Using a process known as a green completion, Devon has reduced methane emissions by more than 25 billion cubic feet in the Barnett Shale area of north Texas.
Green completions have been Devon’s standard practice in the Barnett Shale since 2004. The company uses the same process to complete wells in New Mexico, Wyoming, Oklahoma and south Texas.
Green completions take place during the clean-up stage of the completion, after a well has been hydraulically fractured. The clean-up involves removing the water necessary to fracture the well. During this flow back, natural gas is produced with the water. What makes the well completion “green,” or environmentally friendly, is that the gas is separated from the water and placed in a pipeline instead of being released to the atmosphere.
First, a sand separator (shown at right in this photo) filters out any sand, sending it through a 2-inch pipe into the disposal tank. That filtering leaves a mixture of natural gas and water. The second piece of equipment (in the left side of this photo) separates the water, which then reunites with the sand in the disposal tank. The gas, meanwhile, is diverted into a separate pipe and eventually is sent by pipeline to a processing plant.
This process is repeated several times a week on Devon’s typically rural leasehold in the Barnett Shale. Not long ago, green completions were so uncommon that Devon had to look as far as Wyoming to rent the necessary filtering equipment. Now, more than 2,000 green completions later, that rental equipment is available readily and locally.
Green completions are possible largely because of a team meeting conducted each Friday at Devon’s field office in Bridgeport, Texas. During that meeting, Devon employees representing various areas of expertise discuss the strategy and timing necessary to coordinate pipeline construction and well completions.
The goal is to have a pipeline in place by the scheduled date of the final frack job on any given well. This eliminates a potential delay that could prevent a green completion.
"You have to have a pipeline in place to perform a green completion,” said Jay Ewing, who oversees Devon’s well completions in the Barnett Shale."Our luxury here is that we own our own pipeline. That gives us the flexibility to coordinate well completions with pipeline construction."
Devon performs green completions voluntarily. The procedure generally is not required in the Barnett Shale except in the city of Fort Worth and at Dallas Fort Worth International Airport. The vast majority of Devon’s Barnett Shale wells are outside those locales.
We perform green completions because of two core values that are key to Devon’s success: Always do the right thing, and be a good neighbor. In the case of our green completions practice, it is the right thing for the environment, for the community and for our shareholders.