Overview of Indonesian Geothermal System The Resources Beyond High Enthalpy Magmatic/Volcanic Systems By Dr.Eng. Suryantini ITB 4/3/2017 1
Outline Current Condition of Indonesian Geothermal Resources and its Systems Geology of Geothermal Systems Resources Beyond High Enthalpy Volcanic/Magmatic Associated Geothermal Systems Concluding Remark - The Future of Exploration, Utilization Challenges and Opportunities 4/3/2017 2
Current Condition of Indonesian Geothermal Resources and its Systems 4/3/2017 3
Current Condition of Indonesian Geothermal Resources Sources : MEMR, 2016 GWA Producer GWA Un-Producer GWA in bidding 330 Prospects 69 (<21%) Geothermal Working Areas (GWA) 11 Production GWA (<16% from total GWA or 3% from total prospects) 29,452 MW Potential 2,288 Mwe (7.8%) Proven Reserve 1,438.5 Mwe (63% from Proven or <5% from total potential) Production 4/3/2017 4
Indonesian Geothermal vs Present Day Volcanic Arc Sources : MEMR, 2016 Most of the Prospects are associated with volcanic arc 4/3/2017 5
Tectonic that control volcanoes and geothermal occurrences Most geothermal occurrences is associated with volcanic or magmatic heat sources Other is non-volcanic or amagmatic heat source extinct magmatic at old subduction zone, tectonic extensional domain, or Intra-cratonic basin, or conductive system 6 4/3/2017
Current Condition of Indonesian Geothermal Resources and its Systems 1) Imbalance between resource availability and development Inefficient geothermal energy utilization 2) Geosciences perspective on this condition i.e. a. The prospect is less attractive due to i.e. low potential, unsuitable for world class developer b. Lack of understanding about geothermal system improper project plan suspend of the project c. Misunderstanding of reservoir permeability as drilling target drilling failure suspend of the project 3) Most of geothermal systems that produce electricity is associated with volcanic or magmatic heat source with prominent surface manifestation what if the manifestation is very little and less or inactive? What if the volcanism is absence? 4) Low-Medium Enthalpy has not been explored or studied further 4/3/2017 7
Geology of Geothermal Systems 4/3/2017 8
A geothermal system is any localized geologic setting where portions of the Earth s thermal energy may be extracted from natural or artificially induced circulating fluids transported to a point of use. (Moeck, 2014) Geologic setting has a fundamental influence on the potential temperature, on the fluid composition, the reservoir characteristics and mode of heat transfer (convective or conductive) Failure in understanding this geologic setting (and all the supporting geologic elements that determine the setting) may cause many technical and financial problems that eventually leads to projects suspended or terminated. 4/3/2017 9
Geothermal Plays IGA classification Geothermal Play is adopted from Petroleum Translated to geothermal systems, a geothermal play type might be defined as a geological setting that includes a heat source, heat migration pathway, heat/fluid storage capacity, and the potential for economic recovery of the heat (IGA, 2014) 4/3/2017 10
Indonesian geothermal systems have all possible play types Which play type is your geothermal system? (IGA, 2014) 4/3/2017 11
Depth (km) Magmatic Play Type Active or Recent Magma Intrusion (IGA, 2014) Age of Volcanism - Active magmatism: volcanism <500 yrs - Recent magmatism: volcanism 500-50,000 yrs - Inactive or extinct magmatism: volcanism >50,000 yrs A familiar model for Indonesian Geothermal System. Recent (but not active) intrusions underneath or in the vicinity of volcanoes heat sources, with intensive surface manifestation. An active magma chamber does not always produce volcanism! 4/3/2017 12
Depth (km) Active or recent magmatic play type with intrusive magma chamber. Magma chamber Pluton (IGA, 2014) Influenced by active faulting, deep rooted magmas can intrude beneath flat terrain with no volcanism. Manifestation might be occur An upflow and outflow zone might be occur provided the topography of volcano support this 4/3/2017 13
Depth (km) Extinct magmatic play types controlled by late Cenozoic to Quaternary plutons or batholiths without associated volcanism. In Lardarelo: Pliocent Epoch - At 1.3-3.8 Ma. - Extensional event -Granite intrusion -Low-angle normal faults recharge Metasediments Quartenary granitic pluton (IGA, 2014) Examples are Lardarelo and The Geyser Typically located along continent-continent convergent or transform margins with recent magmatism Surrounding mountain ranges provide high recharge rates of meteoric water Manifestation might be occur Pleistocene Epoch -At 0.2-0.3 Ma -magmatic event primary heat source 4/3/2017 14
Extinct magmatic play types controlled by late Cenozoic to Quaternary plutons or batholiths with associated volcanism. Previous play type can coexist with active or recent volcanism Hence two systems might be coexist (IGA, 2014) 4/3/2017 15 Which one is your systems?
