Drilling Complexity Index Adoption in Kuwait Oil Company for Performance Benchmarking

Abstract The Drilling Complexity Index (DCI) is a tool designed to quantify the complexity of drilling a specific well. It provides an objective measure of how easy or difficult drilling operations are likely to be. Key applications include: Estimating realistic contingency time and cost for budgeting purposes.Supporting decision-making to prioritize resource allocation based on DCI values.Assigning wells to teams or groups according to complexity and well delivery targets.Benchmarking drilling performance. Due to significant variations between well types, separate calculation methodologies and scaling factors have been developed for Development and Deep Drilling Wells. A simple DCI calculation would fail to rank the wells accurately, as numerous operational challenges are inherent to specific well types. Therefore, DCI is calculated as the sum of two components: Base DCI - Determined from field experience and normalized drilling performance data (days per 1,000 ft) across various well types. Wells are ranked from high to low complexity, and corresponding base values are assigned.Additional DCI - Captures incremental complexity caused by specific challenges, including Well profile, Subsurface conditions, Drilling practices, Well design and Drilling and completion program. The DCI calculation model was tested on a range of Development and Deep Drilling wells. The initial results were used to fine-tune the model, and the final version aligned well with observed drilling complexities in the field. When correlating DCI with Non-Productive Time (NPT) & Days per 1,000 ft drilled, a general trend emerged. The correlation strength will be strong as the data inconsistencies are refined in due course with enhanced reporting. The DCI model has been implemented at Kuwait Oil Company (KOC) for Performance benchmarking, Identifying and explaining delays in well delivery schedules. An in-house software application was developed to calculate and track DCI, integrating partially automated inputs from EDM OpenWells. This automation reduces manual data entry, increases accuracy, and supports complexity tracking.