TY - JOUR
T1 - The first repeated absolute gravity measurement for geothermal monitoring in The Kamojang Geothermal Field, Indonesia
AU - Sofyan, Yayan
AU - Daud, Yunus
AU - Nishijima, Jun
AU - Fujimitsu, Yasuhiro
AU - Kamah, Yustin
AU - Yani, Ahmad
AU - Fukuda, Yoichi
AU - Taniguchi, Makoto
N1 - Funding Information:
I would like to thank PERTAMINA for his permission in monitoring study of his area at KGF. We also thank Research Institute for Humanity and Nature (RIHN) for gravity measurement using Absolute gravimeter. I acknowledge the financial support of KAKENHI (Grant-in-Aid for Scientific Research by Japan Society for the Promotion of Science) Category B (No. 21404018 ) for gravity measurement at KGF.
PY - 2015/1
Y1 - 2015/1
N2 - In more than 25 years, repeated gravity measurements (RGM) for geothermal monitoring have been applied in the Kamojang Geothermal Field (KGF), Indonesia. Pertamina has carried out RGM using relative gravimeters at more than 50 benchmarks at KGF since 1984. They used LaCoste-Romberg type G 653, G 655, and Scintrex CG-3 gravimeters to estimate gravity variation. In 2009, we introduced a new microgravity network using A10 (#017) micro-g, a portable absolute gravimeter, which we re-occupied in 2010 and 2011.We identify gravity value changes in production and injection area of KGF as well as changes at the reference station. A linear trend of declining mass of about -17.9. μGal/year at PG48A, a benchmark far from production and injection wells, reveal the temporal gravity variation outside of geothermal reservoirs. The series of monitoring in this present research shows the distribution of large negative gravity changes up to -80. μGal. The large mass loss stays continues to maintain massive production throughout 200. MWe installed capacities at KGF.The absolute gravity measurements improve the result of gravity change data for monitoring. This present study introduces new technology that will enhance the method of reservoir monitoring using repeated precisely-gravity measurements. The use of absolute gravimeter is the best way to account for regional effect, and correct for changes at the base and reference station over time.
AB - In more than 25 years, repeated gravity measurements (RGM) for geothermal monitoring have been applied in the Kamojang Geothermal Field (KGF), Indonesia. Pertamina has carried out RGM using relative gravimeters at more than 50 benchmarks at KGF since 1984. They used LaCoste-Romberg type G 653, G 655, and Scintrex CG-3 gravimeters to estimate gravity variation. In 2009, we introduced a new microgravity network using A10 (#017) micro-g, a portable absolute gravimeter, which we re-occupied in 2010 and 2011.We identify gravity value changes in production and injection area of KGF as well as changes at the reference station. A linear trend of declining mass of about -17.9. μGal/year at PG48A, a benchmark far from production and injection wells, reveal the temporal gravity variation outside of geothermal reservoirs. The series of monitoring in this present research shows the distribution of large negative gravity changes up to -80. μGal. The large mass loss stays continues to maintain massive production throughout 200. MWe installed capacities at KGF.The absolute gravity measurements improve the result of gravity change data for monitoring. This present study introduces new technology that will enhance the method of reservoir monitoring using repeated precisely-gravity measurements. The use of absolute gravimeter is the best way to account for regional effect, and correct for changes at the base and reference station over time.
KW - Absolute gravity measurement
KW - Geothermal monitoring
KW - Kamojang Geothermal Field
UR - http://www.scopus.com/inward/record.url?scp=84902477804&partnerID=8YFLogxK
U2 - 10.1016/j.geothermics.2014.05.002
DO - 10.1016/j.geothermics.2014.05.002
M3 - Article
AN - SCOPUS:84902477804
SN - 0375-6505
VL - 53
SP - 114
EP - 124
JO - Geothermics
JF - Geothermics
ER -