Optimizing well time and its expenditures has become a necessity for which all drilling operators and service companies are challenged on. This requires a combination of well engineering and operations efforts from avoidance of service quality issues that lead to Non-Productive Time (NPT) to the reduction or elimination of Invisible Lost Time (ILT). Traditionally, more focus and efforts are concentrated around the NPT avoidance, as its impact is visible and has a huge and direct financial consequences that leads to increasing well cost. Most oil & gas operators and services companies have as NPTr (NPT rate per 1000 operating hours) one of their main KPIs (Key Performance Indicators) to measure their performance and ranking.

The Invisible Lost Time (ILT) analyses is considered another area of focus where the drilling performance can make a big step change in the way how well operation activities are performed. This doesn't only require the identification and measurement of the ILT impact, but also taking the appropriate measures to reduce and eliminate it from both drilling time and flat time operations. This is essential to remove the variability and bring consistency to the well operations performance among all the rigs and projects.

The approach described in this paper involves the implementation of a tracking tool that uses the rig surface real time data that will be referred as High Frequency data (HF), combined with the Daily Operation Reports, referred as Low Frequency data (LF) to track and display multi-well drilling operation activities comparison (drilling and flat time). This allows to identify any variation and to measure the Invisible Lost Time (ILT) within the different drilling activities and rigs compared to the best and to the benchmarks. Once the ILT is identified and measured, the drilling engineering and operation teams take appropriate actions using LEAN principles and methodology to tackle the inefficiencies and initiate performance improvement opportunities. These are then prioritized based on its impact and assigned as discrete projects for rig and office based teams to address the gaps. Measuring is the first step that leads to control and eventually to improvement. “If you can't measure something, you can't understand it. If you can't understand it, you can't control it. If you can't control it, you can't improve it”. (H.James Harrington).