塔中隆起志留系混源多期油气聚集特征与勘探对策

为了指导塔中隆起的勘探实践,研究了该区志留系混源多期油气聚集特征及其控制因素.结果表明,塔中隆起志留系中沥青及可动油气显示大面积分布.自晚加里东以来,曾经有寒武系和中上奥陶统两套烃源岩三次向志留系砂岩充注.大面积分布的沥青都是寒武系的烃源岩第一期充注后遭到破坏的产物,现今的可动油以中上奥陶统烃源岩晚期充注油气为主,有部分寒武系源岩的贡献.油气聚集在区域盖层之下的多种类型圈闭中.针对潮坪相沉积的薄砂层、大面积叠置分布、输导体系沟通砂体含油气的特点,认为提高勘探成效的基本对策是开展沉积相的精细研究,围绕断层和火山通道,依靠直井寻找油砂层,依靠水平井滚动勘探以获得更好的效果.

Multi-source and multi-stage hydrocarbon accumulation and exploration strategy of the Silurian reservoir in Tazhong uplift

The characteristics and the controlling factors of the hydrocarbon accumulation in the region are studied in order to guide the exploration practices of this region. It is shown that the asphalt and the movable oil shows widely distribute in the Silurian reservoir of Tazhong uplift. The hydrocarbon from the Cambrian and Or-dovician source rocks is captured by the Silurian reservoir in three stages since the late Caledonian movement. The asphalt distributing in large area is the result that oil and gas reservoir is destroyed after the Cambrian source rock pours during the first stage. The movable oil at present is mainly from the Mid-Upper Ordovician source rocks and a part of it is also from the Cambrian source rocks. The oil and gas accumulates in many traps under regional cap rocks. According to the characteristics of the tital-flat facies that the sand layers are thin, they distribute in a large area and superpose, and the oil-bearing sand layers are connected by conduct systems, it is held that the basic strategy to improve the exploration result is studying the sedimentary facies in detail, seeking oil near faults and volcanic vents by drilling vertical wells, and driling horizontal wells to get more reserves and outputs.