4D modelling of seismic signatures of fluid flow in crystalline rocks

结晶岩石中流体流动的地震特征的 4D 建模

• 批准号: 5304210
• 负责人: Professor Dr. Friedemann Wenzel
• 金额: --
• 依托单位: Geophysikalisches Institut (GPI)
• 依托单位国家: 德国
• 项目类别: Infrastructure Priority Programmes
• 财政年份: 2001
• 资助国家: 德国
• 起止时间: 2000-12-31 至 2003-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/5304210?language=en
• 关键词: 4D; modelling; seismic; signatures; fluid

The main objective of this research is to optimize data acquisition of future seismological time-lapse experiments around the site of the Kontinentale Tiefbohrung (KTB) in Germany by predictive numerical modelling. Second objective is to understand how fluid pressure variations manifest themselves in the recorded elastic wavefields given a specific asquisition geometry. These objectives will be achieved by 6 essential steps: (1) Establishment of a three-dimensional elastic model with a professional software tool (GOCAD) on a scale of 10 x 10 km that incorporates the major reflectors found in previous investigations (SE1 and SE2). (2) Development of a realistic model of the SE1 reflector with variable lateral heterogeneities. The model must be consistent with logging results and previous measurements and consists of an elastic background model and a porosity and permeability model of the SE1 reflector. (3) Development of a two-dimensional elastic model of the area between pilot and main hole. (4) Utilization of Gassmann `theory (low-frequency surface seismic) and Biot`s theory (high-frequency cross-hole seismic) to estabilish the influence of pore pressure variations on elastic parameters. (5) Simulation of three-dimensional low-frequency wave propagation from surface sources for variable fluid pressure evolving in the SE1 reflector due to fluid injection. (6) Simulation of two-dimensional higt-frequency wave propagation for a cross-hole experiment%2

这项研究的主要目的是通过预测性数值模拟来优化德国Tiefbohrung(KTB)遗址附近未来地震时延实验的数据采集。第二个目标是了解流体压力变化如何在给定特定采集几何结构的记录弹性波场中表现出来。这些目标将通过6个基本步骤来实现：(1)利用专业软件工具(GOCAD)建立一个10×10公里的三维弹性模型，其中包括以前调查中发现的主要反射面(SE1和SE2)。(2)建立了具有可变横向非均质性的SE1反射面的真实模型。该模型必须与测井结果和以前的测量结果一致，并由弹性背景模型和SE1反射层的孔隙度和渗透率模型组成。(3)建立了先导孔与主孔之间区域的二维弹性模型。(4)利用Gassmann理论(低频地面地震)和Biots理论(高频井间地震)建立了孔压变化对弹性参数的影响。(5)表面源三维低频波传播的数值模拟，模拟了SE1反射体在注液过程中流体压力的变化情况。(6)井间实验的二维高频波传播模拟