In this blog post, we will examine the structure of drillships—developed for exploring oil and natural gas in deep waters—and their core technology, the Dynamic Positioning (DP) system. We will also explore the background behind South Korea’s shipbuilding industry securing a strong competitive edge in the global drillship market in the early 2010s and discuss its significance today.
Drillships Venturing into the Deep Sea in Search of Oil
From the 20th century to the present, humanity has achieved remarkable economic growth based on oil as an energy source. However, as economic growth led to the expanded development of oil resources in relatively accessible areas such as onshore and on the continental shelf, the importance of technologies for exploring and developing oil and natural gas in deeper waters has also grown significantly. Consequently, while humanity is striving to develop and commercialize new energy sources such as solar and wind power, oil continues to occupy a vital position in the global energy supply. As it has become increasingly difficult to secure oil on land and in coastal waters, the prospect of venturing into deeper oceans to explore for oil and natural gas has become a reality, and drillships (offshore drilling vessels) were developed for this purpose.
Simply put, a drillship is a vessel capable of navigating freely at sea while performing drilling operations at specific offshore locations. While this sounds straightforward, drillships incorporate a vast array of technologies designed to ensure stable drilling in deep waters. One of the most significant structural differences between a drillship and a conventional vessel is the large drilling rig installed at the center of the ship; another key element is the propulsion system designed to maintain the ship’s position with precision. In particular, drillships are equipped with powerful propulsion systems, such as multiple azimuth thrusters, which generate thrust in the required directions to control the ship’s position and heading.
How must a vessel’s position be maintained for offshore drilling?
When drilling on land, the ground is fixed, so a drill connected by pipes can bore into the earth from the location where the drilling equipment is installed to extract oil and natural gas. In contrast, at sea, the vessel is constantly moving due to external environmental factors such as waves, wind, and ocean currents; therefore, to ensure stable drilling, the vessel’s position must be maintained with precision. In particular, when drilling in deep waters, significant movement or changes in the vessel’s direction can place heavy loads on the drilling equipment, risers, and drill pipes connected to the seabed; in severe cases, this can damage the equipment or even lead to marine pollution. Ultimately, the core technology required for a drillship is the ability to drill while stably maintaining the vessel’s position and heading in deep waters, and the primary system responsible for this is the DP (Dynamic Positioning) system.
The DP system continuously measures the vessel’s position and heading during offshore drilling operations and automatically adjusts the thrust of multiple thrusters to counteract external forces such as waves, wind, and ocean currents, thereby keeping the vessel in a predetermined position. In this process, a computer receives information from various devices—including the Global Navigation Satellite System (GNSS), gyrocompasses, motion sensors, and wind direction and speed sensors—to calculate the vessel’s current state and the external forces acting upon it. The DP control system then determines the thrust magnitude and direction of each thruster to ensure the vessel maintains its original position and heading. Therefore, the DP system is not merely a technology that uses satellites to track a vessel’s position; rather, it is a comprehensive technology in which positioning devices, various sensors, computer control systems, power systems, and propulsion systems all work together.
Have you ever seen a swan floating on water? On the surface, a swan appears to maintain its position very steadily, but in reality, it rapidly moves its legs underwater to maintain its body’s position. It is easier to understand this concept if you think of the drill ship’s thrusters as the swan’s legs. If a wave pushes against the right side of the drill ship, the thrusters generate thrust in the opposite direction to prevent the vessel from being pushed away. Multiple thrusters adjust their thrust in the necessary directions to counteract the forces acting from the outside. Even in calm conditions without waves, the vessel’s position and heading can be maintained consistently by finely adjusting the thrust of the thrusters. Of course, maintaining position relies not solely on the thrust of these propellers. The vessel’s position and movement must be accurately measured and that information transmitted to the DP control system; the DP computer then continuously calculates the necessary commands for each propeller based on this data. The U.S. Coast Guard also describes the DP system as a structure in which the power system, propulsion system, and DP control system operate in tandem; the control system uses information from various sensors and positioning reference systems to calculate the magnitude and direction of thrust required by the vessel.
Why were drill ships considered high-value-added vessels?
