烃源岩层中异常高压研究——以渤海湾盆地东营凹陷古近系为例

STUDY OF THE ABNORMAL HIGH-PRESSURE IN HYDROCARBON SOURCE ROCKS-TAKING PALEOGENE IN THE DONGYING SAG, THE BOHAI BAY BASIN AS AN EXAMPLE

赵国欣

Zhao Guoxin

浙江大学, 地球科学系, 杭州, 310027 2. 中国石油化工股份有限公司, 胜利油田分公司地质科学研究院, 山东, 东营, 257015

Department of Earth Sciences, Zhejiang University, Hangzhou, Zhejiang 310027, China 2. Research Institute of Geological Sciences, Shengli Oil Field Branch Company, SINOPEC, Dongying, Shandong 257015, China

异常高压对油气成藏具有重要作用。渤海湾盆地东营凹陷古近系沙三、沙四段烃源岩普遍存在异常高压,泥岩的欠压实作用和生烃作用是异常高压产生的主要因素,异常高压的高值区与暗色泥岩厚度大的地区有较好的对应关系。现今异常高压主要分布在2700~3500 m的深度范围,随着深度的增加,异常高压范围增大。应用异常高压研究成藏作用时,要考虑异常高压的时代性。烃源岩中现今异常高压对油藏的保存具有积极的作用,是未来油源灶;古异常高压对排烃是有效的,油气的主要富集区位于大规模生烃后的古异常低压区。

The abnormal high-pressure is very important to oil and gas accumulation.There is abnormal high-pressure in the 3rd and 4th member of Shahejie Formation of Paleogene all over the Dongying Sag,the Bohai Bay Basin.The main factors that lead to the pressure are under-compaction and hydrocarbon generation in the source rocks.The overpressure area is well corresponding with the thickness of source rocks.The present abnormal high-pressure is mainly distributed at a depth range 2 700 m to 3 500 m,and the range becomes bigger with increasing of the buried depth.Times of abnormal high-pressure should be considered when applying abnormal high-pressure to hydrocarbon accumulation.The present abnormal high-pressure in the source rocks has an active effect on the saving of oil and gas and it is oil source kitchen in future.The ancient abnormal high-pressure took an active part in the hydrocarbon migration in the source rocks and there is the main accumulation area of oil and gas.The main oil-gas enriched zones are located in the abnormal high-pressure after hydrocarbon generation in large scale.

https://doi.org/10.11781/sysydz200804340