The Biggest Dig

As the rock pushes up, the pipe gurgles and delivers a long, deep, earthy sneeze.

by Bruce Schimmel

The usually peaceable Friends Center, at the corner of 15th and Cherry, has been making quite a racket lately. They've been drilling very deep wells. Up close, earplugs are not optional.

The man in charge of this noise is William Black, known as Billy. For more than a month, the wiry foreman's three-story drilling rig has been breaking the peace by grinding at the bedrock below.

Black is psyched, today, because one of his holes is about to breach 1,000 feet. That's deeper, he says, than the Comcast Center is high. That's almost as deep as he's ever dug, says the 36-year-old with a weathered face, who learned to drill from his granddad.

"What is this doin' in the friggin' city?" someone screams in the din, which is the gist of what passers-by generally shout.

Billy Black knows what this drilling operation is doing: making history. As part of the Friends Center's $13.5 million initiative to free itself from fossil fuels, this is Philly's first big geothermal installation. Billy is drilling six deep wells, whose constant 50-degree water temperature will be used to heat and cool the building.

It's been tough. Last week, Billy blew out one of two massive diesel-powered compressors that slam water down the hole. The water is needed to lubricate the 6-inch-wide carbide bit as it chews through solid rock.

"We're burning at the drill now," someone yells. That's bad. If the rock damages the drill, they could "shank" a $10,000 bit. And then, says Black, "We've got to go fishing."

Still, Billy and his burly crew of two burrow on. Today is special. They even cancelled their usual end-of-week barbecue, where they cook chicken, sausage and venison burgers.

As they reach 1,000 feet, Billy hollers, "This hole's about to blow!"

Unlike an oil rig eruption, which shoots up into the air, this water hole blows out horizontally, though a giant pipe that's wide enough for two to crawl through.

Right now, that wide pipe is suspended over a mammoth Dumpster. When the rig blows, the pipe will deliver a wallop of highly pressurized slurry, slamming shards of rock into the Dumpster — which should then filter the stone from the water.

Last month, as they passed by narrow rivers that sluice through the bedrock, Black cut through white mica, pink quartz, granite and feldspar. Along the way, they found some pyrite ("fool's gold") and even low-grade ruby.

Some stones are so lovely that Friends' Pat McBee is thinking about selling them to raise funds for the center's upgrade — which includes solar panels and a green roof. (Full disclosure: I contributed.)

The high-speed stone slurry that's about to be upchucked is potentially hazardous. As the rock rushes up 1,000 feet, the big pipe begins to gurgle, and then delivers a long, deep, earthy sneeze — which the Dumpster, fortunately, digests.

It's a success, which means Black and his crew will go home, knowing they can complete this job. Passing this milestone, Black now expects to dig all six holes to their final depth of 1,500 feet in another month, as planned.

Boring into solid bedrock is dangerous, and expensive. The equipment on the site easily costs more than a million dollars. The big red drilling rig alone gulps about 300 gallons of fuel oil every day.

The geothermal portion of the upgrade will cost the center more than $1.3 million. Based on current energy prices, the system is expected to pay for itself in six to eight years.

"It ain't cheap to drill deep," says Billy Black, as he packs up his truck. Still, I expect that Billy and crew will be doing more of this kind of work soon, however dicey and pricey.

Better to dig deep now, than to be buried later.

(bruce@schimmel.com)