Techno-economic assessment of hydrogen pipe storage in decommissioned wellbores sourced from surplus renewable electricity

Abstract

Wellbore decommissioning is the final stage in the life cycle of any oil or gas well and involves placing acceptable well barriers to seal the wellbore. Operators have the obligation to decommission wells safely once they reach the end of their life. This study explores the prospects of repurposing near-to-decommission wellbores for pipe storage, forming a hydrogen-based energy storage system for containing hydrogen produced from surplus renewable electricity. It offers two pathways for hydrogen consumption, 1) Power-to-Hydrogen and 2) Power-to-Power. A conceptual design is presented to repurpose a wellbore into pipe storage to store hydrogen in its gaseous form. The storability of the pipe depends on pipe characteristics, including diameter and length as well as working pressure. Monte Carlo simulations are performed to calculate levelized cost of storage (LCOS) and levelized cost of hydrogen (LCOH) for the proposed method. The LCOS is in the range of 1.33 A$/(kgH2) and 1.66 A$/(kgH2). LCOH including the storage cost is obtained to be in the range of 5.22 A$/(kgH2) and 6.50 A$/(kgH2). This system can potentially integrate green hydrogen into local economies by managing decommissioning costs for the creation of a storage solution for green hydrogen.