Influence of rock thermal conductivity correction on the calculated value of terrestrial heat flow——A case study of Jizhong Depression, Bohai Bay Basin
Author:
Affiliation:

Clc Number:

Fund Project:

  • Article
  • |
  • Figures
  • |
  • Metrics
  • |
  • Reference
  • |
  • Related
  • |
  • Cited by
  • |
  • Materials
  • |
  • Comments
    Abstract:

    Rock thermal conductivity is the basic thermophysical parameter for calculating terrestrial heat flow, the selection and calibration of this key parameter is the basis for correct thermal assessment. Currently, in the calculation of terrestrial heat flow in the Jizhong Depression and even in the Bohai Bay Basin, the Paleogene and Neogene sandy—mud strata, which are less affected by seasonal temperature changes and groundwater activities, are mostly used as the terrestrial heat flow computing formation, and the rock thermal conductivity is also mostly referred to the existing fixed values in the region, but ignore the dependence of thermal conductivity on water saturation, temperature and pressure. This paper calculated and compared the effects of different correction methods on heat flow values from the viewpoint of water saturation correction and temperature—pressure correction of rock thermal conductivity. As a thermal physical property parameter affected by multiple factors, rock thermal conductivity is closely related to lithology or mineral composition, and generally negatively correlated with porosity, and positively correlated with density. The thermal conductivity of sandstone samples in Jizhong Depression at high temperature showed that overall the thermal conductivity decreases with increasing temperature, and the thermal conductivity decreased by 6.8%~11.3% in the temperature range of 30~130℃, the thermal conductivity decrease rate decreases with decreasing thermal conductivity; since sandstones and mudstones have relatively shallow burial depths and low temperature and pressure in situ conditions, meanwhile, the positive and negative effects of temperature and pressure on thermal conductivity can be offset each other to some extent, therefore, especially for samples with thermal conductivity less than 2 W/(m·K), the effect of temperature and pressure on the samples can be ignored. The thermal conductivity average deviation of Tertiary sandstone and mudstone in well JZ03 and well JZ04 in Jizhong Depression after water saturation correction is up to 43.0% and 47.5% respectively. The terrestrial heat flow values calculated without any correction, corrected for water content and porosity for the thermal conductivity of the Tertiary stratum in wells JZ03 and JZ04 are 43.05 mW/m2, 45.39 mW/m2, 61.64 mW/m2 and 52.81 mW/m2, 59.81 mW/m2, 78.14 mW/m2, respectively; Finally, the values of 61.64 mW/m2 and 78.14 mW/m2 calculated from the thermal conductivity corrected by the geometric mean model water saturation corrected are selected as the terrestrial heat flow values of Niubei slope and the central part of the Gaoyang low bulge in Jizhong Depression, respectively.

    Reference
    Related
    Cited by
Get Citation

SONG Jiajia, WANG Guiling, XING Linxiao, LU Chuan, QIAN Jiazhong.2023. Influence of rock thermal conductivity correction on the calculated value of terrestrial heat flow——A case study of Jizhong Depression, Bohai Bay Basin[J]. Geological Review,69(1):2023010026.

Copy
Share
Article Metrics
  • Abstract:
  • PDF:
  • HTML:
  • Cited by:
History
  • Received:September 01,2022
  • Revised:November 22,2022
  • Adopted:
  • Online: February 19,2023
  • Published: