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Balanced cement plug is pumped through drill string or open-ended tubing. 'Balanced Cement Plug' means that the top of cement outside the drillstring/ tubing will be the same height as the top of cement inside the drillstring at the end of pumping. The drillstring/ tubing is then slowly pulled from the wet cement, allowing the cement inside the string to fill the centre of the plug. There are lots of refinements in this method with open hole cement retainers or high viscosity 'cushions' often placed below cement. In vertical hole, most balanced plugs are successful. In extended reach wells, failure rates can be high with cement slumping and mixing with synthetic based muds. A typical checklist to improve cement plug success in extended reach wells would have: 1. Always use a tailpipe. This reduces the disruption to the plug caused by removal of the drillstring. 2. Clean up the hole thoroughly before pumping cement. Cement is an excellent hole cleaner. Many 'flash set' events reported are really packoffs caused by cement picking up a cuttings dune. 3. Put a diverter tool with BIG holes on the bottom of the tailpipe. This directs fluids up the hole during cementing 4. Use a scavenger spacer in front of the cement job to convert the formation from oil wet to water wet. 5. Slow down pumping to 1 BPM while displacing cement into open hole. This reduces mixing of cement and mud. 6. Put a cushion below the cement plug. A cement retainer is best. If a viscous cushion is spotted, weight the cushion to 1 ppg below the cement weight. 7. Gravity is NOT on your side. Cement can stay inside the tail pipe as you pull it from the plug. Pump the volume of cement inside the tailpipe as you pull the tailpipe from the plug. 8. Circulate clean the long way with the bottom of the tailpipe at the planned cement plug top.
Through the power cord that you plug into the wall.
Essentially you're pumping down a mechanical plug that will rest on the lower plug in the float collar. Once the upper plug is seated on the lower plug, there is no longer a flow path for the fluid to go through, resulting in the pressure spike (the "bump").
Most hydraulic ram cylinders should have a refill plug about half way up the barrel. 1) Position the cylinder vertically, and collapse the ram all the way down. 2) With the plug pulled out, fill the cylinder with hydraulic jack oil until it drips out the plug hole. 3) All done. Place the plug back in and test the functionality.
A butt weld is a weld made between two straight cut profiles , a socket , or plug weld is made between a surface and a hole.