Are wells perforated on depth today? ///
In wireline, the issues are remarkably similar to what they have been for decades. Although pipe manufacturing can create nearly identical joints, pipe stretch is well understood and LWD/MWD reduces wellpath uncertainty, the pipe tally is still done manually, and human error can still trump everything else. Thus, the openhole log remains the standard for well depth, and everything is adjusted to it.
Cable stretch is another longstanding issue. Normally, it is compensated for by gradually dialing into the odometer wheel. Cerebus software by CTES is widely used by many of the major wireline vendors. The software can create a stretch chart simply by typing in the factors the cause stretch, i.e., temperature and coefficient of friction. In openhole, this stretch can be gradually dialed out as the logging sonde ascends uphole. However, the software does not account for creep either in cased-hole perforating, openhole sidewall cores or formation testing.
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