TITLE:
Evaluation and Optimization of the Production System of the Mibale Field: Case of the MIB-14ST2 Well in the Offshore of the Coastal Basin of the Democratic Republic of Congo
AUTHORS:
Joel Kabesa Kilungu, Bavon Diemu Tshiband, Dona Kampata Mbwelele, Joseph Lukola Empenga, Dominique Wetshondo Osomba
KEYWORDS:
Evaluation, Optimization, Conversion, Activation, Oil Well
JOURNAL NAME:
Open Journal of Yangtze Oil and Gas,
Vol.9 No.1,
January
31,
2024
ABSTRACT: Optimizing the hydrocarbon production system is a fundamental practice to ensure the recovery of developed reserves while maximizing the yield of the oil field. Therefore, several methods and techniques are used to optimize a production system, but the one used in the Mibale field is nodal analysis because it allows for easy understanding of a production system by quickly identifying the problem in order to find optimal solutions. Located in the offshore coastal basin of the Democratic Republic of the Congo and discovered in 1973, the Mibale field has begun to produce an initial flow rate of 10,000 BOPD since 1976 with only three wells MIB-01, MIB-02 and MIB-03. The studies conducted in 2007, 2010 and 2016 aimed at re-conditioning some wells, resuming water injection and evaluating the remaining quantities of hydrocarbons in the upper Pinda reservoir. To date, the Mibale field has 20 wells including 14 producing wells and 6 injectors and an oil production of 5905 BOPD. Although crossing the reservoir layers containing more 365.1 MMstb of oils on 393 MMstbs of total field oils and activated by Gas-lift activation mode, the MIB-14ST2 has a very low oil output less than 100 BOPD, a well bottom pressure less than 450 psi and a high WOR of over 68%. After collecting field data and consulting works and related reports, we conducted the analysis and interpretation of field data using the simulation software of the hydrocarbon production system called IPM Prosper to identify the causes of the inefficiency of the production system. We understood that this well would produce at the bottom pressure of the zero well a flow rate of 464.978 bbl/day of oil, 30533.822 bbl/day of water and 12.29 stb/day/psi of productivity index. In view of this production capacity of the MIB-14ST2 well and the fluid characteristics of the reservoir and well, the optimization by conversion of the activation mode of the Gas-lift to ESP was applied. After analysis and interpretation of the results, the MIB-14ST2 well would be able to produce 75 Stb/day as oil flow; 4926.6 Stb/day as water flow and 0.022 MMscf/day. For production to take place after 11 minutes 9 seconds, the pump performance needs to be at 2218.06 ft with a frequency of 50 Hertz; the number of 76 stages; 1845.5 psig as suction pressure and 2641.9 Psig as discharge pressure. The total power of the system would be 118.4 hp with a total efficiency of 89.8% and 0.9% as a factor of engine power, which demonstrates that the system is efficient. In view of the results obtained, we note that the production of oil is still very low, which leads to further studies to review the depth of perforation of the well; make the material balance of the remaining reservoir fluids and the petrophysical characteristics of the layers crossing the MIB-14ST2 well. This research will contribute to the optimization of oil production in the upper Pinda reservoir and to a better understanding of its petrophysical behavior.