Temperature and pressure corrections applied to rock thermal conductivity: impact on subsurface temperature prognosis and heat-flow determination in geothermal exploration

An understanding of the subsurface thermal regime is beneficial to many disciplines, including petroleum and geothermal exploration, carbon capture and storage (CCS) and nuclear waste sequestration. This project developed and tested a new methodology for determining subsurface temperature using a non-invasive approach based on the velocity information derived from seismic reflection data. By solving a one-dimensional steady state approximation of Fourier’s Law, it is possible to determine a bulk thermal gradient as a function of depth, enabling the determination of temperatures across an entire volume using this methodology, termed reflection seismic thermometry. There are two principal components to this methodology, requiring 1) a bulk thermal conductivity structure and 2) heat flow and/or temperature data to condition the model. The first component uses an empirical velocity to thermal conductivity transform whilst the second uses sparse temperature data from boreholes or a bottom simulating reflector (BSR) to derive the shallow thermal regime and heat flow. The thermometry workflow has been applied to three case studies; in the Lüderitz Basin, offshore Namibia; the Blake Ridge, offshore USA; and the North Viking Graben (NVG) in the North Sea. In the frontier Lüderitz Basin, a BSR was identified and used to derive heat flow of 60-70 mW m-2. The Aptian source rock interval here was shown to presently be in the gas generative window. On Blake Ridge borehole velocities and a BSR were used to determine heat flow (43-56 mW m-2) and subsurface temperatures. Finally, methodology validation was conducted in the North Sea Basin using a high-resolution 3D full waveform inversion (FWI) velocity dataset calibrated with 141 wells. Forward models of subsurface temperatures were calibrated against the borehole temperatures, with inverse modelling used to derive heat flow at km scale lateral resolution. The availability of a fast track velocity volume for this area allowed comparison with the FWI derived thermal model results. It was found that stacking velocities were lower than well and FWI velocities, leading to overprediction of subsurface temperature. Modelling the temperature profile for CCS well 31/5-7 showed bottom hole temperature (BHT) within 6 °C of recorded BHT. With application and verification of the method in different basins, the versatility of the work conducted is demonstrated. It is envisioned that this technique opens avenues for the seismic characterisation of thermal regime in disparate settings and varied disciplines.

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Subsurface temperature from seismic reflection data: application to the post break up sequence offshore Namibia

10.31223/x5h05z ◽

2021 ◽

Author(s):

Arka Dyuti Sarkar ◽

Mads Huuse

Keyword(s):

Thermal Conductivity ◽

Heat Flow ◽

Seismic Reflection ◽

Surface Heat ◽

Passive Margin ◽

Petroleum Exploration ◽

Subsurface Temperature ◽

Seismic Reflection Data ◽

Surface Heat Flow ◽

Subsurface Temperatures

Accurate estimations of present-day subsurface temperatures are of critical importance to the energy industry, in particular with regards to geothermal energy and petroleum exploration. This paper uses seismic reflection observations of bottom-simulating reflections and subsurface velocities coupled with an empirical velocity to thermal conductivity transform to estimate subsurface temperature in a process dubbed reflection seismic thermometry. The case study is a frontier passive margin extending from the shelf edge to deep water in the central Lüderitz Basin, offshore Namibia. The bottom simulating reflector is used to derive surface heat flow. The thermal conductivity model was applied to seismic processing velocities to determine the subsurface thermal conductivity. Knowledge of surface heat flow and thermal conductivity structure allowed us to estimate subsurface temperatures across the study area. The results suggest the Lüderitz Basin has a working hydrocarbon system with the inferred Aptian Kudu source interval within the gas generation window.

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Subsurface temperature of the northern North Sea Basin

10.31223/x5nk7t ◽

2021 ◽

Author(s):

Arka Dyuti Sarkar ◽

Mads Huuse

Keyword(s):

Thermal Conductivity ◽

Heat Flow ◽

North Sea ◽

Seismic Data ◽

Carbon Capture ◽

Mean Squared Error ◽

Waveform Inversion ◽

Subsurface Temperature ◽

Forward Modelling ◽

Modelling Problem

The North Viking Graben (NVG) is part of the mature North Sea Basin petroleum province and designated as a major carbon storage basin for NW Europe. It has been extensively drilled over five decades with an abundance of well and seismic data in the public domain. As such it serves as an excellent setting to demonstrate the efficacy of a proprietary seismic data led approach to modelling subsurface temperatures using a state-of-the-art full waveform inversion velocity model covering the entire NVG. In a forward modelling problem, an empirical velocity to thermal conductivity transform is used in conjunction with predefined heat flow to predict subsurface temperature. The predefined heat flow parameters are set based on the range of values from previous studies in the area. Abundant well data with bottom hole temperature (BHT) records provide calibration of results. In the inverse modelling problem, BHT’s as well as the velocity derived thermal conductivity are used to solve a 1D steady state approximation of Fourier’s Law for heat flow. In this way heat flow is interpolated over the 12000 km2 model area at a km scale (lateral) resolution, highlighting lateral variability in comparison to the traditional point-based heat flow datasets. This heat flow is used to condition a final iterative loop of forward modelling to produce a temperature model that is best representative of the subsurface temperature. Calibration against 139 exploration wells indicate that the predicted temperatures are on average only 0.6 °C warmer than the recorded values, with a root mean squared error range of 5 °C. BHT for the recently completed Northern Lights carbon capture and sequestration (CCS) well 31/5-7 (Eos) has been modelled to be 97 °C, which is within 6 °C of the recorded BHT. This serves to highlight the applicability of this workflow not only towards enhancing petroleum systems modelling work but also for use in the energy transition and for fundamental scientific purposes.

