Going with the flow
Injection operations, technological innovations key to keeping Rangely's mature oil field viable
RANGELY — In 1946, Roy Cramer’s grandfather moved from Palisade to go to work building a bunkhouse during the boom in drilling in Rangely’s oil field.
About half of the 950 wells in the field were drilled in the 1940s. Thanks to innovative measures that today center on alternating underground injections of water and carbon dioxide, Chevron continues producing oil from this mature field, including from many wells dating back that long ago.
And thanks to continuing technological innovations and up-and-coming young people in the industry with bright new ideas, Cramer, a field production engineer for Chevron, sees oil continuing to flow from the field for a long time to come.
“I would never put an end date on this because you have no idea what’s going to come up,” Cramer said.
For Cramer, the challenges of keeping that flow going are what keep him coming to work each day at a time when he could retire.
“It’s fun. That’s why I stick around,” he said.
OIL’S EARLY DAYS
“It was known from the earliest of times that there was oil in Rangely,” the Rangely Outdoor Museum says in a brochure. “Indians used oil seeping out of the ground for medicinal purposes. There are place names such as Stinking Water Creek where surface waters mixed with oil.”
Drilling dates back to a well drilled in 1901 in the shallow Mancos shale formation, with disappointing results, a history on the town’s website says.
Drilling continued to some degree in the following decades. And in the early 1930s, a well known as the Raven A-1 was drilled by the company now known as Chevron, more than 6,000 feet into the Weber sandstone formation. Oil was discovered in that formation with the drilling of that well, close to what are now Chevron’s offices west of town. But the Great Depression postponed development of the Weber sandstone formation, with drilling beginning in 1943 during World War II and being undertaken in earnest in the years just after the war.
“There were people living in tents all over this town,” said Bud Striegel, who’s now retired from the family pipeline business. Striegel’s dad brought his family to Rangely in 1945 after reading about the drilling boom that was beginning, and a decade later, when Striegel was 14, he went to work in the oil field.
“You couldn’t walk down Main Street without someone stopping and offering you a job,” he said.
“All these streets were just mud,” recalls Derryle Baker, who remembers his mom losing a shoe to the muck while crossing the street.
His family moved to Rangely in 1947, arriving on his fifth birthday. His dad worked for a drilling company and they lived in what was something like a sheepherder’s wagon, with no bathroom or water. Baker remembers later roughnecking on a rig, earning $1.90 an hour, then $2.10 — then $1.90 again during a drilling slowdown — and working lots of overtime.
He’s retired now from what was then Baker Well Service, a family business that later merged with several other companies into Alliance Energy Service. He and Striegel both remember nighttimes looking like daytime in the oil field due to so much gas being flared during the boom. The glow was visible as far away as Baggs, across the Wyoming border, Striegel said.
AFTER THE PEAK
Rangely turned into a major U.S. field. Cramer said oil production in the field peaked at about 82,000 barrels per day around 1956. It produces about 10,000 barrels a day today, shipping the oil by pipeline to a refinery in Salt Lake City.
In 1957, Chevron entered into a 20,000-acre unit agreement with others who had an interest in the oil field, under which Chevron would operate the entire field. The field is known as the Weber Sand Unit and is spread across a mix of Chevron-owned and other private land, along with public land administered by the Bureau of Land Management. In response to the wells’ lower flows, Chevron began injecting water into roughly half of the wells to maintain reservoir pressure and sweep the oil out of the formation and up into the production wells.
That operation peaked in 1986, Cramer said. Chevron was handling about 550,000 barrels of water a day at the peak of water injection operations, about twice as much as it does now, he said.
It was in 1986 that Chevron began buying carbon dioxide for injection into the field. Cramer said carbon dioxide is soluble in water and oil, swelling up and thinning out the oil to help it flow.
Cramer said enhancing oil recovery through carbon dioxide injection is a process Chevron pioneered decades ago in Texas. It’s now commonplace in oil fields in places such as west Texas.
In Rangely, Chevron recovers and re-injects the carbon dioxide, while also continuing to buy carbon dioxide from an ExxonMobil facility in Wyoming and pipe it to Rangely. Cramer said the ExxonMobil facility was created to capture helium, with carbon dioxide being produced as a byproduct.
U.S. Sen. Michael Bennet, D-Colo., has been pushing for legislation to provide for favorable financing for facilities for power plants and industrial facilities to capture and store carbon dioxide, which causes global warming. The carbon dioxide then could be stored underground or used by energy companies for enhanced oil recovery, as Chevron does now.
While Chevron officials weren’t comfortable describing what they do in Rangely as carbon sequestration, Cramer said they’re retaining it, which is something similar.
