A casing program is a process in which engineers and geologists take considerations into account to understand the well and surrounding formations, in order to design the correct intervals of casing that need to be set to protect the well. Casing design is a crucial part in developing and constructing the well. Improper determination of the casing design can result in cost overruns and potential problems with well control. Let’s take a look at the steps that are completed to achieve a “successful casing program.”
First, geologists and engineers study a number of elements to incorporate into the casing program:
- Formation pressure and fracture pressure gradients in the region to be drilled
- Regions of permeable rock, where fluids, such as hydrocarbons, might flow into the well
- Zones of groundwater storage, where risk of contamination will result in high consequences
- Analog wells for use of casing point comparison
Typically a well has three strings of casing in addition to the conductor casing: surface casing, intermediate casing, and production casing.