Case Study: ‘Hydraulic Fracturing Experience in the Wayang Windu Geothermal Field’

Abstract

Moment tensor analysis of micro earthquake data from the Wayang Windu geothermal field provides maximum/minimum stress orientation as well as the magnitude of the stress. Transient testing (fall off tests) conducted at several wells confirm the magnitude of minimum stress of the field. Further analysis of the fall off tests indicate that hydraulic fracturing could be a viable means to improve well productivity at Wayang Windu.
To test this conclusion an injection program to initiate hydraulic fracturing was conducted in two wells. A series of multiple injection rate followed by fall off tests gives the parameters for designing the hydraulic fracturing jobs to improve well performance. An injection program to produce hydraulic fracturing was then conducted. Post test treatment shows that new fractures were created and production improvements were achieved. Average steam mass flow production improved by 50 – 100 % (albeit from a low base).