• ATP Oil & Gas ATPG -- offshore oil and gas development and production company operating in the Gulf of Mexico and the North Sea
  Blue Energy Limited (ASX: BUL) -- diversified publicly listed Australian energy company that undertakes the appraisal and development of CBM and conventional natural gas and conventional oil resources within eastern Australia
  BPZ Energy BZP -- an oil and gas exploration and production company with exclusive license contracts for oil and gas exploration and production covering approximately 2.4 million acres in four properties in northwest Peru
  CARBO Ceramics Inc. CRR -- the world's leading manufacturer of ceramic proppants and supplier of fracture diagnostic services for use in the hydraulic fracturing of natural gas and oil wells
  Caspian Services, Inc (OTC Bulletin Board: CSSV) -- provides geophysical and seismic data acquisition and interpretation services in the Caspian Sea
  Core Laboratories CLB -- reservoir description, production enhancement and reservoir management
  Dawson Geophysical DWSN -- America's leading provider of onshore seismic data acquisition and processing services
  Geokinetics GOK -- a leading global provider of seismic acquisition and high-end seismic data processing services to the oil and gas industry
  Harvest Natural Resources HNR -- an independent energy company with principal operations in Venezuela and business development offices in Russia and the United Kingdom
  Hercules Offshore LLC HERO -- offers assistance in drilling, well service, platform inspection, maintenance, and decommissioning operations in shallow waters
  NATCO Group Inc. NTG -- provides equipment and services to separate oil and oil-within-production streams
  Oil States International OIS -- a diversified oilfield services company with locations around the world
  Parker Drilling Company PKD -- specializes in offshore drilling and workover services in the Gulf of Mexico and international land and offshore markets
  Petroleum Development Corporation PETD -- an independent energy company engaged in the development, production and marketing of natural gas and oil, with operations focused in the Rocky Mountains and additional operations in the Appalachian Basin and Michigan
  Petsec Energy Ltd. (ASX: PSA) -- an independent oil and gas exploration and production company with operations focused in the shallow waters of the Gulf of Mexico and onshore Louisiana Gulf Coast region and on oil in the Beibu Gulf offshore China
  Progress Energy Ltd. (TSE: PGX.UN) -- a Calgary-based, natural gas focused trust targeting sustainable production and reserves per unit through the utilization of its technical capability and capital investment efficiencies
  RPC, Inc. RES -- provides a broad range of specialized oilfield services and equipment primarily to independent and major oilfield companies
  Superior Well Services, Inc. SWSI -- an oilfield services company operating in many of the major oil and natural gas producing regions of the United States
  TransGlobe Energy Corporation TGA -- an oil and gas producer with proved reserves and production operations in The Republic of Yemen, the Arab Republic of Egypt and in Alberta, Canada
  TXCO Resources TXCO -- independent oil and gas exploration and production company that uses advanced drilling technologies and geological modeling to extract hydrocarbons from its large resource base in south Texas
  Unit Corporation UNT -- the fourth largest U.S. premium contract land driller and a fast growing exploration and production company
  Venoco, Inc. VQ -- an independent energy company primarily engaged in the acquisition, exploitation and development of oil and natural gas properties offshore and onshore California and in Texas