Cluster variable aperture (CVA) simulated annealing has been used as an inversion technique to construct fluid flow models of fractured formations based on transient pressure data from hydraulic tests. A two-dimensional fracture network system is represented as a filled regular lattice of fracture elements. The algorithm iteratively changes element apertures for a cluster of fracture elements i...

Recent increases in the use of hydraulic fracturing (HF) to aid extraction of oil and gas from black shales have raised concerns regarding potential environmental effects associated with predictions of upward migration of HF fluid and brine. Some recent studies have suggested that such upward migration can be large and that timescales for migration can be as short as a few years. In this articl...

This paper reviews four critical mechanisms for successful applications of hydraulic fracturing that have emerged or grown in importance over the past 2 decades. These critical issues are managing height growth, decreasing near-wellbore tortuosity, predicting and engineering network versus localized growth geometry, and promoting simultaneous growth of multiple hydraulic fractures. Building on ...

We introduce an approach for the stochastic characterization of geometric and hydraulic parameters a three-dimensional (3D) discrete fracture network (DFN) estimating their uncertainty based on data from tomography experiments. The inversion relies Bayesian framework resulting posterior distribution is characterized by generating samples Markov chain Monte Carlo (MCMC) methods. method evaluated...

Handling flow through fractured media is critical for transient pressure and flow analysis in shale gas reservoirs, because gas production from such low-permeability formations relies on fractures, from hydraulic fractures and fracture network to various-scaled natural fractures, to provide flow channels for gas flow into producing wells. This study presents a numerical investigation of pressur...

The origin of fracture in epithelial cell sheets subject to stretch is commonly attributed to excess tension in the cells' cytoskeleton, in the plasma membrane, or in cell-cell contacts. Here, we demonstrate that for a variety of synthetic and physiological hydrogel substrates the formation of epithelial cracks is caused by tissue stretching independently of epithelial tension. We show that the...

This paper summarises the impact of major earthquakes, 2010–2011, on Christchurch’s water supply network and what recovery measures have been applied, what worked well, what did not and why. A number of issues related to the open nature of the Christchurch water supply network were identified during earthquakes. It was difficult to manage large water supply pressure zones during the post-earthq...

The onshore oil and natural gas industries of China have started a large-scale development when crude oil reserves have been difficult to recover. The stratum fracture modification is an indispensable measure to efficiently develop oil and gas fields. Hydraulic fracturing is the most important reservoir stimulation technique, but it is still faced with various problems such as the failure to fr...