Reactions of petroleum compounds with hematite grain-coatings and their effects on diagenesis and pore structure of clastic reservoir rocks

该项目的目的是研究石油化合物与储集岩矿物表面赤铁矿涂层的相互作用及其对孔隙度（和渗透率）的影响。大量的岩石学研究已经记录了红层中典型的成岩事件序列，导致孔隙结构的实质性改变，从而改变储集岩的孔渗性质。这些反应序列包括，作为最显着的功能，还原漂白的某些领域导致Fe2+动员，石油浸渍和形成增强孔隙度（溶解的水泥和碎屑）在邻近的岩石体积。本方法的概念是石油化合物通过与储层内的赤铁矿反应而氧化，提供酸性物质（例如羧酸），其引起进一步的成岩反应，导致在先前被油污染的储层间隔附近的孔隙空间增强。拟议的研究允许整合广泛的现场证据，无机和有机地球化学实验室数据和实验工作。涉及有机物和矿物质的这一反应顺序的细节将在高温高压条件下的实验室试验中进行研究。将开发具体的取样技术，以分析这一过程中产生的羧酸和其他预期的有机物类。矿物反应将通过分析在实验期间取样的孔隙水中的离子种类以及通过比较实验前后样品砂岩的岩相矿物学特征来监测。

The aim of this project is the investigation of the interaction of petroleum compounds with hematite coatings on mineral surfaces in reservoir rocks and their effects on porosity (and permeability). Numerous petrological studies have documented typical sequences of diagenetic events in red beds leading to substantial alterations of the pore structure and, in consequence, changes in the poro-perm properties of reservoir rocks. These reaction sequences comprise, as the most conspicuous features, reductive bleaching of certain domains resulting in Fe2+ mobilisation, oil impregnation and formation of enhanced porosity (dissolution of cements and clasts) in neighbouring rock volumes. The concept of the present approach is that oxidation of petroleum compounds by reaction with hematite within reservoirs provides acidic species (e.g. carboxylic acids) which cause further diagenetic reactions resulting in the enhancement of porespace in the vicinity of formerly oil-stained reservoir intervals. The proposed study allows the integration of extensive field evidence, inorganic and organic geochemical laboratory data, and experimental work. Details of this reaction sequence involving organic and mineral matter will be investigated in laboratory tests under elevated temperature and pressure conditions. Specific sampling techniques will be developed to analyse carboxylic acids and other expected organic species generated in this process. Mineral reactions will be monitored by analysis of ionic species in the pore water sampled during the experiment and by comparison of petrographic-mineralogic features of the sample sandstones prior and after experiments.