论文部分内容阅读
陕北斜坡东部致密油藏含油层位大多在延长组,通过岩心及测井资料等对G区长4+5储层的非均质性进行分析研究。不同渗透率韵律变化是不同沉积作用下各沉积相的直观体现,同时也反映了储集砂体的非均质性:层内非均质性主要体现为沉积韵律性、沉积构造、砂泥组合形式等方面的差别,层间非均质性通常用砂层钻遇率、单砂层厚度、砂地比等参数来描述,平面非均质性主要表现在孔隙度和渗透率的平面特征上。研究结果表明,从层内非均质性来看,G区长4+5层内非均质性相对较弱,平均夹层数长4+5-1~2最大,其次为长4+5_1~1、长4+5_2~2,长4+5_2~1最小;层间非均质性分析认为G区储层有相对较强的非均质性;平面非均质性反映了不同层段的孔渗变化较为明显,也说明了G区致密砂岩储层非均质性普遍较大,区内物性相对较差,油层相对不发育,平面上主要发育于分流河道砂体中心部位。
Most of the oil reservoirs in the tight oil reservoirs in the eastern part of the northern Shaanxi slope are mostly in the Yanchang Formation. The heterogeneity of the 4 + 5 reservoirs in the G zone has been studied through core and well logging data. The rhythm variation of different permeability is the direct manifestation of each sedimentary facies under different sediments, and also reflects the heterogeneity of reservoir sand bodies. The intra-layer heterogeneity mainly reflects sedimentary rhythm, sedimentary structure, sand and mud combination And so on. Interlayer heterogeneity is usually described by parameters such as sand drilling rate, thickness of single sand layer, sand ratio, etc. Plane heterogeneity is mainly manifested in the plane features of porosity and permeability. The results show that the in-layer heterogeneity of 4 + 5 layers in G zone is relatively weak with the average number of 4 + 5-1 ~ 2 being the largest, followed by 4 + 5 ~ 1, length 4 + 5_2 ~ 2, length 4 + 5_2 ~ 1 is the smallest. Interlayer heterogeneity analysis shows that reservoir G has a relatively strong heterogeneity. Plane heterogeneity reflects the distribution of The pore infiltration is obvious. It also shows that the tight sandstone reservoir in G zone is generally heterogeneous, with relatively poor physical property, relatively undeveloped reservoir and mainly developed in the center of distributary channel sandstone.