高邮凹陷古水动力场及其与油气运聚的关系

Relation between palaeohydrodynamic field and hydrocarbon migration and accumulation in Gaoyou sag

关键词:  高邮凹陷  地层水  古水动力场  含油气系统  油气运聚

Key words:  Gaoyou sag  formation water  palaeohydrodynamic field  hydrocarbon system  hydrocarbon migration and accumulation

摘要:

含油气盆地地下水动力场与油气的运移、聚集和分布规律关系密切。在地层水水化学特征研究的基础上，对 高邮凹陷油气主运移期的古水动力场分布及其对油气运聚的影响进行了研究。结果表明，在油气大规模运移期，高 邮凹陷为典型的不对称型压实流-重力流盆地，形成了上、下两个含油气系统水动力场。在纵向上和平面上,各亚水 动力场具有泥岩压榨水离心流、越流泄水、越流-蒸发泄水、大气水下渗向心流等局部水动力单元类型，油气的运移、 聚集与压实流及其末端的越流泄水区紧密相关。同时还指出，盆地的内斜坡和北斜坡外侧等地区是今后上含油气 系统的勘探潜力区;沙埝以北、柘垛以及码头庄以西等地区是下含油气系统的潜力区，且对下含油气系统应加强深 层油气藏的勘探与研究。

Abstract:

There are close relationships among the hydrodynamic field and the hydrocarbon migration, accumulation and dis-iribution in petroliferous basin. Based on the study of hydrochemical characteristics of formation water, the distribution of palaeohydrodynamic field in main oil-gas migration period and its influence on hydrocarbon migration and accumulation in Gaoyou sag were discussed. The results show that during the main oil-gas migration period,Gaoyou sag was a typical asymmetrical compaction-gravity driven flow basin and it is comprised palaeohydrodynamic subfield of upper petroleum system and palaeohydrodynamic subfield of lower petroleum system. On longitudinal and flat, each subfield is composed of several types of local groundwater hydrodynamic units, which include centrifugal flow caused by mudstone compaction, discharge area by cross-formational flow, or cross-formationai and evaporation, and gravity-induced centripetal flow recharged by meteoric water. The oil-gas migration and accumulation are related closely to compaction driven flow and discharge area by cross-formationai flow. It is indicated that the potential exploration areas of upper petroleum system include the inner slope and the outer region of north slope, and those of lower petroleum system include Zheduo, area to the north of Shanian and area to the west of Matouzhuang, where the exploration and research on deep oil-gas reservoirs should be strengthened.