The area and geological targets of investigation are very well known, several reference wells have been drilled and produced in the past, past operations’ experience and state-
Mud is the primary barrier to avoid any formation influx. It hydrostatically balances the formation pressure. In case of abnormal formation fluid influx, unlikely and limited to small pockets of gas, specific emergency procedures are activated and the well head valves (Blow Out Preventers) are closed to control the emergency. The influx can be detected in its early stage by the surface mud logging unit, which controls the mud volume in and out, and samples and analyzes the fluids out of the well, including the detection of eventual gas traces in the mud.