EX-21 2 pten-ex211_201412316.htm EX-21.1

Exhibit 21.1

Subsidiaries of the Registrant

Name		State of Incorporation or organization
Ambar Lone Star Fluid Services LLC		Texas
Patterson Petroleum LLC		Texas
Patterson UTI Energy Arabia DMCC		UAE
Patterson-UTI Drilling Canada Limited		Nova Scotia
Patterson-UTI Drilling Company LLC		Texas
Patterson-UTI Drilling International, Inc.		Delaware
Patterson-UTI International (Netherlands) Coöperatief U.A.		The Netherlands
Patterson-UTI International Holdings (BVI) Limited		British Virgin Islands
Patterson-UTI International Holdings (Netherlands) One B.V.		The Netherlands
Patterson-UTI International Holdings (Netherlands) Two B.V.		The Netherlands
Patterson-UTI International Holdings GP (BVI), Inc.		British Virgin Islands
Patterson-UTI International Holdings GP 1 LLC		Delaware
Patterson-UTI International Holdings, Inc.		Delaware
Patterson-UTI Management Services, LLC		Delaware
PTEN International Holdings (Netherlands) 1 C.V.		The Netherlands
PTEN International Leasing (Netherlands) 2 C.V.		The Netherlands
Universal Pressure Pumping, Inc.		Delaware
Universal Well Services, Inc.		Delaware