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...There is no generic difference between a "continuous" ...spinner and a "...spinner. In the case of the ...
There is no generic difference between a "continuous" spinner and a "fullbore" spinner. In the case of the fullbore, the spinner element folds into a diameter no greater than that of the tool when in the tubing, but expands into a larger diameter for surveying in the casing. The continuous spinner does not have this capability. The difference between the two is too small to justify a separate discussion of each. The continuous meter derives its name from the need to move the tool fast enough to overcome frictional torque and start the spinner element rotating. It also derives its name from the in-situ calibration procedure that uses logging runs at several different cable speeds with the well shut-in at the surface. Neither continuous nor fullbore, however, can provide a log that is quantitative whenever the fluid velocity is sporadic, that is, changing in the logged interval. The spinner element can rotate either clockwise or counterclockwise (as viewed down the tool barrel). The direction of rotation depends upon the movement of the fluid relative to the barrel of the tool, that is, upon the direction of fluid movement as seen by "rider" on the tool.
...Diverting-spinner flowmeters are the most accurate of the ...spinner devices when low total rates and multiphase flows occur. The stream is diverted through the tool's ...results in a velocity of 3.4 ft/min inside the barrel. Because of the limited clearance between the spinner and the barrel, this velocity is enough to overcome friction and turn the ...
Diverting-spinner flowmeters are the most accurate of the spinner devices when low total rates and multiphase flows occur. The stream is diverted through the tool's barrel, thereby raising the velocity of flow and increasing the sensitivity to the point that diverting spinners can detect rates as low as 10 to 15 B/D. Because of the limited clearance between the spinner and the barrel, this velocity is enough to overcome friction and turn the spinner. Furthermore, a flow of 100 B/D passes through the barrel at 34 ft/min, which is sufficient to start the homogenization of the flow, which eventually eliminates phase influence. In casing, a rate of 2,000 B/D is needed to have the same effect around a continuous spinner.