... Horizontal drilling — in which the drill bit is manipulated so that it cuts at an angle until it runs level through oil-bearing rock — isn't new. Nor is fracking, short for fracturing, where water and sand are pumped down a well at high pressure to fracture oil-bearing rock and improve flow.
But the two together, along with further refinements, can dramatically improve the amount of oil collected from formations.
South of Medicine Lodge, Woolsey just finished a horizontal well.
The special crews brought in used advanced technology and long experience to steer the drill bit into the relatively thin layer oil-bearing rock 4,700 feet down and then stayed in that layer for 4,000 feet.
After the hole was drilled, the frack was done by a large crew running a fleet of powerful pumper trucks that forced 4,200 gallons a minute of water — enough to fill an average swimming pool in eight minutes — plus sand and a small amount of potassium chloride. The fluid, pushed through holes in 30-foot to 80-foot sections of the steel pipe, cracked the rock at the edge of hole. The sand is forced into the cracks to hold them open. ...