珠江口盆地原油高灵敏度分析及油源判识模型的建立

Mixing oil is a ubiquitous phenomenon in oil deposit. The study of mixing oil is a hot concept but difficult point in petroleum geology and geochemistry research. Moreover, it also is the base analysis in the hydrocarbon accumulation dynamics system. During the process of oil exploration, the results about the oil-source and oil-oil correlation are beneficial for the evaluation of petroleum resources and determination of exploration strategies. Thus, the research on the geochemistry characteristics in crude oil and identification of mixed crude oil are of great value for the evaluation of petroleum resources and determination of exploration strategies. .In this study a novel and ingenious device, the gas purge microsyringe extraction is being upgraded, and is proposed to couple with comprehensive two-dimensional gas chromatography/ time-of-flight mass spectrometry (GC×GC/TOFMS) for the characterization of the organic compounds in crude oil. Thus, it can get the abundance and precise geochemical parameters in crude oils collected from Pearl River Mouth Basin (PRMB). Based on the reliable analyzed result, the PRMB comprehensive evaluation system (CES) had been established by using chemometrics to screening significant in numerous geochemical indexes. With the developed model, the crude oils were easily discriminated into three oil classes. Thus, de-convolution of the mixed oils had been done. Consequently, this thesis will offer a new technique for establishing CES and de-convolution of mixed crude oil in PRMB and others basin. All in all, established the analysis method for mixed oils in PRMB for exempla, including precise analytical method and the parameters screening technique and the oil-source correlation method. Thus, based on the precise geochemical parameters and mathematical model, the analytical system can be extended to other basins.

珠江口盆地是我国石油工业重要的原油生产基地，其发育三套烃源岩，包括湖相文昌组，过渡相恩平组和海相珠海组。较早研究表明富含4-甲基甾烷的文昌组湖相泥岩是珠江口盆地最重要的烃源岩。而最近研究表明恩平组烃源岩的显著贡献不可忽略。而主力烃源岩的判识，势必影响对有效烃源岩层位的确认和资源量的评价，甚至对勘探部署等产生误导。.本研究拟对气流吹扫-注射器微萃取仪进行升级改造，建立起能与全二维气相色谱-飞行时间质谱仪耦合联用的在线分析装置，使获得的分析结果更高效、精确和丰富。基于获得的原油地球化学信息，结合多元统计方法筛选出对油源判识具有显著影响的地化指标，建立研究区的综合评价参数体系，并基于该参数建立起该地区的油源判识的数学模型，为混源油的判别及定量判识提供一种新的思路。最终期望能建立在线仪器分析方法、典型地化参数集合的筛选方法和油源关系判识模型，应用至珠江口盆地，并能将该系统的方法推广至其他盆地。

原油是一种极端复杂的混合物，就其化学元素而言，主要是碳元素和氢元素组成的多种碳氢化合物，统称“烃类”，还含硫、氧、氮、磷、钒等元素。对其化学组成进行全面的剖析，可以获得丰富的地球化学信息，若能准确获得样品中地球化学信息并加以整合利用，则能完备的表征原油从生成、运移和储藏整个过程，还能对油气性质(类型与成熟度)、判识沉积环境和地层划分等进行分析。.本研究对气流吹扫-注射器微萃取仪进行升级改造，建立起能与色谱耦合联用的在线分析装置，使获得的分析结果更高效、精确和丰富。并将该方法应用于珠江口盆地原油样品分析，基于获得的原油地球化学信息，结合多元统计方法筛选出对油源判识具有显著影响的地化指标，建立研究区的综合评价参数体系，并基于该参数建立起该地区的油源判识的数学模型，为混源油的判别及定量判识提供一种新的思路。.建立珠江口盆地综合评价参数体系，综合考虑了各类化合物，能更加完备的反映各样品的沉积环境和母质来源特征，并对混原油进行判识。结果表明：混源油样品共15个，其中有7个样品恩平组的贡献率低于30%，有4个混源样品恩平组贡献率在30~50%之间，还有5个混源样品恩平组贡献率超过50%。