The Canadian Association of Petroleum Producers (CAPP) and member companies have released a report focused on seismic events associated with deep well fluid disposal. The document, which also outlines best practices for managing and mitigating potential seismic events from fluid disposal, is a companion to a 2019 report that examined seismicity associated with hydraulic fracturing activities.
Deep well fluid disposal has been a common practice across the industry for decades. Fluids such as saline water, ‘produced’ water (water that naturally comes to the surface mixed with oil or natural gas) or other fluids derived from drilling and production are often disposed by injecting the fluids deep into underground reservoirs.
Seismic events linked to human activities are often referred to as anomalous induced seismicity. Induced seismicity is a rare aspect of fluid disposal, occurring in a small percentage of disposal wells. Typically, these are microseismic events, too small to be felt at the surface, but approximately one per cent of disposal wells have generated events greater than magnitude 3 on the Richter scale.
Although such events can be felt on the surface, evidence suggests that any induced seismicity caused by fluid disposal in the Western Canadian Sedimentary Basin (WCSB) is generally deep beneath the surface and poses no risk to health, safety or the environment.
Incidents of felt seismic events associated with deep well fluid disposal have been reported in Alberta and northeast British Columbia. Seismicity can cause public concerns, which the industry takes seriously. Fluid disposal is provincially regulated in both Alberta and B.C. – the best practices outlined in the document complement those regulations, and help promote industry standards for how to manage seismicity from fluid disposal. Recommended management practices are based on science and consider operational factors, geological setting and historical seismicity levels.
As prudent and responsible operators in resource development, it’s important to gain a better understanding of the types and sources of seismic activity. By supporting research at universities, partnering with federal and provincial agencies, and conducting on-site research, the industry is contributing to a better understanding of seismicity and the potential impacts.
The document was developed proactively by CAPP members, and is available to the public and all industry operators and service companies.