Complex sentence: Production was cut back temporarily in coordination with the Organization of Petroleum Exporting Countries (OPEC) and production levels again reached 600,000 b/d by mid- 1987, which helped increase revenues.
Split into simpler sentences: Production was cut back temporarily in coordination with the Organization of Petroleum Exporting Countries (OPEC). Production levels again reached 600,000 b/d by mid- 1987, which helped increase revenues.