Oil-service firm Cal Dive International Inc., Houston, (Nasdaq: CDIS) E&P subsidiary Energy Resource Technology Inc. (ERT) has acquired Gulf of Mexico Shelf assets from Williams Exploration & Production Co. for $5.5 million in cash and assumption of abandonment obligations. The deal gives ERT an average 30% net working interest in 23 federal Gulf leases and three Texas leases. Structures on the blocks include 31 platforms (eight four-pile, 15 tripod and eight caisson) in up to 200 feet of water. Of 67 wells, 23 produce 7.5 million cu. ft. equivalent of gas per day. ERT now owns interests in 61 offshore leases producing approximately 43 million cu. ft. equivalent per day. "Because production helps us counter the ups and downs of the offshore-contracting market, we are not under the pressure of oil and gas companies to replace reserves and production annually," says Owen Kratz, Cal Dive chairman. -Petroleum Finance Week