Understanding origin of pressure is a key to better well planning

Technological development has made it possible to estimate accurately and to control abnormal pressures; this information can be used to prevent blowouts. In abnormally pressured formations, the pore pressure of the fluids exceeds the pressure that is exerted by a column of saltwater extending to the surface (0.465 psi/ft). The upper limit of abnormal pressure is usually 1.0 psi/ft or the overburden weight. Some causes of overpressures and implications for drilling need mud weights are discussed. (DLC)