Posted August 1, 2013
There’s much that impresses about hydraulic fracturing if you see it up close, which I did during a recent tour of Anadarko Petroleum natural gas operations near Williamsport, Pa.: the technology, the company’s highly skilled workers, the game-changing resource opportunities in the Marcellus Shale and more.
My biggest takeaway: the priority Anadarko assigns to protecting the environment and its workers. Examples:
- Groundwater – Three strings of steel pipe are used for well integrity and to protect the freshwater aquifers that in Pennsylvania can be as deep as 500 feet. The first or outside string (the surface casing) extends to 700 feet below the surface and is encased in cement. Inside the surface casing is the second string (the intermediate casing), which extends to more than 2,000 feet below the surface and is also encased in cement. The production pipe goes about 8,000 feet deep (more than a mile and a half below the aquifer) – think of six Empire State Buildings stacked on top of each other.
- Water – The water needed to hydraulically fracture a well, typically about 4 million gallons, is trucked or piped to a lined fresh-water impoundment. An Anadarko official says farmers often ask the company to leave the impoundments behind when they are no longer needed for operations.
- Closed-loop – Cuttings produced when the well is drilled are separated and stored in steel containers that are then hauled to a regulated disposal site, while drilling fluids are saved and recirculated.
- Spill prevention – During hydraulic fracturing, the entire site is covered with three layers of liner to prevent potential spills from reaching the ground underneath. The liner is surrounded by a small berm to prevent runoff. “Eyes on” employees are assigned to do nothing but oversee appropriate water transfer from trucks to holding tanks to prevent spills, and there’s a truck on stand-by to vacuum up anything that gets on the pad liner – including rainwater.
- Recycling – Water used during hydraulic fracturing that returns to the surface – called flowback – is recycled. Again, even the rainwater that falls on the liner is vacuumed and put into the re-use water tank.
- Snakes – Central Pennsylvania is home to the Timber Rattler. Anadarko protects them by creating habitat and basking areas – for example, laying out boulders for them to sun themselves on – away from natural gas operations. Licensed snake handlers are on call to relocate snakes when necessary. “We are cognizant of where we are and protecting the environment,” says Anadarko’s Robert Montgomery.
Everything Anadarko does is subject to unannounced inspection by state regulators. “For us to work in this state we have to work hand in hand with (state) agencies,” Montgomery says.
Anadarko showed our group three phases of natural gas production: drilling, hydraulic fracturing and production. A typical drill pad covers 3.96 acres, which, through horizontal drilling can collect natural gas from more than 640 acres down below. Drilling goes down more than a mile, then the bit is steered into a gentle arc from vertical to horizontal. The arc is so gradual, over such distance, that the steel pipe safely turns from vertical to horizontal in the process. The horizontal portion of the well can stretch more than 6,000 feet.
After the wells on a pad are drilled, cased and cemented, a device perforates the horizontal part of the production pipe to make small holes in the casing to expose the wellbore to the shale. Then a mixture of water and sand (~99.5 percent) and chemicals (~0.5 percent) is pumped in under high pressure to create micro-fractures in the shale and free natural gas. Sand keeps the fractures open after the pressure is released. The chemicals are chiefly agents to reduce friction and prevent corrosion. Montgomery says the company has become quite efficient with the water it uses:
“Once we start producing water, we reuse it. … It’s more efficient, it’s a better way to do it. We’ve got on-site filtration now that basically cleans up our water. It takes an extra stage of trucking away so we have a lot less trucks on the road. And that’s less traffic, less pollution, less emissions and it’s safer. This water-filtration technology has been developed in the last four or five years on-site, which has made us more efficient.”
At the production site, only the wellheads and equipment to separate natural gas from water it may be mixed with are visible. Eventually, the site footprint will be reduced so that just the wellheads remain, with the surrounding area restored to its pre-drilling state.
Again, it’s a process designed to carefully develop clean-burning natural gas, conducted by people who know what they’re doing. No industrial activity is 100 percent failure-proof 100 percent of the time, but responsible operators like Anadarko are taking every precaution, guided by strong regulations and industry-developed standards, to protect employees and the environment. For Anadarko, it’s professional and personal. “We live here in this community,” Montgomery says. “Our children play here in the forests.”
In return, America is realizing the game-changing nature of shale energy. Blogger Geoff Styles:
The 8 billion cubic feet of estimated lifetime gas production per well could generate more than 1.2 billion kilowatt-hours (kWh) of electricity in a gas-fired power plant. By comparison, a 1.5 MW wind turbine would normally generate less than 80 million kWh over 20 years. So when brought online the five wells on the one pad I visited will together produce energy equivalent to a wind farm of 75 turbines.
That’s not a criticism of energy from wind or any other source – just the facts on the tremendous energy in natural gas from shale, which Anadarko and other natural gas and oil companies are bringing to America every day – safely and responsibly.
ABOUT THE AUTHOR
Mark Green joined API after a career in newspaper journalism, including 16 years as national editorial writer for The Oklahoman in the paper’s Washington bureau. Mark also was a reporter, copy editor and sports editor. He earned his journalism degree from the University of Oklahoma and master’s in journalism and public affairs from American University. He and his wife Pamela live in Occoquan, Va., where they enjoy their four grandchildren.