Thursday, June 21, 2018

Science & Technology: A Joint 3D Inversion Workflow Study of the Darajat Geothermal Steam Field

Geologically consistent multiphysics imaging of the Darajat geothermal steam field (First Break)


Darajat is a vapor-dominated, producing geothermal field in West Java, Indonesia. Located along a range of Quaternary volcanic centres, it is associated with an eroded andesitic stratovolcano, and its reservoir is predominantly comprised of thick lava flows and intrusions in a stratovolcano central facies (Rejeki et al., 2010).

First production from the field was started in 1994 with the installation of a 55 MW plant, and capacity was added in 2000 and 2007 to bring the total to 271 MW.

Several ground geophysics data sets have been acquired during successive surveys – including gravity and magnetotelluric (MT) surveys, and continuing micro-earthquake (MEQ) monitoring (Soyer et al., 2017).

While each survey was independently modelled and interpreted, a quantitatively integrated 3D inversion modelling study had not been undertaken. We present a joint 3D inversion workflow, incorporating the production field model as a structural reference in order to derive mutually consistent subsurface resistivity, density and velocity distributions, as well as relocated MEQ events.

Read More........

Geologically consistent multiphysics imaging of the Darajat geothermal steam field, by Wolfgang Soyer, Randall Mackie, Stephen Hallinan, Alice Pavesi, Gregg Nordquist, Aquardi Suminar, Rindu Intani and Chris Nelson. First Break: Issue: Vol 36, No 6, June 2018 pp. 77 - 83.