DEPARTMENT OF PETROLEUM ENGINEERING, FACULTY OF ENGINEERING

This study compares the production life expectancy of vertical and horizontal wells drilled near sealing boundaries in petroleum reservoirs. Sealing boundaries such as impermeable faults restrict fluid flow and reduce pressure support, significantly affecting well performance and project economics. Analytical modeling based on the radial diffusivity equation and
image well theory was used to calculate pressure decline for both well configurations. Excel- based calculations determined flowing bottom hole pressure over time under identical reservoir conditions (permeability = 27 md, porosity = 0.27, initial pressure = 3,000 psi). Vertical wells were analyzed at five distances from the boundary (24–115 ft), while
horizontal wells were evaluated at five different lateral lengths (20–120 ft). Results showed that horizontal wells dramatically outperform vertical wells near sealing boundaries. The best vertical well (115 ft from boundary) maintained economic production for approximately 200 hours, while the optimal horizontal well (120 ft lateral) produced for about 12,000 hours—a 60-fold improvement. Even moderate horizontal wells (90 ft) exceeded the best vertical well performance by 65%. Key findings include: (1) horizontal wells maintain pressure substantially longer due to
extended reservoir contact; (2) a minimum horizontal length of 90 ft is required for meaningful performance benefits; (3) vertical wells closer than 50 ft from boundaries fail within 30–45 hours; and (4) despite higher drilling costs, horizontal wells provide 20–60 times longer production life, delivering superior economic returns.

The efficient execution of drilling operations hinges upon a comprehensive evaluation of surface facilities, encompassing an array of parameters and factors. This project delves into the intricate web of variables that influence drilling efficiency, wellbore stability, and equipment selection. Through meticulous analysis, it uncovers critical insights into mud weight control, pump displacement, pipe diameter considerations, and the deployment of solids control equipment such as desilters and desanders (hydrocyclone). These findings are poised to empower drilling engineers and operators with the knowledge needed to optimize surface facilities during drilling operations, ensuring a harmonious interplay of equipment, drilling fluid properties, and operational parameters. By bridging the gap between theory and practical application, this project not only contributes to the advancement of drilling engineering but also offers tangible recommendations to enhance drilling endeavours' efficiency, safety, and overall success