公开(公告)号：US3896412A

公开(公告)日：1975-07-22

申请号：US41744573

申请日：1973-11-19

Applicant: TEXACO AG

Inventor： ROHR ULRICH

IPC: E21B47/022 ,  G01V3/34 ,  G01V1/40 ,  G01C9/14

CPC classification number: E21B47/022 ,  G01V3/34

Abstract: The course of a borehole is determined by sending a logging tool down the borehole containing apparatus for measuring an angle of inclination phi and an azimuth angle theta . The signals are transmitted to surface electronics which also receives a signal corresponding to the rate dl/dt of descent of the logging tool into the borehole. A cartesian coordinate system having a reference point at the mouth of the borehole has three coordinates axis perpendicular to each other and identified as AN. AO and TV. The TV axis extends in a vertical direction, the AN axis extends in a horizontal northerly direction and the AO extends in a direction 90* from the AN and TV axial direction. The surface electronics is computer type apparatus which continuously converts the signals corresponding to the angle phi and theta and to the rate dl/dt to a point defining the position of the logging tool at the instant of measurement. As each point is recorded as the logging tool moves through the borehole, a record is made of the course of the borehole. The apparatus and method of the invention also provide for discontinuous operation either at the surface or in the transmission of signals of the logging tool.