摘要
为配合中缅合作的M区块油气勘探,确定该区块英雄岛含油气地层时代与沉积环境,对缅甸英雄岛R-3井2562~2844 m井段10个烃源岩样品进行了孢粉实验分析。通过观察,在每个样品中均发现了较丰富的孢粉化石,共鉴定出85属135种或未定种。该井段的孢粉化石以Momipites和Quercoidites含量丰富,始新世常见分子Sabalpolllenites areolatus断续出现,并见有特征分子Schizaeoisporites eocenicus为主要特征,根据孢粉特征分子和优势属种的分布规律,命名为Schizaeoisporites eocenicus-Quercoidites-Momipites-Sabalpollenites areolatus组合;对比相同井段有孔虫和钙质超微化石的分布时代,推测当前的孢粉组合时代为中晚始新世。依据孢粉组合面貌,对照我国油气区古近纪—新近纪孢粉序列的数据统计结果,系统研究后所建立的划分孢粉植物类型、气温带和干湿度带的3个模式,并结合本钻井其他孢型化石分布特征,认为研究区中晚始新世地层为近海陆地环境,北亚热带、暖温带湿润型古气候沉积。
In order to support the oil and gas exploration in China-Burma cooperation block M and determine the age and sedimentary environment of the oil and gas bearing strata in Ramree Island of this block,a total of 10 source rock samples were collected for sporopollen analysis from the interval 2562-2844 m of well R-3 in Ramree Island,Burma.Abundant sporopollen fossils were found in each sample through observation,and 135 species attributable to 85 genera or undetermined species were identified.The sporopollen fossils in this interval are rich in Momipites and Quercoidites,with Sabalpollenites areolatus,a common molecule in Eocene,appearing intermittently,and characterized by Schizaeoisporites eocenicus.Based on the distribution patterns of sporopollen characteristic molecules and dominant genera and species,one sporepollen assemblage was recognized,namely Schizaeoisporites eocenicus-Quercoidites-Momipites-Sabalpollenites areolatus.By comparing the distribution ages of foraminifers and coccolithus nannofossils in the same interval,it was inferred that the age of sporepollen assemblage was the middle to late Eocene.According to the characteristics of the sporepollen assemblage,the statistical results of Paleogene to Neogene sporopollen sequence data in China’s oil and gas regions,three models for the classification of sporopollen plant types,temperature zones and dry and humid zones established after systematic research,and distribution characteristics of other palynological fossils,we interpret that the study area was offshore land paleoenvironment with subtropical and warm temperate humid paleoclimate in the middle to late Eocene.
作者
史德锋
祝幼华
SHI Defeng;ZHU Youhua(Hainan Branch,CNOOC(China)Limited,Haikou,Hainan 570312,China;Nanjing Institute of Geology and Palaeontology,Chinese Academy of Sciences,Nanjing,Jiangsu 210008,China)
出处
《石油实验地质》
CAS
CSCD
北大核心
2024年第1期136-145,共10页
Petroleum Geology & Experiment
基金
中国科学院战略性先导科技专项(XDB26000000)资助。
关键词
孢粉组合
古环境
中晚始新世
英雄岛
缅甸
sporopollen assemblage
paleoenvironment
middle to late Eocene
Ramree Island
Burma
