Casing and Cement Quiz Flashcards
what are the 4 types of casing?
conductor, surface, intermediate and production
what are the 4 main criteria for casing design?
- Selection of casing grades
- Selection of casing size
- Setting Depth
- Fracture gradient
what are the 3 types of threads?
short rounded, buttress, extreme line
what is a LOT and what is it used for?
Leak Off Test and it is used to find formation strength
what is a FIT and what is it used for?
Formation Integrity Test and is used to test formation and shoe strength
what pressure is P-110 casing rated for?
110,000 psi
what are the 3 functions of casing?
prevention, isolation and support
what is cement slurry?
cement, water and additives
what are the primary forces on casing?
burst (internal pressure greater than external) and collapse (external pressure greater than internal)
what are secondary forces on casing?
buckling, bending, axial compression and torque
what are the 3 conditions casing must be able to withstand?
tension, burst and collapse
what are 3 casing failure mechanisms?
corrosion, shear and collapse
how do you calculate a pressure gradient?
=pressure/depth
what are considerations when it comes to casing set depth?
geological information, offset well data, hole section summaries and pore pressure/fracture gradient
what is a liner?
casing strings that do not extend to surface
know how to use formulas
duh
what are the 4 pipe collapse calculations?
yield strength pressure, plastic pressure, transition pressure and elastic pressure
what are the 5 physical properties of cement?
slurry density, yield, thickening time, compressive strength, and additives
what is the difference between primary and secondary cement?
primary is initial cement pumped downhole, and secondary is repair cement
name 5 of the 9 pieces of equipment used for a cement job
cementing head, centralizer, scratcher, float collar, float shoe, bottom plug, top plug
what does the cement physically do?
bonds the casing to the formation
what is the most popular class of cement?
Class G: surface to 2438m (can be used with accelerators and retardants)
what classes of cement are best for HPHT
Class J
what are the 2 slurry properties?
specific gravity and absolute+bulk volume
what is the factor for finding dry weight of cement? water?
dry cement=slurry volume/0.76
water needed=slurry volume x 0.44
