Encana Corp. on Tuesday reported a bigger-than-expected quarterly loss and a 79% slump in cash flow as sharply lower oil and gas prices continued to hurt the energy producer’s results. Calgary, Alberta-based Encana, which booked another hefty impairment charge of just over $600 million in the quarter ended March 31 due to the commodity-price rout, also recorded a nearly 11% decline in production. Encana has recorded a series of steep quarterly losses , and like many of its oil-patch peers, has slashed capital spending and cut its workforce to shave costs. The company said Tuesday it reduced drilling and completion costs in its core assets during the quarter by between 22% and 44% from year-earlier levels, and lowered general administrative costs. It said it is on track to deliver $550 million of year-over-year cost […]