Geothermal and geopressure assessment with implications for carbon dioxide sequestration, a regional scale study, lower Tuscaloosa formation, Louisiana

The Massive Sand member of the lower Tuscaloosa formation in Louisiana has the potential to be a prolific reservoir for carbon dioxide sequestration. Proximity to near-term anthropogenic carbon dioxide sources and existing infrastructure in the area make Louisiana a viable prospect for carbon capture and storage projects. The geothermal and geopressure conditions of the reservoir indicate that high carbon dioxide densities can be maintained throughout the study area, and substantial sand thicknesses were located. Subsurface depths of the top of the Massive Sand member range from roughly -2500 ft (-762 m) to over -21,000 ft (-6400 m) with a regional basinward dip. Reservoir temperatures range from 44˚C to 196˚C with an average regional geothermal gradient of .029˚C/m. Reservoir pressures, determined from mud weight data, indicate a pressure range from 8 MPa in shallow sections to 71 MPa in the deepest location. A regional top of geopressure was determined and mapped. Carbon dioxide density was calculated and determined to be a minor factor when considering potential injection locations, with a maximum regional range of 212 kg/m3 to 734 kg/m3. Gross sand isopach reveals substantial sand thicknesses with a general trend of thickening basinward and thinning to the north. Although carbon sequestration is best suited for injection above the regional top of geopressure, a normally pressured zone below the regional top of geopressure, associated with anomalously high porosity and permeability and locally thick sand deposits was identified, mapped, and recommended for further investigation as a potential injection site

A Comparative Analysis on the Impact of Bank Contention in STT-MRAM and SRAM Based LLCs

Spin Transfer Torque Magnetic RAM (STT-MRAM) is being extensively considered as a promising replacement for Last Level Caches (LLC), due to its high density, low leakage and non-volatility. However, writes to STT-MRAM are energy intensive and have a high latency. While the high dynamic energy consumption during writes can be compensated by the low static energy consumption, the high latency results in performance degradation. This work shows that in contrast to SRAM-based LLCs, the performance degradation for STT-MRAM is primarily due to bank contention, when trying to satisfy a read request while the bank is being written. We holistically explore the effects of cache banking and cache contention on energy and performance in the LLC of mobile multicore systems, with in-order cores or with out-of-order cores. The detail of the analysis is enabled by highly accurate cache models, based on a 28nm SRAM industry compiler, and an in-house developed STT-MRAM compiler, which generates full STT-MRAM macro designs with silicon-validated MTJ stack and complete parasitic extraction at the 28nm node. Our results show that there is a clear difference in the energy-performance optimal banking configuration between STT-MRAM caches and SRAM caches. These low contention STT-MRAM cache designs with the optimal number of banks save at least 60% cache energy while losing at most single digit percentages in system performance compared to SRAM cache designs. This show an increased potential of using STT-MRAM as a replacement for SRAM in an LLC.EU (FEDER)MINECOComunidad de MadridDepto. de Arquitectura de Computadores y AutomáticaFac. de InformáticaTRUEpu