高邮凹陷戴南组隐蔽油气藏的成因及勘探实践

Origin and Exploration Practice of Ed Concealed Oil and Gas Accumulation in Gaoyou Sag

庞金梅 曹冰

PANG Jin-mei CAO Bing

中国石化 江苏油田分公司 地质科学研究院, 江苏 扬州 225009

Geologic Science Research Institute of Jiangsu Oilfield Branch of SINOPEC, Yangzhou 225009, China

高邮凹陷隐蔽油藏的分布受控于三角洲前缘-前三角洲、近岸水下扇和浊积扇三种相带类型。隐蔽圈闭的有效性与砂地比有关, 砂地比在15%~35%时隐蔽圈闭的保存条件比较好。断层是隐蔽圈闭成藏的关键因素, 能起到沟通油源和侧向封堵的双重作用。高邮凹陷的隐蔽圈闭主要有四种类型, 即断层岩性圈闭、透镜体圈闭、砂岩上倾尖灭圈闭和地层超覆圈闭。不同类型的隐蔽圈闭分布于不同地区。联盟庄、马家嘴地区隐蔽油气藏的勘探实践证明高邮凹陷隐蔽油藏具有比较大的勘探潜力, 是老区挖潜的主要方向。

The distribution of concealed oil accumulation is controlled by the fore part of delta, nearshore fan and turbidite fan in Gaoyou sag.The availability of subtle traps is related to sand content, and seal condition is better while sand content is 15%~35%. Fault is the key factor of subtle traps to oil accumulation, and has the function of linking reservoir and lateral sealing.There are four types of subtle traps in Gaoyou sag, Which is fault-lithologic trap, sandstone up pinchout trap, lens trap and stratigraphic onlap trap.Different subtle traps are distributed in different areas.Oil exploration practice of LMZ and MJZ oilfield has proved that concealed oil and gas accumulation has large exploration potential in Gaoyou sag, which is the main direction in developed area.