东营凹陷古近系烃源岩成熟度特征  

Maturity of Lower Tertiary source rocks in Dongying depression

作　　者：任拥军[1] 周瑶琪[1] 查明[1] 金强[1] 

机构地区：[1]中国石油大学地球资源与信息学院,山东东营257061

出　　处：《中国石油大学学报（自然科学版）》2006年第2期6-10,共5页Journal of China University of Petroleum(Edition of Natural Science)

基　　金：'十五'国家重大科技攻关项目(2001BA605A09)

摘　　要：应用多种有机地球化学成熟度参数，对东营凹陷古近系烃源岩的成熟度随深度的演化特征进行了研究。结果表明，甾、萜的异构化参数、脱羟基维生素E的ω（β/ω）／ω（γ）值、热解转化率、饱和烃碳优势指数（CPI）和奇偶优势值（指数可以有效地确定烃源岩的成熟门限；而镜质体反射率、热解最高峰温和烃指数等是划分烃源岩更高成熟阶段的有效指标。综合利用多种指标确定烃源岩的成熟度，最终可将东营凹陷烃源岩有机质热演化划分出5个阶段：（1）未成熟生物化学作用阶段，对应深度为0～1800m；（2）低熟油生成阶段，对应深度为1800-2600m；（3）成熟阶段，对应深度为2600-3900m；（4）高成熟阶段，对应深度为3900-5100m；（5）过成熟阶段，对应深度大于5100m。东营凹陷古近系主力烃源岩层主要处于成熟和高成熟阶段，常规成熟门限较深，因而具有良好的油气保存条件，适合油气的保存，这也是东营凹陷油多气少的根本原因。Various organic geochemistry maturation parameters were used to study the evolution of maturation with depth varying of the Lower Tertiary source rocks in Dongying depression. The research results show that some parameters were effective to determine the oil window of source rocks. The parameters include homohopane ω （C3122S）/ω （22S ＋ 22R）, sterane ω（ C2920S） /ω（ 20S ＋ 20R）, sterane ω（ C29ββ ） /ω（ αα ＋ ββ） , dehydroxyl-tocopherols ω（β）/ω（γ）, S1/（ S1 ＋S2）, carbon preference index （CPI） and odd-even predominance （OEP）. Moreover, vitrinite reflectance （Ro）, peak temperature （Tmax and S 1/TOC were more effective to high maturation phase. Application of muhiple indices could enhance the reasonability of conclusions. The maturity of source rocks in Dongying depression were divided into immature biochemical process, low mature, oil window, wet gas and dry gas, with corresponding burial depth of 0-1 800 m, 1800- 2600m, 2600-3900 m, 3900-5 100 m and over 5 100 m. The burial depth of oil window in Dongying depression was deeper, which was benefit for hydrocarbon preservation. The main source rocks of the Lower Tertiary have entered oil window, which was the reason that more oil and little gas were found in Dongyng depression.

关 键 词：东营凹陷 古近系 烃源岩 成熟度 

分 类 号：TE122.113[石油与天然气工程—油气勘探]