scholarly journals Mapping of Fault and Hydrothermal System beneath the Seulawah Volcano Inferred from a Magnetotellurics Structure

Energies ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 6091
Author(s):  
Marwan Marwan ◽  
Muhammad Yanis ◽  
Gartika Setiya Nugraha ◽  
Muzakir Zainal ◽  
Nasrul Arahman ◽  
...  
Keyword(s):  
Power Plant ◽  
Heat Source ◽  
3D Structure ◽  
Source Zone ◽  
Geothermal System ◽  
Geothermal Systems ◽  
Entire Area ◽  
Earth Resistivity ◽  
Southern Side ◽  
Northern Side

Magnetotellurics (MT) is an important geophysical method for exploring geothermal systems, with the Earth resistivity obtained from the MT method proving to be useful for the hydrothermal imaging changes of the system. In this research, we applied the MT method to map the geothermal system of the Seulawah Agam volcano in northern Sumatra, a site intended for the construction of a geothermal power plant with an estimated energy of 230 Mwe. Herein, 3D MT measurements were carried out, covering the entire area of the volcano and the various intersecting local faults from the Seulimeum segment in the NW–SE direction. Based on Occam 2D inversion, a conductive anomaly (<10 ohm·m) near the surface was identified in response to specific manifestation areas, including the Heutsz crater on the northern side and the Cempaga crater on the southern side. A further conductive anomaly was also found at a depth of 1 km, which was presumably due to a clay cap layer covering the fluid in the reservoir layer below the surface, where the manifestation areas are formed at various locations (where faults and fractures are found) owing to the fluid in the reservoir rising to the surface. The MT modeling also revealed that the reservoir layer in Seulawah Agam lies at a depth of 2 km with a higher resistivity of 40–150 ohm·m, which is the main target of geothermal energy exploration. At the same time, the heat source zone where magma is located was estimated to lie in two locations, namely, on the northern side centering on the Heutsz crater area and the southern side in the Cempaga crater area. A clear 3D structure obtained via Occam inversion was also used to visualize the hydrothermal flow in the Seulawah Agam volcano that originates from two heat source zones, where one structure that was consistent across all models is the conductive zone that reaches a depth of 5 km in the south in response to the regional faulting of the Seulimeum segment. Based on the MT research, we concluded that the volcano has the geothermal potential to be tapped into power plant energy in the future.

scholarly journals 2D Forward Modeling Geothermal System Gravity Data in South Solok Region, West Sumatra

2021 ◽  
Vol 4 (1) ◽  
pp. 36-44
Author(s):  
Muhammad Nafian ◽  
Belista Gunawan ◽  
Nanda Ridki Permana
Keyword(s):  
Heat Source ◽  
Geothermal Energy ◽  
Gravity Data ◽  
Bouguer Anomaly ◽  
Filter Method ◽  
Geothermal System ◽  
Geothermal Systems ◽  
West Sumatra ◽  
Anomaly Map ◽  
Bouguer Anomaly Map

Indonesia has the greatest potential for geothermal energy in the world. Geothermal has an important role as an alternative fuel because it is a renewable energy source, but its use has not been maximized. One of the areas that have the greatest potential for geothermal energy in South Solok, West Sumatra. Therefore, this study was conducted to determine the geothermal system in the South Solok area, West Sumatra by using the gravity method. The gravity data processing stage requires some software to get the CBA value(Complete Bouguer Anomaly), map contours of the CBA. Anomaly separation with the butterworth filter method, determination of residual anomaly slice points, and 2D modeling of geothermal systems. Based on modeling, the qualitative interpretation interprets the Complete Bouguer Anomaly map which is suspected as a geothermal prospect area is a low anomaly ranging from 7.9 mgal - 9.4 mgal which is marked in dark blue. Meanwhile, quantitative interpretation produces modeling of the AB and CD slicing with a total of four layers. This layer consists of clay rock as a cap rock, sandstone as a reservoir, granite as a heated rock as a heat source, and the last layer in the form of magma as a heat source. The anomaly modeling of these two sections is dominated by granite rock with a density value of 2500 kg/m3 for the AB section and 2550 kg/m3 for the CD section.

