Mechanistic modeling of CO2 well leakage in a generic abandoned well through a bridge plug cement-casing gap

Both known and unmapped plugged and abandoned wells are potential leakage pathways for CO2 from geologic carbon sequestration (GCS) sites. Although many abandoned wells have cement bridge plugs installed to prevent leakage, the seal between the cement and the inner casing wall is subject to failure. In this study, we carried out detailed T2Well simulations of cases of sudden non-Darcy flow of CO2 and brine leakage up the gap between a cement plug and the inner steel casing wall that becomes a fully connected flow path during the post-injection period. The goal of our study was two-fold: (1) to understand the dynamics, rates, and the characteristic temporal signals associated with the onset of leakage through various gap-aperture sizes, and (2) to suggest potential monitoring strategies based on the findings. Simulation results show that the leakage of CO2 and brine upward is transient with interesting phase interference behavior. Time-dependent oscillatory flows with varying pressure, temperature, and flow rates of CO2 and brine show strong dependence on gap aperture. Phase-change and decompression lead to very low temperatures at the top of the well for gap apertures larger than 4 mm suggesting that remote thermal monitoring at the ground surface may be an effective way of monitoring even if well locations are not known a priori. Pressure in the well is also indicative of CO2 leakage. The temporal patterns of changing temperature and pressure may be useful diagnostic signals for leakage detection. Finally, these transient leakage signals may provide information on the cause of leakage and/or characteristics of the flow path that could inform effective remediation design and execution approaches

Color television system for a manned space base Progress report

Color television system for manned space statio

Transfers and Development: Easy Come, Easy Go?

Contrary to the popular notion that money that is easily earned, is also easily spent, economic theory holds that income is fungible. Drawing on the concept of mental accounting, this study theoretically explores when such a link between spending behaviour and the effort dispensed in obtaining income is plausible. Empirically, it is found that the marginal propensity to consume from unearned income is about three times larger than that from earned income, based on household panel data from rural China, with the difference more pronounced when unearned income is transitory and smaller than earned income. The policy implications are real

A Poisson Regression Examination of the Relationship between Website Traffic and Search Engine Queries

A new area of research involves the use of Google data, which has been normalized and scaled to predict economic activity. This new source of data holds both many advantages as well as disadvantages, which are discussed through the use of daily and weekly data. Daily and weekly data are employed to show the effect of aggregation as it pertains to Google data, which can lead to contradictory findings. In this paper, Poisson regressions are used to explore the relationship between the online traffic to a specific website and the search volumes for certain keyword search queries, along with the rankings of that specific website for those queries. The purpose of this paper is to point out the benefits and the pitfalls of a potential new source of data that lacks transparency in regards to the original level data, which is due to the normalization and scaling procedure utilized by Google.Poisson Regression, Search Engine, Google Insights, Aggregation, Normalization Effects, Scaling Effects

Poverty, Risk and Insurance: Evidence from Ethiopia and Yemen

Gunning, J.W. [Promotor]Elbers, C.T.M. [Copromotor

High-Fidelity Archeointensity Results for the Late Neolithic Period From Central China

Archeomagnetism focuses on exploring high-resolution variations of the geomagnetic field over hundreds to thousands of years. In this study, we carried out a comprehensive study of chronology, absolute and relative paleointensity on a late Neolithic site in central China. Ages of the samples are constrained to be ~3,500–3,000 BCE, a period when available paleointensity data are sparse. We present a total of 64 high-fidelity absolute paleointensities, demonstrating the field varied quickly from ~55 to ~90 ZAm2 between ~3,500–3,000 BCE. Our results record a new archeomagnetic jerk around 3,300 BCE, which is probably non-dipolar origin. The new results provide robust constraints on global geomagnetic models. We calculated a revised Chinese archeointensity reference curve for future application. The variations of absolute and relative paleointensity versus depth show good consistency, reinforcing the reliability of our results. This new attempt of combining absolute and relative paleointenstiy provides a useful tool for future archeomagnetic research

The Impacts of U.S. Cotton Programs on the West and Central African Countries Cotton Export Earnings

This study uses a stochastic simulation approach based on a partial equilibrium structural econometric model of the world fiber market to examine the effects of a removal of U.S. cotton programs on the world market. The effects on world cotton prices and African export earnings were analyzed. The results suggest that on average an elimination of U.S. cotton programs would lead to a marginal increase in the world cotton prices thus resulting in minimal gain for cotton exporting countries in Africa.Stochastic simulation, partial equilibrium model, United States, Africa, cotton subsidies, export earnings, Crop Production/Industries, International Relations/Trade,

THE IMPACTS OF U.S. COTTON PROGRAMS ON THE WEST AND CENTRAL AFRICAN COUNTRIES COTTON EXPORT EARNINGS

This study uses a stochastic simulation approach based on a partial equilibrium structural econometric model of the world fiber market to examine the effects of a removal of U.S. cotton programs on the world market. The effects on world cotton prices and African export earnings were analyzed. The results suggest that on average an elimination of U.S. cotton programs would lead to a marginal increase in the world cotton prices thus resulting in minimal gain for cotton exporting countries in Africa.Stochastic simulation, partial equilibrium model, United States, Africa, cotton subsidies, export earnings, Agricultural and Food Policy, Crop Production/Industries, Q11, Q17,