Technical paper related exactly founded:
In-pipe wireless communication for underground sampling and testing (Dec 2017) www.researchgate.net -
It contains details of frequency, antenna´s design. Now I´ll read it to know if it is compatible with ARDUINO.
MANY THANKS!

 

@fermanbi ,
Glad to hear it! Glancing at the abstract, it looks like they are transmitting inside the pipe. The only way to do that is to increase the carrier frequency -- I think you'll find your diameter pipe will be somewhere around 60-75 GHz or so (I'm ballparking -- I did no math to support this).
But I'm glad you found someone who's done what you're going to do. That will definitely save you a great deal of aggravation.