“We do retain the CO2 because it works for us in the reservoir, and it will be there indefinitely,” he said.
TRAINING GROUND FOR EMPLOYEES
These days, the key to Chevron’s continued oil production is a process the company calls WAG, or water-alternating-gas. Chevron alternately injects water and carbon dioxide, shifting between them a week or weeks at a time depending on the well and other factors, to optimize continued oil flow.
“That’s the secret to managing this field,” Cramer said.
Rangely has been a significant part of Chevron’s operations for a long time, and remains a critical component of its Mid-Continent Business Unit, officials say. The complexities and challenges of continuing to produce oil in the field and the innovations that have resulted have made it a notable asset for the company and its employees.
“Rangely has been a learning area for many, many people,” said Nick Moschetti, operations superintendent in Colorado for Chevron.
People who have developed skills in Rangely have gone on to lead Chevron’s operations in other countries, and it continues to be a training ground and provide an opportunity for employees to look for new ways to keep the field flowing.
Corbin Gilbert, 22, who attends a community college in Texas and interned this summer in Chevron’s control-room operations, said he previously had been fairly familiar with downstream, refinery-type oil and gas operations, but not so much with the upstream, production end, much less how that production occurs in Rangely.
“This upstream (operation), taking the gas and oils out of the ground and doing what they do to it, kind of blew my mind, thinking about how it works,” he said.
Thanks to factors such as the field’s age, the volumes of fluids and liquids that are handled, and the abundance of pipelines involved with injection operations, much of Chevron’s Rangely operation focuses on what Moschetti calls asset integrity.
He said Chevron puts a lot of effort company-wide into protecting people and the environment, and in Rangely it has a program to manage all of its lines, wells and other equipment.
“You can’t say you’re an environmentally friendly company without having this piece,” he said.
This summer it undertook what in the industry is called a turnaround operation. As many as 500 workers descended on Rangely and put in 180,000 hours of work over two months inspecting plants and field equipment and making necessary repairs, an undertaking that might be carried out every decade or so.
“We touched pretty much everything that was critical to our operations during the turnaround,” Moschetti said.
With wells dating as far back as the 1940s, Chevron applies corrosion inhibitors to try to protect casings, and if wells fail integrity tests it can run new pipe into them.
Pressure testing of pipelines and inspections of above-ground equipment and tanks are also part of Chevron’s program. And this year Chevron, like other oil and gas companies in the state, had to undergo a pipeline review process that included providing an inventory of pipelines within 1,000 feet of homes, and pressure-testing those lines. The state required the review following an April home explosion in Firestone that killed two people and resulted from gas from a flowline from a nearby well.
Moschetti says while compliance took some effort, Chevron understood the state’s rationale for the review process and supported it. He said a few Chevron pipelines failed during the testing, which was to be expected because Chevron tests lines at or above maximum pressure levels for normal operations.
“I didn’t see anything that was out of the norm for us for our failures,” he said.
Chevron identified 125 flowlines as being within 1,000 feet of structures, as defined by the state’s order. It says 30 wells are within Rangely town limits, but only eight are producing. Eighteen have been plugged and abandoned, and four more are temporarily abandoned with plans to plug them.
While much of the current concern regarding oil and gas operations in Colorado surrounds hydraulic fracturing of wells near homes, no wells have been fracked in Rangely’s town limits for more than 20 years, said Chevron spokesperson Cary Baird. Still, Moschetti said fracking is safe as long as things such as proper casing and cementing of wells occurs.
With Chevron operating such an extensive pipeline network, spills occasionally occur. The Colorado Oil and Gas Conservation Commission in June fined the company $30,000 for a pipeline leak of more than 10,000 gallons of produced water and oil that occurred during a storm that dropped about 1 1/2 inches of rain on its Rangely operations, something a commission staff member described as a unique circumstance involving a unique field. The rain filled all 43 rain-collecting siphons Chevron has in the field, triggering alarms and leading Chevron to do field inspections that led to the leak’s discovery.
Chevron has been spending millions of dollars streamlining and upgrading its Rangely operations, including removing some pipelines from service altogether. Moschetti said perhaps 30 miles of lines are being eliminated.
“When you look at the age of the systems it’s the right thing to do,” he said.
Looking toward the future, Moschetti concedes the field’s economics become tougher each year. Energy companies are producing a lot of oil domestically these days from shale formations using fracking and horizontal drilling, and Moschetti and others at Chevron continue to look for ways to do things more efficiently in Rangely and incorporate better technologies.
Innovations already have added decades to the oil field’s life, and Cramer said when he hosts field visits with young engineers, he suggests to them that prolonging the life of fields like Rangely’s will be in their hands.
“The challenge is, what is it you are going to come up with,” he said he tells them.