Unconventional gas resources have become important as an environment- friendly source of fuel. It is important to understand the pore level geometries of grains and voids in mudrocks in order to understand the flow potential of gas from these rocks. Recent observations of nanopores within carbonaceous material in mudrocks have led to the hypothesis that such material provides conduits for gas migration within the mudrock matrix. This hypothesis requires that the carbonaceous material exist not as isolated grains but as connected clusters of grains within the mudrock. To examine this hypothesis, we develop an algorithm for the grain-scale modeling of the spatial distribution of grains of carbonaceous matter in a matrix of non-carbonaceous material (silt, clay). The algorithm produces a grain-scale model of the sediment which is precursor to a mudrock, then a sequence of models of the grain arrangement as burial compacts the sediment into mudrock. The carbonaceous material is approximated by the simplest possible geometric model of spherical grains. These grains are distributed randomly within a population of other spheres that represent silt and clay grains. A cooperative rearrangement algorithm is used to generate a disordered packing of the grain mixture having a prescribed initial porosity. This model represents the sediment precursor of the shale in its original depositional setting. Periodic boundary conditions are imposed on the packing to eliminate wall-induced artifacts in the grain arrangement; in effect the packing extends infinitely in all three coordinate directions. We simulate compaction of the model sediment by incrementally rescaling the vertical coordinate axis, repeating the cooperative rearrangement calculation with periodic boundaries after each increment. We determine the size distribution of clusters of touching carbonaceous grains, focusing particularly upon the approach toward percolation (when a cluster spans the entire packing). The model allows estimation of threshold fraction of carbonaceous material for significantly connected clusters to form. Beyond a threshold degree of compaction, connected clusters become much more prevalent. Other factors affecting the threshold fraction such as ductility of the carbonaceous material is also evaluated. Ductility is modeled by taking a grain consisting inner rigid core covered by the outer soft shell which can be penetrated and deformed during geometrical transformation. The emergence of large numbers of clusters, or of a few large clusters, increases the probability that nanoporous conduits within the clusters would intersect a fracture in the mudrock. This should correlate with greater producibility of gas from the mudrock. Thus the dependence of the statistics of the clusters upon other parameters, such as the fraction of carbonaceous material, porosity, degree of compaction, etc., could be useful for estimating resource quality. For example, it is observed that the threshold concentration of carbonaceous material in the initial sediments for “significant clustering” enough to approach percolation is about 20 percent of the volume fraction. The degree of compaction needed to get “significant clustering” is 50%. / text

Since the start of the Iraq conflict, world-renowned security expert Paul Rogers has produced a series of monthly reports scrutinising developments in the occupation and the Iraqi response to it, drawing on the unique range of contacts and material available to the prestigious Oxford Research Group. They have become the standard source material for journalists, policymakers and campaigners writing about Iraq. Now, for the first time, Paul Rogers has brought these reports together to provide a detailed and authoritative analysis of the last year in Iraq. A disturbing picture emerges, in which coalition forces repeatedly misread the direction of the insurgency, in which radical groups gain strength through the ongoing (and underreported) loss of civilian lives at the hands of the occupying forces, and in which the US's determination to secure the Persian Gulf's oil and gas resources lock it further and further into a destructive, intractable, and ultimately counter-productive war in the Middle East. Concisely-written and highly accessible, "Iraq and the War on Terror" is an indispensable book for anyone interested the Middle East, US foreign policy and international security. Its conclusions about the extent of the damage caused by the war, and how long the occupation looks set to last, will send shockwaves through policymakers in the US and the UK alike.

As gas production from conventional gas reservoirs in the United States decreases, industry is turning more attention to the exploration and development of unconventional gas resources (UGR). This trend is expanding quickly worldwide. Unlike North America where development of UGRs and technology is now mature and routine, many countries are just beginning to develop unconventional gas resources. Rogner (1996) estimated that the unconventional gas in place, including coalbed methane, shale gas and tight-sand gas, exceeds 30,000 Tcf worldwide. As part of a research team, I helped to develop a software package called Unconventional Gas Resource Advisory (UGRA) System which includes the Formation Analog Selection Tool (FAST) and Basin Analog Investigations (BASIN) to objectively and rapidly identify and rank mature North American formations and basins that may be analogous to nascent international target basins. Based on BASIN and FAST results, the relationship between mature and underexplored basins is easily accessed. To quantify the unconventional resource potential in typical gas basins, I revised and used a computer model called the Petroleum Resources Investigation Summary and Evaluation (PRISE) (Old, 2008). This research is based on the resource triangle concept, which implies that all natural resources, including oil and gas, are distributed log-normally. In this work, I describe a methodology to estimate values of technically recoverable resources (TRR) for unconventional gas reservoirs by combining estimates of production, reserves, reserves growth, and undiscovered resources from a variety of sources into a logical distribution. I have also investigated mature North American unconventional gas resources, and predict unconventional resources in underexplored basins worldwide for case study. Based on the results of testing BASIN and PRISE, we conclude that our evaluation of 24 North American basins supports the premise that basins analysis can be used to estimate UGRs.