In addition, Large plugs must be used to separate the cement from the mud and have to be drilled out, along with any cement In the casing.
With stab-in float collar&shoe, the Drill Pipe is stabbed directly into the Float Shoe or Collar and cement is pumped through the drill pipe until returns reach surface.
Cement is then displaced to the bottom of the Drill Pipe a wiper dart can be used. The drill pipe is then picked up, circulated, and pulled out of the hole.
The Stab In Float collar&shoe is used for cementing large diameter casings lowered on drill pipe. The string presents special cementing consideration due to high displacement volume of large diameter casing.
Problem with high displacement are overcome by using Stab in Cementing Equipment to allow cementing through Drill pipe.
Small diameter inner string off drill pipe is used to displace cement which minimizes displacement volume behind Cement and there by reduces contamination and save time
Drill out of cement inside large casing is minimized by controlling cement top with displacement fluid in drill pipe And Plunger valve in Stab in Shoe
Improve displacement accuracy — cement mixing and pumping continues until cement returns reach surface
Get better cement quality — the reduced cement/mud interface area and high velocity of flow in the Drill Pipe Minimize cement contamination while the short pumping time eliminates the need for cement retarders
Reduce cement volume — conventional displacement requires calculation of excess cement factor, whereas with Stab-in methods excess cement need be no greater than the volume of the drill pipe. No large plugs are needed
Reduce net rig time — circulating, pumping, and drill-out times are minimized
Protect casing — cementing pressures are confined to the drill pipe as in a squeeze job
The Stab-in cementing equipment is available in size 5-1/2”-20”
The Stab-in cement Float Shoe & Collar are also available with Double Valve and any combination