Method for measurement of azimuth of a borehole while drilling

Patent · Tue Mar 21 00:00:00 EST 1989

OSTI ID:5953908

DiPersio, R D; Cobern, M E

A method is described for determining the azimuth angle of a borehole being drilled by instruments contained downhole in the drillstring, including the steps of: sensing with accelerometer means, during a period of nonrotation of the drillstring, the components of Gx, Gy and Gz of the total gravity field Go at the location of the instrument; sensing with magnetometer means, during a period of nonrotation of the drillstring, the components of Hx, Hy and Hz of the total magnetic field Ho at the location of the instrument; the components Gz and Hz being along the axis of the drillstring, the components Gx and the components and Gy being orthogonal to Gz and the components Hx and Hy being orthogonal to Hz; rotating the magnetometer means with the drillstring and obtaining the parameter Hzr which is the Hz component of the magnetic field at the location of the instrument during rotation of the drillstring; determining Ho from values Hx, Hy and Hz sensed during nonrotation of the drillstring; determining the inclination angle of the drillstring; determining the dip angle of the magnetic field; determining the angle between the direction of the magnetic field and the axis of the drillstring at the location of the instrument from Ho and Hzr; and determining the azimuth angle.

• Assignee: Teleco Oilfield Services, Inc., Meriden, CT
• Patent Number(s): US 4813274
• OSTI ID: 5953908
• Resource Relation: Patent File Date: Filed date 27 May 1987
• Country of Publication: United States
• Language: English

Related Subjects

02 PETROLEUM
03 NATURAL GAS
DIRECTIONAL DRILLING
METERING
NATURAL GAS WELLS
OIL WELLS
ACCELEROMETERS
CALCULATION METHODS
DRILL PIPES
INCIDENCE ANGLE
MAGNETOMETERS
ORIENTATION
DRILLING
DRILLING EQUIPMENT
EQUIPMENT
MEASURING INSTRUMENTS
PIPES
WELLS
020300* - Petroleum- Drilling & Production
030300 - Natural Gas- Drilling
Production
& Processing