Recovers accurate samples from soft rock, friable shales and problem clays
The Pitcher Sampler is designed specifically to recover accurate samples from formations that are too hard for thin-wall shelby samplers or too brittle, soft or water-sensitive to permit satisfactory recovery by conventional core barrel type samplers. Several years of successful application in virtually every type of “problem” formation prove that the Pitcher Sampler saves time, saves money…insures exceptional accuracy.
- Heavy-duty, triple ball-bearing hanger is sealed 4-ways against drilling fluid to prevent freeze-ups and insure long, trouble free service.
- No more crumpled shelby tube; no presetting, no surface control needed. Spring-seated tube telescopes into cutter barrel as formation hardness increased.
- Sliding valve directs drilling fluid through shelby tube to hole bottom for thorough flushing action, then automatically diverts fluid from tube when tube contacts bottom.
- Hole remains full gauge…no reaming needed.
- Drilling fluid can’t undercut shelby tube and erode or contaminate sample even in softest materials.
- Samples dry or saturated material with equal speed, ease and accuracy. No core lifter is needed to protect or retain sample.
- Sample all materials- including soft rock -from top to bottom of hole.
- Shelby tubes can be changed in less than 45 seconds.
- Drill can be stopped, rod re-chucked (even raised slightly) without breaking core.
…a tool that relieves you from the limitations of core barrel type samplers.
How it works
Sampler enters hole (Fig. 1). Sliding valve directs drilling fluid through shelby tube to hole bottom for thorough pre-flushing action. The instant shelby tube touches bottom (Fig. 2), it telescopes into cutter barrel to close sliding valve which automatically diverts fluid to annular space between shelby tube and cutter barrel. For remainder of soft formation sampling operation, drilling fluid can’t touch sample, yet high fluid velocity is maintained at cutting bit to clean hole and insure rapid cutter penetration.
In softer materials (Fig. 2), shelby tube leads cutting bit by as much as 6” to eliminate chance contact between drill fluid and sample. Amount of lead is regulated entirely by material hardness. If formation increases in hardness, shelby tube telescopes into outer barrel and compresses spring which, in turn, exerts greater force on tube to insure adequate lead. In harder formations (Fig. 3), cutter may lead shelby tube by as much as 1/2” to core out sample.
A sample loaded shelby tube can be removed (Fig. 4), an empty tube attached, and sampler started down-hole again…all within 45 seconds. There’s no fumbling, no danger of losing tube screw. Hex-headed screw turns “in” to release tube; turns “out” to lock tube securely in place.
|Sample Tube Length