塘沽油田古近系沙河街组沙三段5油组储油层为泥质白云岩,形成于断隆背景下的微咸—半咸、弱还原较深水湖相碳酸盐岩沉积环境,白云岩为次生交代成因,白云石含量低(65%),泥质含量高(30%),储层电性特征具有高自然伽马、高中子、低密度、中声波时差、低—中电阻率的特点,属中—高孔、低渗储层,储集类型为孔隙、裂缝双重孔隙介质,在岩心孔隙度分析资料较少的地区,有效孔隙度的解释方法成为储层评价及储量参数研究的难点.通过应用薄片、岩心物性分析资料及测井资料,采用了交会图、统计图等技术手段,开展了泥质白云岩岩性识别、储层特征研究、储层泥质含量及裂缝孔隙度、基质孔隙度的解释方法研究,为今后类似储层的评价研究提供了方法和依据.%The oil reservoir of five oil groups in the third member of Shahejie Formation of Paleocene in Tanggu Oilfield is argillaceous dolomites which developed in brackish, weak reductive and deeper lacustrine facies carbonate deposit environ-ment under the background of faulted uplift. Dolomite is of secondary replacement genesis, with low content of dolomite ( 65%) and high shale content ( 30%) . The electrical features of the reservoir are characteristic of high natural gamma, high neutron, low density, middle acoustic time difference, and low-middle resistivity. It has medium-high porosity and low permeability, and double porosity of pores and fractures. In the area with less data for core porosity analysis, the ap-proach for interpreting effective porosity becomes the difficult for reservoir evaluation and reserves parameters research. By applying thin slice and core property analysis data as well as logging data, we adopted such technical means as crossplot and statistical chart for interpretive method study on lithology identification of argillaceous dolostone, reservoir features, reservoir shale content and fracture porosity, and matrix porosity, providing means and basis for further evaluation of similar reservoirs.
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