Asia Pacific Journal of Energy and Environment

95-106

Authors: Falae Philips Omowumi

Application of geophysical investigation has been carried out using Vertical Electrical Sounding (VES) at the proposed building site in Ibese Southwest Nigeria to determine the geophysical parameters that can be used to evaluate the structural competence of the subsurface geological characteristics of the site for construction purposes and building development. The Schlumberger configuration was used for the data acquisition. One-dimensional numerical inversion of individual DC resistivity was used to enhance the processing of the results for better achievement of the aim of the study. Models obtained from the 2D inversion of each VES were used for construction of geo-electric sections which exhibit the main geo-electric characteristics of the geological units present in the area. The interpretation results showed that the geo-electric sections consist of three-four layers namely: topsoil, pebble clay, limestone and sand/limestone. The layer resistivities and thicknesses range from 11 - 404 Ohm-m/0.4 - 1.5 m, 2-210 Ohm-m/ 0.8 - 9.2m and 33 - 160Ohm-m respectively. The investigation revealed that the sand/limestone litho unit is to be the most competent for shallow foundation for small to medium engineering structures.

121-155

Authors: Hiwot Teshome Abebe, Prof. Ayalneh Bogale

Current climate variability is already imposing significant challenge to Ethiopia. Therefore, farmers have faced income variability in almost every production season. Problems associated with dependence on rain fed agriculture are common in Ethiopia. Smallholder farmers’ vulnerability from such income variability is also common. Over the years, a range of risk management strategies have been used to reduce, or to assist farmers to absorb, some of these risks. Since insurance is potentially an important instrument to transfer part of the risk, this study try to describe the nature of weather related risks faced by smallholder farmers, assess small holder farmers willingness to pay for the rainfall risk insurance and examine factors that affect the maximum farmers are willing to pay for the rainfall risk insurance. The data was collected from 161 sample households from the two woredas of the study area using closed ended value elicitation format followed by open ended follow up questions. The study uses Logit model to estimate the mean willingness to pay in the close ended format in addition with Tobit model to examine factors that affecting small holder farmer willingness to pay as well as intensity of payment. The mean willingness to pay values are found to be 129.98 and 183.41 birr per hectare for the open and close ended formats respectively. The total willingness to pay for the study area was found to be birr 5,740,244 per year. The tobit model shows six potential explanatory variables affect the willingness to pay value. Income of household and ownership of radio have positive and significant effect on the value of willingness to pay, whereas off-farm income, age of household head, number of livestock owning and availability of public and private gifts have negative and significant effect on willingness to pay value. If the rainfall risk insurance premium is affordable and households have enough information about the service they are willing to pay for the service. Eventually policy makers need to be aware that socio-economic and institutional characteristics of households influence the willingness to pay for rainfall risk insurance services.

172-181

Authors: Fatema Akter Happy, Mohammad Shahedul Hossain, Arifur Rahman

Kailastila gas field located at Golapgonj, Sylhet is one of the largest gas fields in Bangladesh. It produces a high amount of condensate along with natural gas. For the high values of GOR, it may be treated as a wet gas at reservoir condition. Three main sand reservoirs are confirmed in this field (upper, middle & lower).In this study, it has been shown that reservoir parameters of this gas field can be obtained for multilayered rectangular reservoir with formation cross-flow using pressure and their semi log derivative on a set of dimensionless type curve.The effects of the reservoir parameters such as permeability, skin, storage coefficient, and others such as reservoir areal extent and layering on the wellbore response, pressure are investigated.Shut in pressures are used in calculating permeability, skin factor, average reservoir pressure, wellbore storage effect and other reservoir properties. The direction of the formation cross flow is determined, first by the layer permeability and later by the skin factor.Finally, it is recommended to perform diagnostic analysis along with multilayer modeling to extract better results.Reservoir can also be considered as a multilayer cylindrical and can also use these models for other fields.