In the oil industry measured depth (commonly referred to as MD, or just the depth), is the length of the borehole. In conventional vertical wells, this conincides 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 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.
Famous quotes containing the words measured and/or depth:
“Good critical writing is measured by the perception and evaluation of the subject; bad critical writing by the necessity of maintaining the professional standing of the critic.”
—Raymond Chandler (1888–1959)
“Now as at all times I can see in the mind’s eye,
In their stiff, painted clothes, the pale unsatisfied ones
Appear and disappear in the blue depth of the sky”
—William Butler Yeats (1865–1939)