塔中台盆区原油正构烷烃摩尔浓度分布特征及意义  

The Distribution Characteristics of n-alkanes Mole Concentration in the Crude oils of the Central Tarim Basin Platform and its Geochemistry Applications

作　　者：李碧[1] 黄光辉[1] 徐阳东[2] 唐小强[1] 韩金平[1] 

机构地区：[1]教育部油气资源与勘探技术重点实验室,长江大学地球化学系,湖北荆州434023 [2]长江大学地球科学学院,湖北荆州434023

出　　处：《矿物岩石地球化学通报》2011年第1期97-103,共7页Bulletin of Mineralogy, Petrology and Geochemistry

基　　金：国家自然科学基金资助项目(40973041)

摘　　要：塔里木盆地塔中地区原油性质的多样性和复杂性十分罕见;分析表明,成熟作用和源岩相很可能是原油多样性的次要因素,主要影响因素可能与多期成藏或成藏后储层内的次生蚀变作用有关。本文对照正构烷烃摩尔浓度分布图版,辨别了塔中地区不同构造单元原油正构烷烃摩尔浓度的分布类型,分析了原油遭受次生蚀变作用的程度,以及蒸发分馏作用、气洗作用发生的原因及其对原油物性的影响。结果表明,由于运移通道以及与油气源的距离等因素,从塔中Ⅰ号断裂坡折带至中央断垒带,蒸发分馏作用和气洗作用发生的频率逐渐降低,但基态原油分布频率有增高的趋势。并且Ⅰ号断裂坡折带部分凝析油、高蜡油的形成主要与上述蒸发分馏、气洗、晶析等储层内的次生蚀变作用有关。The diversity and the complexity of the oils from the Tazhong area,Tarim Basin,are very rare.The analytical result shows that the maturation and the source rock phase are likely the secondary factors,while the main factor may be multi-stage deposit or secondary alteration in the reservoir.According to the board of the n-alkanes mole concentrations of the crude oil,this paper studied the distributions of n-alkanes＇ mole concentrations in crude oils from the different tectonic units in the Tazhong area,analyzed the degree of secondary alteration of the crude oil,and investigated the causes of evaporation fractionation and gas washing and their impacts to the chemical properties of the crude oils.The results indicated that,because of the factors of different migration channels and migration distance from the oil and gas sources,the frequencies of undergoing evaporative fractionation and gas washing decrease gradually but the frequency of finding crude oils increases from the No.1 fault zone to the central uplift zone of the Tazhong area.The results also suggested that the forming of condensed oils and high wax oils in the No.1 fault zone can be mainly associated with evaporative fractionation,gas washing and crystal fractionation.

关 键 词：塔中地区 正构烷烃摩尔浓度 蒸发分馏作用 气洗作用 高蜡原油 

分 类 号：P618.13[天文地球—矿床学]