大民屯凹陷高蜡油成藏机理研究

Study on High-wax Oil Accumulation Mechanism in Damintun Depression

综合利用地质、地球物理、油气(油藏)地球化学及盆地模拟领域中先进的技术与研究方法,以盆地演化和流体输导格架为成藏背景,从有效烃源岩出发,以能量场演化及其控制的化学动力学、流体动力学和运动学过程为核心,探讨了大民屯凹陷高蜡油的成藏机制与分布规律。精细油源对比表明,大民屯凹陷高蜡油主要来自沙四下段的油页岩,且其成因受沉积母质和沉积环境的双重控制。凹陷沉积—沉降演化史与温度场、压力场演化史三者良好的耦合匹配关系,对高蜡油的生成、保存、运聚成藏等地质因素与地质作用都有着重要的意义。高蜡油以近源充注为主,主充注期为37～33Ma。有效源岩分布、能量场演化和流体输导系统及其决定的流体流动样式共同控制了本区高蜡油的富集与分布。

Petroleum generation, evolution, migration and reservoir forming conditions and its controlling factors of Damintun Depression were discussed. Based on the basin evolution histories and conduit framework and potential source-rock, not only studied the evolution of the energy fields, but also the kinetic and dynamic processes, by integrated geological, geophysical and geochemical means and computer modeling advanced techniques. Detailed oilsource correlation showed that high-wax oil originates from “oil shale” of E2s4^2, and its reasons of generation are mainly due to organic matter and sedimentary environment. The well coupling relationship of particular conformation-sediment development history and appropriate geothermal-pressure circumstance is very avail of high-wax oil accumulation. Petroleum migration paths are mainly near-source charging and its charging history is about 37～33Ma. Highwax oil accumulation and distribution is as a result of fluid flow styles controlled by the energy field evolvement, valid source rocks and fluid conduit systems.