Three negatives about oil rigs are their environmental impact, safety risks, and high cost of operation. Oil rigs can cause significant harm to the environment through oil spills, pollution, and disruption of marine ecosystems. Additionally, oil rig workers face numerous safety risks due to the hazardous nature of the job, such as explosions, fires, and exposure to toxic chemicals. Finally, oil rigs require significant financial investment to construct and maintain, making them a costly endeavor for companies and potentially driving up the price of oil for consumers.