Abstract:

There are the potential domains for oil and gas exploration in the areas with the elevation of 0~5 km and the deep formations of 5~10 km in depth, where some petroleum geology theories and technologies require to be studied. The modification effect and influence of the neotectonic movement on the oil-bearing formations and palaeo-reservoirs are more profound in the high-elevation areas such as Qiangtang Basin and the north part of Qinghai-Tibet area,so the preservation of oil reservoirs is rigorous.The burial depth of ultra-deep reservoirs is normally 5~10 km in the non-marine basins characterized with rapid deposition, thick sedimentary rock and multiple structural layers,which corresponds to the late stage of diagenesis and deep burial period (with temperature and pressure higher than 175℃ and 100MPa, respectively). The development of high-quality clastic reservoirs in ultra-deep formations of China is controlled by deposition, the duration of deep burial (long-term diagenesis and short-term deep burial), the pressurization of fluid and secondary dissolution. The generation of high-quality carbonates reservoirs in the deep and ultra-deep formations mainly depends on dolomitization and dolomite karst.

Key words: non-marine basin, high-elevation formation, ultra-deep formation, clastic reservoir, carbonate reservoir, dolomitization, karst

摘要：

海平面以上0~5km的高海拔地层和埋藏5~10km的超深地层,应是油气勘探的潜在领域,但在其石油地质理论和技术方面有很多问题需要探讨。在高海拔地区(如青藏区),新构造运动对石油地质层系和古油藏的改造和影响很大,并且高海拔油气藏的保存条件也非常严苛。超深层常常分布在中国陆相盆地,其沉积速率大、沉积岩厚度大,加之多构造层叠加,致使超深层常对应于成岩中晚期和深埋阶段(温度高于175℃,压力大于100MPa)。中国超深层优质碎屑岩储层受沉积期特征、深埋时间因素(即成岩过程很长,深埋时间较短)、流体承压程度和次生溶蚀作用的控制。深层与超深层优质碳酸盐岩储层的形成主要依赖于白云石化作用以及白云岩的岩溶改造作用。

关键词: 陆相盆地, 高海拔地层, 超深层, 碎屑岩储层, 碳酸盐岩储层, 白云石化作用, 岩溶