Combining synthetic based drilling fluid formulations with advance bioremediation techniques meets the objective of generating cuttings that turn into a beneficial byproduct instead of a waste.

Drill cuttings continue to be one of the largest volumes of waste generated from drilling operations. Traditional methods of drill cuttings treatment and disposal are designed to mitigate hazards and protect human health and the environment. Advances in current cuttings waste treatment and disposal have yielded improved safety, efficiency and in some cases, result in part of the drilling fluid components being recycled for reuse in drilling operations. An alternative approach to these conventional methods targets beneficial reuse of drill cuttings as a soil or soil amendment. The process begins with identifying soil science targets for the region and then engineering solutions to enhance local soils with the components of the drilling fluids and amendments used in a bioremediation process. By selecting drilling fluid components that can be transformed into beneficial additives for soil, the fluid design is optimized for biotransformation of the base fluid from synthetic hydrocarbons to biomass. Other drilling fluids are selected that contain macro soil nutrients. After the cuttings are generated from the drilling process, bioremediation is used to optimize a byproduct that can be used as a soil or a soil amendment.

Laboratory results have continued to optimize the application of this approach on a case by case basis and the current paper will review a laboratory study focused on a particular drilling fluid formulation and bioremediation technique that reduced the hydrocarbon content, as measured by EPA 8015 B, from 89,700 mg/kg to 3,200 mg/kg in under 30 days. The resulting by product was seeded with native grasses and was able to sustain health plant growth. The specific laboratory information developed in a greenhouse laboratory provides a basis to design the economics and logistics of future field operations with the intent of beneficial onsite reuse of cuttings as soil. The resulting reduction in trucking and disposal of waste is designed to yield both economic and environmental benefits.

The new recently developed information and techniques take the next step in gaining efficiency in the bioremediation process to shorten the time to convert synthetic hydrocarbons to biomass and a development of new additives to further enhance soil properties.

Primary Author / Conference Presenter:
John Candler
M-I SWACO, a Schlumberger Company
Houston, Texas, USA

Co-Author:
Patrick Tyczynski; M-I SWACO, a Schlumberger Company, Houston, Texas, USA