渤海海域沙一段特殊岩性烃源岩特征及生烃模式

韦阿娟，黄 志

（中海石油（中国）有限公司天津分公司渤海石油研究院，天津塘沽 300452）

摘 要：根据岩心、岩屑观察结果以及电性特征分析，将渤海海域沙一段特殊岩性烃源岩按岩性组合分为两类：钙质页岩组合和灰质泥岩组合。结合古地貌、沉积相分析，建立了两类特殊岩性组合的发育模式。生烃热模拟实验表明，两类岩性组合产烃率均较高，钙质页岩组合产烃率最高达500 mg/gTOC，灰质泥岩组合产烃率达300 mg/gTOC。两类岩性组合TOC平均含量均超过了1%，为优质烃源岩。通过地球化学研究，建立了两类特殊岩性组合的生烃模式：钙质页岩组合生油门限相对较浅，为低熟—成熟强双峰型生烃模式；灰质泥岩组合生油门限相对较深，为微弱双峰型生烃模式。

关键词：特殊岩性；优质烃源岩；生烃模式；渤海海域

中图分类号：TE122.1

文献标识码：A

DOI:10.3969/j.issn.1008-2336.2015.02.006

文章编号：1008-2336（2015）02-0006-06

收稿日期：2015-02-13；

作者简介：第一韦阿娟，女，1964年生，高级工程师，硕士，1991年毕业于中国地质大学（武汉）地层古生物专业，主要从事石油地质综合研究。E-mail：weiaj@cnooc.com.cn。

改回日期：2015-03-03

The Special Lithologic Characteristics of Sha-1 Member Source Rocks and Hydrocarbon Generation Models in the Bohai Sea Area

WEI Ajuan, HUANG Zhi

（Bohai Oil Research Institute, Tianjin Branch of CNOOC Ltd., Tianjin 300452, China）

Abstract:The special lithology of Sha-1 Member source rocks in Bohai Sea can be divided into two categories, calcareous shale combination and calcareous mudstone combination, by core or cuttings observation and analysis of electrical characteristics. Combined with analysis of palaeo-geomorphology and sedimentary facies, two kinds of development pattern for the special lithologic combination have been established. The thermal simulation experiments on hydrocarbon generation indicated that the hydrocarbon generated from these two kinds of lithology association was higher, with hydrocarbon yield of calcareous shale combination up to 500 mg/gTOC, and calcareous mudstone combination was about 300 mg/gTOC. Those two kinds were both high quality source rock, with TOC over 1.0%. The hydrocarbon generation models for these two kinds of special lithologic combination have been established through geochemical study. The oil generation threshold depth of calcareous shale combination was shallow, and the hydrocarbon generation model is immature-mature strong double peak model. The oil generation threshold depth of calcareous mudstone combination was very deep, the hydrocarbon generation model is small double peaks model.

Keywords:special lithology; high quality source rock; hydrocarbon generation model; Bohai Sea area

渤海湾盆地渤海海域沙一时期构造环境稳定，整体处于坳陷期，物源输入少，且该时期为温暖潮湿热带—亚热带气候，盆地为平衡补偿，导致湖水浅、咸、清澈而广阔[1]，因而除了正常砂泥岩沉积外，还有丰富的特殊岩性，主要包括碳酸盐岩、生屑灰岩、油页岩、钙质页岩及灰质泥岩等，因此，渤海海域沙一段常被称为特殊岩性段[2]。

近年来渤海海域的油气勘探取得一系列重大突破，特别是渤东探区更是相继发现蓬莱9-1与蓬莱15-2等大型油田。……