TY - JOUR
T1 - Physical properties of G-class cement for geothermal well cementing in South Korea
AU - Won, Jongmuk
AU - Lee, Dongseop
AU - Na, Kyunguk
AU - Lee, In Mo
AU - Choi, Hangseok
N1 - Funding Information:
The authors appreciate the support partially by the Korea Agency for Infrastructure Technology Advancement under the Ministry of Land, Infrastructure and Transport of the Korean government (No. 13 Construction Research T01) and by National Research Foundation of Korea Government ( NRF-2014R1A2A2A01007883 ).
PY - 2015/8/1
Y1 - 2015/8/1
N2 - The cement material adopted for a new geothermal well project in South Korea is specialized as the G-class cement, which is commonly used in the oil-well industry, and regulated by the API (American Petroleum Institute). In order to maintain the optimal generating performance of geothermal wells, physical properties of the cementing material should be satisfactory. In this paper, the significant material properties (i.e., groutability, uniaxial compressive strength, thermal conductivity, bleeding potential, phenolphthalein indication) of the G-class cement were experimentally examined, with consideration of various water-cement (w/c) ratios as mix proportion. Important findings through the experiments are as follows; (1) Groutability of the G-class cement increases with the addition of a small amount of retarder. (2) There would be a structural problem when the w/c ratio is kept extremely high in order to obtain acceptable groutability. (3) Thermal conductivity of the G-class cement is small enough to prevent heat loss during circulating up hot steam or water from the deep underground to the ground surface. (4) The G-class cement used for geothermal-well cementing causes no bleeding problem. (5) The phenolphthalein indicator is applicable to distinguishing the G-class cement from the drilling mud.
AB - The cement material adopted for a new geothermal well project in South Korea is specialized as the G-class cement, which is commonly used in the oil-well industry, and regulated by the API (American Petroleum Institute). In order to maintain the optimal generating performance of geothermal wells, physical properties of the cementing material should be satisfactory. In this paper, the significant material properties (i.e., groutability, uniaxial compressive strength, thermal conductivity, bleeding potential, phenolphthalein indication) of the G-class cement were experimentally examined, with consideration of various water-cement (w/c) ratios as mix proportion. Important findings through the experiments are as follows; (1) Groutability of the G-class cement increases with the addition of a small amount of retarder. (2) There would be a structural problem when the w/c ratio is kept extremely high in order to obtain acceptable groutability. (3) Thermal conductivity of the G-class cement is small enough to prevent heat loss during circulating up hot steam or water from the deep underground to the ground surface. (4) The G-class cement used for geothermal-well cementing causes no bleeding problem. (5) The phenolphthalein indicator is applicable to distinguishing the G-class cement from the drilling mud.
KW - Free fluid content
KW - G-class cement
KW - Geothermal well cementing
KW - Groutability
KW - Thermal conductivity
KW - Uniaxial compressive strength
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U2 - 10.1016/j.renene.2015.01.067
DO - 10.1016/j.renene.2015.01.067
M3 - Article
AN - SCOPUS:84923031282
VL - 80
SP - 123
EP - 131
JO - Renewable Energy
JF - Renewable Energy
SN - 0960-1481
ER -