I am trying to add a utility sink in our garage in a house with a finished basement.

There is an area between the two floors where I can run the drain with enough slope to connect to the main drain line of the house. However, the problem is it would be about 18ft of pipe. I wouldn't have access to the area where I run the pipe, but am only pushing the pipe through to the other side. The problem is securing the drain pipe as I don't have access to the middle area where the pipe runs.

Any ideas or suggestions? If it is a simple drain line for a utility sink should it still be secured somehow besides at the two ends?