Damping device for an output shaft in a gearbox

Dart-operated big bore by-pass valve

Data and/or PowerSwivel

Deep draft drilling platform

Deep drill hammer

Deep hole rock drill bit

Deep vibrator apparatus and method of use

Deep water drilling with casing

Deep water riser system for offshore drilling

Deep water slim hole drilling system

Deep-borehole drilling device with magnetic coupling

Deep-drilling apparatus with hydrostatic coupling

Deepwater drill string shut-off valve system and method for...

Deflection apparatus

Deflection swivel and method

Deformable blades for downhole applications in a wellbore

Delayed phase changing agent for invert emulsion drilling fluid

Deployable sensor apparatus and method

Derrick

Derrick assembly capable of conveying pipe sections between a dr