Search results
Results from the WOW.Com Content Network
Well logging, also known as borehole logging is the practice of making a detailed record (a well log) of the geologic formations penetrated by a borehole.The log may be based either on visual inspection of samples brought to the surface (geological logs) or on physical measurements made by instruments lowered into the hole (geophysical logs).
It is the most common method of reference for locations in the well, and therefore, in oil industry speech, "depth" also refers to the location itself. Strictly, depth is a vertical coordinate related to elevation, albeit in the opposite direction. However, "depth" in a well is not necessarily measured vertically or along a straight line.
A caliper log is a well logging tool that provides a continuous measurement of the size and shape of a borehole along its depth [1] and is commonly used in hydrocarbon exploration. The measurements that are recorded can be an important indicator of wash-outs, cave ins or shale swelling in the borehole, which can affect the results of other well ...
Other measurements often require separate LWD tools, which communicate with the MWD tools downhole through internal wires. [citation needed] Measurement while drilling can be cost-effective in exploration wells, particularly in areas of the Gulf of Mexico where wells are drilled in areas of salt diapirs. The resistivity log will detect ...
The measurements made must then be corrected for elastic stretch and temperature.[1] There are many types of wireline logs and they can be categorized either by their function or by the technology that they use. "Open hole logs" are run before the oil or gas well is lined with pipe or cased.
Driller's depth measurement is tied to drilling operations and other closely associated activities such as logging while drilling), measurement while drilling, and coring. Driller's depth is always recorded, and it constitutes the primary depth system, unless it is later superseded by a more accurate measurement such as the depth from an open ...
(a) is an imaginary line representing the true vertical depth, while line (b) is the borehole itself, and its length is called the measured depth.. In the oil industry measured depth (commonly referred to as MD, or just the depth) is the length of the drilled borehole. [1]
Measurements include self-potential, natural gamma ray, acoustic travel time, formation density, neutron porosity, resistivity and conductivity, nuclear magnetic resonance, borehole imaging, well bore geometry, formation dip and orientation, fluid characteristics such as density and viscosity and formation sampling.