International Research Journal of Engineering and Technology (IRJET) e-ISSN: 2395 -0056 Volume: 04 Issue: 04 | Apr -2017 www.irjet.net p-ISSN: 2395-0072 © 2017, IRJET | Impact Factor value: 5.181 | ISO 9001:2008 Certified Journal | Page 767 An Empirical Correlation for Two-Phase Inflow Performance Relationship in Horizontal Oil Wells Ramadan Emara 1, 2 1 (Home) Mining and Petroleum Engineering Department, Faculty of Engineering, Al Azhar University 2 (Secondment) Petroleum and Natural Gas Technology Department, Faculty of Engineering, The British University in Egypt ---------------------------------------------------------------------***--------------------------------------------------------------------- Abstract - The appropriate method to increase the well productivity in low permeability and naturally fractured reservoirs is the horizontal well because of its large reservoir contact area. Several investigators have utilized reservoir simulation to evaluate the horizontal well performance in solution gas drive reservoirs. This research scrutinizes the performance of a two phase inflow for a horizontal oil well producing through the boundary dominated flow regime. A 430 data points were collected from simulation of 43 data sets of fluid property, relative permeability and reservoir geometry. All data sets were investigated from initial pressure to minimum bottom-hole pressure. Linear regression analysis was used to develop an empirical inflow performance relationship (IPR) based on the simulator outcomes. Statistical analyses were used to evaluate the performance of the developed correlation. The obtained outcomes include an average relative error (ARE) of 0.78, an average absolute error (AARE) of 2.37 and coefficient of regression (R 2 ) of 0.995. The presented IPR relationship was compared to other horizontal inflow performance relationships available in literature. The proposed correlation exhibited suitable approximations of well performance over a wide range of operating circumstances. Key Words: Two-phase IPR; Solution gas drive reservoir; Horizontal oil well IPR. 1. INTRODUCTION The main task of a petroleum engineer is to enhance the well productivity. The horizontal well is the suitable solution for this purpose because of its reservoir contact area. The horizontal well accomplishes higher ultimate recovery than a vertical well in certain reservoir condition. In low permeability and naturally fractured reservoirs, the horizontal well represents the economic solution. The horizontal well represents an appropriate method for both production and injection in several enhanced oil recovery applications. Many researchers have used reservoir simulation to study the horizontal oil well behavior. These researches have led to present empirical correlations of IPR to estimate the performance of a horizontal oil well. In 1968, Vogel 1 investigated the performance of a vertical well in a solution gas drive reservoir. He developed an empirical IPR based on the investigation of simulation outcomes, and it was simple to apply and gain rapid approval by industry. In 1973, Fetkovich 2 scrutinized data of multi-rate tests accomplished in 40 boundary- dominated flow oil wells of 6 different oil reservoirs. He displayed that, once the gas saturation of oil wells becomes larger than the critical gas saturation, the typical inflow performance relationship (IPR) of gas wells can also be applied for oil wells. The presented IPRs were for vertical oil wells and could not be suitable for horizontal oil wells. In 1987, Plahn et al. 3 utilized a reservoir simulator to study the effect of different reservoir rock and fluid properties on the behavior of multiphase flow of horizontal oil wells in a solution gas drive reservoir. They presented a set of type curves to predict the production from horizontal oil wells. In 1989, Bendakhlia and Aziz 4 investigated the horizontal oil wells performance in a solution gas drive reservoir using a commercial reservoir simulator. The authors concluded that, the reservoir fluid and rock properties did not affect significantly on the IPRs. They presented an IPR function of the stage of reservoir depletion. In 1990, Cheng 5 investigated the performance of slanted and horizontal oil wells using a vertical/horizontal/slanted well simulator (Boast VHS). The author observed that, the IPRs for horizontal and slanted wells proceed like to the Vogel’s IPR parabolic shape. He developed separate empirical IPRs corresponding with various angles. In 1998, Retnanto and Economides 6 scrutinized the horizontal and multibranched oil well performance in a solution gas drive reservoir using reservoir simulation. Based on nonlinear regression the authors developed an empirical IPR using simulation results. In 2005, Wiggins 7 investigated the performance of a horizontal oil well in a solution gas drive reservoir. The well was fully penetrating the reservoir producing through the boundary dominated flow regime. He presented two IPRs base on simulator results linear regression analysis. In 2013, based on linear regression analysis, Jabbar and AlNuaim 8 introduced an equation of IPR for a horizontal oil well producing from a solution gas drive reservoir using simulation results. The authors regressed the coefficients of the Harrison exponential equation to produce their equation. In 2013, Mohammadreza et al. 9 presented a Vogel-type IPR relationship based on regression analysis. They concluded that, the coefficients of their equation is a function of vertical and horizontal permeability ratio. In 2015. Ali Musa and Enamul 10 developed correlations of IPR based on regression analysis of actual data. The data was 62