Offshore Transition Technologies—Reducing Emissions and Environmental Impact with Practical, Quantifiably Proven Solutions

Abstract

Minimizing greenhouse gas emissions per barrel is becoming a key imperative in the current oil and gas industry. However, choosing solutions that reduce carbon footprint demonstrably while driving high performance is a daunting process. Technology solutions exist today that drive high performance whilst quantifiably reducing emissions and environmental impact in the oil and gas industry. Specific offshore technology solutions of this kind were investigated. The United Nations has 17 Sustainable Development Goals out of which 7 were identified that can be impacted by the investigated technologies through design, operations, and partnerships. Life-cycle assessments based on ISO-14044 and GHG Protocol Standards were performed to identify the environmental benefits, such as avoided emissions or reduced energy consumption, when compared to an industry standard approach. Multiple internal reviews were conducted to confirm data integrity, validity of the reference technology, and functional unit of comparison. A ‘cradle to grave’ approach was considered to understand the impactful phases of the product or service life-cycle comparison. Three key emission themes and challenges were identified for the oil and gas operations: decarbonizing drilling and completions, decarbonizing production, and eliminating methane and flaring emissions. Within these themes, there are several transition technologies that are applicable for offshore oil and gas. Among these are subsea boosting systems, subsea multiphase compression systems, wireline deep transient testing, offshore slop water treatment, digitally connected performance services, multilateral well junction technology, subsea workover control systems, and all-electric subsea and surface actuators. A life-cycle assessment was performed on each of these technologies to identify their environmental benefits. Using subsea multiphase compression when compared to topside compression reduced energy consumption by 2.9 TWh and emissions by 1.44 million metric tons CO2e over 10 years. Similarly, using subsea boosting in place of gas lift reduced energy consumption by 270 GWh and emissions by 131 kt CO2e over 10 years. Wireline deep transient testing eliminated a drill-stem test and associated flaring in offshore West Africa resulting in avoided emissions of 5500 t CO2e by minimizing the need for surface infrastructure. Multilateral well junction technology reduced emissions up to 20,000 t CO2e due to reduction in construction of wells. A subsea workover control system, when compared with a traditional intervention workover control system, reduced 6377 t CO2e in a field with five subsea trees. Quantified environmental impacts add credibility to the transition technologies which is important for transparency in often sensitive topic during this energy transition period. New transition technologies are actively being developed and identified. In addition to the mentioned technologies, other technologies are being investigated in the industry, including, for example, integrated offshore electrification, which and reduce well count and improve production profiles and eliminating flaring during not only production but also after stimulation and well clean-up.