Drill bit having a failure indicator

Patent · Tue Oct 22 04:00:00 EDT 1985

OSTI ID:5700036

Daly, J E; Pastusek, P E

A drill bit comprising a bit body detachably secured to a drill string having a chamber therein to receive drilling fluid at a first pressure from the drill string, a nozzle for exit of the drilling fluid to the space between the bit body and the well bore at a second pressure lower than the first, and a depending leg; a roller cutter; a bearing assembly for rotatably mounting the roller cutter on the leg; a lubrication system in the bit body comprising a reservoir of lubricant, passaging for flow of lubricant from the reservoir to the bearing assembly, a seal member for blocking flow of lubricant out of the bit, an expansible chamber for pressurizing the lubricant to a third pressure greater than the second but less than the first, and a biased diaphragm for pressure compensation secured in a recess in the bit body in fluid communication at one side thereof with the lubricant and at the other side thereof with the drilling fluid in the space between the bit body and the well bore; and a sensor for sensing a decrease in the pressure of the lubricant below a predetermined level and operating to cause a signal indicating the decrease in lubricant pressure to be generated at the drill rig, whereby upon loss of the lubricant in the lubricant system a signal indicating such loss will be provided at the drill rig.

• Assignee: Reed Rock Bit Company
• Patent Number(s): US 4548280
• OSTI ID: 5700036
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020300* -- Petroleum-- Drilling & Production
03 NATURAL GAS
030300 -- Natural Gas-- Drilling
Production
& Processing
CONTROL
DESIGN
DRILL BITS
DRILL PIPES
DRILLING EQUIPMENT
DRILLING FLUIDS
EQUIPMENT
FLUID MECHANICS
FLUIDS
GEARS
HYDRAULICS
LOSSES
LUBRICANTS
LUBRICATION
MACHINE PARTS
MECHANICS
MONITORING
NOZZLES
PIPES
PRESSURE CONTROL
PRESSURIZING