What are the differences between casing and tubing in general?

Casing is generally a steel pipe installed in wellbore and is cemented in place to prevent Wellbore collapse, cross flow of fluids between different reservoirs and to control abnormal formation pressures. Tubings are usually run inside casing (cased hole) and serves as a conduit through which oil and gas is produced. It is basically a tube inside casing which is used to produce reservoir fluids.

You don't cement the tubing, you can take it out whenever you want.

Casing pipes are used to protect the well from the rubble either tubing used for the purposes of many of us pumping nitrogen

Casings  usually from20" to7" which are run after drilling hole size of24",171/2" ,121/2" and81/2"  after running casing string cementing job is done to make a cement barrier for zonal / reservoir isolation so that channeling of reservoir fluid may be prevented. Casing is very necessary for smooth drilling operations in deep and ERD wells so that hole collapsing may be got rid of.

 

Tubings are run after drilling. Tubings are of51/2 to23/8" in well completions to safe and cost effective maintenance of wells in production phase of well.  Thru tubing we safely and efficiently produce wells according to reservoir volume and nature.

 

Regards

A SATTAR

E (PRODUCTION)-PPL