Extensional domain play type, with possible fault controlled fluid flow paths. (IGA, 2014) The elevated mantle principal heat source high thermal gradient deep faults or permeable formations fluid circulation path Non-magmatic, may be fault zone controlled or fault-leakage controlled at the system scale. Segmented faults are more favorable for geothermal systems than large faults with large offsets 4/3/2017 16
Conduction-Dominated Play Types Passive geothermal systems absence of fast convective or fluids dynamics Passive tectonic plate settings no significant recent tectonism or magmatism. Favorable geologic setting : extensional, divergent margins and grabens, or lithospheric subsidence basins, foreland basins within orogenic belts, and crystalline basement underlying thermally insulating sediments, Classified based on natural porosity permeability ratio within the potential reservoir rock, and the absence or presence of producible natural reservoir fluids. Intracratonic Basin Type, Orogenic Belt Type, and Basement Type 4/3/2017 17
Conduction-Dominated Play Types Intracratonic Basin Type Orogenic Belt Type 4/3/2017 18
Resources Beyond High Enthalpy Volcanic/Magmatic Associated Geothermal Systems 4/3/2017 19
Key point of volcanic or magmatic geothermal system 1. Age of volcanism determine the maturity of volcanism radiometric age dating? 2. An active magma chamber does not always produce volcanism geophysics? 3. Intrusion not beneath the system but in the vicinity, what if composite volcano? Or caldera? geophysics? 4. Most of geothermal exploration is guided by the occurrence of manifestation, in absence of surface manifestation or when the upflow-outflow zone is subtle Exploration concept play significant roles 5. An insight into the whole model or concept is necessary 4/3/2017 20
Tangkuban Perahu Is Ciater part of Tangkuban Perahu System? 4/3/2017 21
Patuha 4/3/2017 22
Wayang Windu, Darajat and Kamojang Is there any geothermal system between Darajat-Kamojang? Is there any potential at Malabar north of Wayang Windu? Kamojang Wayang Windu Darajat 4/3/2017 23
Silangkitang - Sarula Namora Silangkitang 4/3/2017 24
Muaralaboh 4/3/2017 25
Integrating regional data from petroleum exploration Would it be possible to find Extensional domain play type 4/3/2017 26
Integrating with regional data from petroleum exploration : Lesson Learned Geothermal System in Sumatra is controlled by volcanism due to subduction and mega strike slip Great Sumatran Fault which lies on continental granitic basement. It is a unique complexes system. Understanding the tectonic, geology and play type is crucial for discovery of geothermal system. Try to elaborate all geological data even from petroleum exploration or other survey Discuss the data, share the knowledge Blind system may be discovered 4/3/2017 27
Discuss the data, share the knowledge to get the complete picture 4/3/2017 28
What about geothermal system in Sulawesi and others in eastern Indonesia? Hall and Wilson, 2000 4/3/2017 29
Conduction dominated in sedimentary basin Geothermal Potential at the Sedimentary Basin in Sumatera Utilization of abandoned petroleum well (~700 abandoned well in Sumatera only) Regional Heat flow map is necessary 4/3/2017 30 There are >60 Tertiary Sedimentary Basins in Indonesia
Conduction Dominated Orogenic Belt Type 1. Sunda Orogeny : Java Southern Mountain Ranges Sumatera Barisan Mountain Ranges 2. Banda Orogeny : Sulawesi Mountain Ranges 3. Melanesia Orogeny : West Papua Papua New Guinea Mountain Ranges 4. Talaud Orogeny : Talaud Tifore ridge 4/3/2017 31
The potential of conductive dominated in orogenic belts Sunda Orogeny Melanesia Orogeny Banda Orogeny Talaud Orogeny 4/3/2017 32
Concuding remark: The Future Exploration and Utilization Challenges and Opportunities 4/3/2017 33
Integrating tectonic and regional geology to better understand the geothermal system both for volcanic magmatic or non volcanic Collecting radiometric dating as many as possible Start to carry out exploration program in conduction dominated Think out of the box 4/3/2017 34
. Thank You.. 4/3/2017 35