Global Urban Symposium

Archive for January, 2012

Casing pipe is a pipe with a large diameter. It is generally inserted into a borehole and normally held into place using cement. Placing a casing pipe in a borehole aids the drilling process in so many ways. The first purpose of putting a casing pipe includes the prevention of unstable upper formation of large caverns. Another is to seal off high pressure zones from the surface to avoid potential blowout. The third purpose of using casing pipe is to avert the contamination of fresh water well zones. Casing pipe provides a strong upper foundation for deeper drilling. It also isolates the different pressures or fluids of different zones and prevents fluid loss into production zones.

There are different casing intervals commonly used in oil and gas well. First in the list is the conductor casing wherein a casing pipe serves a support during drilling operations. In conductor casing collapse of loose oil is prevented and there is a flowback returns during drilling and cementing of the surface casing.

The second used interval is the intermediate casing which is a must in longer drilling. This is used to avoid blowouts that may cause hydrostatic pressure which may result to deeper formations. Next is the surface casing which main function is to isolate fresh water zones from any form of contamination during the drilling process and completion. The common size of a surface casing is 13 3/8 inches and it has the strictest regulations due to environmental concerns. The last two intervals used in oil or gas well are the production casing and production liner.