鄂尔多斯盆地南泥湾油区长6致密储层有效厚度评价

Evaluation of Effective Thickness of Chang-6 Tight Reservoir in Nanniwan Oil Area,Ordos Basin

有效厚度的识别是石油地质储量计算的核心,利用钻井、测井、录井、岩心实验等地质资料,综合储层特征、四性关系研究成果,最后建立合理的有效厚度评价标准。分析表明,鄂尔多斯盆地南泥湾油区长6油层组属于低-特低孔、致密储层,方解石胶结作用是导致致密的主因,通过构建孔、渗、饱测井解释模型,及产油层四性响应特征,确定研究区长6油层组有效厚度下限:孔隙度为8%、渗透率为0.30 mD、声波时差为223μs/m、深感应电阻率为30Ω·m且RILD≥-1.1667×Ac+306.33,含油饱和度为40%。

The identification of effective thickness is the core of the calculation of petroleum geological reserves.Based on the geological data such as drilling,logging,logging and core experiment,and the research results of reservoir characteristics and four property relations,a reasonable effective thickness evaluation standard is finally established.The analysis shows that the Chang-6 oil layer group in Nanniwan oil area of Ordos Basin belongs to a low to ultra-low porosity and tight reservoir,and calcite cementation is the main factor leading to the compaction.Through the construction of well logging interpretation model of porosity,permeability and saturation,and the response characteristics of the four properties of the oil layer,the lower limit of the effective thickness of the Chang-6 oil layer group in the study area is determined:porosity is 8%,permeability is 0.30 mD,and acoustic time difference is 223μs/m,deep induction resistivity is 30Ω·m,and RILD≥-1.1667×Ac+306.33,oil saturation is 40%.