In every phase of the life of an oil and natural gas well, we’re safeguarding the people involved – workers and neighbors alike – with planning, design, drilling, completion and production operations using proven best practices, technologies, tools and materials.
Ensuring well integrity
At Devon, we’re focused on protecting the safety and health of our workers involved in drilling operations and committed to protecting the environment and neighboring communities.
Safety and environmental stewardship start with the planning and design of the wellbore, including the selection of equipment, materials and drilling techniques. We design our wells to meet high standards for the strength of the steel pipes that form the well, known as casing, and the quality and quantity of cement we use to separate and protect the multiple layers of casing. This attention to well construction keeps fluids in their proper place and protects groundwater zones for the life of the well.
During drilling operations, casing integrity is confirmed through pressure tests. Acoustic measurements let us know that the cement is properly bonded to the casing and to the surrounding rock formation.
During production operations, we continue to verify the well’s integrity by monitoring tubing and casing pressures, and by analyzing gas and water produced by the well. We also conduct periodic pressure tests and casing inspections.
Safe fluids management
In the design phase before we drill a well, we determine the drilling fluids that will be used. Devon prefers to use water-based fluids, but some rock formations require us to use oil-based fluids. When we use oil-based fluids, we employ a closed-loop system for safety and environmental protection. In keeping with the EPA Spill Prevention, Control and Countermeasure (SPCC) Rule, we maintain plans at drilling locations to minimize the impact of potential spills. We follow local, state and federal guidelines when handling drilling fluid and mud systems.
After a well is drilled, the next step is to complete it using a process known as hydraulic fracturing. Water, sand and additives are pumped into the wellbore to create or restore small fractures in the rock to stimulate production from new or existing oil and gas wells. Water and sand make up 98 to 99.5 percent of the mixture. A full registry of wells and chemical additives, along with much more information about hydraulic fracturing, is available at fracfocus.org. Devon played a leading role in the creation of fracfocus in 2011, and continues to be a leading contributor of information to the site.
Devon’s EHS policies, protocols and operational expectations for well safety are clearly communicated in safety tailgate meetings at field locations. We pride ourselves on worker safety and empowerment; all of our crews have Stop Work Authority. Anyone may stop a job at any time if the person notices a potential hazard or is unsure about a task. This workplace culture helps keep people safe and protects the environment by reducing the risk of spills or emissions.