陕北马岭地区延长组长71储层特征及评价

综合应用岩心、铸体薄片、扫描电镜、x射线衍射、粒度及压汞曲线等资料，对马岭地区长71储层的岩石学特征、物性特征、孔喉特征和非均质性等进行了研究。结果表明：马岭地区长71储层属于低孔一特低孔、超低渗一特低渗储层，非均质性强；影响储层储集性能的主要因素为沉积环境、骨架颗粒性质及成岩作用。沉积环境是储层物性差的根本原因，后期成岩压实和胶结作用使储层物性变差，溶蚀作用对储层有一定的改造作用。根据储层物性参数及孔隙结构参数，将研究区储层分为4类，马岭地区长71储层以Ⅲ类为主。

Characteristics and assessment of the Chang-71 reservoirs from the Yanchang Formation in the Maling region, northern Shaanxi

The petrographic, physical and pore throat characteristics and heterogeneity of the Chang-71reservoirs from the Yanchang Formation in the Maling region, northern Shaanxi are discussed on the basis of core observation, cast section, scanning electronic microscope, X-ray diffraction analysis, grain-size analysis and mercury-injection curves. The Chang-71reservoirs in the Maling region are characterized by low to extralow porosity, uhralow to extralow permeability and intense heterogeneity. The main factors influencing the reservoir capacity include sedimentary environments, nature of sketchetal grains and diagenesis. The sedimentary environments, paulopost diagenesis and cementation are responsible for poor physical properties of the reservoirs, and dissolution led to the modification of the reservoirs. In the light of the physical and porosity parameters, the reservoirs in the study area may be classified into four types, and the Chang-71 reservoirs in the Maling region are dominated by the Ⅲ type.