Most mature oil reservoirs or fields tend to perform below expectations, owing to high level of associated gas production. This creates a sub-optimal performance of the oil production surface facilities; increasing oil production specific operating cost. In many scenarios oil companies flare/vent this gas. In addition to oil production constraints, associated gas flaring and venting consists an environmental disasters and economic waste. Significant steps are now being devised to utilise associated gas using different exploitation techniques. Most of the technologies requires large associated gas throughput. However, small-scale associated gas resources and non-associated natural gas reserves (commonly referred to as stranded gas or marginal field) remains largely unexploited. Thus, the objective of this thesis is to evaluate techno- economic of gas turbine engines for onsite electric power generation called gas- to-wire (GTW) using the small-scaled associated gas resources. The range of stranded flared associated gas and non-associated gas reserves considered is around 10 billion to 1 trillion standard cubic feet undergoing production decline. The gas turbine engines considered for power plant in this study are based on simple cycle or combustion turbines. Simple cycle choice of power-plant is conceived to meet certain flexibility in power plant capacity factor and availability during production decline. In addition, it represents the basic power plant module cable of being developed into other power plant types in future to meet different local energy requirements. This study developed a novel gas-to-wire techno-economic and risk analysis framework, with capability for probabilistic uncertainty analysis using Monte Carlo simulation (MCS) method. It comprises an iterative calculation of the probabilistic recoverable reserves with decline module and power plant thermodynamic performance module enabled by Turbomatch (an in-house code) and Gas Turb® software coupled with economic risk modules with @Risk® commercial software. This algorithm is a useful tool for simulating the interaction between disrupted gas production profiles induced by production decline and its effect on power plant techno-economic performance over associated gas utilization economic life. Furthermore, a divestment and make- up fuel protocol is proposed for management of gas turbine engine units to mitigate economical underperformance of power plant regime experienced due to production decline. The results show that utilization of associated gas for onsite power generation is a promising technology for converting waste to energy. Though, associated gas composition can be significant to gas turbine performance but a typical Nigerian associated gas considered is as good as a regular natural gas. The majority of capital investment risk is associated with production decline both natural and manmade. Finally, the rate of capital investment returns decreases with smaller reserves.

The issue of gas flaring and the attendant environmental effects have become a common sight in the Niger Delta. Apart from being a wastage of natural resources, it is a menace to the global existence of man. The incidences of acid rain and the disruption of economic life of the locals, basically farming and fishing, have led to consistent and irresistible agitation by the people of the Niger Delta for an end to gas flaring. The consistent release of harmful gases through gas flaring, with devastating effect on the surrounding environment of the Niger Delta region is discussed in this work. This dissertation examines why successive governments have not succeeded in their quest for a solution to gas flaring; policies and regulations are not being effectively implemented, and why despite the fact that flaring has been outlawed in Nigeria since 1st January 1984, it is still going on 24 years after. Flaring continues unabated undermining the consequences it has on the people and the effects on climate change. Interviews and case studies were used to examine the factors responsible for the non implementation of government policies and regulations, and why the consistent extension of flare-out deadline. Countries with outstanding results were examined in order to draw a baseline for the Nigeria situation. The research revealed that the Nigerian government has not enforced environmental regulations effectively because of its interests in the business of the multinationals. In addition there has been the dependence of environmental monitoring and regulatory agencies on government funding. This has drastically affected the proficiencies of the control and the insignificant penalties imposed on companies that flare gas. The need for government to play the role of an umpire rather than business partner with the multinationals is therefore of paramount importance. It is also pertinent that the regulatory and monitoring agencies be independent of government's supervision. More stringent measures, (ranging from more cost per a thousand standard cubic feet of gas flared to closure of platform(s) and/or outright withdrawal of license), should also be put in place to serve as deterrent to erring oil companies. / Thesis (M.Ing. (Development and Management Engineering))--North-West University, Potchefstroom Campus, 2009.

The issue of gas flaring and the attendant environmental effects have become a common sight in the Niger Delta. Apart from being a wastage of natural resources, it is a menace to the global existence of man. The incidences of acid rain and the disruption of economic life of the locals, basically farming and fishing, have led to consistent and irresistible agitation by the people of the Niger Delta for an end to gas flaring. The consistent release of harmful gases through gas flaring, with devastating effect on the surrounding environment of the Niger Delta region is discussed in this work. This dissertation examines why successive governments have not succeeded in their quest for a solution to gas flaring; policies and regulations are not being effectively implemented, and why despite the fact that flaring has been outlawed in Nigeria since 1st January 1984, it is still going on 24 years after. Flaring continues unabated undermining the consequences it has on the people and the effects on climate change. Interviews and case studies were used to examine the factors responsible for the non implementation of government policies and regulations, and why the consistent extension of flare-out deadline. Countries with outstanding results were examined in order to draw a baseline for the Nigeria situation. The research revealed that the Nigerian government has not enforced environmental regulations effectively because of its interests in the business of the multinationals. In addition there has been the dependence of environmental monitoring and regulatory agencies on government funding. This has drastically affected the proficiencies of the control and the insignificant penalties imposed on companies that flare gas. The need for government to play the role of an umpire rather than business partner with the multinationals is therefore of paramount importance. It is also pertinent that the regulatory and monitoring agencies be independent of government's supervision. More stringent measures, (ranging from more cost per a thousand standard cubic feet of gas flared to closure of platform(s) and/or outright withdrawal of license), should also be put in place to serve as deterrent to erring oil companies. / Thesis (M.Ing. (Development and Management Engineering))--North-West University, Potchefstroom Campus, 2009.

