The Geoscience BC's Peace Project acquired, interpreted, and shared new baseline scientific information about groundwater resources in the Peace region of northeastern British Columbia.
This project provides critical baseline information about the Peace region’s geology for future groundwater research.
Groundwater has been poorly understood in the Peace region of northeastern BC and was identified as an area with significant knowledge gaps by the influential Council of Canadian Academies’ 2014 report Environmental Impacts of Shale Gas Extraction in Canada. Northeastern BC is an area of significant unconventional natural gas development. ‘Unconventional’ gas extraction is the combination of vertical and horizontal drilling, together with hydraulic fracturing (fracking), required to access the natural gas, including shale gas, tight gas, coal bed methane, and methane hydrates from within the tight rock.
The Peace Project set out to locate and map shallow aquifers, specifically those within paleovalleys – the thick buried river (or glacial) deposits that usually contain coarse-grained sediments, such as gravels or coarse-grained sand. These rock units (aquifers) are excellent reservoirs for groundwater to flow through. Fine-grained sediments, such as muds and silts, tend to make poor aquifers.
Geoscience BC and partners completed the Peace Project between 2015 and 2018. The increased understanding of aquifers and shallow groundwater in the Peace region makes it possible for First Nations, energy companies, communities and government to make informed decisions about the use and protection of water resources.
The Peace Project:
The Peace Project was the first large-scale effort to map northeastern BC’s groundwater, using helicopters carrying geophysical equipment. The geophysical data and knowledge generated by the project has greatly increased the current understanding of shallow aquifers in the region. Regulators may use this independent baseline information to create policies to protect groundwater resources in the region.
The Peace Project was supported by several partners, including Progress Energy Canada Ltd., ConocoPhillips Canada, BC Ministry of Forests, Lands and Natural Resource Operations and Rural Development, Northern Development Initiative Trust, BC Oil & Gas Research and Innovation Society, the Ministry of Environment & Climate Change Strategy, the BC Oil & Gas Commission, and the Ministry of Energy, Mines & Petroleum Resources. It had additional support from the Peace River Regional District and the Canadian Association of Petroleum Producers.
The Peace project covers 9,600 km2, an area roughly a quarter the size of Vancouver Island. The area included the northern part of the Montney play, an area of enormous natural gas potential. The National Energy Board (NEB) estimates that “the thick and geographically extensive siltstones of the Montney Formation are expected to contain 12,719 billion m³ (449 Tcf) of marketable natural gas, 2,308 million m³ (14,521 million barrels) of marketable natural gas liquids (NGLs), and 179 million m³ (1,125 million barrels) of marketable oil.”
Natural gas development involves drilling vertical wells to a depth of approximately 3 km, then drilling a horizontal leg of 1-3 km in length away from the vertical well bore. The horizontal leg is then hydraulically fractured to access the gas within the tight rock. As these techniques have advanced in the last 15 years, it has become possible to economically develop this extensive, unconventional siltstone resource. Energy companies, such as Progress Energy, Conoco-Phillips and Painted Pony, have been active in the Montney in recent years.
Given ongoing natural gas development, First Nations and local communities are interested in finding out more about the groundwater resources beneath their feet and ensuring that the resource is used responsibly.
The first step in understanding groundwater in the region was to build a thorough understanding of sediment types and where they occur. An initial airborne electromagnetic (EM) geophysical survey was used for the Peace Project because it is a non-invasive, cost-efficient way to study geology below the surface. It was the first regional-scale survey to map sediment types in the Peace.
For the survey, a helicopter flew 9,600 km2 (roughly 21,000 line km at 600 m spacing) of the Peace region between Hudson’s Hope, Charlie Lake and Pink Mountain during July and August 2015. A 16 m by 28 m ‘hoop’ suspended below the helicopter collected information about how well the sediments and water below the earth’s surface respond to small amounts of electricity: the power source was a car battery.
In addition to the EM survey, geological mapping and hydrogeological (rock and water) data from new and existing oil and gas boreholes and water wells was collected. In tandem with the new EM survey data, the mapping and borehole information was used to calibrate the findings of the geophysical survey and to produce new maps, two-dimensional (2D) cross-sections and three-dimensional (3D) block models mapping the distribution of sediments and aquifers below the surface in the Peace region. Some additional holes were also drilled to ‘groundtruth’ Peace Project findings.
Finally, all of the data and interpretations generated during the Peace Project was combined in a single report, published in May 2018.
This report presents details of the survey operations, data collection and the results. The report delivers the survey data as a Geosoft GDB file (7GB – available on request); EM inversion results as a Geosoft GDB file, Geosoft geophysical grid (.grd), .tiff, .map and .pdf map files(magnetic and electromagnetic); and grid (.grd),.map and .pdf files of layers and sections from the inverted TEM conductivity model. The report does not include any geological interpretations of the geophysical dataset.
The derived qualitative geological interpretation highlights include: differentiation of different facies within the glacial cover, confirmation of several near surface resistive features associated to paleovalleys and/or areas of thick Quaternary cover identified by previous studies of borehole data, and the presence of other near surface resistive features that could be of hydrogeological relevance.
The objective was to test the validity of the geological model; not to locate shallow Quaternary and/or bedrock aquifers. The report provides a rationale as to why each area was selected. The locations of potential wells are overlain on resistivity depth slices and sections from the Peace project area, and a well prognosis provides the information on resistivity values and geological formations versus depth for each of the proposed locations.