Mark Identification

SIERRA ENGINEERING

Serial Number

75185834

Filing Date

Oct 23, 1996

Trademark by

DRENNON/CASTILLO LTD.-I

Classification Information

on-site petroleum engineering services to implement the treatment and stimulation of oil and gas wells to enhance production, including the design and the on-site supervision and implementation of fracturing procedures by hydraulic fracturing and well casing perforating procedures by gun perforating

Treatment of Materials