Drilling the oil and gas well is the most important job for finding the hydrocarbon resources below the earth. Many risks/complexities are involved in fulfilling this complex job. Oil and gas well drilling companies are using different types of key performance indicators (KPIs) to measure the performance of the drilling operations, for example, time versus depth, rate of penetration, non-productive time, etc. There is no standardization or benchmarking available for comparing these KPIs. Drilling companies are using different references for these KPIs as per their policies or norms. This research paper presents the application of the well complexity calculator, which is developed on a broader range of parameters to calculate different types of complexities. These complexities can be used as a standardized reference and the KPIs are compared with them. For this purpose, drilled wells camouflaged data obtained from different oil and gas well drilling companies in Pakistan, which were used to measure their complexities by the well complexity calculator. Accordingly, relationships of these complexities are presented against different industry-wide used Drilling KPIs achieved on the wells, like Dry Hole Drilling Days, Feet per Day, Dry Hole Drilling Days per 10 K Feet, Dry Hole Drilling Cost, NPT Percentage, and Non-Productive Time (NPT). It is found that with the increase of well complexities, all the KPIs showed an increase/decrease in specific trends; except NPT Percentage, this trend verifies the authenticity of the well complexity calculator. NPT Percentage did not show any relationship against the well complexities, although it is one of the widely used Drilling KPIs. Besides this, a comparison of one of the Absolute Drilling KPIs “Dry Hole Drilling Cost” and one of the Normalized Drilling KPI “Dry Hole Drilling Cost Per Foot” is also compared against the well complexities, and trends confirm that the use of such normalized KPI alone is only acceptable when design and all the properties of the Wells are similar, which is usually not the case. It is also found that instead of using NPT Percentage or single-factor normalized KPIs, Absolute Drilling KPIs like Non-Productive Time recorded in hours, Dry Hole Drilling Days, and Dry Hole Drilling Cost vs Well Complexities are better tools to compare the performance of the Wells, since the ratio of output is not taken against the single-input parameter like depth but instead against the combination of different types of parameters. Based on Complexities vs the KPI relationship, an improved modular approach is presented to carry out KPI benchmarking and performance evaluation and comparison.
