A & G ENGINEERING
ABU DHABI NATIONAL OIL CO.
ALASKA TANKER CO.
ANADARKO PETROLEUM CORP.
APACHE CORP.
ARCHER WELL CO. INC.
ARCHROCK INC.
BAKER HUGHES INC.
BASIC ENERGY SERVICES INC.
BELCO MANUFACTURING CO. INC.
BP OIL SHIPPING CO. USA
BRITISH PETROLEUM (BP) PLC
BUCKEYE FABRICATING CO.
BUKEYE PARTNERS LP
BUMI ARMADA
BW OFFSHORE
C&J ENERGY SERVICES LTD.
CALFRAC WELL SERVICES LTD.
CAMERON INTERNATIONAL CORP. (SCHLUMBERGER LTD.)
CARBO CERAMICS INC.
CHESAPEAKE ENERGY CORP.
CHEVRON CORP.
CHINA PETROLEUM AND CHEMICAL CORP.
CIM-CCMP GROUP
CLH GROUP
COLUMBIAN STELL TANK CO.
CONOCOPHILLIPS
CONTAINMENT SOLUTIONS INC.
CORE LABORATORIES N.V.
CSI COMPRESSCO LP
DANANG RUBBER JOINT STOCK CO.
DEVON ENERGY CORP.
DHT HOLDINGS INC. (NYSE: DHT)
DOVER CORP.
DRILL-QUIP INC.
ECOPETROL SA
ENBRIDGE INC.
ENI
ENTERPRISE PRODUCTS PARTNERS LP
EOG RESOURCES INC.
EQUINOR ASA (FORMALLY KNOWN AS STATIOL ASA)
ESSAR SHIPPING LTD.
EURONAV NV (NYSE: EURN)
EXXON MOBIL CORP.
FLOTEK INDUSTRIES INC.
FLUOR
FORBES ENERGY SERVICES LTD.
FORUM ENERGY TECHNOLOGIES INC.
FRONTLINE LTD (NYSE: FRO)
GAZPROM
GENER8 MARITIME (NYSE: GNRT)
GENERAL ELECTRIC CO.
GEOSPATIAL INSIGHT LTD.
GIBSON ENERGY INC. (TSX: GEI)
HALLIBURTON CO.
HORIZON TERMINALS LTD.
INTERNATIONAL-MATEX TANK TERMINALS
LLC
J.J. UGLANDS COS.
KAZMUNAIGAS EXPLORATION PRODUCTION
KEY ENERGY SERVICES INC.
KEYSTONE ALASKA LLC
KINDER MORGAN INC.
KNUTSEN OAS SHIPPING
KPLER SAS
KUWAIT OIL TANKERS CO.
KUWAIT PETROLEUM CORP.
L.F. MANUFACTURING INC.
MAGELLAN MIDSTREAM PARTNERS LP (NYSE: MMP)
MARATHON OIL CORP.
MERCURIA
MODEC
MOL GROUP
NATIONAL IRANIAN OIL CO.
NATIONAL NIGERIAN PETROLEUM COMPANY (NNPC)
NATIONAL OILWELL VARCO INC.
NATURAL GAS SERVICES INC.
NAVIOS MARITIME PARTNERS L.P. (NYSE: NMM)
NEWPARK RESOURCES INC.
NORDIC AMERICAN TANKERS LTD (NAT) (NYSE: NAT)
NUSTAR ENERGY L.P.
OCCIDENTAL PETROLEUM CORP.
OIL AND NATURAL GAS CORP. LTD.
OIL STATES INTERNATIONAL INC.
OILTANKING GMBH
OJSC LUKOIL
OMAN TANK TERMINAL CO. LLC (OTTCO)
OMV AKTIENGESELLSCHAFT
ORBITAL INSIGHT ENERGY
OSG SHIP MANAGEMENT INC.
PERTAMINA
PETROBRAS
PETROCHINA
PETROECUADOR
PETROLEO BRASILEIRO S.A.
PETROLEOS DE VENEZUELA
PETROLEOS MEXICANOS
PETROLEUM DEVELOPMENT OMAN LLC
PETROLIAM NASIONAL BERHAD
PKG EQUIPMENT INC.
PLAINS OF AMERICAN PIPELINE
POLY PROCESSING CO. LLC
PTT (THAILAND)
QATAR PETROLEUM
RED EWALD INC.
REMOTE SATELLITE SYSTEMS INTERNATIONAL
RIGNET INC.
Rosneft
ROYAL DUTCH SHELL PLC
RPC INC.
Saudi Aramco
SCHLUMBERGER LTD.
SEVENTY-SEVEN ENERGY INC.
SHIP FINANCE INTERNATIONAL LTD. (SFL)
SHIPPING CORP. OF INDIA
SONANGOL EP
SONATRACH
SUNOCO LOGISTICS PARTNERS L.P. (NYSE: MMP)
SYNALLOY CORP. (SYNL: NASDAQ)
TECHNIPFMC
TEEKAY CORP.
TEEKAY TANKERS LTD. (NYSE: TNK)
TENARIS S.A.
TETRA TECHNOLOGIES INC.
TOTAL S.A.
TRAFIGURA
TRAPIL
TRICAN WELL SERVICES LTD.
TSAKOS ENERGY NAVIGATION LTD. (TNP) (NYSE: TNP)
URSA GLOBAL OIL STORAGE MONITORING
VOPAK
VORTEXA
WEATHERFORD INTERNATIONAL PLC
WEIR GROUP PLC
ZCL COMPOSITES INC.