Global Drillships Market By Type (10, 000 ft Drilling Depth, 20, 000 ft Drilling Depth, 30, 000 ft Drilling Depth, 40, and 000 ft Drilling Depth), By Application (Shallow Water, Deep Water, and Ultra-deepwater), By Region, and Key Companies - Industry Segment Outlook, Market Assessment, Competition Scenario, Trends and Forecast 2019-2028