Hazardous waste drilling mud management – A case study on remediation technologies Presented at: Oil Industry and the Environment Seminar (NOTES 2015) April 27, 2015 Hesam Hassan Nejad Ph.D. Candidate, Oil & Gas Engineering Supervisors: Dr. Kelly Hawboldt and Dr. Lesley James

Outline Drilling Mud Fundamentals Regulations on Waste Drilling Mud Remediation Technologies Chemical techniques Biological techniques Thermal techniques Physical techniques Technical Comparison of Individual Technologies

Waste Drilling Mud Production Purpose of Drilling Mud: Prevent blowouts Balance & control pressure Minimize corrosion Lubricate and cool Remove drill cuttings [1] Schematic of how drilling mud is produced How the shale shaker works

Drilling Mud Composition A solid-liquid slurry Very high viscosity High content of oil and heavy metals Bentonite, barite, and other polymers The composition of the drilling mud depends on the: Type of drilling fluid in use Composition of the formation What affects the composition? Types of drilling mud

Non-Aqueous vs Water Based Drilling Fluids Non-Aqueous Based Drilling Fluids Diesel-based fluids Aromatic content 25%, 2% ≤ PAH ≤ 4 %) Low toxicity mineral oil-based fluids 0.001% ≤ PAH ≤ 0.35% Synthetic-based fluids (SBFs) PAH ≤ 0.001% [2] What affects the composition? Types of drilling mud Water Based Drilling Fluids

Waste Drilling Mud Disposal Depending on the regulation, the treatment may vary Local authorities may have their own regulations Inject waste drilling mud into a formation with high porosity and high permeability In the absence of overboard disposal, another option is to bring it to shore for land disposal EPA Regulations Environmental Protection Agency (EPA) and Oslo and Paris Commission (OSPAR) regulations [3]: Oil on solid particles should not exceed 1% (wt./wt.) Hazardous metal concentrations should be less than specific amounts Toxicity characteristics leaching procedure (TCLP) - What are EPA and OSPAR regulations ? - Hydrocarbon and hazardous metal concentrations should be simultaneously considered before landfilling

Waste Drilling Mud Disposal - Newfoundland Regulations Oil Based Drilling Fluids At no time can be discharged to sea Synthetic Based Drilling Fluids Required to have a PAH concentration of < 10 mg/kg and be able to biodegrade under aerobic conditions Oil on cuttings retention limit of 6.9% wet weight Water Based Drilling Fluids Discharge of drill cuttings associated with water based drilling muds is permitted [4] - What are EPA and OSPAR regulations ? - Hydrocarbon and hazardous metal concentrations should be simultaneously considered before landfilling

Current Treatment Technologies Waste drilling mud treatment technologies are categorized into four main groups: Chemical treatment Biological Treatment Thermal Treatment Physical Treatment - Brief intro for the next section

Chemical Treatment Current Technologies Destroys the contaminants or converts them to harmless compounds. The most common chemical methods involve oxidants such as hydrogen peroxide and ozone Disadvantages: High cost Ineffective at higher pH [5] What are chemical treatments? How they work and disadvantages

Chemical Treatment Current Technologies Another chemical treatment option is to solidify/stabilize the hazardous waste to convert them into less toxic materials. Many reports have been published regarding adding some chemicals for drilling mud solidification such as lime, cement, and aluminum sulphate Advantages: Relatively short processing time Effective Disadvantages: Increase in waste volume Difficult to implement Need for other chemical compounds increases cost - How solidifying works and may increase the waste volume

Biological Treatment Current Technologies Biotechnologies involve the use of micro–organisms to degrade or mineralize the organic components of drill waste Advantages: Cost effective Green process Disadvantages: Slow reaction times Long processing times Temperature sensitivity [6] How the biological technologies work for organic matter removal?

Thermal Treatment Current Technologies Removes or destroys hydrocarbon pollutants in the drilling waste by desorption, incineration, gasification, volatilization, and pyrolysis (or a combination thereof) Advantages: Very effective High volume reduction Disadvantages: Toxic gas production High energy requirement Very expensive No oil recovery [7] Thermal treatments are the sole treatment technologies capable of reaching EPA’s 1% limit Advantages and diosadvantages

Surfactant Enhanced Washing Current Technologies Physical Treatment: Surfactant Enhanced Washing Surfactants (detergent) reduce the interfacial tension (IFT) between the water and oil phases Surfactants liberate the oil from the solid surface Surfactants can be used in mixtures with/without additives [8] [9] How surfactants work in principle Difference between cationic, anionic and non-ionic surfactants

