大庆长垣萨尔图-葡萄花-高台子油层组倾斜油水界面形成机理与增储潜力

大庆长垣萨尔图-葡萄花-高台子油层组（萨葡高油层组）发育倾斜油水界面，前人研究成果无法解释长垣北翼油水界面加深和长垣东、西两翼油水界面海拔差异等现象，制约了油藏增储挖潜。油水界面受油水密度差、界面张力、毛细管半径和遮挡条件、水动力条件等因素控制。以界定油底、水顶为目标，通过系统分析萨葡高含油组合的油气成藏过程，明确了水动力作用、后期构造变动和储层物性变化等因素导致大庆长垣东北部油水界面降低，局部发育的断层及隔层对油水界面也具一定影响。以叠前地震资料为基础，提出油水界面地质统计学反演技术，通过分析油水密度差来确定油水界面，该方法深化了油藏边部倾斜油水界面储层认识，适用于油藏边部、井资料缺失地区的地质研究。以倾斜油水界面认识和油水界面地质统计学反演技术为指导，优选萨尔图北部构造东北侧和长垣北部过渡带三、四条带葡萄花一油层为有利挖潜区，提高了大庆长垣萨葡高油层组的增储潜力。

Formation mechanism and reservoir increasing potential of inclined oil-water interface in Saertu-Putaohua-Gaotaizi reservoir groups of Daqing placanticline

Inclined oil-water interface is developed in Saertu-Putaohua-Gaotaizi reservoir groups (Sapugao reservoir groups) of Daqing placanticline. Previous research results cannot explain the deepening of the oil-water interface in the north wing of Daqing placanticline and the altitude difference of the oil-water interface in the east and west wings, which restricts the reservoir increasing potential. The oil-water interface is controlled by such factors as oil-water density difference, interfacial tension, capillary radius and capillary barrier conditions, as well as hydrodynamic conditions. By systematically analyzing the oil and gas reservoir-forming process of Sapugao oil-bearing combination, it is determined that hydrodynamic action, later structural change, and physical property change of reservoirs lead to the lower oil-water interface in the northeast of Daqing placanticline, and the locally developed faults and barriers also have a certain impact on the oil-water interface, aiming to define the oil bottom and water top. Further, the geostatistical inversion technology of oil-water interface is proposed based on the pre-stack seismic data, and the oil-water interface is determined by analyzing the oil-water density difference. This method deepens the understandings of the reservoir with inclined oil-water interface at its edge, and is suitable for the geological research in areas where oil reservoir edge and well data are missing. Guided by the understanding of inclined oil-water interface and the geostatistical inversion technology of oil-water interface, preference is given to the favorable potential tapping areas covering the northeast of northern Saertu and Putaohua reservoir group I in transition zone Ⅲ and Ⅳ in the north of the placanticline, which promotes the reservoir increasing potential of Sapugao reservoir groups in Daqing placanticline.