Safety and environmental stewardship are our priorities throughout the life cycle of our oil and natural gas wells. We safeguard our workers and neighbors alike by planning, designing, drilling, completing and producing our wells using proven best practices, technologies, tools and materials.
Attention to well construction
Ensuring well integrity to protect people and the environment starts 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, pressure tests confirm casing integrity. Acoustic measurements let us know that the cement is properly bonded to the casing and to the surrounding rock formation.
Our Well Construction (WellCon) Center is devoted to optimizing drilling and completion engineering on all Devon wells and allows our staff to monitor real-time data and make adjustments to avoid potential issues before they occur. We also regularly conduct blowout prevention drills on our drilling rigs and audit drills as part of our field-review process.
We continue to verify the well’s integrity during production operations 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.
Managing fluids to minimize impacts
Determining the drilling fluids that will be used is part of the design phase before we drill a well. We prefer to use water-based fluids, but some rock formations require the use of 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 keep 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% 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 Frac Focus in 2011 and continues to be a leading contributor of information to the site.
We regularly communicate Devon’s environmental, health and safety (EHS) policies, protocols and operational expectations for well safety in safety tailgate meetings at field locations. We pride ourselves on worker safety and empowerment; all our crews have Stop Work Responsibility. 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.