Chemical interactions in carbonate rock–seawater, silty sand–seawater, clay rock–seawater, basalt–seawater, and granite–seawater systems, where the term “seawater” denotes the compositions of halite, epsomite, and sylvinite stages of seawater densification, were simulated at 25, 100, 200, and 300°С and various pressures in order to assess the ability of rocks to generate hydrocarbons. Based on the efficiency of hydrocarbon generation, the rocks are arranged in the following series: clay > silty sandstone > carbonate > mafic rocks; felsic rocks are unproductive. It is shown that with an increase in the weight rock/water ratio (R/W), which may be taken as the conditional time (degree) of metamorphism, the reduction potential (lgfH2) of rocks, i.e., their ability to generate hydrocarbons, increases. At R/W → 1, the reduction potentials (lgfH2) for carbonate, clay, and silty sandstone are –2.74, –2.45, –2.57 at 100°С, –1.2, –1.1, –1.0 at 200°С, and –0.5, +0.3, –1.2 at 300°С, respectively, which shows a clear advantage of clay at high temperatures (pressures) in terms of its ability to reduce chemical elements and generate hydrocarbons. Thermodynamic modeling of interactions in a closed water–mineral precipitate–natural organic matter system at the T–P parameters of diagenesis was performed. A mature type of kerogen and associated substances (water-dissolved hydrocarbons, nitrogen compounds) are formed in the system in the course of the reactions. It is shown that the removal of CO2 (g) and N2 (g) from the system promotes hydrocarbon and kerogen formation reactions. It was found that the water phase changes insignificantly during kerogen formation. In general, the effect of desalination and changes in pH and Eh, as well as the increase in the content of CO2 dissolved in the water, is significant.

中文翻译：

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岩石-水-有机物质系统的热力学模拟和碳氢化合物的起源

碳酸盐岩-海水、粉砂质砂-海水、粘土岩-海水、玄武岩-海水和花岗岩-海水系统中的化学相互作用，其中术语“海水”表示海水致密化的岩盐、泻盐和钾盐阶段的成分，分别为在 25、100、200 和 300°С 以及各种压力下进行模拟，以评估岩石生成碳氢化合物的能力。岩石按生烃效率排列为：粘土>粉质砂岩>碳酸盐>基性岩；长英质岩石是非生产性的。结果表明，随着可作为变质作用条件时间（程度）的重量岩水比（R/W）的增加，岩石的还原潜力（lgfH2），即其生烃能力，增加。在读/写 → 1，碳酸盐、粘土和粉砂岩的还原电位 (lgfH2) 为 –2.74、–2.45、–2.57 在 100°С、–1.2、–1.1、–1.0 在 200°С，以及 –0.5、+0.3、–1.2分别在 300°С，这表明粘土在高温（压力）下在减少化学元素和生成碳氢化合物的能力方面具有明显优势。在成岩作用的 T-P 参数下，对封闭的水-矿物沉淀-天然有机物系统中的相互作用进行了热力学模拟。在反应过程中，系统中会形成成熟类型的干酪根和伴生物质（水溶烃、氮化合物）。结果表明，从系统中去除 CO2 (g) 和 N2 (g) 促进了碳氢化合物和干酪根的形成反应。发现在干酪根形成过程中水相变化不显着。