This work concerns detailed numerical modelling of injection fracturing in chalk formations under 2–3 km burial. The conditions and properties are chosen to resemble field as typically found oil fields subject water the Central Graben North Sea off-shore Denmark, Norway UK, but studied phenomena general irrespective geographical location technological application. complexity reality is a challe...

We present a decentralized, behavior-based approach to assembling and maintaining robot formations. Our approach dynamically grows formations from single robots into line segments and ultimately larger and more complex formations. Formation growth occurs by negotiation when robots are in close proximity. The approach has been validated using simulation as well as experiments with physical robot...

The individual feathers in the skin of a developing chicken embryo are arranged in a precise array within a series of so-called 'tracts'. The images above show nascent feather buds in the legs of embryos at 8–9 days of incubation. Buds are added sequentially across the forming feather tract, as shown by the range of developmental stages in the image at top left. (In all three upper images, buds...

This paper treats the problem of the merging of formations, where the underlying model of a formation is graphical. We first analyze the rigidity and persistence of metaformations, which are formations obtained by connecting several rigid or persistent formations. Persistence is a generalization to directed graphs of the undirected notion of rigidity. In the context of moving autonomous agent f...

Multi-agent formations have been recently the subject of many studies. An important operational challenge, largely unaddressed in the literature, is to ensure that functionality of the formation is retained should agents be lost through misadventure, mission reassignment, and so on. In the context of sensor networks, it is also important to allow for the loss of multiple sensors as the low qual...

A multiphysics data analytic platform is established for imaging poroelastic interfaces of finite permeability (e.g., hydraulic fractures) from elastic waveforms and/or acoustic pore pressure measurements. This accomplished through recent advances in design non-iterative sampling methods to inverse scattering. The direct problem formulated via the Biot equations frequency domain where a network...

• We present a generic CO 2 storage model to predict pressure changes above the caprock due fast hydraulic communication and partially undrained loading. The pore increase induced by loading is non-negligible, up 1% of in injection zone. Fast across usually results higher yet more gradual than that caused solely help understand signals measured four field projects. Commercial-scale development ...

Coupled multiphase flow and geomechanics models are computationally costly and complex to implement. In order to take advantage of petascale and future exascale computing power, parallel domain decomposition offers an opportunity for decoupling realistic subsurface problems. The basic idea is to reduce the complexity of these multiphysics problems by applying the coupling only in those domains ...