Surfactant Enhanced Washing Current Technologies Physical Treatment: Surfactant Enhanced Washing Advantages: Cost-effective Easy to implement Disadvantages: Usually ineffective in hydrocarbon removal May increase waste volume Advantages and disadvantages of surfactant-enhanced washing

Surfactant Enhanced Washing Current Technologies Physical Treatment: Surfactant Enhanced Washing Cationic Surfactants: Hazardous nature to humans and nature Very high soil sorption Anionic Surfactants: Lower toxicity than cationic surfactants CMC values greater than cationic and non-ionic surfactants Least adsorption to soil (significant advantage) Non-ionic Surfactants: Intermediate sorption Low biotoxicity CMC values much less than anionic and cationic surfactants How surfactants work in principle Difference between cationic, anionic and non-ionic surfactants

Supercritical Fluid Extraction Current Technologies Physical Treatment: Supercritical Fluid Extraction Supercritical Fluids posses: Temperature above the critical temperature Pressure above the critical pressure Liquid-like densities Gas-like viscosities Zero surface tension Carbon dioxide is the most widely used supercritical fluid: Non-flammability Chemically inert Low toxicity Low environmental impacts Low critical temperature and pressure (31oC and 74 bar) Why supercritical can be very efficient? Why Supercritical CO2?

Supercritical Fluid Extraction Current Technologies Physical Treatment: Supercritical Fluid Extraction Advantages: Efficient No/less solvent required Short extraction times Easy to separate pollutants from the solvent Disadvantages: High cost More safety issues Advantages and disadvantages of SFE?

Technical Comparison 76 Factor Treatment Method 18 9 5 Total 73 67 65 Weighting Treatment Method Chemical Thermal Physical Biological Removal Efficiency 30 20 28 18 Environmental Pollution Volume of produced waste 10 6 9 Hazardous pollution caused 8 1 Cost Capital cost 4 Operational cost Energy requirements 7 Processing time 5 Particle size (ability to treat very fine particles) Total 100 73 67 76 65 These technologies have been ranked according to their capability considering each factor

Recommendations According to the literature, no current technology, except the thermal treatment processes, is capable of achieving the NL or EPA’s regulations of 6.9% or 1% oil on cuttings, respectively There is a need for a combined process with appropriate pre and post treatment processes to treat the waste drilling mud As recommended, physical treatments are suitable candidates for designing and developing a combined method to treat the waste drilling mud to meet the strict regulations These technologies have been ranked according to their capability considering each factor

Future Work There is no sole technology, except thermal treatment, capable of reaching disposal regulations, there is a need to find alternative solutions including combination physical technologies to treat the drilling mud for land disposal. Research is currently being conducted at Memorial University to test the optimal removal efficiency using surfactant enhanced washing and supercritical fluid extraction processes. These technologies have been ranked according to their capability considering each factor

References [1]. Growcock, F. and T. Harvey (2005). Drilling fluids. Drilling Fluids Processing Handbook. ASME Shale Shaker Committee. Burlington, MA, Gulf Professional Publishing. [2]. A. M. Shaikh, Environmental Management of Drilling Mud, Master’s thesis, Delft University of Technology, January 2010 [3]. OSPAR convention for the protection of the marine environment of the north east Atlantic, OSPAR Commission summary record OIC 2002, ANNEX 12, 2002 [4]. J. Whitford, Stantec Limited, Cuttings Treatment Technology, Evaluation Environmental Studies Research Funds Report No. 166. St. John’s, NL, July 2009, ISBN 0-921652-85-2 [5]. Ozone secondary disinfection system, Public swimming venues under MAHC compiliance, January 1st, 2013 [6]. Available at: https://www.sintef.no/projectweb/nomremove/water-treatment- processes/biological-treatment/ [7]. Available at: http://www.eisenmann.com/en/products-and-services/environmental- technology/waste-disposal/rotary-kiln.html [8] P. Yan et al., Remediation of oil-based drill cuttings through a biosurfactant-based washing followed by a biodegradation treatment, Bioresource Technology 102 (2011) 10252–10259 [9]. Thomkatt, Understanding Basic Chemicals, Available at: http://www.janitorkatt.com/understanding-basic-chemicals

Acknowledgements Dr. Lesley James and Dr. Kelly Hawboldt for developing this project and their kindest help and support throughout the whole project Leslie Harris Centre of Regional and Policy Development for partially funding this project through their 2014-15 MMSB Waste Management Applied Research Fund Supported by

Thank You for Your Attention