SBIR Phase II: Inversion of Geophysical Measurements for Fracture Geometry

这个小型企业创新研究(SBIR)第二阶段项目考虑了一种检测和量化岩石中自然裂缝系统的创新方法。裂缝系统的几何形状控制着许多油气储集层和含水层的渗透率。石油、天然气和环境应用都需要新的工具和技术来量化裂缝几何形状，从而能够预测渗透率。在第一阶段的研究中，开发了一种根据各种地球物理测量数据进行裂缝几何学反演的方法。这是通过将裂缝几何与各种各向异性、应力相关的属性(包括渗透率、电导率和地震速度)与最大熵正则化准则相结合的正演模型来实现的。事实证明，可以使用相对较少的地球物理测量来进行反演，以便对裂缝几何形状进行统计描述，并具有一定的预测能力。根据这一原则证明，在第二阶段，这种方法现在将成为研究和理解油气和环境应用中裂缝系统行为的交互工具。为了实现这一点，将改进正演模型，针对这一特定问题调整反演算法，并通过案例研究验证算法。通过定义油藏流体流动模拟器的实际输入参数，这一新功能可能会为勘探、开发和油藏动态活动提供许多改进。开发新的创新和成本效益高的勘探和油藏模拟技术符合我们的国家利益，这些技术将延长油气藏的使用寿命，并延长该国能够生产出具有竞争力的价格的石油和天然气的时间。L

This Small Business Innovation Research (SBIR) Phase II project considers an innovative method for detecting and quantifying natural fracture systems in rock. The geometry of the fracture system controls the permeability of many oil and gas reservoirs and aquifers. Both oil and gas and environmental applications require new tools and techniques to quantify the fracture geometry, thus allowing prediction of permeability. During the Phase I research an inverse method was developed for fracture geometry from diverse geophysical measurements. This was accomplished by combining forward models relating fracture geometry to various anisotropic, stress-dependent properties including permeability, electrical conductivity, and seismic velocity with a maximum entropy regularization criterion. It was demonstrated that a relatively small number of geophysical measurements could be used to invert for a statistical description of the fracture geometry with some predictive power. Following this proof of principle, in Phase II, this method will now be turned into an interactive tool for studying and understanding fracture system behavior for oil and gas and environmental applications. To accomplish this, the forward models will be refined, the inversion algorithm will be tuned for this specific problem, and the algorithms will be validated using case studies. This new capability will likely provide many improvements to exploration, development, and reservoir performance activities by defining realistic input parameters for reservoir fluid flow simulators. It is in our national interest to develop new innovative and cost effective exploration and reservoir simulation technologies which will extend the useful lifetime of oil and gas reservoirs and extending the period of time that competitively priced oil and natural gas can be produced in this country. l