(Reuters) – BHP Group ( BHPB.L ) ( BHP.AX ) touted bullish plans on Monday to expand in oil and gas after quitting a disastrous foray into U.S. shale, defying investors who want the world’s biggest miner to cast off the business. FILE PHOTO: Visitors to the BHP (formerly known as BHP Billiton) booth speak with representatives during the Prospectors and Developers Association of Canada (PDAC) annual convention in Toronto, Ontario, Canada March 4, 2019. REUTERS/Chris Helgren The company’s petroleum head said the business is set to deliver strong returns and cash flow through the 2020s and beyond, supported by high-potential projects in the Gulf of Mexico, Western Australia and Trinidad & Tobago. Petroleum, which accounted for about 16% of BHP’s underlying earnings in 2018/19, could potentially generate margins of more than 60% over the next decade, Geraldine Slattery, President Operations Petroleum, told a briefing. Excluding the shale business, the company’s oil and gas arm has long had some of the strongest returns in the group’s portfolio, including iron ore, copper and coal. With projects awaiting approval, the division could support average annual volume growth of up to 3% in the decade to 2030, and deliver average internal rates […]