Primary Cementing Flashcards
What is Primary Cementing
The introduction of a cementitious material or cement slurries into the annulus between casing and open hole or previous casing or both
Objetives for primary Cementing
Provide zonal isolation
Protect the casing string against corrosion
Support axial load of casing strings and strings to be run later
Support the borehole
Meet government regulations
The size of the casing depends on
The depth of the well
The size of the open hole
The drilling objective
The expected hydrostatic and formation pressures
The type of completion once the well is drilled.
Types of Casings
Conductor Surface Intermediate Production Casing Liners and Tie-Backs
Conductor Casing Purpose
Prevents washing out under the rig
Provides elevation for flow nipple
Protects shallow sands from contamination
Advantages of stab in cementing
Less cement contamination Less channelling Small displacement volume Pump until cement to surface Less job time (rig time) Less cement
Outside Cementing (Top Job) key points
Bring cement to surface Macaroni tubing used Max. depth 250-300 ft High friction pressures Non-standard connections
Surface Casing purpose
Protect surface fresh water formation
Case off unconsolidated or loss areas
Provide a competent mechanical base for subsequent operations (BOP, casings, etc.)
The BOP Stack parts
Anular preventer Blind rams Shear rams Pipe rams Kill line Choke line
Intermediate Casing(s) purpose
Isolate hole into workable sections
Seal off nonproductive, high-pressure zones above the zone of interest.
Two Stage Cementing key points
Separation and isolation of zones
Reduces hydrostatic
Can leave zone in the annulus uncemented (cement at TD and surface)
Production Casing(s) or Liner(s) purpose
Isolates the pay zone from other formations and the fluids in them.
Protective housing for production equipment.
Subsurface artificial lift
Multiple zone completion
Screens for sand control
Identification of casing
OD Weight Grade Burst pressure Collapse pressure Thread type
Thread Types
8 Round
Buttress
VAM
Hydrill
Basic Cementing Process
Use the two-plugs method for pumping and displacement cement slurry down through the casing and up the annulus.
Process is completed when a pressure increase at the surface and displacement is terminated.
Leave the well shut in for a time to allow the cement to harden before completion work or drilling out