SHELL CANADA SEES BETTER PROFIT, LOWER SPENDING <Shell Canada Ltd>, 72 pct owned by Royal Dutch/Shell Group, anticipates an improved level of earnings in 1987, assuming a continuation of prices and margins that existed at the end of 1986 and early 1987, the company said in the annual report. Shell previously reported 1986 operating profit fell to 130 mln dlrs, excluding a 24 mln dlr unusual gain, from 146 mln dlrs in the prior year. The company also said 1987 capital and exploration spending of 420 mln dlrs will be 160 mln dlrs lower than last year, due to the uncertain short-term outlook.