鄂尔多斯盆地华庆油田长8_1储层可动流体赋存特征及影响因素

针对鄂尔多斯盆地华庆油田长81储层可动流体赋存特征研究薄弱的现状,应用核磁共振、铸体薄片、恒速压汞等实验资料,对华庆油田长81储层可动流体的赋存特征和影响因素进行了研究。结果表明:不同物性的T2谱形态主要表现为双峰态,物性越好,可动流体饱和度越高,其中渗透率对可动流体参数的敏感性显著强于孔隙度;矿物成分成熟度、胶结及溶蚀作用是可动流体赋存特征的重要影响因素,其中伊利石含量、碳酸盐含量、高岭石含量对可动流体的赋存不利;绿泥石含量、矿物成分成熟度对可动流体的赋存具有一定的积极作用;喉道是引起微观孔隙结构内部非均质性的关键因素,制约着可动流体的赋存特征、流体渗流能力及油气采收率。

Characteristics of movable fluids in the Chang 81 reservoir, Yanchang Formation in Huaqing oilfield, Ordos basin and the influencing factors

The occurrence of movable fluids in the Chang 81 reservoir of the Huaqing oilfield in the Ordos basin is poorly understood. This study explored the characteristics of these movable fluids and their influencing factors by using nuclear magnetic resonance, casting thin sections and constant-speed mercury injection. The result shows that the T2 spectrum pattern of the samples with different physical properties display twin peaks. The better the physical property is, the higher the movable fluid saturation is. The sensitivity of permeability to movable fluids is significantly stronger than that of the porosity. The compositional maturities of the mineral, cementation and dissolution are the most critical factors controlling the occurrence of the movable fluids. Illite content, carbonate content and kaolinite content are harmful to the occurrence of movable fluids, but chlorite content and the maturity of mineral composition are good for it. The characteristics of pore throat are a key factor affecting the heterogeneity of the inner micro-pore structure which restricts the movable fluid occurrence, fluid percolation ability and recovery efficiency of oil and gas.