Final answer:
The advancement in oil drilling that has substantially reduced the environmental impact of drilling is directional drilling.
Step-by-step explanation:
The advancement in oil drilling that has substantially reduced the environmental impact of drilling is known as directional drilling.
Directional drilling is a technique where the drill bit is steered to reach the desired oil reservoir by deviating from the vertical. It allows for drilling multiple wells from a single location, reducing the number of surface disturbances, and minimizing the footprint of the drilling operation. This technique also reduces the need for additional access roads and infrastructure, minimizing the impact on the environment.
Another advantage of directional drilling is that it allows access to oil reserves that are located beneath sensitive environments, such as national parks or protected areas. Instead of having to drill directly underneath these valuable habitats, directional drilling can reach the oil reservoir from a distance, avoiding any potential harm to the environment.