济阳拗陷生物降解原油地球化学特征及其地质意义  

Geochemical characteristics of biodegraded oil, Jiyang Depression: Implications for geology

作　　者：高长海[1] 张新征[2] 李豫源 王兴谋[3] 张云银[3] Gao Changhai;Zhang Xinzheng;Li Yuyuan;Wang Xingmou;Zhang Yunyin(School of Geoscience, China University of Petroleum （Huadong）, Qingdao, Shandong 266580, China;Geo- logical Logging Company, Sinopec Shengli Oilfield Company, Dongying, Shandong 257064, China;Geophysical Research Institute, Sinopec Shengli Oilfield Company, Dongying, Shandong 257015, China)

机构地区：[1]中国石油大学(华东)地球科学与技术学院 [2]中石化胜利油田地质录井公司 [3]中石化胜利油田物探研究院

出　　处：《天然气勘探与开发》2018年第2期47-54,共8页Natural Gas Exploration and Development

基　　金：国家科技重大专项(编号:2016ZX05006-007;2017ZX05001-001);山东省自然科学基金项目(编号:ZR2017MD028);中国石化科技攻关项目(编号:P15084)

摘　　要：渤海湾盆地济阳拗陷浅层稠油十分发育,储量巨大,是今后勘探开发的重要目标。利用色谱、色谱—质谱等技术方法,结合原油微生物降解模拟实验,系统阐述了济阳拗陷生物降解原油的地球化学特征。结果表明:(1)济阳拗陷生物降解原油总体上遭受了中等—严重程度的生物降解作用,造成饱和烃含量低、芳烃含量高、非烃+沥青质含量高的特征;(2)多数原油正构烷烃损失严重,部分残留少量类异戊二烯烃;甾烷类化合物发生不同程度降解,重排甾烷、孕甾烷相对含量随降解程度的增加而降低;萜烷类化合物以三环萜烷为主,三降藿烷Ts丰度普遍低于Tm,伽马蜡烷含量相对较高,部分萜烷中出现25-降藿烷系列;耐降解的芳烃类化合物也遭受了后期改造作用。基于稠油油藏与浅层气藏的成因关系、量化关系及分布关系,结论认为:由已知稠油油藏顺源寻找关联未知浅层气藏或由已知浅层气藏逆源寻找关联未知稠油油藏的联合勘探将是立体勘探的必由之路。In Jiyang Depression, Bohai Bay Basin, most shallow formations are rich in heavy oil. So, they should be taken as the key exploration and development targets in the future. Some geochemical characteristics of biodegraded oil in this depression were analyzed systematically by using chromatography and chromatography-mass spectrometry, together with simulation experiments on crude-oil biodegradation. Results show that（1） the biodegraded oil generally underwent certain moderate to severe biodegradation, resulting in two features of poor saturated hydrocarbon but rich aromatic hydrocarbon and non-hydrocarbon＋asphaltene; and（2） the n-alkane in most crude oil was seriously destroyed, partly remaining a small amount of isoprenoid. The sterane compounds suffered various degradation degrees, and the relative content of both diasteranes and pregnanes decreased with an increase of degradation degree. The terpane compounds are mainly composed of tricyclic terpane, their abundance of trisnorhopane（Ts） is lower than that of Tm, gammacerane content is higher, and 25-norhopanes appear in some steranes. The degradation-resistance aromatic compounds also went through the late reformation. Based on the original, quantitative and distribution relations between heavy oil and shallow gas reservoirs, it is concluded that the indispensable way of exploration with multiple layers should be the joint one to search for unknown heavy-oil reservoirs according to the distribution of known shallow gas reservoirs and vice versa.

关 键 词：渤海湾盆地 济阳拗陷 生物降解原油 地球化学特征 浅层气藏 联合勘探 

分 类 号：P618.13[天文地球—矿床学]