| Authors |
Sepulveda F, Melia K, Kelley M, Utami A, Estrella C M, Robertson G, Subekti D, Atayde R, Siega F |
| Abstract |
Geothermal operators drill wells to meet fuel and injection demands, and these wells are required to be drilled cost-effectively, safely and in compliance with industry and regulatory standards and codes. In 2023, Mercury (MCY) initiated a drilling program across three geothermal fields which provided an opportunity for MCY to implement and perfect a Well Delivery Process (WDP). A WDP is a cross-disciplinary framework designed to facilitate quality assurance, risk mitigation, and effective stakeholder communications. In this paper, we present an overview of the WDP with emphasis on the interplay of drilling and reservoir management disciplines during pre-drilling stages. The process starts with Well Targeting, where a business objective is articulated, and target options are identified and ranked leveraging geoscience and reservoir information, and other relevant inputs (e.g., plant & steamfield, regulatory). Once a target is selected, Well Prognosis takes place detailing expected geological, reservoir, and drilling conditions, while-drilling testing requirements, and contingency plans. Using well prognosis information, Conceptual and Detailed Well Design is undertaken, where directional drilling plans are developed and casing configurations evaluated against required design factors. A third-party peer review process is completed as part of well design. During Drill and Test-Well-On-Paper (DWOP & TWOP), the geothermal operator and contractors meet and discuss drilling execution, and testing and operational requirements. Final drilling and testing programs are completed with the inputs from these sessions. Case studies from a recent drilling campaign in New Zealand are discussed to illustrate the efficacy of the WDP to achieve successful drilling outcomes. |