Primary Casing Cementing Flashcards
What is open hole completion
When casing is suspended and cemented above the producing zone
What are other names for production casing
Long string, flow string, oil string, production string
What is minimum compressive strength for cement before drilling out
500 psi
Conservation Laws state that a minimum Waiting On Cement (WOC) must be take place. What is that time?
72 Hours
What does WOC mean
WOC is non-productive time waiting on cement to develop strength and bond the casing in the hole
The final casing string is referred as
Flow string, long string, oil string, production string
Why would we pump cement in two, three, or four stages
To decrease the hydrostatic pressure of the fluid column in the annulus, help protect weak zones against high pressure, and help prevent lost circulation
What primary technique do we use for cementing
single-stage primary cementing job using the two plug displacement method
What is the Primary Purpose for Cementing Casing
Zonal isolation (Isolate wellbore in fresh water zones), Casing protection against corrosion, burst, collapse, and drilling shocks
The proper performance of the hydraulic seal achieves the following
Excludes unwanted fluids from the production stream, confines stimulation treatments to the producing formation, assures integrity of the casing shoe for well control, exercises control over the production formation, prevents contamination of freshwater aquifers by formation fluids
Set cement must develop sufficient mechanical strength to
Prevent fracture or shatter when perforated, provide casing support, absorb shock of the drill collars when drilling out, prevent casing buckling, support the formation
What purpose does conductor casing serve
- Serves as a conduit for raising circulating fluid high enough to return to the pit
- Supports part of the wellhead load where the ground support is inadequate or where the well is going to be drilled to an extreme depth.
- Prevents washing out under rig
- Confines circulating fluids
Is a BOP stack attached to the conductor casing
No
What is the depth range for conductor casing
20 to 1,500 ft.
What are the ranges for conductor casing size
16 inch to 30 inch