绥滨坳陷城子河组泥岩盖层封闭能力综合评价

Comprehensive evaluation procedure of sealing capability of mudstone caprocks in early exploration period in Chengzihe formation of Suibin Depression,Sanjiang Basin

在分析绥滨坳陷城子河组泥岩盖层宏观发育特征及地球物理信息所反映的微观封闭特征的基础上,选取孔隙度、盖层厚度、单层厚度、泥地比及沉积环境等参数定义了评价泥岩盖层封闭能力的综合评价系数,并对城子河组泥岩盖层进行了综合评价。分析表明,该区城子河组泥岩盖层分布较广,单层厚度小,横向连续性差,但总厚度较大,以叠合累加方式对油气藏起封盖作用;中、西部地区泥质盖层质量相对较好,封闭能力较强。

Based on the analysis of macroscopic development feature and the microscopic sealing characteristics reflected by geophysics information,the comprehensive evaluation coefficient was defined and calculated to evaluate the sealing capability of the mudstone caprocks in Chengzihe formation of Suibin Depression,Sanjiang Basin according the factors of porosity,total thickness of caprocks,single cap formation thickness,ratio of mudstone/forma-tion and sedimentary environment.The analysis results show that the mudstone covering strata have the characteristics of wide distribution,small thickness,weak continuity in horizon and great total thickness in this district.The thick mudstone caprocks can preserve the oil and gas reservoirs by means of stacking.The quality of the mudstone caprocks in the middle and west region is preferable with strong sealing capability.