Listen to Encana's management team discussing the company's Q4 & year-end 2013 results in a live webcast and see the quarterly results documents.
We ensure sound monitoring and control during all stages of our operations.
Monitoring the integrity of the wellbore is extremely important in protecting groundwater throughout the lifecycle of a well. We are diligent in ensuring the wells we drill meet our operational needs without adversely impacting the environment. The integrity of our casing and cement system can be evaluated through field inspection and wellbore logging at any point during the life of a well.
After we’ve installed and cemented our casing, before we begin our hydraulic fracturing operations, we conduct pressure tests to ensure the wellbore’s integrity. These tests are conducted at high enough pressures to determine whether or not the integrity of the casing will meet our operational needs. All equipment is tested to make sure it’s in good working condition.
We constantly monitor pressure during hydraulic fracturing, so that any unexplained change from the fracturing design or a drop in pressure can be detected and analyzed before we continue operations. If any fluids were to flow into non-targeted areas, we would immediately notice a drop in pressure. In the case of unusual or unexpected behaviour during hydraulic fracturing, the operation is shut down immediately.
A recently developed technology, known as microseismic monitoring, allows us to monitor microseismic events associated with hydraulic fracturing in three dimensions and in real time. Where it is used, microseismic monitoring provides a way to evaluate important elements of each hydraulic fracture treatment, such as vertical extent, lateral extent and fracture complexity. We can then decide when to end one fracturing stage and begin the next.
We use a variety of tests to ensure wellbore integrity after we’ve completed a hydraulic fracture treatment. For example, we can conduct surface casing vent tests. These tests allow us to test the integrity of our casing cement by gauging whether or not gas rising from deep underground is migrating through the cement and up to the surface. If gas is escaping, we can take steps to fix the problem.