GWI - 2010Toronto

P.D.C. Bits(Poly Crystalline Diamond Compact)

Presented by: Roger RussellRussell Drilling Co., Inc.

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“A Tool For Predictable Performance.”

The Diamond bit was introduced over 60 year ago by Hughes Tool Company. But until recently it was not easily available to the

Ground Water Industry.

P.D.C. Tools will most likely replace other tools we are currently using, or have used in the past.

∙ Pros – High R.O.P. inexpensive & repairable. Cons – Poor performance on all rocks, increases wear on∙

drilling rig & less likely to have a gauge hole.

“Blade, drag or fishtail type bits normally manufactured in a chevron or step type bit.”

“Claw Type Bit”

• Pros – Inexpensive, field repairable and not likely to wear out.

• Cons – Quick to ball up, very unpredictable performance, poor performance on rocks and takes up space on shop floor.

“Roller Cone Bit.”

• Pros –Very available, new, used, and surplus. Wide price range and a type for every application

• Cons – Moving parts, driller must understand performance & condition of the bit. Must watch for worn or locked bearings and teeth.

Pros for using P.D.C. bits – Widely used in energy exploration with extensive R & D. Extremely predictable performance yielding 30% and higher R.O.P. over roller cone bits with good gauge control, no moving parts. Produces uniform cuttings.

Wide range of manufacturers ,new, used, domestic, import and surplus. P.D.C. cutters are used on many drilling tools replacing traditional carbide tools.

Cons for using P.D.C. bits – Poor performance on rocks 4” or higher on mohs scale like granite & basalt. Easily damaged by impact. Many bits are designed for directional drilling.

P. D. C. bits require good fluid flow to reduce double cutting of rock. Because of the cutting action, less fluid maintenance is

required.

For top performance , mud systems must out perform the rig & bits.

P.D.C. bits can produce rifling in the borehole & cause the bit to back off when tripping pipe not properly torqued.

Increased fluid flow will be necessary to clean the hole. The use of polymers & dispersant will reduce clays from sticking.

“Closing Thoughts.”

“Life is Tough.”

“It is even tougherwhen you’re stupid.”

“Think!”

“My dog Lizzy – Planning for Global Warming!”