scholarly journals Resistivity Models of Pantar Island Geothermal System East Nusa Tenggara, Indonesia

2020 ◽  
Vol 5 (3) ◽  
pp. 127-132
Author(s):  
Yoqi Ali Taufan ◽  
I. Syafri ◽  
D. Risdianto ◽  
A. Zarkasyi ◽  
T. Rahadinata ◽  
...  
Keyword(s):  
Heat Source ◽  
3D Models ◽  
High Resistivity ◽  
Geothermal System ◽  
Geothermal Systems ◽  
Low Resistivity ◽  
Resistivity Method ◽  
Geological Conditions ◽  
The Difference ◽  
Clay Cover

The subsurface geological conditions of a geothermal system are vital objects to be considered in geothermal exploration. The Magnetotellurics survey was conducted to explore for geothermal potential in Pantar Island. This is to achieve deeper penetration compared to our previous study that adopted resistivity method to determine reservoir zones based on rock resistivity models. The difference in rock resistivity in geothermal systems provides subsurface geological information in the form of low resistivity that associated the clay cap zones (high conductive), the medium resistivity zones associated with the reservoir zones, and high resistivity associated with a heat source. The results of 2D and 3D models from MT data show that the low resistivity value (<20Ωm) as a clay cover zones, this layer from the surface to -1000 meters. Medium resistivity values ​​(20-100 Ωm) starting from depths -1000 meters to -2000 meters associated with reservoirs zones, high resistivity values (> 200 Ωm) starting from depths of -2000 meters are considered as heat source from the Pantar geothermal system.

scholarly journals Increase of power and efficiency of the 900 MW supercritical power plant through incorporation of the ORC

2013 ◽  
Vol 34 (4) ◽  
pp. 51-71 ◽  
Author(s):  
Paweł Ziółkowski ◽  
Dariusz Mikielewicz ◽  
Jarosław Mikielewicz
Keyword(s):  
Power Plant ◽  
Heat Source ◽  
Steam Turbine ◽  
Hybrid System ◽  
Heat Recovery ◽  
Reference Conditions ◽  
Hot Water ◽  
Operational Parameters ◽  
Reference Case ◽  
Unit Power

Abstract The objective of the paper is to analyse thermodynamical and operational parameters of the supercritical power plant with reference conditions as well as following the introduction of the hybrid system incorporating ORC. In ORC the upper heat source is a stream of hot water from the system of heat recovery having temperature of 90 °C, which is additionally aided by heat from the bleeds of the steam turbine. Thermodynamical analysis of the supercritical plant with and without incorporation of ORC was accomplished using computational flow mechanics numerical codes. Investigated were six working fluids such as propane, isobutane, pentane, ethanol, R236ea and R245fa. In the course of calculations determined were primarily the increase of the unit power and efficiency for the reference case and that with the ORC.

scholarly journals Biofilm Forming Bacteria during Thermal Water Reinjection

Geofluids ◽  
2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Máté Osvald ◽  
Gergely Maróti ◽  
Bernadett Pap ◽  
János Szanyi
Keyword(s):  
Thermal Water ◽  
Oxygen Demand ◽  
Geothermal System ◽  
Biological Processes ◽  
Geothermal Systems ◽  
The Past ◽  
Surface System ◽  
Buffer Tank ◽  
Physical And Chemical ◽  
Phenol Index

