Legacy Field: Modern Design - How Higher Rated Equipment can Unlock Value in Existing Deepwater Fields

Abstract As technology has evolved to access deeper and more challenging reservoirs in deepwater assets, application of new technology within existing brownfield areas can unlock significant value through a variety of engineering design changes. A recently executed deepwater well design demonstrated that continual improvement in ratings and operational efficiencies of equipment lowered costs by 30% and potentially increased the life of the existing asset as well as new fields. A "Minimum Functional Objective" (MFO) approach was taken on a deepwater well, evaluating the minimum requirements of an existing well design for potential cost improvements. Each aspect of well design: casing, mud, cement, and drilling bottom hole assembly (BHA) design was challenged to determine the most optimal alternative given current technology available within industry. The well design applied the latest technology that was developed for other deeper, more challenging subsurface environments. The project achieved successful benchmarked performance via improved drilling efficiencies and reduced well cost of 30%. The brownfield well leveraged a higher rated intermediate casing string and production liner hanger from a recent high pressure high temperature greenfield to eliminate the tieback string. Casing points were deepened using managed pressure drilling (MPD) technology removing an entire hole section. The higher rated intermediate string and MPD system enabled eliminating reamers as an additional time and cost savings. Other operational efficiencies were found with MPD, wellhead, and suspension plug design to further de-risk operations and lower cycle time. The importance of technology breakthroughs and increased rating envelopes were critical to achieve this result. A variety of novel technologies adopted within the last 5-10 years enabled this design. Supplier-led solutions that improve equipment ratings and operational efficiencies are critical for extending asset life and increasing well queue within brownfield assets.