Six Sigma in the oil industry

Six Sigma is a data driven process improvement methodology based on DMAIC cycle (Define – Measure-Analyze – Improve – Control). This methodology can be applied successfully in oil industry.
Examples of measurable indicators specifics of this industry can be: tilting the geologic layer, saturation pressure, viscosity (under standard conditions), density of oil, oil type (waxy or not-waxy), type of water from deposit (salinity), porosity of the basic rock, etc.
Here is an example of successfully Six Sigma project with purpose to reduce the risk coefficient of drilled wells.