Shining light on shale: geomechanics and 4D fracture characterization

页岩的亮点：地质力学和 4D 裂缝表征

基本信息

批准号：
NE/M001458/1
负责人：
Julian Mecklenburgh
金额：
$ 74.17万
依托单位：
University of Manchester
依托单位国家：
英国
项目类别：
Research Grant
财政年份：
2014
资助国家：
英国
起止时间：
2014 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=NE%2FM001458%2F1
关键词：
Shining light shale geomechanics 4D

项目摘要

The successful development of a shale gas industry in the UK can be aided by improved understanding of the fracture and physical properties of these rocks. The key petrophysical properties that determine how fractures initiate and grow are determined on the scale of flaws in the rock. Laboratory measurements of these properties are essential to successful modelling studies of hydraulic fracture, and hence optimisation of production. In this research a range of innovative technologies will be used including, for the first time, 3D observation and quantification of hydrofracture growth with time inside the rock by means of synchrotron X-ray tomography coupled with location of crack growth events using acoustic emissions. This will show how hydrofractures initiate and develop, the role of pre-existing flaws in their initiation, the amount of fluid pressure required to initiate them, and how their form might be modified to optimize gas production. Interpretation of the results depends on parallel measurements of the strength, friction and resistance to fracture, and also permeability to fluids, because rock strength depends on the extent to which fluids can penetrate their pores. These properties are also affected by the mineralogy, organic content and microstructure of the shale. Therefore we will test several shales with different such characteristics. These properties also determine, in ways yet to be understood, the stability of boreholes. Permeability of shales to gas and liquids is also known to depend on value of the fluid pressure in the pores for a given depth of burial, thus it changes as gas pressure is drawn down by production. Knowledge of this pressure sensitivity is essential for the successful interpretation of well tests, from which gas in place and likely reservoir yield must be estimated. Thus this research will produce results that can impact on a range of aspects of shale gas exploitation.

通过对这些岩石的破裂和物理特性的了解，可以帮助英国的页岩天然气行业的成功发展。确定裂缝启动和生长的关键岩石物理特性是根据岩石中缺陷的规模确定的。这些特性的实验室测量对于成功建模液压骨折研究至关重要，因此对生产进行了优化。在这项研究中，将首次使用一系列创新技术，包括第一次通过同步X射线断层扫描和岩石内部的时间观察和定量氢反骨折生长，并使用声学排放，以及裂纹生长事件的位置。这将显示出液压的启动和发展，既有缺陷在其启动中的作用，启动它们所需的流体压力量以及如何修改其形式以优化气体产生。结果的解释取决于对裂缝强度，摩擦和抗性的平行测量，以及对流体的渗透性，因为岩石强度取决于流体可以穿透毛孔的程度。这些特性还受页岩的矿物学，有机含量和微观结构的影响。因此，我们将测试具有不同特征的几个页岩。这些特性还以尚未理解的方式确定了钻孔的稳定性。还已知页岩对气体和液体的渗透性取决于给定的埋葬深度的孔中流体压力的值，因此随着气压的产生降低，它会变化。对这种压力敏感性的了解对于成功解释井测试是必不可少的，必须估算出气体和可能的储层产量。因此，这项研究将产生可能影响页岩气剥削各个方面的结果。