Performance of a well with lateral and vertical wellbores

Abstract

This thesis presents three major topics: analysis of pressure transient behavior of horizontal wells, analysis of pressure transient behavior of slanted wells, and performance analysis of wells with lateral and vertical wellbores. Additional analysis of actual well test data is also provided. For horizontal wells, we focus on analysis pressure solution for pseudoradial flow. Limited entry slanted wells are considered in this work by comparing wells with different angles and evaluating the performance. Modeling and performance analysis of a well with lateral and vertical wellbores is the last topic. The specific tasks achieved in this work include the following: We have compared four methods for analyzing pseudoradial flow found in the literature (Odeh and Babu, Joshi, Kuchuk et al., and Lichtenberger) and verified their methods using reservoir simulation. We found that the methods by Kuchuk et al. and Joshi are the most accurate while the method by Lichtenberger has the biggest error. We have modeled and examined the performance of slanted wells with different angles. The well length is equal to formation thickness and is kept constant. It has proven that the performance of slanted wells is proportional to the increase of the well angles only up to 60°. Further increasing the well angle will not make the well performance better than a vertical well. We have modeled and analyzed performance of combination wells. We compared the performance of vertical, slanted, and combination wells. Based on that comparison, the combination well has the best performance compared to other well geometries. By having a lateral section beside the vertical section, the performance of the well changes significantly. We have performed an analysis of actual injectivity test data from a well with lateral and vertical wellbores. The proper analysis obtained by correcting the pressure changes confirmed that the semilog straight line shows infinite acting radial flow. The permeability is 62.3 md, obtained by taking a correct slope of 260 psi/cycle. As of now, the radius of investigation is 8287 ft. It needs 7.9 years of injection to reach 850 psig of wellhead pressure.