstone with gypsum were drilled in this well as K2p, T1q, P2l, S1g. This paper systematically analyzes the macroscopical, microcosmic and electrical characters of cap formations. Sealing capability of each cap formation was comprehensively evaluated and classified. Through analysis of geological factors which influenced validity of cap formations, it was considered that multi-period tectonic movements and thin continental facies cover formation were main factors that caused relatively poor cap formation sealing conditions.