| Abstract |
Geothermal generation projects are capital intensive and other renewables are seeing continuously decreasing levelized cost of electricity (LCOE) on a large scale. In order to stay competitive, geothermal operators need innovative and cost-effective solutions to maintain production and defer the large capital costs of new wells. The failure, decline, or interruption of a well can have a significant impact on individual well production and station output. The challenges presented by down-hole issues in geothermal wells requires innovative solutions to maintain cost competitiveness of geothermal energy. This paper discusses some of the significant improvements we have made to geothermal well intervention and highlights the process and client/contractor partnership that enabled these advancements. In New Zealand, Western Energy has pioneered the application of coiled-tubing intervention (CTU) in geothermal wells for operations that previously were the exclusive domain of drilling rigs. Western has demonstrated significant value to geothermal generation companies through the use of CTU’s in well abandonments, fishing operations, acid stimulation, well initiation and mechanical scale cleanouts. This has resulted in achieving operational goals at significantly lower cost, reduced generation downtime and improved effectiveness. Two examples of Western’s innovation are: 1) well abandonments, where a step-change in process and continuous improvement initiatives have combined to provide effective abandonment of wells at 75% less cost than previous rig-based solutions, and 2) scale cleanouts, where our new Live Well Cleanout method enables scale cleanouts to occur with the well flowing, minimizing production downtime and maximising cleanout efficacy, coupled with an order of magnitude reduction in cost. A critical factor in the success of these innovations has been the effective client-contractor partnership between Western Energy and Contact Energy Limited. The development of new approaches and technology were enabled by and significantly enhanced by, the collaborative working relationship, shared goals, long-term approach and innovative contracting models. Western continues to look for new opportunities to bring step-change to geothermal well operations and welcomes the challenge to deliver more innovation and value for geothermal operators. |