As such, drill ships—which integrate a wide range of technologies—are high-value-added vessels requiring a much higher level of design and construction expertise than ordinary merchant ships. In particular, during the early 2010s when the offshore drilling market was booming, the price of a single shallow-water drill ship reached hundreds of millions of dollars, and the construction of a single vessel required enormous amounts of technology and capital. At that time, South Korean shipbuilders demonstrated very strong competitiveness in this ultra-deepwater drillship market, and large-scale orders continued to pour in, led by Samsung Heavy Industries and Daewoo Shipbuilding & Marine Engineering. In fact, even in 2013, South Korean shipbuilders secured a significant volume of orders in the global drillship market, demonstrating their world-class competitiveness.
The reason South Korean shipbuilders were able to capture such a large share of the drillship market at that time was not simply due to their shipbuilding expertise. Unlike ordinary ships, drill ships require the integration of various technologies into a single vessel—including not only hull design but also the technology to integrate drilling equipment, a dynamic positioning (DP) system to maintain the ship’s position at sea, a powerful propulsion system, and power supply and control systems. Therefore, building a single drill ship required a comprehensive combination of shipbuilding technology, offshore plant technology, electrical and electronic technology, and automatic control technology. Given that South Korean shipbuilders secured a series of orders for shallow-water drillships based on these complex technologies, drillships at that time served as a prime example of the South Korean shipbuilding industry’s advanced technical capabilities.
From an economic perspective, drill ships also held significant importance for the South Korean shipbuilding industry at the time. As these were high-value vessels costing hundreds of millions of dollars each, a single order generated a greater economic impact than that of a typical ship. In particular, during the early 2010s, international oil prices remained high, leading to active investment in deepwater and ultra-deepwater oil field development; consequently, demand for offshore drilling equipment, including drill ships, increased significantly. As this market environment aligned with the technical capabilities of South Korean shipbuilders, drill ships gained attention as one of the high-value-added export items representing the South Korean shipbuilding industry.
However, the situation in the drill ship market changed drastically following the subsequent decline in international oil prices and the contraction of offshore drilling investments. As the offshore drilling industry entered a slump in the mid-2010s, new orders plummeted, and the market faced difficulties, with a significant number of already-built drill ships remaining idle for extended periods. Consequently, the large-scale influx of new orders seen in the past did not continue, and the notion that a fixed number of drill ships ordered each year would generate massive export revenue is no longer directly applicable to the current situation. Therefore, the expression referring to drillships as South Korea’s “flagship export earner” should be understood within the context of the strong competitiveness that South Korea’s shipbuilding industry demonstrated in the drillship market in the early 2010s.
From today’s perspective, the drillship market presents a different picture than in the past. Since demand in the offshore drilling market fluctuates significantly depending on international oil prices and the investment plans of energy companies, it is difficult to conclude that this is a market where new drill ships are ordered on a large scale as in the past. On the other hand, as offshore energy development continues, interest in the reactivation, retrofitting, and maintenance of existing drill ships is growing, and in the offshore plant sector—including drill ships—the role of shipbuilders with advanced technological capabilities remains crucial. Furthermore, South Korea’s shipbuilding industry is currently strengthening its competitiveness by focusing on high-value-added vessels such as LNG carriers, and since the 2020s, the competitive landscape of the global shipbuilding market has become even more intense than in the past due to the growth of China’s shipbuilding industry. Therefore, the significance of drillships today should not be evaluated solely by order volume or market share, but rather recognized as highly sophisticated vessels that integrate various cutting-edge technologies to perform complex offshore operations in deep waters.
Ultimately, the most important value of a drillship does not lie solely in its size or price. To carry out drilling operations in the middle of the deep sea while being subjected to waves, wind, and ocean currents, the vessel’s position must be maintained with precision; this requires precision control technologies—including DP systems—and propulsion technologies. In particular, the DP system is a core technology in which a computer calculates the required thrust based on information collected by position sensors and various motion and environmental sensors, and controls multiple thrusters to maintain the vessel’s position and heading.
In the early 2010s, South Korean shipbuilders secured a strong competitive edge in the global drillship market because they possessed the technical capabilities to apply and commercialize these complex technologies on actual large vessels. Although orders for drillships have since declined significantly due to changes in the market environment and the competitive landscape has shifted, drillships remain a flagship vessel that demonstrates the high technological level of the shipbuilding and offshore industries. Therefore, rather than being evaluated solely based on strong export performance during a specific period, drill ships can be considered a symbolic example of the South Korean shipbuilding industry’s technological prowess, as they require the integration of ship design and construction technologies, as well as drilling, propulsion, power, and automatic control technologies, all within a single vessel.
