Lessons Learned from Constructing Atlanta Field Wells: A Milestone in the Deepwater Offshore Oil Industry

Abstract

Listen

Translate article

Abstract The successful commercial exploitation of the Atlanta field, the world's first ultra-deepwater heavy oil project, is a milestone in the offshore industry. The technological solutions and innovations applied so far, allowed the Early Production System (EPS), which at first would be a big prototype for studying technical solutions and understanding the behavior of the reservoir and aquifer, to become a standalone project. With this, the EPS was extended, and a fourth well was added to the initial 3-well design. The success of production, which has already accumulated 25 million barrels of oil produced, confirmed the performance of the large aquifer, simplifying and reducing project costs, but has caused significant dynamic depletion in the vicinity of producing wells. Currently, the powerful ESP into the producer wells apply a drawdown of approximately 120 bar, certainly one of the highest in the world. The robustness and correct design of the sand control used in the wells has allowed this operation. This depletion added additional challenges to the construction of the 4th, 5th and 6th wells and an even narrower operating window was expected. To deal with these uncertainties, the drilling operations included a new determination of the geomechanical properties of the reservoir. Also, the OHHGP with AICD used 3 different proppants, with density of 2.71g/cm3, 1.34g/cm3 and 1.08 g/cm3, the latter being the first use in OHHGP. Also 3 fluids were used in the OHHGP Lessons learned and the innovations that allowed the construction of the 4th EPS well, such as this pioneer OHGP operation, are depicted in this paper.