Darrell P. Salisbury and Robert L. Sloan, Process for Cleaning Pipe Dope and Other Solids from Well Systems, U.S. patent 5,676,763, granted Oct. 14, 1997.
John D. Watts and Beverly W. Ramos, Wedgethread Pipe Connection, U.S. patent 6,682,101, granted Jan. 27, 2004; see claim 24.
