WELL FLUID PRODUCTION PROFILING USING AN OXYGEN ACTIVATION FLOW METER

摘要

1505437 Measuring flow-rate of water in borehole TEXACO DEVELOPMENT CORP 6 Oct 1976 [3 Nov 1975] 41439/76 Heading G1A The volume flow-rate of undesired water flow within the casing 102 of a borehole which has entered via perforations 106 in the casing is measured by the use of neutron activation analysis apparatus comprising a pulsed source 126 of fast neutrons and longitudinally spaced detectors D 1 , D2, the source causing activation of oxygen nuclei to form unstable nitrogen NSP16/SP the gamma radiation decay from which is detected. The ratio of the counts from the two detectors is used to determine v, the velocity of the water flow. An expression is provided which illustrates how the count-rate for a detector depends on v, and on the volume flow V, amongst other quantities which are all known dimensions or constants. The volume flow is calculated from V = vF where F is the known cross-sectional area of the casing. The apparatus used is substantially identical to that described in Specification 1505446.