Exhibit 1.2—Oil and gas drilling operations may lead to environmental impacts—text version
2012 Fall Report of the Commissioner of the Environment and Sustainable Development
Fall 2012 Report—Chapter 1
Exhibit 1.2—Oil and gas drilling operations may lead to environmental impacts
This image illustrates five methods used in oil and gas drilling operations.
The first method to drill subsea wells makes use of floating production, storage, and offloading vessels.
The second drilling method uses a floating semi-submersible rig, which includes a derrick, pontoons, and anchors. The rig is then connected through a riser and blowout preventor to the well.
The third drilling method uses a jack-up rig sitting on the ocean floor, which includes a derrick, rig legs, and a spud can.
The fourth drilling method uses a gravity-based structure, also on the ocean floor, which includes a flare boom, an ice wall, and a drill shaft. This method has the capacity for oil storage.
The fifth method shows the use of a seismic survey vessel to understand geological formations below the ocean floor. This method begins by bouncing sound waves off of geological formations, sending them to acoustic receivers (streamers) that are floating on buoys at sea level.
Beneath the five methods, the accidental impacts are listed:
- oil spills
- chemical spills
- gas releases
- dropped objects
Also beneath the five methods used in oil and gas drilling operations, the operational impacts on the environment are listed:
- solid and liquid wastes (including sewage, drainage, and dust)
- muds, cuttings, and sediments
- discharges of cooling water, ballast water, brines, and drilling chemicals
- air emissions from power generation, ventilation exhaust, fuel, and chemical storage
- noise and light
- disturbance of seabed and rock dumping
Source: Adapted from the OSPAR Commission and environmental assessments