Calgary-based Tourmaline Oil Corp. has agreed to buy Bonavista Energy Corp., also headquartered in Calgary, in a $1.45 billion deal that is the latest example of an accelerating trend of consolidation among oil and gas producers across Canada and the United States. Once completed, the half-cash-half-stock deal will cement Tourmaline’s top position in the Deep Basin region of Western Alberta. In a press release, Tourmaline – already the country’s largest natural gas producer – said that the deal is expected to boost production by approximately 10 percent and is expected to add $450 million in annual net operating income for the next three years. The deal is anticipated to be completed in the second half of November, subject to regulatory approvals and customary closing conditions.