In this study, a deepwater pipeline-riser system that experienced hydrates was modelled in MAXIMUS 6.20 (an integrated production modelling tool) to understand, predict and mitigate hydrates formation in typical deepwater system. Highlights of the results from this study suggest that the injection of low-dosage hydrate inhibitors (LDHIs) into the hydrate-forming structures within the multiphase flow stream disperses the hydrates particles in an irregular manner and subsequently decreases the nucleation rate of the hydrate and prevents the formation of hydrates. This study found that the cost of using monoethylene glycol was significantly higher than that of LDHI by over $500/day although low-dosage hydrate inhibitors have initial relatively high CAPEX. In the long run, its OPEX is relatively low, making it cost-effective for hydrate inhibition in deepwater scenarios.

The quest for cleaner sources of energy in the world today has paved way for scientists and researchers to delve into renewable energies like the geothermal energy. Researches on the enormous potential that a geothermal reservoir could posses are currently underway. However, there is limited information on the quantity and quality of geothermal reserves in Nigeria. Extraction of this geothermal heat will improve power generation and the availability of scarce electricity in Nigeria. This work is aimed at using a mathematical model to estimate the quantity of recoverable heat by first estimating the total heat in place and then the heat losses associated with heat transfer in a wellbore. In this work, we were able to ascertain the heat in place as well as recoverable geothermal heat for geothermal regions in Nigeria having a temperature-at-a depth range of 50°C – 110°C and also a higher temperature-at-a depth range of 150°C – 250°C. Heat losses were considered for pipe tubings with 1 inch, 2 inches and, 3 inches diameter. A higher recoverable of 92% was gotten when the 1 inch pipe diameter was used. 87% and 76% recoverable were also gotten when the 2 inches and 3 inches diameters were used respectively. Nigeria has the potential of generating 74Megawatts of electricity from just one geothermal reservoir which could provide electricity for villages and small towns.

Optimal production of gas from gas condensate reservoirs have been a major concern to the petroleum industry. Enormous liquid dropout lost to the reservoir during depletion process has been found to restrict the flow of gas near the wellbore, thereby reducing wellbore productivity. The search for the optimal production strategy to produce gas and even the condensed liquid has resulted to the use of enhanced production technique such as gas cycling, water flooding or wettability alteration. Gas cycling is used in gas condensate reservoirs to improve permeability to gas by evaporating the condensed liquid. Where the cycling is commenced early It may defer the dew point pressure. The challenge is the choice of the best production strategy to effectively recover gas trapped by the condensed liquid hydrocarbon and the condensed liquid hence enhancing the productivity of gas condensate reservoirs. In this study, technical and economic approaches are combined to evaluate the potentials of different production strategies using various injection rate and pressures. In the study dynamic uncertainty parameters that influence recovery of gas, condensate and production profile determination are considered. Model that can predict the recovery of gas was developed by the integration of experimental design, fluid characterization and reservoir compositional simulation. The research investigated a range of production strategies in gas cycling project using the predictive model to assess the effects of the reservoir and production parameters on recovery of gas and condensate. The best strategy was established from the optimal injection rate and the effective injective pressure. The work concluded that cycling is best started above dew point pressure. It also established the minimum injection pressure below which gas cycling is uneconomical.

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Reservoir gas can condense to liquid when reservoir pressure declines below dew point pressure. This liquid will remain in the formation and then reduce productivity and deliverability of wells due to blockage problem. A method of improving the recovery is allowing for aquifer water influx/water injection and gas injection to maintain reservoir pressure and prevent it from falling rapidly.This paper investigates the influence of aquifer support on gas-condensate reservoir. A zerodimensional (material balance) approach was used for the reservoir model and prediction. Optimal hydrocarbon production and effect of aquifer influx were studied using different aquifer sizes. Results of gas volumes, condensate and total fluid recovery in percentage were analyzed for the case study reservoir without aquifer influx as the first scenario and with aquifer influx as the second scenario. The results show that aquifer influx reduces condensate accumulation in the reservoir by driving them to the surface.