Basin-Scale Analysis and Options for Produced Water from Tight-Gas Sand Reservoirs, Uinta Basin, Utah
The production and disposal of water from tight-sand gas reservoirs in the eastern Uinta Basin, Utah, and elsewhere affects the economics of gas resource development and has recently become a topic of much public debate because produced water is the largest-volume waste stream associated with these unconventional gas plays. Environmentally sound management of produced water can be a significant cost associated with gas extraction, so there is an economic incentive to minimize this waste stream and/or reuse produced water in hydrocarbon development, and companies are actively pursuing these technologies. Balancing the water-use needs and produced-water disposal requirements associated with shale/tight-sand gas development creates significant material handling challenges to both industry and regulators. These challenges are complicated by an operating environment where many individual producers of varying sizes exist within a field, each with varying water needs and production, and a production timescale of decades for the basin as wells play out and new ones are completed. Over 328 BCFG and nearly 50 million bbls of water were produced from the Uinta Basin in 2013. The major tight-gas sand reservoirs in the basin are the Tertiary (Eocene) Wasatch Formation and several formations in the Cretaceous Mesaverde Group. Three major components of our study are: (1) compilation and analysis of past and new information on the thickness, structure, depth, lithology, water quality, and temperature of all aquifer/reservoir units in the basin from the surface (alluvium) down through the Jurassic Glen Canyon Group; (2) mapping of reservoirs/aquifers (structure, thickness, porosity, permeability, lithology) and produced water (quantity, geochemistry, temperature); and (3) statistical analysis of water production quantity and quality to identify and forecast volume trends for each discrete tight-sand gas-producing interval. These components will be incorporated into an evaluation of the existing infrastructure for produced water management/reuse and the recommendations for best management practices of the produced waters in the eastern part of the Uinta Basin.
AAPG Datapages/Search and Discovery Article #90193 © 2014 Rocky Mountain Section AAPG Annual Meeting, Denver, Colorado, July 20-22, 2014