Theoretical Investigation of Geochemical Processes

地球化学过程的理论研究

• 批准号: 9117393
• 负责人: Harold Helgeson
• 金额: $ 50.67万
• 依托单位: University of California-Berkeley
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1992
• 资助国家: 美国
• 起止时间: 1992-01-15 至 1997-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9117393&HistoricalAwards=false
• 关键词: Theoretical; Investigation; Geochemical; Processes

It has become increasingly apparent in recent years that understanding the organic/inorganic interface and the geobiochemical role of bacteria and clay minerals in sedimentary basins is crucial to development of accurate, comprehensive models of equilibrium and mass transfer in diagenetic processes. A myriad of reversible and irreversible reactions occur in these processes, all of which are in principle amenable to thermodynamic analysis. For example, thermodynamic calculations can be used together with compositional data to identify stable and metastable equilibrium states in diagenetic systems and assess kinetic constraints on reaction progress. Calculations of this kind can be carried out with the aid of equations of state developed in this laboratory over the past several decades. These equations make it possible to investigate the chemical and thermodynamic consequences of reactions among a wide variety of minerals, gases and aqueous species at elevated temperatures and pressures. The purpose of this proposal is to request long-range support for continuation of this research in the context of diagenetic processes with emphasis on organic/inorganic reactions and those of geobiochemical interest. The goals of the project over the next five years include comprehensive calculation of the thermodynamic properties of organic liquids, solids, gases and aqueous species as a function of temperature and pressure, investigation of the extent to which metastable equilibrium prevails among organic molecules in petroleum, aqueous species in oil field brines, and authigenic mineral assemblages in hydrocarbon reservoirs and source rocks, quantification of thermodynamic constraints on the role of bacteria in diagenetic processes at elevated temperatures and pressures, and calculation of mass transfer involving organic/inorganic reactions and clay minerals in sedimentary basins.

近年来，越来越明显的是，了解沉积盆地中有机/无机界面以及细菌和粘土矿物的地球生物化学作用，对于建立准确、全面的成岩过程平衡和传质模型至关重要。在这些过程中发生了无数可逆和不可逆的反应，所有这些反应原则上都可以用热力学分析来解释。例如，热力学计算可以与成分数据一起使用，以确定成岩系统中的稳定和亚稳定平衡状态，并评估反应过程的动力学约束。这种计算可以借助这个实验室在过去几十年里发展起来的状态方程来进行。这些方程式使得在高温高压下研究各种矿物、气体和水之间的化学和热力学反应成为可能。本提案的目的是请求长期支持在成岩过程的背景下继续进行这项研究，重点是有机/无机反应和地球生物化学的兴趣。该项目未来五年的目标包括：全面计算有机液体、固体、气体和含水物质的热力学性质随温度和压力的变化，研究石油中有机分子和油田盐水中含水物质之间的亚稳平衡程度，油气藏和烃源岩中的自生矿物组合，高温高压下细菌在成岩过程中作用的热力学约束的量化，以及沉积盆地中有机/无机反应和粘土矿物的传质计算。