Direction and angle maintenance tool and method for adjusting and maintaining the angle of deviation of a directionally drilled borehole

Patent · Tue Jan 27 04:00:00 EST 1987

OSTI ID:6822879

Welborn, A E

This patent describes a direction and angle maintenance tool for drilling directionally oriented boreholes, comprising: (a) a mandrel having a longitudinal bore, an upper end attachable to a rotary drill pipe, a lower end attachable to a rotary drill bit sub and a reduced diameter section; (b) a sleeve, rotatably attachable around the reduced diameter section of the mandrel, the sleeve having an eccentric longitudinal bore forming a weighted side, and a gauge insert which is longitudinally and fixedly attached to the weighted side the longitudinal bore being of sufficient diameter to allow free relative rotation between the mandrel and the sleeve and (c) a means, attachable to the sleeve and the insert, for longitudinally and fixedly attaching the gauge insert to the sleeve on the weighted side. A method is described for adjusting and maintaining the angle of deviation of a directionally drilled borehole, comprising the steps of: (a) attaching between a drill string and a drill bit a direction and angle maintenance tool; (b) attaching to the sleeve on the weighted side the gauge insert of a particular thickness so as to achieve a desired deviation from vertical; (c) lowering the drill string, the tool and the bit into a borehole; and (d) rotating the drill string relative to the tool and drilling to a desired depth at the desired deviation from vertical.

• Assignee: NOV; EDB-87-053211; NOV-87-046584
• Patent Number(s): US 4638873
• OSTI ID: 6822879
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
020300* -- Petroleum-- Drilling & Production
03 NATURAL GAS
030300 -- Natural Gas-- Drilling
Production
& Processing
42 ENGINEERING
420206 -- Engineering-- Mining & Drilling Equipment & Facilities-- (1980-1989)
BOREHOLES
CAVITIES
CONTROL EQUIPMENT
DEPTH
DIMENSIONS
DIRECTIONAL DRILLING
DRILL BITS
DRILL PIPES
DRILLING
DRILLING EQUIPMENT
DRILLS
EQUIPMENT
INCIDENCE ANGLE
MEASURING INSTRUMENTS
NATURAL GAS WELLS
OIL WELLS
PIPES
ROTARY DRILLS
WELLS