One can watch the history of the offshore oil and gas industry unfold on a helicopter flight out of Houma, La., to most any platform in the Gulf of Mexico. From the short-legged shallow platforms to the floating giants tethered to the seafloor, the industry’s march into the Gulf’s deeper waters over the past century is clearly visible. However, time is no friend to these structures, and like the wells they support, the day always come when history’s signposts must fade away. A new approach presented at the 2016 Offshore Technology Conference (OTC) offers a different way to help operators decommission their aging wells and structures.

At the beginning of 2011 there were more than 4,500 idle wells and 783 idle structures in the U.S. federal waters of the Outer Continental Shelf. These aging assets pose an environmental risk, prompting operators to feel a renewed pressure to decommission idle infrastructure sooner rather than later, according Gary Siems of Montco Oilfield Contractors in his OTC presentation.

“In a four-year period, there were 183 structures and 1,082 wells toppled by hurricanes,” he said.

The increased number of toppled assets led the U.S. Department of the Interior’s Bureau of Ocean Energy Management Regulation and Enforcement to issue guidelines that specified that lease operators had to permanently decommission and remove wells and structures no longer useful for oil and gas production as soon as possible, but no later than five years after cessation of production, he said.

In his presentation, Siems compared the old, multistep way of decommissioning a structure and well with a new and better optimized process that employs the newest technologies to get more work done safely and at a lower cost.

He noted that the eleven steps typical to the traditional process are performed sequentially, with most requiring separate and specialized workers and equipment.

“The traditional method is what I like to call the ‘minivan’ model,” he said. “It’s very slow but gets the job done.”

He highlighted in his talk a forecast conducted in January 2011 by an independent operator needing to decommission its idle iron inventory of 245 wells and 93 structures over a five-year period to be $409 million using the traditional methods.

“That’s very expensive for a mid-size operator,” he said. “We had to look for something different. We needed a new idea.”

That idea came in the form of a new optimized decommissioning methodology that employed the size and capabilities of a newly designed and constructed 335-ft self-elevating, self-propelled liftboat. The new boat provided the space and lifting capacity necessary to perform the majority of the work steps concurrently—rather than sequentially—and in just one spread mobilization.

“This change from the traditional minivan approach is what I call the Ferrari method,” he said. “It is sleeker, faster and allows us to get more done in less time.”

According to Siems, over a 30-month period the new concurrent model resulted in 140% more wells and structures being removed over the number expected to have been removed using traditional methods. Using the optimized method, decommissioning costs were reduced to $278 million, he said.