ABSTRACT
Coning tendencies in oil rim reservoirs pose serious hindrance to optimizing oil
production in the thin oil beds as unwanted fluids tend to replace the oil in the
production stream, which invariably limits the ultimate oil recovery. In this study,
a semi-analytical method of estimating critical production rate (qoc) and optimum
horizontal well placement (hopt) was developed for reservoirs with thin oil zones
sandwiched between gas cap and bottom water. Also, proxy models was generated
for qoc and hopt from analysis carried out with the developed semi-analytical
method. Accurate estimation of qoc and hopt can help control coning tendencies in
oil rim reservoirs, thereby improving the cumulative oil recovery. The developed
semi-analytical method was done by applying the principle of nodal analysis to
graphically combine the two Joshi (1991) models of estimating critical rates in gasoil reservoir system and oil-water reservoir system respectively. The resultant
graphical solution can therefore estimate the qoc and hopt for gas-oil-water reservoir
system (i.e. oil rim reservoirs). Estimates made from applying the semi-analytical
method to a set of oil rim reservoir data obtained from the Niger Delta oil field,
gave the critical rate and optimum horizontal well placement from GOC, as
6600stb/d and 14ft respectively. When this result was compared with the result
calculated from the existing Papatzacos et al (1989) method, the developed semianalytical result shows a favorable comparison with 2.5% difference in obtained
values. Experiment design was further performed using Plackett-Burman design to
evaluate the individual effect of the reservoir parameters in estimating qoc and hopt
in oil rim reservoirs. The result indicates that, among the parameters considered,
horizontal permeability, kh; oil formation volume factor, Bo; and the oil column
thickness, h; have the most significant effect in estimating critical rate, while two
parameters, oil column thickness, h, and oil density, ρo, have the most significant
effect in estimating optimum horizontal well placement in oil rim reservoirs. The
advantage of the semi-analytical method developed in this study is that, unlike
other models, it can estimate hopt with a corresponding qoc which an oil rim
reservoirs may be produced without the incidence of water and/or gas coning.
Library, T. & IBUCHUKWU, O (2021). A Novel Approach For Estimating Critical Rate And Horizontal Well Placement In Oil Rim Reservoirs. Afribary. Retrieved from https://afribary.com/works/a-novel-approach-for-estimating-critical-rate-and-horizontal-well-placement-in-oil-rim-reservoirs-1
Library, The Public Access, and ONWUKWE IBUCHUKWU "A Novel Approach For Estimating Critical Rate And Horizontal Well Placement In Oil Rim Reservoirs" Afribary. Afribary, 26 May. 2021, https://afribary.com/works/a-novel-approach-for-estimating-critical-rate-and-horizontal-well-placement-in-oil-rim-reservoirs-1. Accessed 30 Jun. 2022.
Library, The Public Access, and ONWUKWE IBUCHUKWU . "A Novel Approach For Estimating Critical Rate And Horizontal Well Placement In Oil Rim Reservoirs". Afribary, Afribary, 26 May. 2021. Web. 30 Jun. 2022. < https://afribary.com/works/a-novel-approach-for-estimating-critical-rate-and-horizontal-well-placement-in-oil-rim-reservoirs-1 >.
Library, The Public Access and IBUCHUKWU, ONWUKWE . "A Novel Approach For Estimating Critical Rate And Horizontal Well Placement In Oil Rim Reservoirs" Afribary (2021). Accessed June 30, 2022. https://afribary.com/works/a-novel-approach-for-estimating-critical-rate-and-horizontal-well-placement-in-oil-rim-reservoirs-1