An Integrated Approach to Manage Drilling Waste to Minimise Environmental Impacts

Abstract

Managing environmental impacts associated with drilling is a challenge to oil & gas ompanies and in recent year more efforts are exerted in increasing production levels hence increasing drilling activities and associated environmental concerns. Key environmental issues associated with onshore drilling activities include release to the atmosphere & groundwater and generation of hazardous wastes. Over the last few years, ADCO has intensified its drilling activities to meet challenging production targets and over the last 10 years number of drilled wells has almost doubled. In order to minimize environmental impacts of drilling activities addressing environmental issues became central to work planning and regarded as a business objective. The majority of drilling wastes includes drilling fluids & cuttings and if these are not managed effectively they may result into soil & groundwater contamination and could harm to biota. In order to minimize the environmental impact of drilling waste an integratedwaste management scheme was developed to implement Zero Discharge and 100% HSE concepts from drilling locations and this scheme includes: Two waste disposal wells for Water Based Mud (WBM) for injection in the deeper aquifers. Reconditioning of Oil Based Mud (OBM) at reconditioning plant for reuse Thermal Desorption Unit (TDU) for treating OBM Cuttings In 2017, approximately a Million feet of wells were drilled resulting in generation of 200,000 tons of WBM cuttings and 40000 tons of OBM cuttings. OBM Cuttings were treated at TDU and 12000 bbls of oil was recovered. In addition, approximately 100 K bbl. of waste WBM and other drilling fluids were injected in deeper formation. 99.9% of oil from OBM cuttings is reclaimed as a fuel and the final inert material used for manufacturing cement blocks. The outcome the solution is converting drilling hazardous wastes through 100 % recycling into environmentallyfriendly and beneficially-used products. The concept of 3Rs- Reduce, reuse& recycle is applied for managing drilling waste to protect the environment.