论文部分内容阅读
应用三维地震资料对柴达木盆地西南区古近系—新近系坡折带类型、分布和演化进行了系统研究,发现高原咸湖所特有的“短周期沉积坡折带”和断裂坡折带在研究区均有发育,前者大致呈SN分布,除上干柴沟组(N1)不发育外,其他层段都有分布,控制了低位体系域的发育,是分流河道向水下分流河道或水下分流河道向滩坝或前缘滑塌浊积扇突变的分界线;昆北、阿拉尔、七个泉、红柳泉断层,以及SN向调节断裂阿拉尔东和Ⅷ号断层属持续发育型断裂坡折带,而Ⅺ号断层在上干柴沟组(N1)沉积期相对不发育,属间断发育型断裂坡折带。向南倾为主的逆向型断裂坡折带以下可容空间增大,向北倾为主的顺向型断裂坡折带以上发育反向小断槽和突起小断隆,下方均是砂体堆积的有利场所,前者控制砂体沿断层走向展布,后者常发育悬浮和跳跃组分为主的滩坝砂体。研究区发现的7个主要岩性油藏都分布于坡折带以下,对油藏进行解剖后发现沉积坡折带和断裂坡折带不仅直接控制了有利砂体的分布,还控制了岩性圈闭和构造—岩性圈闭的发育,另外,两者结合可以组成断裂—砂体复合输导系统,主导了油气运移的路径,因此可以说坡折带具有“控砂”和“聚油”的双重作用,坡折带附近是岩性油藏富集区带,将成为下一步岩性油藏勘探的重点方向。
Using the 3D seismic data, we systematically studied the type, distribution and evolution of Paleogene-Neogene slope-break belt in the southwest of the Qaidam basin and found that the “short-period sedimentary slope break zone” and the fault slope The break zones all developed in the study area. The former was roughly SN-distributed, and except for the upper Ganchaigou Formation (N1), there was distribution in other intervals, controlling the development of low-level system tract, The demarcation line between sudden change of turbidite fan from bank or submarine distributary channel to beach dam or foreland; Faults of Kunlun, Alar, Qiquan and Hongliuquan and fault Alardong and Ⅷ of SN regulation break down While the fault of fault Ⅺ is relatively undeveloped during the sedimentary period of Upper Ganchaigou Formation (N1), which belongs to the fault-type faulted slope break. The southward-oriented reverse fault-break slope below the allowable space increases, and the northward dip-oriented forward fault-break slope above the development of small reverse-thrust fault and the small protuberances, the bottom is sand body Accumulation of favorable sites, the former control of the distribution of sand along the strike of the fault, which is often the development of levitation and jumping components of beach-sand bodies. The seven major lithologic reservoirs found in the study area are distributed below the slope break. After the reservoir is dissected, it is found that the sedimentary slope break and fault slope break zone not only directly control the distribution of favorable sand body but also control the lithology Traps and tectonic-lithologic traps. In addition, the combination of the two can form a fracture-sand composite system and dominate the path of hydrocarbon migration. Therefore, it can be said that the slope break zone has a “controlled sand” and “Poly oil ” dual role, near the slope break zone is a lithologic reservoir enrichment zone, will be the next key direction of the exploration of lithological reservoirs.