Amount of drilling waste (drill mud and cuttings) and strategies for treatment and disposal

The previous data do not include the amount of waste generated in drilling activities. This information is provided below:

Waste from drilling (tons)

2014 2015 2016
Cuttings and water-based fluids 93,489 169,025 131,240
Cuttings and non water-based fluids 11,980 74,584 38,132

Management of waste from drilling activity (cuttings and fluids) is addressed in the company's Environmental Performance Practices (EPP). These guidelines establish common standards, regardless of the geographic areas in which the company operates and of each country's specific legislation.

Best practice: Processing of drilling muds at the Margarita asset (Bolivia) using the heat desorption technique.

Heat desorption consists of heating drill muds and cuttings (with initial hydrocarbon concentrations of up to 50%), allowing water and oil to evaporate and condense to leave a dry solid (ash) with a hydrocarbon content of between 0.1% and 0.5%.

This waste had already been treated using bioremediation techniques, although it was difficult to use biological methods to degrade it since it had such a high hydrocarbon concentration.

Heat desorption enabled us to process and finally dispose of 7,000 tons of oil-based cuttings. We also recovered 0.9 million liters of diesel and 0.5 million liters of water. The diesel recovered was used to prepare base fluid and water for processes such as ash cooling and dust control on pathways.