• Stone Energy Corp., Lafayette, La., will buy Gulf of Mexico properties for $300 million from Conoco Inc. Net production was 9,700 bbl. of oil and 20.9 million cu. ft. of gas per day during the first half of 2001. Remaining producing reserves are estimated to total 18.5 million BOE. Separately, Howell Corp., Houston, will acquire Conoco's interest in the Elk Basin Field in Wyoming and Montana for $26 million. Howell is currently the field operator. Its share of production will increase approximately 2,150 net bbl. of liquids a day, 86% oil, and it will own approximately 64% of the working interest in the field. • Devon Energy Corp., Oklahoma City, has amended its acquisition of Mitchell Energy & Development Corp. to preserve the tax-free status of the deal, valued at about $3.1 billion, by allowing the cash portion to represent no more than 60% of the total offer. Devon shareholders will exchange each of their shares for one share of a new holding company, while Mitchell shareholders will get 0.585 share of the new company and $31 cash per share of Mitchell. • Pioneer Natural Resources Co., Dallas, will purchase half (12.5%) of Houston-based Mariner Energy's (25%) interest in the Gulf of Mexico Aconcagua Field (Mississippi Canyon 350) and an additional 5.6% interest in the Canyon Express pipeline project for $25.5 million, bringing its total interest in the field to 37.5%. interest in the pipeline to 23.5%. The deepwater gas field is one of three being developed as part of the pipeline project, which will have a capacity of 500 million cu. ft. of gas per day, or 117.5 million cu. ft. per day net to Pioneer. • Clayton Williams Energy Inc., Midland, has sold its assets in three East Texas fields to Samson Lone Star LP for approximately $15.8 million, net. • Aroc Inc., Houston, has merged with Aroc Texas Acquisition Inc., a wholly owned subsidiary of MPac Energy LLC., and has also become a wholly owned subsidiary of MPac, for $0.06 cash per Aroc share. • Aspen Group Resources Corp., Oklahoma City, has acquired 44 producing wells from Saco Oil Co. for $1,125,000 cash, primarily in the El Dorado Field, Kansas. As operator, Aspen's average working interest in the properties will be 46.5% with an average net revenue interest of 40%. The acquisition adds an estimated 317,000 net bbl. of oil to its reserves and approximately 53 bbl. of oil per day to its current production in the field. • Consolidated Odyssey Exploration acquired a working interest in the Wimberly No. 2 well in the Barnett Shale from Golden Arch Resources. The well had an initial production rate of more than 300,000 cu. ft. of gas per day. • Touchstone Resources Ltd. has sold its undivided 20% leasehold working interest in the Brookshire Dome project in Waller County, Texas, to Sanka Ltd. for $1.25 million cash. • Carneros Energy Inc., Houston, has acquired Gotland Oil Inc., which owns interests in 101 oil wells and 11gas wells in the San Joaquin and Sacramento basins, Calif., and has proved reserves of 2.5 million BOE. • Tartan Energy Inc., Calgary, will acquire R&R Resources LLC's Lost Hills assets in the San Joaquin Basin, Bakersfield, Calif., including a 55% working interest in 880 acres of shallow oil and gas leases, for 27.84 million Tartan shares and a promissory note for US$900,000 convertible into Tartan shares. • Copper Creek Ventures Ltd. has entered into an agreement with CP Resources to earn a 35% interest in the Salt Wells development project in south-central Wyoming. The project consists of four phases upon contiguous lands covering approximately 20,000 acres. • Copper Ridge Explorations Inc. will acquire a 100% working interest in two leases covering 1,440 acres within the Denver-Julesberg Basin in southwestern Nebraska. • Solana Petroleum Corp. will acquire from Trenton Black River Gas Partners Inc. a 35% participation right in a joint venture formed to explore for deep gas on approximately 80,000 acres in northwestern West Virginia. The objective is the Ordovician Trenton-Black River limestone formations in the Rome Trough of the Appalachian Basin of West Virginia. • Duke Energy Hydrocarbons, Houston, has formed an exploration partnership with Houston Energy Inc., to be called Elite Exploration LP, to develop prospects on the Texas and Louisiana coasts and offshore. Duke Energy Hydrocarbons will fund staffing and technical-data acquisition; Houston Energy will contribute prospects. • Peter Robertson, president of ChevronTexaco Overseas Petroleum, will replace Richard Matzke as vice chairman when Matzke retires next year. • Gary Evans has been elected to succeed Matthew Lutz, who retired in September, as chairman of Magnum Hunter Resources Inc. Evans will retain his current positions of president and chief executive officer. • Steven J. Malcolm has been named president and chief operating officer of The Williams Cos., Tulsa. Malcolm was executive vice president of Williams. Keith E. Bailey will remain chairman and chief executive officer until retirement in 2002. • Noble Affiliates Inc., Houston, has named James C. Day, chairman and chief executive officer of Noble Drilling Corp., to its board. Day is also on the board of Global Industries Ltd. • Former Devon Energy Corp. executive James Payne has joined Nuevo Energy Co., Houston, as chairman, president and chief executive. Payne replaces interim president and chief executive Phillip Gobe, who will return to the position of chief operating officer. • Peter A. Dea has been named president, chief executive officer and director of Western Gas Resources Inc., Denver. Dea was most recently chairman and CEO of Barrett Resources Corp. Lanny F. Outlaw, Western's current president and CEO, will continue as a director after his retirement. Separately, William J. Krysiak has been named chief financial officer. He was vice president of finance. • Philip C. Ackerman will succeed Bernard J. Kennedy as chief executive officer of National Fuel Gas Co. Kennedy will remain chairman until year-end and continue to serve as a director. Ackerman has been president of National Fuel Gas Co. since 1999, and developed the company's E&P subsidiary, which now provides 40% of National Fuel Gas' earnings. • Norris R. Harris has been named president of Westfort Energy Ltd., Jackson, Miss. Harris was responsible for geophysics in the U.K. and Nigeria for Mobil Oil Corp. Whitney J. Pansano Jr. has resigned as president, for health reasons. • Keith S. Hewitt has been appointed to the Solana Petroleum Corp. board. Hewitt was a director of Emerald Energy Plc and general manager of Emer-ald Energy Colombia in Bogota. • John J. O'Connor has been named president of worldwide E&P for Amerada Hess Corp., New York City. Prior, O'Connor was president of worldwide E&P for Texaco Inc. • Thomas P. Chambers has been promoted to vice president, corporate planning, of Apache Corp. Chambers joined Apache in 1995 as director of planning. • Thomas M. Hamilton, chairman and chief executive officer of EEX Corp., has joined the board of FMC Technologies Inc.