Slippage Past Plungers

In slippage past a closely fitted plunger, the flow between the  plunger and the barrel is in the viscous range, so leakage or slippage is inversely proportional to the absolute viscosity and to the plunger length. Technical Data used in the field explained in petroleum courses in Rawalpindi. It is directly proportional to the plunger diameter, the differential pressure between the two ends of the plunger, and the cube of the diametric clearance.

The absolute viscosity of well fluids commonly pumped will range from approximately 1 to 100 cp at temperatures existing at the pump setting. In some cases the viscosity may be as high as 1,000 cp. As a result of viscosity variations, the slippage past the plunger of a particular plunger-pump assembly with a given plunger fit, length, and diameter may vary by as much as 100 to 1 under fairly common conditions. and as much as 1,000 to 1 under extreme conditions with the same differential pressure across the plunger. Some more details of petroleum courses in rawalpindi are as under.

Thus it is seen that a plunger pump may operate with acceptable efficiency in a well producing a highly viscous oil, whereas the same pump operated at the same speed and stroke may fail to deliver any oil to the surface when installed at the same depth in a well producing oil of low viscosity.

If we assume that the volume of the barrel below the plunger is completely filled during the upstroke, this rate of leakage can occur only during the upstroke, or approximately one-half of the total time. The net slippage past the plunger is 5.72 cu in./min, or 0.85 B/D. The displacement of a 21/4-in. pump operating at fifteen 48-in. strokes per minute is 426 BID, and the slippage in this case is only about 0.2%, which is insignificant. The results of this and other plunger clearances with 3-cp oil. TSK Training for Skills and Knowledge is the best institute in Rawalpindi Islamabad for Pakistani Students who wants to join oil field after petroleum courses in islamabad.