NewQuest footprint in Blawan-Ijen WKP, First Discovery of hidden geothermal in Indonesia

Geothermal potential according to Geological Agency of Indonesia data in December 2019 was 23.9 GW is spread over 351 locations in 30 provinces across Indonesia. Blawan-Ijen Geothermal Area ( WKP ) is located in the Banyuwangi and Bondowoso Districts in the east Java Province.

WKP Ijen manage by Medco Cahaya Geothermal and Ormat Indonesia has become Indonesia’s geothermal hot spot in the last 4 years because Ijen is the first geothermal discovery for East Java province, Ijen Slim hole is the first deep slim hole flowing in Indonesia in 2016. Now the national and international geothermal communities are waiting for the result of well testing of IJN 6-1 well, a standard exploration well, what is the MW output ( MW ) of the well.

The most interesting part of Geothermal Exploration in WKP Ijen is “Hidden Reservoir”, the term hidden was first used by NewQuest Technology in paper entitled Discovering “Hidden” Geothermal Reservoir in Blawan-Ijen Geothermal Area (Indonesia) Using 3-D Inversion of MT Data.

The following is a paragraph in the NewQuest paper that describes this hiding condition:

Unimpressive surface manifestations are found in the northern caldera margin within Blawan area, including bicarbonate springs with temperature between 35 – 50OC. The only “rather impressive” manifestation is Ijen crater lake with abundant solfatara located in the eastern margin of the caldera. Unfortunately, the fluid has extremely low pH of less than 0.3. The rest of the caldera has no other surface manifestations. Accordingly, the crucial questions are: (1) Any geothermal reservoir exists within the caldera? (2) If yes, is the reservoir fluid: high temperature with neutral pH? (3) Where to find the promising zone (high temperature, high permeability and neutral fluid)? Those questions are challenging to answer within such “hidden” geothermal area The slim hole drilling program in 2016, which the total depth reached 2000 m, finally discovered high temperature (283oC) and neutral reservoir in Blawan-Ijen geothermal area. This is one example of the 3-D MT inversion role for discovering “hidden” geothermal reservoir.

The involvement of NewQuest / NewQuest personal in the WKP Ijen survey began in 2015 and can be divided into 3 parts as below:

In 2015 through Makara Mas; Remote Sensing Analysis, Reprocessing & 3-D Modeling of Existing MT Data, Additional Geophysical Survey MT and Gravity, Conceptual Modeling and Resources Assessment, Well Targeting

In 2016, NewQuest Geotechnology; Slim Hole Drilling Evaluation, Simulation of Standard-Big Hole Production and Updating Conceptual Model and Resources Assessment

In 2017 – 2018, through Research Grant of University Indonesia; Geological Mapping, Geophysical Survey Gravity and Magnetic

Discovery story of Ijen hidden reservoir can be read :

https://newquest-geotechnology.com/pdf.php?file=download/paper/20170202.pdf

More story on slim hole drilling in Ijen can be read on

https://pangea.stanford.edu/ERE/db/GeoConf/papers/SGW/2020/Adityatama.pdf