Three-dimensional analysis of coupled thermohaline flow and reactive transport in fractured geothermal reservoirs

裂缝性地热储层温盐流与反应输运耦合的三维分析

基本信息

批准号：
175644494
负责人：
Professor Dr. Thomas Graf
金额：
--
依托单位：
Institut für Strömungsmechanik und Umweltphysik im Bauwesen
依托单位国家：
德国
项目类别：
Independent Junior Research Groups
财政年份：
2010
资助国家：
德国
起止时间：
2009-12-31 至 2015-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/175644494?language=en
关键词：
Three dimensional analysis coupled thermohaline

项目摘要

Studying coupled 3D thermohaline flow and reactive transport in fractured materials is important in the context of estimating lifetime and efficiency of geothermal reservoirs. Thermal energy extraction with the common Hot Dry Rock method will lead to steep gradients of water temperature, water density and presumably solute concentration. As a result, chemical reactions (precipitation/dissolution) and a modification of the flow regime due to coupled thermal-solutal (“thermohaline”) flow is expected to occur in the 3D fractured reservoir. To date, a number of coupled geoprocesses in the 3D subsurface have not yet been investigated. These include, amongst others, thermohaline flow in fractured rock, 3D variable-density flow in fractured rock, and the effect of reactive transport on geothermal reservoir efficiency. In particular, this project will focus on (i) the study of viscosity-effects on variable-density flow in porous and fractured-porous reservoirs, (ii) the impact of chemical reactions on geothermal reservoir efficiency, (iii) the study of variable-density flow in 3D fractured reservoirs, (iv) thermohaline (“double-diffusive”) convection in fractured geothermal reservoirs, (v) the transient analysis of thermohaline flow in porous media, and (vi) the efficient representation of complex 3D fracture networks in a finite-element mesh of variable topography and inclined hydrogeological units. The goal of this project is to provide adapted and efficient modelling tools to theoretically examine coupled processes. Numerical models are useful tools because systems of high complexity can be studied, which is difficult and sometimes impossible in field or laboratory experiments. The results of this project will (i) yield fundamental knowledge on the above mentioned coupled geoprocesses in 3D fractured rock as well as their interaction, (ii) assist in the identification of important processes relevant for the long-term operation of georeservoirs, (iii) help to identify the relevant parameters, (iv) provide adapted tools for the long-term prediction of reservoir productivity and efficiency, and (v) help to estimate the relative importance of individual coupled processes.

在估计地热储层的寿命和效率的背景下，研究偶联的3D热盐流和反应性转运很重要。使用常见的热岩石方法提取热能将导致水温，水密度和大概是固体浓度的钢梯度。结果，预计在3D断裂的储层中，预计由于耦合热溶剂（“热盐”）流动引起的化学反应（降水/溶解）和由于耦合热溶剂（“热盐”）流动的修饰。迄今为止，尚未研究3D地下的许多耦合地理处理。其中包括裂缝岩石中的热盐水流，以及反应性转运对地热储层效率的影响。特别是，该项目将重点介绍（i）对多孔和破裂的孔储层可变密度流的粘度效应的研究，（ii）化学反应对地热储层效率的影响，（iii）研究3D分裂储量的可变密度流量的研究储层，（v）多孔培养基中热盐流的瞬时分析，以及（vi）可变地形和倾斜水文地质单位的有限元网格中复杂3D断裂网络的有效表示。该项目的目的是为理论上检查的耦合过程提供适当有效的建模工具。数值模型是有用的工具，因为可以研究高复杂性的系统，这在现场或实验室实验中很困难，有时是不可能的。 The results of this project will (i) yield fundamental knowledge on the above mentioned coupled geoprocesses in 3D fractured rock as well as their interaction, (ii) assist in the identification of important processes relevant for the long-term operation of geoservoirs, (iii) help to identify the relevant parameters, (iv) provide adapted tools for the long-term prediction of reservoir production and efficiency, and (v) help to estimate the relative单个耦合过程的重要性。