Reactive Transport Processes in Acid Stimulation of Carbonate Rocks

考虑到世界上50-60%的石油和天然气储量包含在碳酸盐系统中，了解这些系统中的地质力学和流体动力学状况对于规划和评估储层策略以及降低地质风险至关重要。地下系统中碳酸盐岩的地质力学性质受到同变形或变形后的物理化学成岩作用（如溶解、胶结和沉淀）的影响。这些过程演变了岩石的地质力学景观，导致岩石的岩石物理性质的改变，如渗透率和孔隙度，对流动行为产生不可避免的影响。对于碳酸盐岩系统，成岩作用控制裂缝的产状、构型和属性。这是碳酸盐岩储层管理的一个关键因素，因为碳酸盐岩系统作为低基质孔隙度油气储层的性质意味着这些系统只有在通过裂缝生成或断层再活化提高渗透率时才能生产。应将成岩信息纳入更准确的地质力学模型和更现实的裂缝模式，用于流体流动模拟的建设。此外，发生在孔隙水平的物理和化学成岩作用和生成，传播和/或在多孔介质中的微观功能的再活化的空间和时间尺度，施加在碳酸盐岩储层中的综合地质力学流动模拟的多尺度问题。在这个项目中，成岩作用的地质力学效应与合成碳酸盐岩储层中的油气开采策略的多相流耦合。将研究压力和温度对矿物（碳酸盐组分）沉淀和溶解的影响，将化学反应与流动耦合。此外，将着眼于孔隙网络和层析成像的非均质性和对化学成岩作用和裂缝中碳酸盐溶解的影响。使用的软件：COMSOL Multiphysics（化学工程和CFD模块）。

Considering that 50-60% of the world's oil and gas reserves are contained in carbonate systems, the understanding of geomechanical and hydrodynamical regimes in these systems are essential for planning and evaluating the reservoir strategies and reducing the geological risks. The geomechanical properties of carbonate rocks in the subsurface systems are under influence of syn- or post-deformation physico-chemical diagenetic processes such as dissolution, cementation and precipitation. These processes evolve the geomechanical landscape of the rock, leading to alterations of petrophysical properties of rock such as permeability and porosity with inevitable effects on flow behaviour. For the carbonate systems the diagenesis controls fracture occurrence, architecture and attributes. This is a key factor for management of carbonate reservoirs, because the nature of carbonate systems as low-matrix-porosity hydrocarbon reservoirs, imply that these systems can be productive only when permeability is enhanced by fracture generation or faults reactivation. The diagenetic information should be incorporated into construction of more accurate geomechanical models and more realistic fracture patterns for use in the fluid-flow simulation. Moreover, the spatial and temporal scales of occurrence of the physical and chemical diagenesis at pore level and generation, propagation and/or reactivation of micro-features in the porous media, impose a multiscale problem for an integrated geomechanical-flow simulation in carbonate reservoirs. In this project the geomechanical effects of diagenesis are coupled with multiphase flow for hydrocarbon production strategy in a synthetic carbonate reservoir. Effects of pressure and temperature on precipitation and dissolution of minerals (carbonate-components) will be investigated, in coupling chemical reactions with flow. Additionally will be looked to the pore network and tomography heterogeneities and influence on chemical diagenesis and dissolution of carbonates in fractures. Software to be used: COMSOL Multiphysics (Chemical Engineering and CFD modules).