| Title | Assessing the Effectiveness of Deflagration in Multi-Feedzone Wells |
|---|---|
| Authors | P. Bixley, K. Mclean, Y. Wei Lim, D. Wilson |
| Year | 2016 |
| Conference | New Zealand Geothermal Workshop |
| Keywords | Deflagration, Stimulation, Injectivity, Fluid Velocity, Geothermal. |
| Abstract | Deflagration as a means to improve well permeability and productivity has now been trialled in several geothermal fields. For geothermal production wells the effectiveness of deflagration has been somewhat equivocal. During 2015, Contact carried out deflagration trials in three production wells. To provide an immediate indication of the effectiveness of these trials it was decided to use the overall well injectivity index as the primary indicator of improved well performance. The results seemed somewhat disappointing at the time, with only small improvements in the overall well injectivity when comparing results from pre and post-deflagration tests. However, modelling the test data with a simple spreadsheet shows that in multi-feedzone wells the overall injectivity may not be sensitive to large changes of injectivity at an individual feedzone. It appears that an improvement in production is the only definitive measure of the effect of deflagration and this may not become apparent for several weeks, or months as the well recovers from cold water injection required to cool the well sufficiently to perform the deflagration operation. |