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Modification of an Electronic Downhole Water Sampler
Author(s) -
Idler Gerald E.
Publication year - 1980
Publication title -
groundwater
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.84
H-Index - 94
eISSN - 1745-6584
pISSN - 0017-467X
DOI - 10.1111/j.1745-6584.1980.tb03645.x
Subject(s) - piston (optics) , needle valve , bevel , seal (emblem) , contamination , petroleum engineering , ball valve , spark plug , check valve , geology , environmental science , materials science , mechanical engineering , engineering , art , ecology , physics , wavefront , optics , visual arts , biology
A common problem with a downhole water sampler consisting of a reservoir for fluids and a remote controlled motor‐operated piston valve assembly has been sample contamination due to damage or destruction of the O‐ring seal on the piston of the sampler. O‐ring damage results from shaving by sharp edges in the entry‐ports area or from erosion by high fluid velocities through the entry ports when sampling at depths below water level greater than 2,500 feet (762 meters). Beveling of sharp edges in the entry ports and modification of the piston by installation of a needle valve and seat solved the problem of O‐ring damage and resultant loss of sample integrity. Other modifications include a high pressure needle valve in the removable reservoir chamber bottom that allows the reservoir to be drained while pressurized, and an O‐ring piston in the reservoir chamber that permits collection of water samples that are essentially free from contamination by surface air. With the latter modifications, the sampler can also be used for injecting brine or other tracers in quantities as large as 34 fluid ounces (1 liter).