也门探区1区块第一口风险探井烃源岩地球化学特征  

Geochemical Characteristics of the Source Rocks from the First Risky Exploration in Block 1 of Yemen

作　　者：张文艳[1] 包建平[1] 朱翠山[1] 肖飞[1] 

机构地区：[1]油气资源与勘探技术教育部重点实验室(长江大学)长江大学地球化学系,湖北荆州434023

出　　处：《石油天然气学报》2012年第1期25-30,165,共6页Journal of Oil and Gas Technology

基　　金："十一五"国家重大专项课题(2008ZX05056-001)

摘　　要：也门探区1区块第一口风险探井自上而下存在下白垩统Saar组、上侏罗统Nayfa组、Lam组和Meem组4套海相烃源岩。依据烃源岩中有机质丰度、有机质类型和有机质成熟度资料,发现Saar组属于潜在的较好烃源岩;Nayfa组和Lam组属有效的中等烃源岩;Meem组则属有效的优质烃源岩。生物标志物的分析结果表明4套烃源岩均富含重排甾烷,但在萜烷系列组成上存在较大差异,主要表现为Lam组以富含伽马蜡烷和C34和C35升藿烷的优势为主要特征,显示咸水环境水体分层下的产物;而Meem组因新藿烷系列异常丰富而有别于其他层位烃源岩,显示浅水、弱还原环境下的沉积特点;尽管Nayfa组也具有C34和C35升藿烷的优势现象,且正构烷烃具有偶碳优势,但伽马蜡烷含量很低,显示强还原条件下水体没有分层的沉积特征;Saar组的正构烷烃系列呈奇碳优势,姥植比高,贫新藿烷和伽马蜡烷物,表明它形成于浅水、还原性弱的沉积环境。There were four sets of marine source rocks in the first risky well in Block 1 of Yemen Zone,from the upper to the bottom they were Sa'ar,Nayfa,Lam and Meem Formations respectively.According to the basic geochemical data of organic abundance,organic types and its maturity,it was found out that Sa'ar Formation belonged to a potential and better source rock,Nayfa and Lam Formations were the middle and effective source rocks,Meem Formation was an effective and optimal source rock.The biomarker analysis result indicates that there are of abundant diasterane in four sets of the source rocks.However,there are big differences in trterpanes among them.In Lam Formation,gammacerane is relatively abundant and C34-35 homohopane preference is very obvious,it displays a kind of saline,it strongly stratifies in salt water environment;as for Meem Formation,it has abnormally abundant neohopanes,thus it was different with the source rocks in other strata,it indicates that depositional characters under shallow water and weak reductionb.In Nayfa Formation,although there is C34-35 homohopane preference and even-carbon predominant for normal alkanes,however,gammacerane is lower,it indicates that they were deposited in strong reduction without stratified environment.The odd-carbon normal alkanes and C27 steranare are observed,Pr/Ph ratios are higher,but gammacerane is lower in Sa'ar Formation,it shows there exists a king of shallow and suboxic depositional environment.

关 键 词：也门探区 1区块 烃源岩 生物标志物 沉积环境 

分 类 号：P618.13[天文地球—矿床学]