| Pass |
A sequence during a log, where the toolstring is moved either up or down, and data collected. A production log may consist of many passes at different tool speeds and/or flow rates. |
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| Payzone |
Rock in which oil and gas are found in exploitable quantities. |
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| Perforations |
Holes made through steel casing into the formation, to allow fluids to flow from the formation into the casing. The location of the perforations may then be identified by running a CCL log. |
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| Permeability |
The property of a formation which quantifies the flow of a fluid through the pore spaces and into the wellbore. |
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| Permittivity |
One of the physical parameters of a medium, determining its ability to store electrical energy in an electric field, and equal to the ratio of the electric flux density to the electric field strength at any point. |
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| Petroleum |
A generic name for hydrocarbons, including crude oil, natural gas liquids, natural gas and their products. |
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| PGR |
Gamma Ray Tool. Measures incident gamma radiation, for example for depth correlation and identification of radioactive scale. |
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| Phase |
In the context of oil wells: oil, gas or water. Two phase: a mixture of oil/water, gas/water or gas/oil. Three phase: a mixture of gas/oil and water. |
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| Photomultiplier |
A light amplifier, used with a scintillation crystal to detect gamma rays. |
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| PKJ |
Knuckle Joint: a deployment device allowing flexibility between tools in a toolstring. |
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| Platform |
An offshore structure that is permanently fixed to the seabed. |
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| PLP |
Production Logging Panel. Provides tool power and signal decoding for Sondex surface readout production logging tools. |
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| PMT |
Photomultiplier tube. Forms part of the Sondex PGR tool which measures incident gamma radiation. |
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| PNT |
Production Neutron Tool. An electronics section with source sub attached, the tool can be used at the bottom of a toolstring to ascertain the presence of gas and determine mineralogy and shaliness. |
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| POOH |
Pull Out Of Hole. |
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| Porosity |
The percentage of void in a porous rock compared to the solid formation. |
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| Possible reserves |
Those reserves which at present cannot be regarded as 'probable' but are estimated to have a significant but less than 50% chance of being technically and economically producible. |
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| Potentiometer |
An electrical device or circuit to reduce voltage by a known factor. |
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| PRC |
Roller Centraliser: a device with spring-loaded arms, fitted with rollers to reduce friction, designed to ensure centralisation of all or part of a toolstring, |
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| Primary recovery |
Recovery of oil or gas from a reservoir purely by using the natural pressure in the reservoir to force the oil or gas out. |
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| Printrex plotter |
A brand of continuous paper thermal printer, used to present log results. |
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| Probable reserves |
Those reserves which are not yet proven but which are estimated to have a better than 50% chance of being technically and economically producible. |
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| Production Logging |
The process of acquiring and analysing data from a producing well, in order to assist oil companies to enhance or control production, or find problems. |
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| Proven field |
An oil and/or gas field whose physical extent and estimated reserves have been determined. |
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| Proven reserves |
Those reserves which on the available evidence are virtually certain to be technically and economically producible (i.e. having a better than 90% chance of being produced). |
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| PRT |
A Tool which measures the temperature of the wellbore. |
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| PSI |
Pounds per Square Inch, a unit of pressure. |
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