Gas Hydrates: An Overview on the Niger Delta Continental Front (Published)
The formation of gas hydrates occurs when gas molecules are trapped in a lattice of water molecules at temperatures above 0°C and pressures above one atmosphere.The Niger Delta occupies the central region of West Africa’s Gulf of Guinea. With a land area of some 75,000 km2, it forms the largest delta system in Africa. It continental depth holds a deposit of gas hydrates. The gas hydrate deposit in this region is mostly biogenic, however, small amounts have been found to be thermogenic in nature. The clathrates in this region have 99% methane formation statistics up to the depth which is 1500+ meters below sea level. The hydrates found have been observed to contain sedimented light hydrocarbon alkane gases.These clathrate reserves hold significant amount of energy that is estimated to be more than twice the combined carbon of coal, conventional gas and petroleum reserves and as such holds more commercial and economic value. Gas hydrate can serve as a sustainable energy resource and also as a means of storing and transporting natural gas from one end to the other.This paper presents an overview of gas hydrate in the Niger Delta continental front. It describes the nature of the hydrate formed in the Niger Delta region based on it geological formation. It showcases the huge energy potential of hydrate in the Niger Delta, and how it can posit as a sustainable energy resource to meet the ever-growing energy need of Nigeria and the world at large.
Keywords: Niger-Delta, continental front, gas hydrates
Quantitative Analysis of Heavy Metals in Produced Water from Ndx 011 in Niger-Delta Oil Field (Published)
Oil and gas production is usually accompanied by water (brine), which is referred to as produced water. As oil and gas production declines, the quantity of water production from same reservoir increases. These produced waters have many components, which mostly have adverse environmental impacts. One of such components are the heavy metals which are numerous. Produced water sample from Niger Delta crude oil was investigated for five (5) heavy metals. The analysis was carried out using an Ultraviolet Visible Spectrophotometer. The analysis was carried out (in line with industry standard) on the produced water sample in order to determine the concentrations of the heavy metals present. The results obtained from this analysis showed that the concentrations of one out of the five heavy metals investigated (Arsenic (As)) was more than the allowable limits set by regulatory bodies. Arsenic (As), Boron (B), Manganese (Mn), Tin (Sn), and Barium (Ba) have concentrations of 0.9599mg/L, 0.0955mg/L, 0.000433mg/L, 0.31730mg/L, and 0.0019mg/L respectively compared with maximum limits set by the regulatory bodies as 0.3mg/L Arsenic, 5mg/L Boron, 0.004mg/L Manganese, 10mg/L Tin and 1.3mg/L Barium. This showed that the produced water from oil and gas activities in Niger Delta region of Nigeria should be tested and treated for Arsenic and other present heavy metals that may have concentrations higher than standard limits set by regulatory bodies before disposal and/or re-use.
Keywords: Heavy Metals, Niger-Delta, Produced water, crude oil
Economic Evaluation of Selected Artificial Lift Methods in a Marginal Oil Field in the Niger Delta (Published)
Marginal fields require production optimization and proper management due to uncertainties surrounding the size, reserves and operational strategies and costs. One of the ways of achieving optimal development is by using an efficient artificial lift method early or later in the field life, that will increase recovery and profitability. However, knowing the best artificial lift method to use for a situation could sometimes be challenging. In this study, a techno-economic comparison of Continuous Gas Lift (CGL) and Electrical Submersible Pumps (ESP) was carried out for a marginal oil field in the Niger Delta to choose the optimal method. Well and reservoir models were built to generate production forecasts under natural flow, CGL and ESP. Economic models were formulated, incorporating cost for each artificial lift method, oil price and estimated revenue from oil and gas sales to determine the Net Present Value (NPV), Internal Rate of Return (IRR) and Profitability Index (PI). Risk and sensitivity analyses were carried out. When natural flow was not feasible and artificial lift preferred, CGL was characterized by high initial capital while ESP tended to have higher operating cost. Ultimate Recovery (UR) increased by 8.6% with the use of ESP but by 6.7% with CGL. The ESP also gave an NPV of $1.48 Million, IRR of 46.0% and PI of 1.50 while CGL gave an NPV of $2.03 Million, IRR of 31.4 and PI of 1.49. Higher profits were obtained when the artificial lift methods were installed after natural flow had been exhausted. Profitability of the marginal field using artificial lift was affected by oil price, fiscal terms and the cost of the lift methods.
Keywords: Artificial lift, Fiscal terms, Marginal fields, Niger-Delta, Profitability criteria