鄂尔多斯盆地西南缘中生界石油勘探思路与对策

Thoughts and tactics about oil exploration in Mesozoic reservoir on southwest margin of Ordos Basin,China

鄂尔多斯盆地西南缘三叠系延长组主要发育大型岩性圈闭油藏,储层致密,直井自然产能低,如何对其实现经济有效开发一直是困扰地质人员的主要问题之一。作者根据多年油气地质研究,结合勘探实践经验,认为该区油气成藏具有"主源定型、双向排烃、岩性控藏、近源成藏"的特点,油气高产主要受储层品质、油气充满度以及断裂-裂缝发育程度等因素控制,有利的"源、储、疏、高压封存"四元配置是该区石油富集高产的最主要因素,进而提出了针对性的勘探思路与对策,即综合利用勘探开发一体化模式、水平井分段压裂技术和黄土塬三维地震技术可实现经济有效的勘探开发。

The Yanchang Formation（Triassic）reservoir in the southwest of Ordos Basin is a large scale typical lithological reservoir.Because the reservoir is tight and the natural productivity of the vertical well is low,and how to achieve economic development is the main problem to puzzle the geological workers.Based on long-term research of oil and gas and combined with the oilfield exploration experiences,the authors indicates that the oil and gas accumulation in this area is characterized by＂the main source rock determines the type,the expulsion of hydrocarbon is in two ways expulsion of the lithology controls the reservoir,and the oil accumulation nears source rocks＂.The high production of the oil and gas is mainly controlled by the quality of reservoirs,the hydrocarbon-filling degree and the development of fault-fractures.The favorable disposition with＂source rock,reservoir,migration and high-pressure seal＂is the most critical factor controlling oil accumulation with high productivity of this area.Based on the above,the authors put forward thethoughts and tactics for exploration,that is,the comprehensive utilization of exploration and development methods,the effective use of hydraulic fracturing technology in horizontal wells and 3D seismic technology in loess tableland can make this reservoir＇s exploration and development efficiently and economically.