深部流体及其油气成藏效应研究现状

Present research status of the deep fluid and their effectiveness on oil/gas generation

随着对沉积盆地的研究从骨架到内部流体,再到圈层间流体的相互作用,对沉积盆地内油气形成的认识不断深入。深部流体是影响油气形成的一个重要因素,根据进入盆地的深部流体的化学组分与同位素特征,可以把深部流体分为两种组合类型,高氧逸度环境下,以CO2+H2O为主成分(富CO2流体);低氧逸度的流体,主要组分为CH4+H2+H2O(富H流体)。有机质热降解生烃是缺氢的过程,幔源富H流体的注入可补偿烃源岩生烃过程中所缺乏的氢,从而提高烃源岩的产烃率。富CO2的深部流体,可以改造储层孔隙,形成大量原生与次生的混合型孔隙,改善储层物性。

The understanding of the formation of petroleum is deepened as the study of the sedimentary basin is advanced from its framework into its interior fluids and their interactions between different layers. The deep fluid is an important factor influencing the formation of petroleum. Based on the isotopic characteristics of the deep fluid that entered into the basin, two different kinds of style can be recognized. Under the high＇ oxygen fugacity condition, the fluid is composed of CO2＋H2O （rich CO2 fluid）; under the low oxygen fugacity, the fluid is composed of CH4＋H2 ＋H2O（rich H2 fluid）. The formation of hydrocarbon from organic matter degradation is a lacking hydrogen process; the H2 rich fluid can compensate the hydrogen in this process, and increase the production rate of hydrocarbon. The CO2 rich fluid can rebuild the pore space forming a mixed pore network composed of both original and derived pores and improving the physical properties of the reservoir.