鄂尔多斯盆地谭家营区长6储层基本特征及分类研究

Basic Characteristics and Classification of Chang 6 Reservoir in Tanjiaying District, Ordos Basin

摘要: 通过岩心观察、铸体薄片及扫描电镜观察、压汞等物性测试，研究了鄂尔多斯盆地谭家营区长6储层的基本特征，选取厚度、岩性、毛管压力、物性等参数对储层进行分类与评价。研究结果表明，长6储层主要为分流河道和分流河道间沉积环境下发育的砂岩储层，碎屑组分以长石含量为最高，细砂的含量一般在70%以上，杂基含量中等；储集空间以原生孔隙、残余溶蚀孔及微裂缝为主，孔隙多被方解石胶结，部分被绿泥石胶结；储层孔隙度最大值为13.8%，最小值为2.5%，平均值为9.0%；渗透率最大值20.49 × 10⁻³ μm2，最小值0.01 × 10⁻³ μm2，平均值为0.85 × 10⁻³ μm2；孔隙度与渗透率相关性较好，相关系数达到0.84。长61储层比长62孔隙度较大，渗透率分布范围相对较窄，储层非均质性强，连通性差，具有弱亲油特征。主要为IIIa类和IIIb类储层，占各类储层总和的83.3%左右。

Abstract: Through the observation of cores, thin sections and scanning electron microscope observation, and mercury injection test, the basic characteristics of Chang 6 reservoir are studied. The reservoirs are classified and evaluated by taking parameters such as thickness, lithology, capillary pressure, physical properties, etc. The research result shows that the reservoirs of Chang 6 are mainly sandstone reservoirs developed in the sedimentary environment between distributary channels and distributary channels. The content of detrital components is the highest in feldspar, the content of fine sand is generally more than 70%, and the content of matrix is medium. The reservoir space is mainly composed of primary pores, residual dissolution holes and micro-cracks, and the pores are mostly cemented by calcite and partially cemented by chlorite, and the pores are usually cemented by calcite and partially cemented by chlorite. The maximum porosity of the reservoir is 13.8%, the minimum is 2.5%, and the average value is 9.0%. The maximum permeability is 20.49 × 10⁻³ μm2, the permeability minimum value is 0.01 × 10⁻³ μm2. The average value is 0.85⁻³ μm2. The correlation between porosity and permeability is good, and the correlation coefficient reached 0.84. The Chang 61 reservoir has larger porosity than the Chang 62 reservoir, relatively narrow permeability distribution, strong heterogeneity of the reservoir, poor connectivity and weak oil affinity. There are mainly IIIa and IIIb reservoirs, accounting for 83.3% of the total reservoirs.