Lab-Scale Permeability Enhancement by Chemical Treatment in Fractured Granite (Cornubian Batholith) for the United Downs Deep Geothermal Power Project, Cornwall (UK)

A hydrothermal doublet system was drilled in a fault-related granitic reservoir in Cornwall. It targets the Porthtowan Fault Zone (PTF), which transects the Carnmenellis granite, one of the onshore plutons of the Cornubian Batholith in SW England. At 5058 m depth (TVD, 5275 m MD) up to 190 °C were reached in the dedicated production well. The injection well is aligned vertically above the production well and reaches a depth of 2393 m MD. As part of the design process for potential chemical stimulation of the open-hole sections of the hydrothermal doublet, lab-scale acidification experiments were performed on outcrop analogue samples from the Cornubian Batholith, which include mineralised veins. The experimental setup comprised autoclave experiments on sample powder and plugs, and core flooding tests on sample plugs to investigate to what degree the permeability of natural and artificial (saw-cut) fractures can be enhanced. All samples were petrologically and petrophysically analysed before and after the acidification experiments to track all changes resulting from the acidification. Based on the comparison of the mineralogical composition of the OAS samples with the drill cuttings from the production well, the results can be transferred to the hydrothermally altered zones around the faults and fractures of the PTF. Core Flooding Tests and Autoclave Experiments result in permeability enhancement factors of 4 to >20 and 0.1 to 40, respectively. Mineral reprecipitation can be avoided in the stimulated samples by sufficient post-flushing.

Briefly Noted

The appellants originally brought this case against the World Bank Group's financing arm, the International Finance Corporation (IFC), alleging that IFC negligently funded (via a company based in India) a power project in India that damaged the appellants' environment, health, and livelihoods. The issue of whether IFC was immune from suit under the International Organizations Immunities Act of 1945 went to the Supreme Court, which decided in 2019 that international organizations enjoy the same immunity from suit that foreign governments enjoy under the Foreign Sovereign Immunities Act—meaning that they can be sued in the U.S. if their actions fall within one of the exceptions to the FSIA, including the exception for “commercial activities.” The Supreme Court's decision was published in full in Volume 58, Issue 3 of International Legal Materials. This was a reversal from existing jurisprudence, which had held that international organizations (unlike foreign governments) had near-absolute immunity from lawsuits under the Foreign Sovereign Immunities Act and the International Organizations Immunities Act. The case was remanded to the D.C. District Court, which dismissed the complaint in February 2020 because the “gravamen” of the complaint occurred outside the U.S., rendering the commercial activities exception inapplicable. Budha Jam et al. appealed that decision to the D.C. Circuit Court, which affirmed the lower court's decision in July 2021. The Court rejected the appellants' argument that the significant activity was IFC decision-making in the U.S., agreeing with the District Court that the gravamen of the complaint occurred outside the U.S.

Grid-Tie Rotating Solar Rooftop System Using Atmega

This paper presents a grid-tie rotating solar rooftop system solar power project which is powered by using Atmega 328 microcontroller. It includes solar panel, LCD display, and battery charging circuit and an inverter circuit with sun tracking capability. This project represents whether a particular industrial or residential load would be powered by the photovoltaic panel or the company. This project is based on Atmega 328 micro-controller which controls the solar array by rotating it consistently with the position of sun. This energy obtained from the solar array is then stored in battery which is then sent back to power the domestic or industrial area. The remaining energy is then reverted to the power house through the gird-tie system. Hence with the assistance of this project, power usage can be reduced by the renewable source of energy and profit can be earned with the help of the power which is fed back to the grid.

Causes of Design Change Depending on Power Project-Types in Ghana

Design change is a common but significant problem in construction projects. Issues of delay, cost overruns, claims, and disputes in projects occur as a result. However, design change studies in the power-project area are less often discussed. As a result, the primary objective of this study was to identify important cause factors of design changes according to different power-project types in Ghana. Following a thorough assessment of the literature, 36 potential causes were identified, which were narrowed down by expert reviews to 30. In this study, power projects were classified into three categories: power plant, renewable, and distribution and transmission. The results indicate owner-related financial problems as the most important cause of design change for all three project types, followed by the second and third most significant in each of the categories, respectively: errors and omission in design and problems or unforeseen site conditions in power plant projects; deficient quality and quantity of resources and inflation and changes in interest and exchange rates in renewable projects; and problems or unforeseen site conditions and changes of plans in distribution and transmission projects. Based on the findings, power-project stakeholders are able to comprehend the dynamics of design change and develop effective design management strategies to reduce impact.