Changes

* In EOR projects, maintaining injection efficiency by evaluating the injection profiles of individual wells in a field

* In EOR projects, maintaining injection efficiency by evaluating the injection profiles of individual wells in a field

Production logs include (1) those designed to detect flow in and around pipes (temperature, noise, radioactive tracer, flowmeter, and fluid identification logs) and (2) those designed to evaluate flow quantitatively. Often combinations of these logs are required to be effective<ref name=pt09r22>Schlumberger,, 1989, Cased hole log interpretation principles/applications: Houston, TX, Schlumberger Educational Services, Document No. SMP-7025.</ref><ref name=pt09r3>Atlas Wireline Services, 1986, Interpretative methods for production well logs, 3rd ed.: Houston, TX, Document No. 9441.</ref><ref name=pt09r23>Society of Petroleum Engineers, 1985, Production logging: Richardson, TX, SPE Reprint Series No. 19.</ref>.

Production logs include (1) those designed to detect flow in and around pipes (temperature, noise, radioactive tracer, flowmeter, and fluid identification logs) and (2) those designed to evaluate flow quantitatively. Often combinations of these logs are required to be effective.<ref name=pt09r22>Schlumberger,, 1989, Cased hole log interpretation principles/applications: Houston, TX, Schlumberger Educational Services, Document No. SMP-7025.</ref><ref name=pt09r3>Atlas Wireline Services, 1986, Interpretative methods for production well logs, 3rd ed.: Houston, TX, Document No. 9441.</ref><ref name=pt09r23>Society of Petroleum Engineers, 1985, Production logging: Richardson, TX, SPE Reprint Series No. 19.</ref>

===Flow detection in and around pipe===

===Flow detection in and around pipe===

The most effective technique with radioactive tracers is the ''velocity shot'' technique, illustrated in [[:file:production-logging_fig3.png|Figure 3]]. The tool is stationary during such a test, and the gamma count rate is recorded at the surface. In [[:file:production-logging_fig3.png|Figure 3]], tests were made above, between, and below the perforations, and the surface recordings are shown to the right of the well sketch. The highest velocity and flow rate are recorded above the perforations, while zero flow is detected in the lowest interval. By measurement of the traveltime between detectors, Δt, and using the known spacing between detectors D₁ and D₂, the flow rates can be calculated and an injection profile constructed, as shown on the right of the figure.

The most effective technique with radioactive tracers is the ''velocity shot'' technique, illustrated in [[:file:production-logging_fig3.png|Figure 3]]. The tool is stationary during such a test, and the gamma count rate is recorded at the surface. In [[:file:production-logging_fig3.png|Figure 3]], tests were made above, between, and below the perforations, and the surface recordings are shown to the right of the well sketch. The highest velocity and flow rate are recorded above the perforations, while zero flow is detected in the lowest interval. By measurement of the traveltime between detectors, Δt, and using the known spacing between detectors D₁ and D₂, the flow rates can be calculated and an injection profile constructed, as shown on the right of the figure.

In producing wells, spinner flowmeters are used to measure the bulk flow rate, even in multiphase flow conditions<ref name=pt09r2>Anderson, R. A., Smolen, J. J., Laverdiere, L., Davis, J. A., 1980, A production logging tool with simultaneous measurements: Journal of Petroleum Technology, February, p. 191–198.</ref>. Two such flowmeters are shown in [[:file:production-logging_fig4.png|Figure 4]]. The ''full bore flowmeter'' in [[:file:production-logging_fig4.png|Figure 4(a)]] is run continously across the interval of interest, while the basket type flowmeter in [[:file:production-logging_fig4.png|Figure 4(b)]] uses stationary measurements. Although these devices can determine the bulk flow rate, fluid identification tools are required to evaluate the kinds of fluids present in the flow. These fluid identification instruments measure the pressure gradient, bulk density, or capacitance of the flowing mixture. The flowmeter and fluid identification devices are usually run as a combination on the same tool string. Results typical of such a tool string are shown in [[:file:production-logging_fig5.png|Figure 5]]. In this example, zone A produces water, while the zones above it are all gas producers. A plug set between zones A and B will be effective at eliminating the water production in this example.

In producing wells, spinner flowmeters are used to measure the bulk flow rate, even in multiphase flow conditions.<ref name=pt09r2>Anderson, R. A., Smolen, J. J., Laverdiere, L., Davis, J. A., 1980, A production logging tool with simultaneous measurements: Journal of Petroleum Technology, February, p. 191–198.</ref> Two such flowmeters are shown in [[:file:production-logging_fig4.png|Figure 4]]. The ''full bore flowmeter'' in [[:file:production-logging_fig4.png|Figure 4(a)]] is run continously across the interval of interest, while the basket type flowmeter in [[:file:production-logging_fig4.png|Figure 4(b)]] uses stationary measurements. Although these devices can determine the bulk flow rate, fluid identification tools are required to evaluate the kinds of fluids present in the flow. These fluid identification instruments measure the pressure gradient, bulk density, or capacitance of the flowing mixture. The flowmeter and fluid identification devices are usually run as a combination on the same tool string. Results typical of such a tool string are shown in [[:file:production-logging_fig5.png|Figure 5]]. In this example, zone A produces water, while the zones above it are all gas producers. A plug set between zones A and B will be effective at eliminating the water production in this example.

==Mechanical integrity logs==

==Mechanical integrity logs==