Well-to-Well Gaslift System: Innovative and Cost Effective Approach to Unlock Field Potential and Extend Field Development Life

Abstract

Commissioned in 2008, J field operates as an unmanned satellite platform that sends its hydrocarbon to an existing D complex 50km away via a full well stream (FWS) subsea pipeline. Sustaining production became challenging as reservoir pressure started depleting. Besides that, due to gas break through, high gas-oil-ratio (HGOR) wells were closed-in as the gas from these high pressure (HP) wells was exerting backpressure to the low pressure (LP) wells when they commingle at the production manifold. To address this surface constraint, a well-to-well (WTW) gaslift system was introduced in 2016 by utilizing the gas from HGOR wells as the gas lift (GL) supplier to LP wells. This initiative proved to be a success as the overall liquid production from J increased by 20% resulting from revival of idle LP wells, improved recovery from existing LP wells and re-activation of HGOR wells. After 3 years of commissioning, the reservoir pressure from the initial GL supply wells started depleting and unable to cater for the gradual increase in gaslift demand by the LP wells. This setback caused an unplanned deferment of ~1.0 kbod to the LP wells. To avoid prolong production interruption, the team successfully identified a new virgin gas zone in one of the existing well at J8. However, converting this LP well into a HP/gaslift supply well required both subsurface intervention as well as surface modification. Hence, this paper discusses the methodology applied to overcome the constraints via an integrated approach from various disciplines resulting in a significant value creation through production sustenance contributing to increase in J's field production life.