深层碳酸盐岩地热储层多维度孔缝描述与致裂提效机理研究

As the carrier of underground hot water and geothermal energy, the carbonate is also studied for its importance of geothermal reservoir. It has the advantages of great potential and good development conditions, but it has strong heterogeneity, various types of hole, and underground hot water states, and with the unfavorable features such as unclear occurrence and seepage flow patterns.. The project intends to focus on the limited utilize of geothermal resources characterized by dense structural and under underdeveloped pores of the carbonate reservoir, selects the lower section of the Wumishan Formation, the Proterozoic, with superior geothermal conditions but with low water volume as a sample. We plan to research as follows with the highlighting of integration of geological and engineering studies.. 1. Establishing heat storage comprehensive structure with fine layered.. 2. Describe the multi-scale 3D pore characteristics of carbonate geothermal reservoir from the perspective of micro-structure, and quantify spatial distribution and connectivity.. 3. Comparative research of 4D real-time percolation lows and flow models in natural conditions and fractured reservoir form basin to micro stages.. 4. Evaluation of fracture mechanism and suitable fracturing method based on rock mechanics properties.. We plan to find out the spatial pattern of pore distribution, the relationship between pore-fluid occurrence-seepage field-slotting potential, and develop a suitable, reproducible, suitable method for the thermal storage of carbonate rocks of the carbonate reservoir, and to improving effective geothermal process, increase geothermal energy recovery and reduce development costs.

碳酸盐岩是地下热水和热能赋存的重要载体，也是重要的热储类型，具有潜力大、可开发条件好等优势，但也存在非均质性强、孔缝类型多样、热水赋存和渗流规律不清等不利特征。项目拟聚焦当前碳酸盐岩孔洞欠发育且非均质性极强的致密热储地热资源动用有限的问题，选择地热条件优越但水量较小的元古界雾迷山组下部一-二段热储为研究对象，突出地质-工程一体化和天然-改造对比评价，开展：1）建立热储综合结构精细分层优选甜点；2）从微观结构角度深化对碳酸盐岩热储多维度三维孔隙结构特征，并定量化空间分布和连通性；3）对比评价天然状态和改造后微观-盆地尺度的四维实时渗流规律及流动模型；4）突出岩石力学性质评价致裂机理和适宜的致裂方法。查清孔隙分布的空间规律，厘清孔隙-流体赋存-渗流场-造缝潜力之间的相互联系，探索可推广、可复制的适合深层碳酸盐岩热储有效的增产提效工艺方法，以期提高地热能采收率并降低开采成本。

深部碳酸盐岩热储分布广、资源量大，但也存在非均质性强、岩性致密、可持续性开采难度大等问题。本项目依托雄安新区深部岩溶热储为研究对象，通过实际数据处理与实验模拟分析，研究热储沉积环境与空间分布规律，攻关雄安新区碳酸盐岩型热储改造关键技术。研究揭示了研究区储层岩石的力学性质与不同温度和压力条件下的化学反应；结合沉积、岩石力学、孔缝发育规律综合描述，对白云岩为主的致密型热储人工改造可行性进行了分析，提出了一套增产提效方案。与雄安新区 D22 井对接，对室内实验和模拟提出的方案进行现场实践，对方案的有效性进行了验证，总结完善提出了优化的深层碳酸盐岩热储增产提效措施，具有可推广、可复制、可提效的优势。