Experimental Evaluation of Fluid Mineral Interactions at Elevated Temperatures and Pressures Utilizing Isotopic Doping

方解石和斜长石的溶解/沉淀反应在成岩过程中会对沉积岩的孔隙度和渗透率产生巨大的影响。众所周知，这种反应也是地热系统中喷口流体化学的重要控制因素。因此，重要的是了解影响这些矿物反应速率的因素，因为它们相对于石油或天然气生产的时机可能对主要碳氢化合物储量的开发至关重要，或者它们的时机可能强烈影响热液矿床中的矿化地点或程度。该项目将启动一系列水热实验，定量评估流体化学、颗粒大小(表面积)、温度和压力对方解石和斜长石矿物反应速度的影响，这些相已被证明显著影响石油储集层的孔隙度清单，并对地热流体的化学非常重要。利用同位素示踪剂测量动力学和热力学参数是一种新的实验方法，特别适合于研究沉积物成岩作用和热液蚀变过程，在这些过程中，反应往往非常接近平衡。

Dissolution/precipitation reactions involving calcite and plagioclase can have an enormous impact on the porosity and permeability of sedimentary rocks during diagenesis. Such reactions are also known to be important controls on the vent fluid chemistry in geothermal systems. It is thus important to understand the factors influencing the rates of these mineral reactions, since their timing relative to the production of oil or gas can be crucial to the development of major hydrocarbon reserves, or alternatively their timing may strongly influence the locus or extent of mineralization in hydrothermal ore deposits. This project will initiate a series of hydrothermal experiments which quantitatively evaluate the influence of fluid chemistry, grain size (surface area), temperature and pressure on reaction rates for mineral reactions involving calcite and plagioclase feldspar, phases which have been shown to significantly affect the porosity inventory of petroleum reservoirs, and are demonstrably important to the chemistry of geothermal fluids. The use of isotopic tracers to measure kinetic and thermodynamic parameters is a new experimental approach which is especially well suited to the study of sediment diagenesis and hydrothermal alteration processes, where reactions often proceed very close to equilibrium.