(July 9, 2019, 1:59 PM EDT) -- HOUSTON — A hydraulic fracturing well services company on July 3 sued two other well services companies in Texas federal court, alleging that they knowingly infringe on patents related to a fracking fluid pumping system (U.S. Well Services Inc. v. TOPS Well Services LLC, et al., No. 19-225, S.D. Texas)....