Managing Flow Challenges of Mature Production Wells Through Unconventional Gas Lifting Strategy: An FPSO Case Study

Abstract

Mature deep-water production wells are exposed to enormous flow assurance challenges, as well as reduced productivity index and performance over time. One of the most common flow assurance challenges, especially for deep water wells tied to a production facility, includes well slugging due to increasing water production, depleting reservoir pressure, and a reduction in the gas-oil ratio. While conventional gas lifting methods are one of the most reliable options for enhancing productivity, production wells that were not designed with the gas lift option may suffer significant production losses and flow challenges due to increasing water production, which could lead to well shut-ins and revenue loss. The objective of this paper is to demonstrate how the use of unconventional gas lift methods can enhance production optimization in high-water-cut wells tied to a Floating Production Storage and Offloading facility. The paper adopted a mixed-methods data gathering approach, which involves the utilization of representative field production data and practical field experience as primary data sources, while reviewing technical theories and qualitative data from research and peer-reviewed papers on the subject matter as secondary data sources. The paper successfully demonstrated how a practical and unconventional strategy was employed for gas lifting of high-water production wells, effectively managed well slugging problems, and enhanced the field production optimization effort of deep-water wells tied to a production facility. The unconventional strategy, which yielded about 700 bpd increase in oil production from the mature assets, could be deployed by operators as a temporary solution to manage flow issues and optimize well production, considering the significant cost savings and minimal technical modifications required when compared to other production enhancement methods for subsea wells.