Numerical Analysis of Well Testing Using Flow Data Taken at the Surface

Well-testing is the analysis of reservoir and well behavior based on time. Obtaining the true value of changes in reservoir parameters plays a major role in creating an accurate and current model of the reservoir. The most crucial factor in achieving this objective is pressure, which is determined by a downhole pressure gauge. Operational issues and additional expenses are brought on by the use of pressure gauges at the well's bottom for the employer company. Surface well testing, which installs flow and pressure measurement devices at the wellhead, is another approach to well testing. The benefits of this technology include a significant cost reduction, ease of installation and data collection, easier operations, reduced risk, the ability to collect data for extended periods of time, and the ability to determine the impact of borders in large reservoirs. The difficulty of calculations and the insertion of errors as a result of the impact of well-column circumstances on the recorded data are the method's most significant issues. In this study, using Pipesim software, data obtained at the surface of a well located in a conventional undersaturated oil reservoir is converted to bottom-hole data, then analyzed, and finally, the properties of the reservoir are obtained. In comparison to the conventional well test method, the results demonstrate that the surface well test method can accurately forecast permeability, skin, productivity index, average pressure, and reservoir radius with error rates of 6.2, 17.3, 4, 7, and 13.3%, respectively.