Automatic Production Rate Estimation Workflow Considering the Reservoir Flow Regime - Kuwait Integrated Digital Oilfield

Abstract

This paper presents an automated workflow that can estimate the oil and gas rates of a well, with the high frequency data, distinguishing the behavior of the reservoir under transient flow and pseudo steady state flow conditions. The new approach matches the wellhead pressure of a well model with the current value reported by a SCADA system, by adjusting the bottomhole pressure. For transient flow, it considers the response of the inflow performance relationship as a function of time. For pseudo steady state flow, it considers the declination of the reservoir pressure. The estimation of the production rate is carried out every 15 minutes, and the total daily produced volume is calculated based on the effective flowing time. To evaluate the accuracy of the new well rate estimation workflow, the output of the workflow is evaluated using two different criteria. Initially, the estimated oil and gas productions are compared with data from a real well test that is used as a quality control point. Secondly, considering that the fluid properties remain stable over time (water cut and gas-oil ratio), the critical flow through a choke valve defines a historical production trend that is used to quantify the deviation of the estimated values. As a result of the new workflow application, the difference between the estimated and measured rates decreased from 10% to 3%. The novelty of the new method is that it reduces the error of the estimated oil and gas production rates using the actual reservoir pressure behavior and provides more precise data for the different reservoir engineering analyzes.