Emergency Landing [ATC]

On Sunday, July 18th, I was flying a Cessna 172 from Midland, TX to Baytown, TX doing a routine pipeline patrol. Upon entering Houston Intercontinental's (KIAH) Class Bravo Airspace, I began to experience a very rough engine plus a rapid oil leak. The flight ended in an off-airport landing. Myself and the airplane sustained absolutely no damage on landing.