Spill prevention and Response

Offshore Well

offshore Oil and natural gas deposits are pressurized by the weight of the layers of soil and rock above them. When an exploratory drill taps into one of these deposits, the seal is broken so that the pressurized oil and/or gas flows up and out of the well. Modern wells control the pressure of the flow to keep oil and gas from escaping into the environment. For example, most wellheads are equipped with two types of blowout preventers (BOPs) and additional shut-off valves are installed on the lines carrying oil and waste products to field processing centers. All of these safety devices are linked to a master switch that can shut down the entire system in the event of severe weather or other potentially hazardous circumstances.

Prevention Tactics and Technologies

Blowout Preventers (BOPs)

Most drilling rigs feature multiple blowout preventers, providing backup protection should a BOP fail.

Ram BOPs - consist of two halves of a cover for the well, split down the middle. Hydraulic cylinders attached to each of the halves hold them apart, allowing oil or gas to flow through the well opening. However, if sensors within the well detect a pressure spike, the cylinders are released so the two halves of the cover snap together, sealing the wellhead.

Annular BOPs - are used to seal off blowouts in the space between the wall of a well and the well pipe or drill string. The sealing element resembles a large rubber doughnut that is mechanically squeezed inward to close tightly around the pipe.