Reinjection of heat-depleted thermal water has long been in the center of scientific interest in Hungary regarding around 1000 operating thermal wells. While the physical and chemical aspects of reinjection have partly been answered in the past years, the effects of biological processes are still less known. We carried out our investigations in the surface elements of the Hódmezővásárhely geothermal system which is one of the oldest operating geothermal systems in Hungary. About one-third of the used geothermal water has been reinjected since 1998 by two reinjection wells at the end of the thermal loops. During the operation, plugging of the surface system was experienced within a few-day-long period, due to biological processes. The goal of our research was to find the dominant species of the microbial flora and to make a proposal to avoid further bacterial problems. We found that the reinjected, therefore the produced, water’s chemical oxygen demand, phenol index, and BTEX composition basically determine the appearing flora on the surface. When the concentration of these compounds in the thermal water is significant and residence time is long enough in the buffer tank, certain bacteria can be much more dominant than others, thus able to form a biofilm which plugs the surface equipment much more than it is expected.

scholarly journals Utilisation of bleed steam heat to increase the upper heat source temperature in low-temperature ORC

2011 ◽  
Vol 32 (3) ◽  
pp. 57-70 ◽  
Author(s):  
Dariusz Mikielewicz ◽  
Jarosław Mikielewicz
Keyword(s):  
Power Plant ◽  
Low Temperature ◽  
Heat Source ◽  
Silicone Oil ◽  
Hot Water ◽  
Working Fluid ◽  
Preliminary Heating ◽  
Source Temperature ◽  
Heat Source Temperature ◽  
Steam Heat

Utilisation of bleed steam heat to increase the upper heat source temperature in low-temperature ORC In the paper presented is a novel concept to utilize the heat from the turbine bleed to improve the quality of working fluid vapour in the bottoming organic Rankine cycle (ORC). That is a completely novel solution in the literature, which contributes to the increase of ORC efficiency and the overall efficiency of the combined system of the power plant and ORC plant. Calculations have been accomplished for the case when available is a flow rate of low enthalpy hot water at a temperature of 90 °C, which is used for preliminary heating of the working fluid. That hot water is obtained as a result of conversion of exhaust gases in the power plant to the energy of hot water. Then the working fluid is further heated by the bleed steam to reach 120 °C. Such vapour is subsequently directed to the turbine. In the paper 5 possible working fluids were examined, namely R134a, MM, MDM, toluene and ethanol. Only under conditions of 120 °C/40 °C the silicone oil MM showed the best performance, in all other cases the ethanol proved to be best performing fluid of all. Results are compared with the "stand alone" ORC module showing its superiority.

scholarly journals Multi-objective optimization of ORC geothermal conversion system integrated with life cycle assessment

2018 ◽  
Vol 70 ◽  
pp. 01012
Author(s):  
Dominika Matuszewska ◽  
Marta Kuta ◽  
Jan Górski
Keyword(s):  
Life Cycle Assessment ◽  
Life Cycle ◽  
Organic Rankine Cycle ◽  
Rankine Cycle ◽  
Geothermal System ◽  
Geothermal Systems ◽  
Multi Objective Optimization ◽  
Geothermal Resources ◽  
Multi Objective ◽  
Conversion Technology

This paper details the development of a systematic methodology to integrated life cycle assessment (LCA) with thermo-economic models and to thereby identify the optimal exploitation schemes of geothermal resources. Overall geothermal systems consist of a superstructure of geothermal exploitable resources, a superstructure of conversion technology and multiple demand profiles for Swiss city. In this paper, an enhanced geothermal system has been chosen as exploitable resources. The energy conversion technology used in modelling is an organic Rankine cycle, which can be used to supply heat and electricity. In the Swiss case four demand profiles periods are considered: summer, interseason, winter and extreme winter, the city Nyon serving for the example case study. The multi-objective optimization system, that uses an evolutionary algorithm, is employed to determine the optimal scheme for some of the prepared models, with exergy efficiency and environmental impact as objectives.

