The formation of emulsion is one of the challenges facing the oil and gas industry today. This is normally encountered when water is dispersed as fine droplets in the bulk of oil. This study presents the treatment techniques used by Nigeria Petroleum Development Company in Oredo field in breaking crude oil emulsion. Wells 2L and 4L were used for the analysis. Crude samples were obtained at the upstream of chemical injection points to ensure the samples were true representatives of the crude from the wells in the field. Chemical demulsifiers (DM1, DM3, DM4, and DM5) were formulated in the laboratory which was used in the treatment of 100ml of emulsion. Results show that DM3 and DM5 were the most effective chemical demulsifiers formulated in the laboratory for Oredo wells 2L and 4L respectively and also, temperature is an indispensable determining factor in the treatment of emulsion.

Globally, there are different techniques applied in the industry such as analog, volumetric, decline curve, material balance and simulation methods to estimate hydrocarbon reserves which depends upon the volume and quality of available data with some levels of uncertainties. The analogy method is applied by comparing factors for the current fields or wells while the volumetric method implies the determination of the extent of the reservoir, pore volume of the reservoir rock and the content of fluid within the reservoir pore volume when production and pressure data from field become available, decline curve analysis and material balance calculations become the predominant methods of calculating reserves since the hydrocarbon reserve estimates is a continuous process for a field that is producing. This study presents a report on the material analysis of Ugua J2 and J3 reservoirs with MBAL prior to the field's dynamic reservoir simulation. The available data were validated and the analytical plot of pressure and production data indicated that J2 and J3 reservoirs are communicating. Hence multi-tank material balance analysis approach linked with transmissibility was adopted to model the reservoirs. The Hurst-Van Everdingen radial aquifer model was selected as the most likely case. The oil initially in place value obtained for J2 and J3 are 125.006 and 80.689 MMstb.