Comparison of CO2 trapping in highly heterogeneous reservoirs with Brooks-Corey and van Genuchten type capillary pressure curves

Geological heterogeneities essentially affect the dynamics of a CO2 plume in subsurface environments. Previously we showed how the dynamics of a CO2 plume is influenced by the multi-scale stratal architecture in deep saline reservoirs. The results strongly suggest that representing small-scale features is critical to understanding capillary trapping processes. Here we present the result of simulation of CO2 trapping using two different conventional approaches, i.e. Brooks-Corey and van Genuchten, for the capillary pressure curves. We showed that capillary trapping and dissolution rates are very different for the Brooks-Corey and van Genuchten approaches when heterogeneity and hysteresis are both represented.Comment: 10 pages 6 figure

‘Demand pull’ government policies to support Product-Service System activity: the case of Energy Service Companies (ESCos) in the UK

Product-Service Systems (PSSs) constitute a family of service-based business models designed to satisfy our societal needs in an economically and environmentally sustainable manner. To date however PSS application has remained niche due to a variety of critical barriers. This paper explores how ‘demand pull’ national government policies could support PSS activity by addressing these barriers and cultivating market demand. Lessons are drawn from a case study of how regulatory, economic incentive, informative and procurement policies have supported Energy Service Company (ESCo) activity in the UK; a sub-set of the PSS family focused on energy service provision. Subsequently five policy recommendations are presented to support PSS activity: (1) balancing economic incentives and regulatory disincentives; (2) promoting indirect policy support; (3) redesigning existing market structures; (4) promoting locally-led PSS activity; and (5) creating stable policy frameworks. The paper warns however that national government policy cannot easily address all PSS barriers, such as customer preferences, international developments, technological progress and inherent business model weaknesses, pointing to the need for other complementary solutions. Furthermore, other governance actors beside national government could also implement PSS supporting policies

Seismic Imaging of Sequestered Carbon Dioxide

Time-lapse, three-dimensional seismic surveys have imaged an accumulation of injected CO 2 at the Sleipner field, in the North Sea basin. The changing pattern of reflectivity suggests that CO 2 accumulates within a series of interbedded sandstones and mudstones beneath a thick caprock of mudstone. Nine reflective horizons within the reservoir have been mapped on six surveys acquired between 1999 and 2008

Subparallel thrust and normal faulting in Albania and the roles of gravitational potential energy and rheology contrasts in mountain belts

The active tectonics of Albania and surrounding regions, on the eastern margin of the Adriatic Sea, is characterized by subparallel thrust and normal faulting which, we suggest, is likely to be related to gravitational potential energy contrasts between the low-lying Adriatic Sea and the elevated mountainous areas inland. We calculate the magnitude of the force which the mountains and lowlands exert upon each other as a result of this potential energy contrast. It is likely that this force is largely supported by shear stresses on faults, and if so, the average stresses are less than ∼20 MPa. Alternatively, if the mountains are supported by stresses in the ductile part of the lithosphere, the stresses are likely to be ∼80–240 MPa in magnitude. The mountains of Albania are significantly lower than other ranges, such as the Peruvian Andes, which are thought to be extending in response to potential energy differences, and we discuss the relation between Albania and these other, higher, mountain belts from the perspective of differences in lithosphere rheology. We suggest that the lowlands of western Albania and the Adriatic Sea may have been weakened through time as a result of the deposition of large thicknesses of sediment, which lead to heating of the crystalline basement, a reduction in the potential energy contrast that could be supported by the lowlands, and so normal faulting in the mountains of eastern Albania