| Due to the breakthroughs in buried hills and unconventional oil and gas in recent years, the results of previous resource evaluation are not enough to support the exploration in Liaohe Depression. Based on analysis on the heterogeneity of source rocks and reservoirs, and the main controlling factors of conventional oils in buried hills and volcanic rocks, shale oil and tight oil, four patterns of hydrocarbon accumulation are setup such as lateral-docking of source-reservoir, immigration from out-source by fault-unconformity, accumulation in-source or near-source, and source-reservoir integrated shale oil. A comprehensive evaluation including analogy, genesis and statistics methods are used to assess the conventional oil resource in Liaohe Depression. The total amount is 40.96×108 t, including 27.39×108 t in clastic rocks, 11.42×108 t in buried hills, and 2.15×108 t in volcanic rocks. Shale oil of 3.56×108 t and tight oil of 1.92×108 t are predicted respectively by using small panel volume method. According to the distribution of remaining oil resources, many favorable exploration plays are suggested. As for the conventional oil, the tectonic belts of Xinglongtai, Shubei－Gaosheng, Rongshengpu, and Jing’anpu are the favorable zones for buried hill reservoir; Huanshu slope belt, Niuju－Qinglongtai tectonic belt, Jingxi steep slope belt, and Lengdong－Leijia tectonic belt are the favorable zones for clastic reservoir; the tectonic belts of Xiaowa－Yuehai, Dapingfang－Kuihuadao, and Yushutai－Gaizhoutan are concurrent zones for both buried hill and clastic reservoir; Huangyure－Huangshatuo tectonic belt is the favorable zone for volcanic reservoir. As for the unconventional oil, the Paleogene Shahejie-4 shale with carbonate interlayer in Leijia area of West Sag is the main target for shale oil, and the glutenite reservoir in the west steep slope of Damintun Sag is the main target for tight oil. |
