EP 0174603 B1 19880323 - AZIMUTH-MEASURING METHOD FOR INCLINED BOREHOLES
Title (en)
AZIMUTH-MEASURING METHOD FOR INCLINED BOREHOLES
Publication
Application
Priority
FR 8413764 A 19840907
Abstract (en)
[origin: US4637480A] In a method of measuring azimuth for non-vertical drilling, during rotation of the drill pipe string two components of the magnetic field are measured continuously within a cylindrical section of the drill pipe string. This section is fabricated from the ferromagnetic steel usually employed for fabricating the drill pipes. The two components are measured by a magnetometer and lie along two axes perpendicular to the axis of the section and rotating with it. At the moment when the component of the acceleration due to gravity is maximum along one of these two axes, an accelerometer device commands the calculation and recording of the ratio of the two measured components of the magnetic field. On the basis of the value thus recorded, the measured inclination of the drill pipe string and the local inclination of the magnetic field, the azimuth of the drill pipe string relative to magnetic north is calculated. The method may be used for the continuous determination of the position of a drilling tool during the progress of drilling along a curve.
IPC 1-7
IPC 8 full level
G01C 9/00 (2006.01); E21B 7/04 (2006.01); E21B 47/02 (2006.01); E21B 47/022 (2012.01); G01C 17/02 (2006.01)
CPC (source: EP US)
E21B 47/022 (2013.01 - EP US)
Designated contracting state (EPC)
BE DE FR GB NL
DOCDB simple family (publication)
EP 0174603 A1 19860319; EP 0174603 B1 19880323; BR 8504308 A 19860701; DD 239632 A5 19861001; DE 3561963 D1 19880428; FR 2570120 A1 19860314; FR 2570120 B1 19870925; JP S6171314 A 19860412; NO 853472 L 19860310; US 4637480 A 19870120
DOCDB simple family (application)
EP 85111200 A 19850905; BR 8504308 A 19850906; DD 28040185 A 19850906; DE 3561963 T 19850905; FR 8413764 A 19840907; JP 19750085 A 19850906; NO 853472 A 19850904; US 77372885 A 19850909