Fracture Network Engineering (FNE) is the engineering design of rock mass disturbance through the use of advanced techniques to model fractured rock masses numerically, and then correlate field observations with simulated fractures generated within the models. Microseismic (MS) monitoring is a standard tool for evaluating the geometry and evolution of the fracture network induced during a hydraulic treatment, principally by source locating MS hypocenters and visualizing these wi th respect to the treatment volume and infrastructure (Figure 1). The integrated use of Synthetic Rock Mass (SRM) modeling of the hydraulic fracturing with Enhanced Microseismic Analysis (EMA) provides a feedback loop where the SRM is constrained by the information provided by the MS data, and the in-situ behavior of the fracture network is better understood, which leads to informed decisions on future field operations. This paper discusses the technologies used in FNE and some of the developmental challenges we face in order to provide a more efficient and robust application of the approach.
The challenge of developing an effective network of fractures is part of a general issue that arises in many sectors of rock engineering; namely, how to characterize and predict the mechanical behavior of a rock mass through an engineering project. The analytical complexity of these problems, and inability to test the rock mass behavior directly on the large scale, has led to the development of a variety of empirical rules that are used widely in practical rock engineering design. As projects become more ambitious and extend beyond prior experience, such rules become increasingly unreliable. Therefore, attention is turning to numerical models, aided during development and validation by in-situ observation, to establish the large-scale response of rock in practical situations. Hydraulic treatments now are widely used to engineer a fractured rock volume.