Analysis of the Thermodynamic Performance of Kalina Cycle System 11 (KCS11) for Geothermal Power Plant: Comparison With Kawerau ORMAT Binary Plant

2009 ◽  
Author(s):  
Xinli Lu ◽  
Arnold Watson ◽  
Joe Deans
Keyword(s):  
Power Generation ◽  
Power Plant ◽  
Heat Source ◽  
Gas Turbines ◽  
Effective Means ◽  
Specific Power ◽  
Kalina Cycle ◽  
Geothermal Power Plant ◽  
Thermodynamic Performance ◽  
Geothermal Power

Since the first geothermal power plant was built at Larderello (Italy) in 1904, many attempts have been made to improve conversion efficiency. Among innovative technologies, using the Kalina cycle is considered as one of the most effective means of enhancing the thermodynamic performance for both high and low temperature heat source systems. Although initially used as the bottoming cycle of gas turbines and diesel engines, in the late 1980s the Kalina cycle was found to be attractive for geothermal power generation [1, 2, 3]. Different versions (KSC11, KSC12 and KSC13) were designated. Comparison between Kalina cycle and other power cycles can be found in later studies [4, 5, 6]. Here we examine KSC11, because it is specifically designed for geothermal power generation, with lower capital cost [3]. We compare this design with the existing Kawerau ORMAT binary plant in New Zealand. In addition, parametric sensitivity analysis of KCS11 has been carried out for the specific power output and net thermal efficiency by changing the temperatures of both heat source and heat sink for a given ammonia-water composition.

Oil and Gas Drill Bit Technology and Drilling Application Engineering Saves 77 Drilling Days on the World’s Deepest Engineered Geothermal Systems EGS Wells

2021 ◽  
Author(s):  
Jennifer Cardoe ◽  
Gunnar Nygaard ◽  
Christopher Lane ◽  
Tero Saarno ◽  
Marc Bird
Keyword(s):  
Oil And Gas ◽  
Average Run Length ◽  
Renewable Energy Sources ◽  
Pilot Project ◽  
Geothermal System ◽  
Drill Bit ◽  
Geothermal Systems ◽  
Geothermal Heat ◽  
Run Length ◽  
Run Lengths

Abstract An Engineered Geothermal System (EGS) pilot project was commissioned to prove the economic viability of an industrial scale geothermal heat plant in Finland. The project aims to generate 40 MW of emission free heat energy, supplying up to 10% of the city of Espoo’s district heating needs. Two wells of 6400 m MD and 6213 m MD (measured depth) were drilled through formations of hard, abrasive granitic gneiss with maximum measured 560 MPa UCS (unconfined compressive strength). Typical dull conditions of lost and worn cutting structure and gauge diameter wear of between 3/16-in to ¼-in contributed to excessive torque, stuck incidences, low rate of penetration (ROP) and difficulties achieving build rate. To address these drilling challenges, this paper explores the interplay between new cemented carbide compact technology, drill bit design, and drilling parameter road mapping. The directional section of the first well was drilled with an average ROP below 2 m/hr and run length averaging 56 m per bit. The well took 246 drilling days and 44 BHAs (bottom hole assemblies) to achieve TD (total depth). Between the first and second well an application specific drill bit design package and step-wise parameter program were implemented. Design enhancements included improved gauge protection, bit hydraulics for minimizing cone erosion and subsequent TCI (tungsten carbide insert) compact loss. Novel hybrid TCI materials technology was introduced having a 100% improvement in wear resistance and durability as compared with conventional grades, to drill these hard and abrasive granitic formations. New BHAs and drilling plan were selected based on the bit design selection to reduce wear on BHA components, improve directional control and reducing drilling dysfunctions. Once these factors were under control, a low risk approach to extending the bit revolution limits (krev) for the roller cone sealed bearings could be implemented based on downhole parameters and previous bit dulls, leading to longer run lengths. The combination of bit design and material enhancements with a properly selected BHA and drill plan increased run lengths and ROP. The second well’s 8.5-in directional section was drilled with a 13% increase in average ROP and a 69% increase in average run length without exceeding krev limits. Well on well, a 77 day reduction in AFE (authorization for expenditure) was realized. We demonstrated the combination of oil and gas bit and BHA design, drilling plan, and new cutting material capabilities can reduce EGS well construction costs in order to make these renewable energy sources economical.

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