Okay little one, you know how sometimes when you take a bath, you might see white stuff around the edges of the tub? That's called "scale," and it's made of minerals that build up over time. The same thing can happen in pipes and oil wells where there is a lot of water mixed with oil.
This can cause big problems for the people who work in the oil industry because that scale can clog up the pipes and make it harder to get the oil out of the ground and to the places where it needs to go.
So, the people who work in the oil industry have figured out ways to stop the scale from forming in the first place. They use special chemicals called "scale inhibitors" that can be added to the water in the oil well, and these chemicals help prevent the minerals from sticking together and making scale.
Think of it like putting on sunscreen before you go outside to play so you don't get a sunburn. The scale inhibitors are like the sunscreen, and they help protect the pipes and oil wells from getting all clogged up with scale.
By using these scale inhibitors, the people in the oil industry can keep everything running smoothly and safely, and we can keep using oil to power our cars and homes.