【摘要】 为了明确北部湾盆地乌石凹陷流沙港组二段有利储层发育主控因素,基于铸体薄片、常规物性、测井解释等资料,分析了流沙港组二段储层岩石组分、成岩强度、孔喉结构等特征,指出了有利储层分布与油气勘探方向。研究结果表明:①流沙港组二段北部缓坡—东北部中央反转构造带储层较南部陡坡带—凹陷中心储层压实弱、喉道粗、粒间孔发育,南部陡坡带西段储层较东段储层压实弱、不稳定组分含量高、次生孔发育;②流沙港组二段有利储层主要受沉积环境与沉积水动力造成的粒度及泥质杂基、古地温场造成的压实强度的控制,局部受岩石组分差异与通源断裂控制的有机酸溶解和相对早期油气充注保护的影响;③流沙港组二段三角洲沉积、中等压实区的北部缓坡—东北部中央反转构造带最有利,次为较低古地温场的南部陡坡带西段中等—强溶蚀扇体,W6构造和W8构造为两个有利勘探方向。结论认为,该研究成果为区带目标优选与评价提供了支撑,并得到了钻探证实。更多还原

【Abstract】 In order to determine the factors controlling the development of favorable reservoirs of the second Member of Liushagang Formation in the Wushi Sag of Beibu Gulf Basin, the rock compositions, diagenetic intensity,pore-throat structure and other characteristics of the reservoir of the second Member of Liushagang Formation were analyzed with the casting thin section, conventional physical property and logging interpretation data as the research objects. In addition, the distribution and exploration direction of favorable reservoirs were pointed out. And the following research results were obtained. First, compared with the reservoir in the steep slope belt-sag center in the southern area, the reservoir of the second Member of Liushagang Formation in the gentle slope of northern area and the central inversion structure belt of northeastern area is weaker in compaction, larger in throat sizes and more developed in intergranular pores. And the reservoir in the western section of the steep belt in the southern area is weaker in compaction, higher in the content of unstable compositions and more developed in secondary pores than that in the eastern section. Second, the favorable reservoirs of the second Member of Liushagang Formation are controlled by the particle sized dominated by sedimentary environment and sedimentary hydrodynamics, the shale matrix and the compaction strength caused by palaeogeothermal field, and locally affected by the organic acid dissolution controlled by rock compositional difference and source connecting fault and the earlier hydrocarbon charging preservation. Third,the most favorable zone is the gentle slope in the north and the central inversion structure belt in the northeast in the moderate compaction of delta sedimentary facies of the second Member of Liushagang Formation, which is followed by the moderate-strong dissolution fan in the western section of steep slope in the southern area of lower palaeogeothermal field, and W6 and W8 structures are two favorable exploration directions. It is indicated that the cognitions provide the support for the zonal target selection and evaluation and are verified in actual drilling.更多还原