煤成烃过程中铀的影响研究

Organic-inorganic interaction is ubiquitous in the process of formation, evolution, concentration and accumulation of multi-energy resources of oil, gas, coal and uranium. Inorganic geochemistry factors also alter the process of hydrocarbon generation and evolution of hydrocarbon source rocks while that organic matter accelerate concentration and mineralization of inorganic minerals by the strong adsorption and reduction environment from the organic matter of oil, gas and coal. The coal-formed gas has important significance in the natural gas industry of China. Uranium content of coal and coal measure strata is usually high. Petroliferous basins in north China is in a regional geological background with high uranium content. Former study shows that uranium can affect the hydrocarbon amount and generating process of hydrocarbon source rock, promote the generation of hydrocarbon prior, and prominently increase the hydrocarbon yield. Uranium closely coexisted with organic energy minerals also play some roles in the generating process of coal-formed hydrocarbons. This project study the effects of uranium on the hydrocarbon generation of coal using simulation experiment. The study on the effects has some indication to the exploration activity of coal-formed gas, and may increase the resource extent and reserves of coal-formed gas, contribute to the study on the mechanism of hydrocarbon generation of the coal, provide basal experimental data and theoretical references for the study of the mechanism of multi-energy mineral deposits coexisting in the same basin, deepen and consummate the hydrocarbon origin theories.

在油、气、煤、铀多种能源矿产形成演化富集成藏（矿）过程中，有机-无机相互作用普遍存在，在有机质的吸附作用及其所提供的氧化-还原环境为无机矿产的富集成矿起促进作用的同时，无机地球化学因素也影响了有机岩的生烃演化。煤成气在中国天然气工业中有重要意义。煤及煤系地层中的铀含量普遍较高，中国北方含油气盆地总体处于铀含量较高的区域地质背景之中。此前的有关研究表明，铀的存在可以影响到烃源岩油气的生成量及过程，可以使Ⅲ型烃源岩烃类的生成时间提前，同时对烃产量也有较明显的增加。同样，与有机能源矿产密切共生的无机铀在煤成烃的形成中也应该具有一定作用。该课题通过模拟实验，研究铀在煤生烃过程中的作用，对该作用的研究将可能会对煤成气的勘探具有一定的提示作用，并可能会新增煤成气的资源量和储量；有助于推动煤成烃机理的研究；为多种能源矿产同盆共存成藏（矿）机理的研究提供基本的实验素材和理论支持；深化和完善油气成因理论。

该课题的研究在山东黄县北皂低熟煤（Ro=0.38%，TOC=79.00%）中加入碳酸铀酰溶液，进行铀对煤生烃演化的影响的生烃模拟实验工作，以探讨铀在煤生烃演化中的作用。实验结果显示，铀的参与，在低温阶段(不大于400℃)可以显著增加煤生烃模拟实验中液态烃的产率，并增加煤生烃模拟实验中的总烃产率；铀可使煤生烃过程产物CH4的产出量提高，生成的烃类的干气化程度增加；铀在煤的生烃演化过程中具有重要的作用。铀在煤生烃演化过程中的作用及机理值得开展进一步研究工作，为多种能源矿产共存成藏(矿)机理的研究及多能源矿产协同勘探与综合开发提供理论指导与依据。