Submersible Pump Fills the Bill in Handling Driller's Mud   KZN-Series Submersible Pumps

The Company

West Texas Premix Pits (WTPP) (USA) is a Midland-based surface rental company that manufactures and sells premix pits, trash pumps and safety showers to oil and gas drillers in the Midland-Odessa area. Recently, some of WTPP's clients were looking for an efficient solution for recirculating and reusing the drilling mud necessary for drilling new wells.

The Challenge

Fluids play an integral role in oil and gas exploration and production. When a new well is drilled, some form of fluid is needed. The base of this drilling fluid, or mud, can be freshwater or saltwater (brine) or it may be an oil- or synthetic-based liquid. The type of fluid and the additives used are determined in part based on the composition of the rock being drilled into. Cost and environmental impact are also considerations. The mud may also be modified as drilling progresses and the underground environment changes. The mud serves a number of important functions:

lubricating and cooling the drill bit, thereby extending its life
transporting rock fragments (cuttings) to the surface,
preventing the wellbore from caving in before the casing is inserted, and
preventing the oil or gas from entering the well before it's completed.

Ideally and increasingly, this fluid is recycled during drilling. To facilitate reuse, cuttings are allowed to settle out in a reserve pit and the remaining liquid is pumped back to the wellbore.

As part of its services, WTPP installs and maintains the reserve pits used during oil and gas exploration. The pits are roughly one-acre ponds that hold from two to ten feet of drilling fluid that may be from brine or freshwater. The mud coming up out of the hole with the cuttings is deposited into one side of the pit and allowed to settle out, and the fluid that's reused is pumped out of the other side of the pit.

Not surprisingly, moving all of this liquid requires pumps. And, although they are using a conventional pit configuration, WTPP is has developed a system for floating the pumps on top of the liquid in the pit. WTPP builds specialized baskets to hold the pumps so they're sitting in just six to eight inches of water at the end of the pit away from where the cuttings settle.

"It helps the drilling rig pick up cleaner fluid because the pumps are taking fluid off the top," said Danny Freeman, owner of WTPP. "As the stuff settles out they have cleaner drilling fluid, and that results in faster drilling."

WTPP needed a supply of heavy duty pumps that could operate in reliably under varying conditions and without needing to be completely submerged.