DETERMINANTS OF PRODUCTIVITY INDEX IN INFINITE-ACTING RESERVOIRS: A CRITICAL EXAMINATION OF MILLER-DYES-HUTCHINSON AND VOGEL MODELS

Abstract

This work presents a critical analysis of the Productivity Index (PI) of infinite-acting reservoirs. A PI model was developed from the combination of Miller-Dyes-Hutchinson and Vogel`s models by incorporating key reservoir factors such as permeability, net pay thickness, porosity, total compressibility, viscosity, formation volume factor, wellbore radius, and skin factor. The Plackett-Burman design was employed to investigate the impact of these factors on PI, and the results revealed that permeability, net pay thickness, skin factor, and viscosity are the most significant factors affecting PI. The findings of this research provide valuable insights into the behaviour of infinite-acting reservoirs, indicating that permeability and net pay thickness have a positive impact on productivity index, while skin factor and viscosity have a negative impact. The PI is time-dependent. Thicker net pay zones increase productivity index, Lower skin factor increases petroleum index, and production index decreases over time due to the logarithmic term. Conclusively, analysing early-time data makes the understanding of well behaviour easier, the understanding of reservoir properties is crucial in optimizing production strategies, and optimizing well completion design minimizes skin factor. By applying transient analysis, operators can gain valuable insights into the behaviour of infinite-acting wells and optimize production strategies.