In the
oil industry measured depth (commonly referred to as MD, or just the depth) is the length of the drilled
borehole.
In conventional vertical wells, this coincides with the
true vertical depth, but in
directional or
horizontal wells, especially those using
extended reach drilling, the two can deviate greatly. For example, at the time of writing (2012) a borehole in Odoptu field,
Sakhalin-I, has the greatest measured depth of any borehole at 12,345 m, but most of this is horizontal, giving it a true vertical depth of only 1,784 m. For comparison, the
Kola Superdeep Borehole
The Kola Superdeep Borehole SG-3 () is the deepest human-made hole on Earth (since 1979), which attained maximum true vertical depth of in 1989. It is the result of a scientific drilling effort to penetrate as deeply as possible into the ...
has a slightly shorter measured depth at 12,262 m, but since this is a vertical borehole, this is also equal to the true vertical depth, making the Kola Superdeep Borehole deeper by a factor of 6.9.
See also
*
Depth in a well
*
True vertical depth
*
Driller's depth
References
Petroleum engineering
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