The accurate estimation of original oil in place (OOIP) and the optimization of reservoir production performance are critical tasks in petroleum engineering, the material balance MB method is a powerful technique used to study reservoir performance and describing the important properties of the reservoir, including the estimates of original oil in place, and the strength of aquifer. It also provides the understanding of drive mechanisms at work.This paper aims to determine the OOIPof the Zenad oil field using both volumetric Method, Material Balance method identified by MBAL software. Additionally,it seeks to detect the presence of an aquifer in the field, characterize its strength, and predict future reservoir performance. In this study energy plot are used as diagnostic tools to identify the aquifer type based on the signature of production and pressure behavior. Two scenarios involved in MBAL software; the first isbuilding a reservoir model without aquifer connecting, and the other tested different aquifer models to matching observed reservoir and simulation data. The findings of this work showed that, Schilthuis Steady State model best describes the Zenad aquifer with a minimum standard deviation of 0.17365. Results also indicated that the Zenad oil field has a weak aquifer. The OOIP value estimated by the volumetric method is 405 MMSTB, while MBAL software estimates it at 465 MMSTB, a difference of about 12% due to early data collection issues and heterogeneities in reservoir parameter calculations. Future production show that injecting 5400 STB/D of water with a flow rate of 3000 STB/D will yield 69.6 MMSTB of cumulative oil and a recovery factor of 14.9% by 2032. With a flow rate of 4000 STB/D, injecting 7500 STB/D of water will sustain pressure, increasing cumulative oil to 72.98 MMSTB and the recovery factor to 15.67%.
K.Alhaj et al. (Mon,) studied this question.