【作者】 叶聪林；

【导师】 张铭杰； 郑国东；

【作者基本信息】 兰州大学 ， 地球化学， 2010， 硕士

【摘要】 含油气盆地水-岩相互作用是储层的物理性质的主要制约因素之一,它贯穿储层的整个成岩过程,对储层物性的发展、演化意义重大,并对油气的分布、成藏规律及油气开采的效率具有重要的影响。本文利用有机碳硫仪、X-射线荧光及-射线衍射等实验技术综合分析了研究区砂岩有机碳含量、常量元素丰度和主要矿物成分等,对民和盆地地表的砂岩储层中的水-岩相互作用进行了系统研究。取得了以下主要认识：(1)民和盆地砂岩储层主要为长石石英砂岩,及少量的岩屑砂岩和长石砂岩。岩石成分成熟度较高,粒度偏细,磨圆度为次圆状至次棱角状,分选性中等。XRD及XRF数据显示油苗或无油苗的砂岩中矿物主要有石英、长石、少量方解石及粘土矿物。石英含量变化范围为45%-90%,平均65%,多呈线状接触,有明显的次生加大现象。长石主要分为钾长石和斜长石。两者含量相差不大,钠长石含量略大于钾长石,二者总含量为20%-40%。方解石含量较低,平均为1.6%,而在远离油苗处砂岩中含量略高,达到4.7%-6.2%。(2)民和盆地砂岩储层的次生孔隙类型主要包括：溶蚀粒内孔隙、溶蚀粒间孔隙、矿物晶间孔隙以及裂缝等四种基本类型。(3)油苗处砂岩总碳量为1.00%-1.61%,有机碳含量为0.69%-1.05%；泥岩夹层中总碳量为0.15%-0.20%。未含油地层砂岩中总碳量为1.09%,有机碳含量为0.04%。(4)石油在侵位储层过程中会释放出大量的酸性流体介质,使储层体系的孔隙流体的pH值降低,导致储层矿物的溶解与沉淀,如长石、方解石等。原油作为一种还原性物质可与某些氧化性矿物发生氧化还原反应,生成低价态盐,二氧化碳和水等。油气进入储层后,使孔隙流体粘度变大,阻碍了Na+(Mg2+)及K+(Ca2+)迁移,抑制了钾长石的钠长石化(白云石化作用)的进行。更多还原

【Abstract】 The physical properties of the reservoir largely depends on the characteristics of reservoir rocks, the structural geological background of the petroliferous basins, hydrodynamic conditions, and water-rock interactions characteristics and so on. The water-rock interaction involves in the entire reservoir diagenetic evolution and the whole process of oil and gas from the formation, migration and accumulation, and it also associates with the distribution oil and gas. In this paper, we use some comprehensive methods to analyze organic matter content of sandstone, the main element abundance and the mineral composition features of the sandstone reservoirs, as well as the water-rock interaction in it. The results are summarized below.The reservoir rocks in the Minhe Basin are mainly feldspar and quartz sandstone, including a few feldspar sandstones and lithic sandstones. The secondary porosity types of the sandstones are mainly dissolution pores between grains, intragranular dissolution pores, intergranular authigenic porosity and cracks. Organic carbon experimental data show that the sandstone of oil leaks are 1.00%-1.61%, the mudstone are 0.17%-0.13%, non-oil-bearing sandstone is 0.04%. XRD data show that the minerals of the sandstones are mainly quartz, feldspar, calcite and a small amount of clay minerals.The emplacement of oil in the reservoir made the pH value of the reservoir lower, leading to some dissolution and deposition. As a reducing substance, crude oil and some oxidative minerals can occur redox reaction and produce low-cost state salt, CO2, H2O, etc. And it also inhibits the metasomatism.更多还原