METHOD DETERMINING DIRECTION OF HOLE ( VERSIONS ) Russian patent published in 1998 - IPC

FIELD: drilling. SUBSTANCE: proposed method determining direction of hole during drilling includes determination of angle θ of inclination and angle ϕ of turn relative to upper side of hole from measurements of acceleration of gravitational force and determination of azimuthal angle ψ from measurements of magnetic field . These angles are determined in coordinate systems XYZ and NEV related to coordinate conversions through angles of Euler. Specifically and are measured at least at two depths of hole so that ϕ_i≠ ϕ_i+1. In this case ψ_i and ψ_i-1 are calculated from B_i= [ϕ_i]^т[θ_i]^т{[ψ_i]^тB_e}+B_p and , where i is number of measurement; is local magnetic field of Earth and is disturbing magnetic field. As result disturbing magnetic fields emerging due to presence of overheated section or due to proximity of steel drill to magnetic elements during drilling or due to closeness of logging string to device measuring B are determined accurately. EFFECT: enhanced accuracy of method. 6 cl, 3 dwg