辽河盆地大民屯凹陷异常压力特征和成因及勘探意义

The Characteristics and Origin of Overpressure in Damingtun Depression of Liaohe Basin and Petroleum Exploration Signif icance

史建南 姜建群 路成刚 张福功

SHI Jian-nan JIANG Jian-qun LU Cheng-gang ZHANG Fu-gong

中国地质大学 研究生院, 湖北 武汉 430074; 石油大学 资源与信息学院, 北京 昌平 102249; 辽河油田 勘探开发研究院, 辽宁 盘锦 124010

Graduates College of China University of Geosciences, Wuhan 430074, China; Resources & Information College of Petroleum University, Changping 102249, China; Exploration & Development Institute of Liaohe Oil Field, Panjing 124010, China

作者结合辽河盆地大民屯凹陷的测井、地质、地震和钻井资料,利用等效深度法从沉积和生烃的角度将本区泥岩压实特征分为强超压型、超压型、局部超压型和正常压实型四种,平面上,靠近各洼陷沉积中心部位是过剩压力的高值分布区;纵向上看,S33段下部、S34、S4段地层内超压相对强烈,最大压力系数可达 1.55,超压带发育幅度大、规模大。凹陷中部的断裂对异常压力分布起着重要的分割作用。快速沉积和生烃作用是本区超压形成的主要原因。

Integrating logging, geological, seismic and drilling data and by means of equivalent depth, four types of compaction style in Damingtun depression are recognized from the view of sedimentation and hydrocarbon generation. They are stong overpressure, overpressure, local overpressure and normal compaction. From the point of plane, the high overpressure occurred in the center of sag. From the point of vertical, there exists relative high overpressure in the bottom of S33 formation, S34 and S4 formation. The highest overpressure factor is up to 1.55. Overpressure is strong and exists widely. The faults act as important shelf for the occurrence of overpressure. Overpressure is mainly due to fast sedimentation and hydrocarbon generation.