摘要
黄骅坳陷内已发现的第三系深层油气藏中几乎都与异常压力有关,形成超压封闭型油气藏。黄骅坳陷第三系深层存在四种超压封闭型油气藏,其共同特点是:油气藏处于超压封闭系统,压力系数一般为1.3～1.6;从多口井泥岩声波时差曲线和异常压力曲线中,可以看出在2800m以下深层普遍存在异常压力带(欠压实带),并可明显划分出三个异常压力带,分别控制各自的成藏动力系统;超压异常与储集层、含油性三者具有互相制约的因果关系,表明在超异常压力带(欠压实带)的下伏砂层出现异常高的孔隙值,并往往成为良好的产油层;超异常压力区和超压区内的低压区控制着油气的分布;异常压力形成期与异常孔隙发育带及油气大量生成期三者有机匹配,可能成为深层油气富集的重要条件。
Nearly all the discovered Tertiary deep layer oil-gas reservoirs in Huanghua Depression are related to abnormal pressure. They are overpressure-sealed type oil-gas reservoirs, which can be divided into four kinds. Their common features are that the reservoir is in a overpressure-sealed system of pressure coefficient being 1.3～1.6. There generally exist abnormal pressure zones (undercompaction zones) below 2800 meters which can be clearly separated into three and each controls its own reservoir forming dynamic system, the abnormal overpressure regions and the low pressure areas within the overpressure region control oil-gas distribution, the organic matching of the forming time of abnormal pressure, abnormal porosity development zone, and oil-gas peak generation stage is the important condition of forming deep layer oil-gas enrichment zones.
关键词
黄骅坳陷
深层
异常压力
油气藏
油气运移
Huanghua Depression, deep layer, abnormal pressure, oil-gas reservoir
