W & T Offshore Inc.
W. P. Oil Ltd.
Wagner Oil Co.
Waldorf Corp.
Walter International
Wapiti Energy LLC.
Ward Petroleum Corp.
Warwick Oil and Gas Inc.
Washington Energy Resources
Watermark Corp.
Watson Energy Inc.
Waveform Energy Ltd.
Weatherford International
Wedge Group Inc.
Wellspring Partners
Wertheim Schroder & Co.
Westco Energy LLC.
Westech Energy Corp.
Western Hub Properties LLC.
Westhall Associates Inc.
Westinghouse Credit Corp.
Westmoreland Coal Co.
Westport Resources Corp.
Wexpro Co.
White Oak Energy
Whiting Petroleum Corp.
Wichita River Oil Corp.
Wildcat Petroleum Partners
Wilshire Enterprises Inc.
Winfield Energy Corp.
Wintershall Oil and Gas Corp.
Wold Oil Properties Inc.
Wood Energy Corp.
Woodlands Resources Co.
Woodside Energy
WPS Energy Services
Wynn-Crosby Energy Inc.
W. Mc Ilwaine Thompson, Jr.
W. T. Neal Trust
Wainoco Oil & Gas Co.
Walsh Production Inc.
Walters, Holt & Fields
Ward Lake Energy
Warren American Oil Co.
Wascana Energy Inc.
Washington Gas Light Co.
Watford Energy Ltd.
Wave Energy Ltd.
WBI Production Inc.
Wedge Energy Inc.
Wells Fargo Energy Capital
Wepco Energy LLC.
West Newport Oil Co.
Westcoast Energy International
Western Gas Resources Inc.
Western Operating Co.
Westim Energy
Westlinks Resources Ltd.
Westport Oil & Gas Co. Inc.
Westwin Energy I LP.
WHC Trust
White Stone Energy
Whitmar Exploration Co.
Wilbanks Exploration Inc.
Windsor Energy (U.S.) Corp.
Wintershall Aktiengesellschaft
Wiser Oil Co.
Wolverine Exploration Co.
Woodhurst Holdings Ltd.
Woodside Australian Energy
Worth National Bank
WRT Energy Corp.
Wyoming Minerals Ltd.