Company Overview	9 Months Ended
Sep. 30, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Company Overview	Note 2 — Company Overview We are an international offshore energy services company that provides specialty services to the offshore energy industry, with a focus on well intervention and robotics operations. Traditionally, our services have covered the lifecycle of an offshore oil or gas field. In recent years, we have seen an increasing demand for our services from the offshore renewable energy market. We provide services primarily in deepwater in the Gulf of Mexico, Brazil, North Sea, Asia Pacific and West Africa regions. Our North Sea operations are subject to seasonal changes in demand, which generally peaks in the summer months and declines in the winter months. Our services are segregated into three reportable business segments: Well Intervention, Robotics and Production Facilities (Note 10). Our Well Intervention segment provides services enabling our customers to safely access offshore wells for the purpose of performing production enhancement or decommissioning operations. Our well intervention vessels include the Q4000, the Q5000, the Q7000, the Seawell, the Well Enhancer, and two chartered monohull vessels, the Siem Helix 1 and the Siem Helix 2. Our well intervention equipment includes intervention riser systems (“IRSs”), subsea intervention lubricators (“SILs”) and the Riserless Open-water Abandonment Module (“ROAM”), some of which we provide on a stand-alone basis. Our well intervention segment also includes our ownership interest in Subsea Technologies Group Limited (“STL”). Beginning in May 2019 we held a 70% controlling interest in STL, and in June 2021 we acquired the remaining 30% interest. Our Robotics segment provides offshore construction, trenching, seabed clearance, inspection, repair and maintenance services to both the oil and gas and the renewable energy markets globally. Our Robotics services also complement well intervention services. Our Robotics segment includes remotely operated vehicles (“ROVs”), trenchers, a ROVDrill and two robotics support vessels under long-term charter, the Grand Canyon II and the Grand Canyon III, as well as spot vessels as needed. Our Production Facilities segment includes the Helix Producer I (the “HP I”), a ship-shaped dynamically positioned floating production vessel, the Helix Fast Response System (the “HFRS”) and our ownership of oil and gas properties. All of our current Production Facilities activities are located in the Gulf of Mexico.

Company Overview

9 Months Ended

Sep. 30, 2021

Organization, Consolidation and Presentation of Financial Statements [Abstract]

Note 2 — Company Overview

We are an international offshore energy services company that provides specialty services to the offshore energy industry, with a focus on well intervention and robotics operations. Traditionally, our services have covered the lifecycle of an offshore oil or gas field. In recent years, we have seen an increasing demand for our services from the offshore renewable energy market. We provide services primarily in deepwater in the Gulf of Mexico, Brazil, North Sea, Asia Pacific and West Africa regions. Our North Sea operations are subject to seasonal changes in demand, which generally peaks in the summer months and declines in the winter months. Our services are segregated into three reportable business segments: Well Intervention, Robotics and Production Facilities (Note 10).

Our Well Intervention segment provides services enabling our customers to safely access offshore wells for the purpose of performing production enhancement or decommissioning operations. Our well intervention vessels include the Q4000, the Q5000, the Q7000, the Seawell, the Well Enhancer, and two chartered monohull vessels, the Siem Helix 1 and the Siem Helix 2. Our well intervention equipment includes intervention riser systems (“IRSs”), subsea intervention lubricators (“SILs”) and the Riserless Open-water Abandonment Module (“ROAM”), some of which we provide on a stand-alone basis. Our well intervention segment also includes our ownership interest in Subsea Technologies Group Limited (“STL”). Beginning in May 2019 we held a 70% controlling interest in STL, and in June 2021 we acquired the remaining 30% interest.

Our Robotics segment provides offshore construction, trenching, seabed clearance, inspection, repair and maintenance services to both the oil and gas and the renewable energy markets globally. Our Robotics services also complement well intervention services. Our Robotics segment includes remotely operated vehicles (“ROVs”), trenchers, a ROVDrill and two robotics support vessels under long-term charter, the Grand Canyon II and the Grand Canyon III, as well as spot vessels as needed.

Our Production Facilities segment includes the Helix Producer I (the “HP I”), a ship-shaped dynamically positioned floating production vessel, the Helix Fast Response System (the “HFRS”) and our ownership of oil and gas properties. All of our current Production Facilities activities are located in the Gulf of Mexico.