• Pure Resources Inc. , Midland, Texas, subsidiary Pure Resources II Inc. plans to acquire Hallwood Energy Corp. , Denver, for $12.50 per common share and $10.84 per preferred share, totaling $268 million, including assumed debt. At year-end 2000, Hallwood had 121.8 million cu. ft. of gas 6.2 million bbl. of oil of proved developed reserves, primarily in the San Juan Basin, N.M., Colorado, south Texas, Permian Basin and onshore south Louisiana. • Peoples Energy Production has acquired three adjoining fields in Starr and Hildalgo counties in south Texas from Sierra Mineral Development LC, general partner of Sierra 1996-I LP, for $123 million. Two of the fields, Alvarado and North La Reforma, are producing 30 million cu. ft. of gas per day, gross, from 28 wells with multipay sandstone reservoirs within the Vicksburg Trend. The third field, El Staggs, has no proven reserves at this time. The Oil & Gas Asset Clearinghouse provided technical and transaction services. • Pioneer Natural Resources Co., Dallas, plans to merge with Pioneer Natural Resources USA Inc. , a subsidiary, and 46 Parker & Parsley limited partnerships. The partnership interests will be converted into the right to receive cash and Pioneer common stock. Pioneer has not set a minimum number of partnerships that must participate to complete the mergers. Pioneer USA is sole or managing general partner of the partnerships. Pioneer estimates that its offer will total approximately $102 million. • Patina Oil & Gas Corp., Denver, has sold its interest in Louisiana's Lake Washington Field, Plaquemines Parish, La., to Swift Energy Co. , Houston, for $30.5 million. Proved reserves are 7.1 million bbl. of oil and 3.7 billion cu. ft. of gas or 7.7 million BOE. Current production is approximately 1,000 BOE per day net to the purchase. In another deal, Patina acquired a 50% interest in the Castlegate coalbed-methane development project in Carbon County, Utah, from JM Huber . The acquired leases cover approximately 45,000 gross acres. JM Huber retained a 50% interest in the project. Gas is currently being produced from six wells on the property. In another deal, Patina acquired approximately 51,000 gross acres on the Antelope Arch in Fremont and Sweetwater counties, Wyo., within the Green River Basin. • Tulsa-based The Williams Cos.' E&P unit has purchased producing and undeveloped leasehold interests in two properties in Sublette County, Wyo., for $15 million. • Castle Energy Corp. , Radnor, Pa., plans to acquire interests in 21 operated wells and approximately 6,500 gross acres in east Texas from a private company for $10.6 million. Proved reserves are approximately 12.5 billion cu. ft. of gas and 191,000 bbl. of oil. Castle expects its annual production to increase approximately 30%. • Dominion Exploration & Production Inc. and Pioneer Natural Resources Co. have acquired Mariner Energy Inc. 's remaining 20% interest in the Devils Tower development project in Mississippi Canyon Block 773, deepwater Gulf of Mexico. The sale, for an undisclosed amount, increases Dominion's working interest from 60% to 75%. Pioneer's interest is now 25%. • ATP Oil & Gas Corp., Houston, has acquired six producing properties in the Gulf of Mexico with daily production of 7 million cu. ft. of gas and 340 bbl. of oil. Financial terms of the deal were not disclosed. This is the second Gulf of Mexico property package acquired by ATP since its initial public offering in February. The acquisitions have added net proved reserves of approximately 21 billion cu. ft. equivalent. • Panaco Inc. , Houston, has purchased a 100% working interest in West Delta Block 52 Field from Delta Petroleum Corp. , Denver, for $4 million. The acquisition includes seven producing oil wells, one saltwater disposal well and 18 shut-in wells for a total of 26 existing wellbores. Current production is approximately 300 bbl. of oil per day. Net to Panaco are 6.6 billion cu. ft. equivalent of reserves. • Amalgamated Explorations Inc. , Denver, has acquired an additional 539 net leased acres, now held by production, bringing Amalgamated's current land position to approximately 1,800 acres in the Boone Dome gas field area in Wyoming. Separately, Cabot Oil & Gas Corp. , Houston, has acquired 23,000 net acres of leases including the Cedar Ridge area that is between the Cave Gulch/Waltman and Madden fields and bordered by the Boone Dome area to the southeast. • Berry Petroleum Co. , Taft, Calif., has acquired a 15.83% nonoperated working interest in the Fort Union coalbed-methane leases in the South Joe Creek Field, Wyo., for $2.1 million. The properties are in the fairway of the Powder River Basin and are comprised of leases totaling approximately 5,800 acres. The company estimates proved reserves net to its interest to be 2.2 billion cu. ft. of gas. Currently 18 wells are producing 1.8 million cu. ft. per day. • Derek Resources Corp. , Vancouver, has acquired Asdar Group 's rights and interests in the LAK Ranch oil property in Wyoming for US$852,571. Asdar was the owner of a 25% working interest and a small overriding royalty in the property. • Gasco Energy Inc. , Denver, has acquired privately held Pannonian Energy Inc., also of Denver, for 14 million common shares. Pannonian has an interest in more than 30,000 acres in Uinta Basin, Utah. Gasco was formerly San Joaquin Resources Ltd. • Petroleum Development Corp. , Bridgeport, W.Va., has acquired a 25% working interest in a new Red River well in McKenzie County, N.D., with a right to participate at a 25% working interest in development prospects. This acquisition includes the right to participate as a 50% working-interest owner in seven additional prospect areas in Dunn and McKenzie counties, N.D. The new Red River well is currently producing approximately 300 bbl. of oil and 300,000 cu. ft. of gas per day. PDC also acquired the right to earn a 25% working interest in 17 existing wells and in new wells in the Clear Creek Field in Emery County, Utah. The initial acquisition cost for the properties was $3.5 million. • St. Mary Land & Exploration Co., Denver, subsidiary Nance Petroleum Corp. has exercised its option with Caribou Land & Livestock Montana LLC and now controls approximately 70,000 acres of leases in the Hanging Woman Basin of Montana and Wyoming for coalbed-methane development. Reserve potential is estimated to exceed 100 billion cu. ft. net to St. Mary's interest. Revenues are anticipated by 2003. • Stratford American Corp., Phoenix, has acquired SA Oil and Gas Corp., a privately held company, for 755,948 common shares. SA Oil and Gas owns working and royalty interests in 87 properties in Oklahoma and Texas, and it had 2000 revenues of $550,000. • Denbury Resources Inc., Dallas, has acquired nearly all of the working interest in the West Mallalieu and Olive fields in southwestern Mississippi for $3.8 million. Denbury estimates 8 million bbl. of oil should be recoverable from West Mallalieu. In a separate deal, Denbury acquired 14,000 leasehold acres in the Barnett Shale gas play in the Fort Worth Basin, near Fort Worth, Texas. • Comanche Energy Inc., Tulsa, plans to acquire certain assets from Rosewood Partners LLC in the Bovina Field in Mississippi for 33 million common shares. • Hadro Resources Inc., Reno, Nev., plans to acquire a 70% net revenue interest in approximately 224 acres of leases in the Buttonwillow gas field in the southern San Joaquin Valley of Kern County, Calif., from Clearview Mineral Resources Corp., a British Columbia company, for $150,000.