塔西南坳陷麦盖提斜坡奥陶系白云岩油气的发现及其勘探启示

发布时间：2018-03-21 15:18

本文选题：塔里木盆地西南坳陷　切入点：麦盖提斜坡　出处：《天然气工业》2017年04期 　论文类型：期刊论文

【摘要】：塔里木盆地西南坳陷(简称塔西南坳陷)罗斯2井在奥陶系蓬莱坝组白云岩储层中获得高产工业气流,成为麦盖提斜坡近20年来最重大的油气发现。为了明确该区下一步的油气勘探方向,根据麦盖提斜坡及周缘的油气发现历程,分析了奥陶系已钻井的成功、失利因素,研究了奥陶系石灰岩风化壳和内幕白云岩储层的分布特征,厘清了油气成藏与构造圈闭形成、演化的关系,明确了该区奥陶系油气成藏的主控因素,讨论了油气分布与新元古代裂谷的关系。结果表明:①麦盖提斜坡奥陶系白云岩比石灰岩储层更发育,中奥陶统鹰山组上段石灰岩风化壳储层主要分布在断裂带,储层空间主要为高角度未充填裂缝,下奥陶统鹰山组下段和蓬莱坝组内幕白云岩储层横向分布稳定,储层空间主要为小型溶蚀孔洞,在地震剖面上表现为"串珠"状反射特征;②油气发现主要集中在断裂带,构造围斜部位奥陶系白云岩岩溶储集体形成的岩性圈闭是下一步的主要勘探目标;③寒武系烃源岩的分布状况是决定该区奥陶系油气勘探成功率的关键因素,受塔西南坳陷新元古代裂谷控制,坳陷中段是油气勘探的有利区带,发育奥陶系—上寒武统白云岩与石炭系泥岩、下寒武统白云岩与中寒武统膏盐层等多套油气生储盖组合。
[Abstract]:Ross 2 well in southwest depression of Tarim Basin obtained high industrial airflow in dolomite reservoir of Penglai formation, Ordovician. It has become the most important oil and gas discovery in the past 20 years. In order to determine the next oil and gas exploration direction in the area, the success and failure factors of the Ordovician drilling have been analyzed according to the oil and gas discovery history of the Maigeti slope and its periphery. The distribution characteristics of weathering crust and inside dolomite reservoir of Ordovician limestone are studied, the relationship between hydrocarbon accumulation and the formation and evolution of structural traps is clarified, and the main controlling factors of hydrocarbon accumulation in Ordovician in this area are clarified. The relationship between oil and gas distribution and Neoproterozoic rift is discussed. The results show that dolomite of Ordovician system is more developed than limestone reservoir on the Wei 1 Maigaiti slope, and limestone weathering crust reservoir of upper member of Yingshan formation of middle Ordovician is mainly distributed in fault zone. The reservoir space is mainly high angle unfilled fractures, and the inside dolomite reservoir of the Lower Ordovician Yingshan formation and Penglai Dam formation is stable in lateral distribution, and the reservoir space is mainly small dissolution pore. In the seismic profile, the "beaded" reflection characteristics of oil and gas discovery are mainly concentrated in the fault zone. The lithologic trap formed by the karst reservoir of Ordovician dolomite is the main exploration target in the next step. The distribution of Cambrian source rock is the key factor to determine the success rate of exploration of Ordovician oil and gas in this area. Controlled by the Neoproterozoic rift in the southwest depression of the Tarim Basin, the middle part of the depression is a favorable zone for oil and gas exploration. There are several sets of oil-gas reservoir cap assemblages, such as Ordovician and Upper Cambrian dolomite and Carboniferous mudstone, Lower Cambrian dolomite and Middle Cambrian gypsum salt layer, etc.
【作者单位】：中国石油勘探开发研究院西北分院;
【基金】：中国石油天然气股份有限公司重大科技专项“塔西南及新区油气成藏条件研究及目标优选”(编号:041012120005)
【分类号】：P618.13

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