Environmental Award
Apache and Encana

Water Stewardship in Practice – The Debolt Water Treatment Project

The Horn River Basin has the potential to be Canada’s first large-scale, commercial shale gas development. In 2007, Apache and Encana formed a 50/50 joint venture partnership to take advantage of this unique opportunity and to begin an active drilling program. This partnership brought together two companies, viewed under other circumstances as competitors, to share in developing infrastructure designed to reduce their environmental impact in the area.

Given the low permeability of the Horn River shale, hydraulic fracturing of the target formation is required to recover natural gas from this play. An abundant and economical supply of water is required for hydraulic fracturing, a proven technology that is critical to the successful development of this resource.

Stakeholders have become increasingly concerned with water use in shale gas operations; in particular the quantity of freshwater use and corresponding impact to water resources. In order to address these concerns, Apache and Encana examined possible alternatives to surface water sources. This initiative is directly in line with both companies’ shared commitment to good-neighbour practices, sustainable development and CAPP’s RCE Water Management Guideline.

The Debolt formation was originally identified during early operations in the basin. Test results, from a study completed in 2007, indicated that the Debolt reservoir was a deep sub-surface, non-potable aquifer capable of supplying water for fracturing operations. The Debolt aquifer occurs at depths of approximately 500 to 1,100 metres and holds saline water with total dissolved solids content ranging from 15,000 to 40,000 mg/L, and an H2S concentration of 65 mg/L, making this water generally unfit for most common uses. Tapping this unique water source required much effort, dedication and innovation from both companies.

Challenges of designing a process to use this water supply included: the isolated location, lack of waste disposal options, poor quality of access roads, harsh winter temperatures and lack of power. After investigating several effective methods of sweetening, many innovations in water treatment were required to effectively address these challenges.

With the shared vision to reduce dependence on fresh surface water sources in the Two Island Lake area of the Horn River Basin, Apache and Encana began initial laboratory testing, and field trials, which finally resulted in the construction of a full-scale plant. The plant went into operation in June of 2010.

The Debolt water treatment plant is the first of its kind. Over the course of only two years, Apache and Encana have decreased their use of surface water, securing access to an integrated water treatment and distribution system, which allows for the full recovery and re-use of fracture stimulation fluids, allowing for the development and growth of the play with low environmental costs.