辽河外围中生代盆地“下洼找油气”理念

辽河外围盆地小规模、呈狭条带状分布的中生代凹陷分割性强且紧邻隆起区,因而凹陷以近物源、多物源沉积为主.沉积条件决定了各凹陷储集层物性普遍较差,多方向物源交汇,形成砂泥交替沉积.储集层的低渗透性使得油气横向和垂向均以短距离运移为主,平面上油气紧邻生油洼陷分布或位于生油洼陷内,纵向上紧邻生油岩分布.根据该认识,提出"下洼找油气"勘探部署原则,自2004年实施"下洼找油气"勘探部署以来,辽河外围中生代凹陷取得了良好的勘探效果,获得了勘探上的新突破.陆家堡凹陷五十家子庙洼陷、交力格洼陷和三十方地洼陷、钱家店凹陷胡力海洼陷、龙湾筒凹陷额尔吐洼陷、张强凹陷章古台洼陷和七家子洼陷、元宝山凹陷中央洼陷带及奈曼凹陷中央洼陷是该区下一步勘探目标.图4表2参10

Concept of "seeking for oil and gas deep down depressions" in Liaohe peripheral Mesozoic basin

Small-scale and strip Mesozoic sags in the Liaohe Oilfield peripheral basin are strongly divided and close to massifs, so they are mainly proximal and polyenic deposits. Reservoirs in the sags have poor properties and multidirectional, intersected sources which form sand-shale alternating deposits. Low permeability in the reservoirs causes oil and gas to migrate in short distances horizontally and vertically, and be distributed close to or in hydrocarbon kitchens horizontally and close to oil source rocks vertically. The principle of "seeking for oil and gas deep down depressions" was proposed. Since its practice in 2004, good exploration results have been achieved. The next exploration targets in this area are the Wushijiazimiao, Jiaolige and Sanshifangdi subsags in the Lujiabao sag, the Hulihai subsag in the Qianjiadian sag, the Eertu subsag in the Longwantong sag, the Zhanggutai and Qijiazi subsags in the Zhangqiang sag, the central subsag in the Yuanbaoshan sag, and the central subsag in the Naiman sag.