Changes

Noise logs are also used to evaluate fluid movement downhole. Unlike temperature surveys, noise logs are not run continuously across the interval of interest. Instead, a number of stationary readings are taken at different depths downhole. The movement of fluids, especially gasses, generates turbulence or noise, which gets louder as the flow rate or pressure drop increases. [[:file:production-logging_fig2.png|Figure 2]] shows how a noise log can be effective at detecting movement downhole. In this schematic diagram, a source, sink, and restriction to flow are the noise sources. The frequency spectrum of the noise is also observed to further improve the understanding of flow downhole.

Noise logs are also used to evaluate fluid movement downhole. Unlike temperature surveys, noise logs are not run continuously across the interval of interest. Instead, a number of stationary readings are taken at different depths downhole. The movement of fluids, especially gasses, generates turbulence or noise, which gets louder as the flow rate or pressure drop increases. [[:file:production-logging_fig2.png|Figure 2]] shows how a noise log can be effective at detecting movement downhole. In this schematic diagram, a source, sink, and restriction to flow are the noise sources. The frequency spectrum of the noise is also observed to further improve the understanding of flow downhole.

Radioactive tracer surveys use a tool composed of an ejector capable of ejecting shots of radioactive tracer material into the flow stream, usually of an injection well. Such an instrument has either one or two gamma ray detectors spaced below the ejector. By various techniques, the operator chases the ejected radioactive material as it moves with the injected fluid. By noting the position, time, and size of the tracer signal, an accurate overview of the injection profile can be established. Special techniques are also available to detect injected fluid channeling through the cement to undesirable zones. A schematic diagram of a tracer tool is shown in [[:file:production-logging_fig3.png|Figure 3]].

Radioactive tracer surveys use a tool composed of an ejector capable of ejecting shots of radioactive tracer material into the flow stream, usually of an injection well. Such an instrument has either one or two [[Basic open hole tools#Gamma ray|gamma]] ray detectors spaced below the ejector. By various techniques, the operator chases the ejected radioactive material as it moves with the injected fluid. By noting the position, time, and size of the tracer signal, an accurate overview of the injection profile can be established. Special techniques are also available to detect injected fluid channeling through the cement to undesirable zones. A schematic diagram of a tracer tool is shown in [[:file:production-logging_fig3.png|Figure 3]].

[[file:production-logging_fig4.png|thumb|{{figure number|4}}Two types of flowmeters, (a) Full bore flowmeter, (b) Diverting basket type flowmeter.]]

[[file:production-logging_fig4.png|thumb|{{figure number|4}}Two types of flowmeters, (a) Full bore flowmeter, (b) Diverting basket type flowmeter.]]