苏里格气田桃2区块下古生界岩溶古地貌恢复研究

Research of Lower Paleozoic karst paleomorphologic restorationin Tao2 block of Sulige gasfield

近年来．随着苏里格气田勘探开发工作的不断深入．桃2区块下古生界气藏表现出较强的开发潜力因此，合理有效地开发下古生界气藏将是苏里格气田持续稳产的重要手段。研究成果表明，古风化壳的存在是下古生界天然气成藏的重要因素．而古地貌代表了地层沉积和成岩作用的背景．因而在储层的形成和演化过程中具有重要意义通过对奥陶系不整合侵蚀面上下地层组合情况的深入分析，把印模法与残厚法结果有机结合．深入探讨了奥陶系风化壳古地貌恢复的方法思路及其古地貌发育特征，探索了古地貌恢复的方法，建立了解释和恢复古地貌单元属性的综合地质模型为下一步进行储层精细描述、指导桃2区块勘探与生产做好铺垫。

In recent years, the Lower Paleozoie gas reservoirs in the Tao2 block showed strong development potentials, along with the continous deepening of Sulige gas field exploration and development. Therefore, reasonable and effective development of the Lower Paleozoic gas reservoirs is an important means of sustainable production stabilization in Sulige gasfield. Research results in recent years show that the existence of paleo-weathering crust is an important factor for the Lower Paleozoie to form a SRCA with natural gas. The paleo-geomorphology represents the background of the deposition and diagenesis of the strata. So they are of great significance in the process of forlnation anti evolution of the reservoirs. This paper aims to discuss deeply the paleo-geomorphntogic development characteristics, the method and train of thoughts of paleogeomorphologic restoration of the Ordovician weathering crust through in-depth analysis of combination of strata on or beneath the Ordovician unconformity erosion surface, and the organic combination of moulage method and residual thickness method results. The method of paleogeomorphologic restoration is sought nut. A comprehensive geological model is established that can be used to explain and restore the attributes of the palaeogeomorphologie mitt. This paves the way for the next step fine description of reservoirs and guiding the exploration and production of the Tao2 block.