Most mature oil reservoirs or fields tend to perform below expectations, owing to high level of associated gas production. This creates a sub-optimal performance of the oil production surface facilities; increasing oil production specific operating cost. In many scenarios oil companies flare/vent this gas. In addition to oil production constraints, associated gas flaring and venting consists an environmental disasters and economic waste. Significant steps are now being devised to utilise associated gas using different exploitation techniques. Most of the technologies requires large associated gas throughput. However, small-scale associated gas resources and non-associated natural gas reserves (commonly referred to as stranded gas or marginal field) remains largely unexploited. Thus, the objective of this thesis is to evaluate techno- economic of gas turbine engines for onsite electric power generation called gas- to-wire (GTW) using the small-scaled associated gas resources. The range of stranded flared associated gas and non-associated gas reserves considered is around 10 billion to 1 trillion standard cubic feet undergoing production decline. The gas turbine engines considered for power plant in this study are based on simple cycle or combustion turbines. Simple cycle choice of power-plant is conceived to meet certain flexibility in power plant capacity factor and availability during production decline. In addition, it represents the basic power plant module cable of being developed into other power plant types in future to meet different local energy requirements. This study developed a novel gas-to-wire techno-economic and risk analysis framework, with capability for probabilistic uncertainty analysis using Monte Carlo simulation (MCS) method. It comprises an iterative calculation of the probabilistic recoverable reserves with decline module and power plant thermodynamic performance module enabled by Turbomatch (an in-house code) and Gas Turb® software coupled with economic risk modules with @Risk® commercial software. This algorithm is a useful tool for simulating the interaction between disrupted gas production profiles induced by production decline and its effect on power plant techno-economic performance over associated gas utilization economic life. Furthermore, a divestment and make- up fuel protocol is proposed for management of gas turbine engine units to mitigate economical underperformance of power plant regime experienced due to production decline. The results show that utilization of associated gas for onsite power generation is a promising technology for converting waste to energy. Though, associated gas composition can be significant to gas turbine performance but a typical Nigerian associated gas considered is as good as a regular natural gas. The majority of capital investment risk is associated with production decline both natural and manmade. Finally, the rate of capital investment returns decreases with smaller reserves.

The need for energy and the associated economic benefits from the oil and gas deposits found mainly in the Niger Delta region of Nigeria necessitated the exploration and exploitation activities being carried out by the oil and gas Companies. However, these exploration and exploitation activities due to their unpredictable nature have a huge potential for environmental pollution as been experienced in the form of oil spills, gas flaring, irresponsible disposal of waste and several other activities that have resulted in the environmental degradation of the Niger Delta region. In the light of these, the Federal Government of Nigeria having experienced the consequences of pollution of the environment during the Koko Toxic Waste Dump incident in the then Bendel State in 1987 established a regulatory body tasked with the responsibility of harmonizing the economic interest from the oil and gas exploration and exploitation activities with the sustainability of the natural environment by developing well structured and articulated policies aimed at guiding the operations of the oil and gas operators, track their compliance and administer appropriate punitive measures for non compliance. However, this research work which is aimed at evaluating the impact of the environmental protection policies in upstream oil and gas activities in the Niger Delta region, involved the use of questionnaires and interviews. These questionnaires were completed by the management and staff of three major oil and gas companies operating within the area, the Department of Petroleum Resources and members of the Host communities. The interview was carried out to provide relevant feedback on their assessment of the impact made by the environmental protection policies on the upstream oil and gas activities in their operational areas/host communities. The study however concluded that “Although there is a regulatory body tasked with the responsibility to develop, implement and track compliance of the environmental protection policies in the upstream oil industry, the body is ineffective and as such the impact of the environmental protection policies is inadequate. Appropriate informed recommendations on the improvement strategies to the identified gaps that resulted in the unfavorable conditions were also provided. / Thesis (M.Ing. (Development and Management Engineering))--North-West University, Potchefstroom Campus, 2011

The need for energy and the associated economic benefits from the oil and gas deposits found mainly in the Niger Delta region of Nigeria necessitated the exploration and exploitation activities being carried out by the oil and gas Companies. However, these exploration and exploitation activities due to their unpredictable nature have a huge potential for environmental pollution as been experienced in the form of oil spills, gas flaring, irresponsible disposal of waste and several other activities that have resulted in the environmental degradation of the Niger Delta region. In the light of these, the Federal Government of Nigeria having experienced the consequences of pollution of the environment during the Koko Toxic Waste Dump incident in the then Bendel State in 1987 established a regulatory body tasked with the responsibility of harmonizing the economic interest from the oil and gas exploration and exploitation activities with the sustainability of the natural environment by developing well structured and articulated policies aimed at guiding the operations of the oil and gas operators, track their compliance and administer appropriate punitive measures for non compliance. However, this research work which is aimed at evaluating the impact of the environmental protection policies in upstream oil and gas activities in the Niger Delta region, involved the use of questionnaires and interviews. These questionnaires were completed by the management and staff of three major oil and gas companies operating within the area, the Department of Petroleum Resources and members of the Host communities. The interview was carried out to provide relevant feedback on their assessment of the impact made by the environmental protection policies on the upstream oil and gas activities in their operational areas/host communities. The study however concluded that “Although there is a regulatory body tasked with the responsibility to develop, implement and track compliance of the environmental protection policies in the upstream oil industry, the body is ineffective and as such the impact of the environmental protection policies is inadequate. Appropriate informed recommendations on the improvement strategies to the identified gaps that resulted in the unfavorable conditions were also provided. / Thesis (M.Ing. (Development and Management Engineering))--North-West University, Potchefstroom Campus, 2011