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四川盆地二、三叠系长兴组—飞仙关组礁、滩气藏勘探的不断突破需要更进一步弄清其礁、滩体分布及其控制因素。为此,在对比分析各种过井资料及三维地震资料的基础上,研究了晚二叠世区域古地貌格局、拉张作用、长兴组—飞仙关组体系域等对开江—梁平海槽形态和礁、滩分布、发育的影响。结论认为:①晚二叠世末,四川盆地呈“三隆三凹”的古地貌格局,其对礁滩的分布起到了重要的控制作用;②拉张作用的不均衡性使得环开江—梁平海槽台缘斜坡带坡度陡缓存在差异,这一差异影响着礁滩发育的早晚和连续性;③层序演化结果表明龙潭期以海侵体系域为主,长兴组中后期为高水位体系域,体系域的变迁使得近台缘地区可能发育多期礁体。此外,还对台缘地区微古地貌的刻画方法进行了探讨,认为台缘生物礁的分布形态可以是沿台地边缘弯曲展布的串珠状礁体,也可能是与海槽斜交的斜列式分布的礁体。最后根据研究结果,划分出了有利勘探区带。
The continued breakthrough in exploration of the Bei and Triassic Changxing Formation-Feixianguan Formation reef and shoal gas reservoirs in the Sichuan Basin needs to be further clarified on the distribution of reefs and beaches and their controlling factors. Based on the comparative analysis of various over-well data and 3D seismic data, the paper studies the palaeogeomorphology and extension in the Late Permian, the systematic study of Changxian-Feixianguan Formation, Slot morphology and reef, beach distribution, developmental effects. The conclusion is as follows: (1) At the end of Late Permian, the paleogeomorphic pattern of “Sanlongsan” in Sichuan Basin played an important role in controlling the distribution of reefs; (2) - The steep gradient of the ramp slope of Liangping sea trough has differences, which affects the early and late reef beach development and continuity. ③ The sequence evolution shows that the Longtan period is dominated by the transgressive system tract and the middle and late period of Changxing Formation is high The changes of water system tract and system tract make it possible to develop multi-stage reefs near the margin. In addition, the method of portraying the micro-paleogeomorphology in the marginal area is also discussed. It is believed that the distribution pattern of the marginal reef can be beaded reef bent along the edge of the platform, or obliquely inclined to the trough Reef-style distribution. Finally, according to the research results, we divide the favorable exploration zone.