- Industry: Oil & gas
- Number of terms: 8814
- Number of blossaries: 0
- Company Profile:
A map that displays the degree of correlation between wells as a vector that points from one well to another, the length of the vector being related to the degree of correlation from a correlogram. These maps are used in automatic correlation of well logs across a field and indicate where formations are continuous or are terminated. <br><br>Reference:<br><br>Poelchau HS: 鈥淐oherence Mapping - An Automated Approach to Display Goodness-of-Correlation Between Wells in a Field,鈥?Mathematical Geology 19, no. 8 (1987): 833-850.
Industry:Oil & gas
A mark or marker applied to a sand line or similar wire rope to indicate a specific depth or as a means of indicating the end of the line is nearing surface during retrieval. The term may also be used for magnetic or physical marks applied to wireline or coiled tubing strings.
Industry:Oil & gas
A marine flooding surface separating the underlying lowstand systems tract from the overlying transgressive systems tract. Typically, this is the first major flooding surface following the lowstand systems tract.
Industry:Oil & gas
A magnetic mark placed on a logging cable as a reference for depth measurements. The marks are placed on the cable at regular intervals, usually 100 ft (30 m) or 50 m (164 ft), under a certain tension in a workshop. The intervals may change slightly as a function of tension downhole, but this change can be corrected for. During logging operations, the marks are detected by a magnetic mark detector, and then used to check and correct the depth read by the depth wheel.
Industry:Oil & gas
A low-volume fluid pump with controllable discharge rate used to inject chemical additives to the mixing or pumping system. Dosing pumps frequently are used to inject fluids that may be difficult to mix efficiently in batch-tank systems because of their low volume.
Industry:Oil & gas
A long cable, installed on most drilling and workover rigs, used when swabbing or bailing in the production tubing or wellbore tubulars. The sand line is typically stored and operated on a winch drum that is part of the rig drawworks. The sand line is capable of significantly higher tensile forces than slickline or electric wireline.
Industry:Oil & gas
A logging tool based on an arrangement of simple metallic electrodes working at low frequency (less than 500 Hz). The term includes conventional electrical logs, laterologs, micrologs and other microresistivity logs. Electrode devices are used for both wireline and measurements-while-drilling logs. In all electrode devices, a current (I<sub>O</sub>) and a voltage (V<sub>O</sub>) are measured on the appropriate electrodes or combinations of electrodes. The apparent formation resistivity is then determined by:<br><br> R<sub>a</sub> = K V<sub>O</sub> / I<sub>O</sub>, where K is a system constant for the device concerned.
Industry:Oil & gas
A log with a depth scale chosen to show sufficient detail of the formation. The most common scales are 1/200 or 5 in. /100 ft.
Industry:Oil & gas
A logging instrument capable of making relative gravity measurements at stations along the borehole with a sensitivity and repeatability in the microGal range (about 1 part in 10<sup>-9</sup> of the Earth's gravity field)<br><br>The only commercial measurement device capable of this precision is the LaCoste & Romberg borehole gravimeter, although several research projects have been proposed to replace this classic technology.
Industry:Oil & gas
