the present invention generally relates to containment and control of an oil spill caused by a damaged or broken riser in deepwater . more specifically , the present invention relates to a reusable unit that will contain oil spills to a specific location and will also allow oil to be harvested as it flows to the top of the unit while minimizing or even eliminating any environmental clean - up cost . the unit of the present invention is dropped over a damaged or broken riser in a closed positin , the unit is released and stabilized in sections until the surface is reached and the containment unit is completely erected .