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Integrated Subsurface Temperature Modeling beneath Mt. Lawu and Mt. Muriah in The Northeast Java Basin, Indonesia

Open Geosciences ◽

10.1515/geo-2019-0027 ◽

2019 ◽

Vol 11 (1) ◽

pp. 341-351

Author(s):

Bagus Endar B. Nurhandoko ◽

Rizal Kurniadi ◽

Susilowati ◽

Kaswandhi Triyoso ◽

Sri Widowati ◽

...

Keyword(s):

Thermal Conductivity ◽

Heat Flow ◽

Surface Temperature ◽

Geological Model ◽

Subsurface Temperature ◽

Geothermal Heat ◽

Conductivity Model ◽

Temperature Modeling ◽

Survey Line ◽

Thermal Conductivity Model

Abstract The subsurface temperature has many impacts on geological phenomena such as hydrocarbon generation, geothermal energy, mineralization, and geological hazards. The Northeast Java Basin has various interesting phenomena, such as many oil fields, active faults, mud eruptions, and some active and dormant volcanoes. We measured temperature data from tens of wells along a 130 km survey line with an average spacing of 5 km. We also measured the thermal conductivity of rocks of various lithologies along the survey line to provide geothermal heat flow data. We propose integrated modeling for profiling the subsurface temperature beneath the survey line from Mt. Lawu to Mt. Muriah in the Northeast Java Basin. The modeling of subsurface temperature integrates various input data such as a thermal conductivity model, surface temperature, gradient temperature, a geological model, and geothermal heat flow. The thermal conductivity model considers the subsurface geological model. The temperature modeling uses the finite difference of Fourier’s law, with an input subsurface thermal conductivity model, geothermal heat flow, and surface temperature. The subsurface temperature profile along with survey line shows some interesting anomalies which correlate with either subsurface volcanic activity or the impact of fault activity.

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Subsurface temperature, thermal conductivity, and heat flow near Aiken, South Carolina

Journal of Geophysical Research Atmospheres ◽

10.1029/jz070i022p05635 ◽

1965 ◽

Vol 70 (22) ◽

pp. 5635-5644 ◽

Cited By ~ 7

Author(s):

W. H. Diment ◽

I. W. Marine ◽

James Neiheisel ◽

G. E. Siple

Keyword(s):

Thermal Conductivity ◽

South Carolina ◽

Heat Flow ◽

Subsurface Temperature

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Characteristics of geothermal reservoirs in the Wumishan Formation and groundwater of the Middle-Upper Proterozoic and the geothermal status in the Beijing–Tianjin–Hebei region: Implications for geothermal resources exploration

Energy Exploration & Exploitation ◽

10.1177/0144598718798100 ◽

2019 ◽

Vol 37 (2) ◽

pp. 811-833 ◽

Cited By ~ 1

Author(s):

Liang Zhang ◽

Hancheng Ji ◽

Liang Chen ◽

Jinxia Liu ◽

Haiquan Li

Keyword(s):

Thermal Conductivity ◽

Heat Flow ◽

Atmospheric Precipitation ◽

Geothermal Resources ◽

Geothermal Exploration ◽

Geothermal Reservoirs ◽

Terrestrial Heat Flow ◽

Groundwater Supply ◽

Taihang Mountain ◽

Wumishan Formation

Exploration of the geothermal resources in the Beijing–Tianjin–Hebei region has been kept for tens of years, and the recent success of geothermal exploration in the Xiongxian County provides a new model for the utilization of geothermal resources in this area. This research integrates the formation of temperature obtained from hydrocarbon drilling, experiments of reservoirs’ micro-characteristics and physical property, and employs the previous works on the regional geological settings to investigate the geothermal reservoirs and geothermal status. The microphotography indicates that the reservoir space is dominated by supergene karst in the Wumishan Formation which is mainly controlled by the topography when the interval emerged. The groundwater in the Pre-Paleogene has the similar composition of the hydrogen and oxygen isotope with the atmospheric precipitation, and the salinity of the groundwater has an increasing trend from the Taihang Mountain and the Yanshan Mountain to the depocenters, which indicates the groundwater originates from the atmospheric precipitation of the Taihang Mountain and the Yanshan Mountain and transports to the depocenters. The thermal conductivity of the lower carbonate rocks is much higher than the upper clastic intervals. This difference makes the upper clastic intervals of the Paleogene and the Neogene good seals for geothermal reservoirs and leads to the regional anomaly of the terrestrial heat flow: the intrabasin highs have a thicker thickness of the Pre-Paleogene carbonate deposition with high thermal conductivity, which results in high efficient thermal transmission and high terrestrial heat flow. Consequently, this research suggests that the intrabasin highs and slopes are the favourable areas for geothermal exploration with reservoirs of good quality, high terrestrial heat flow and efficient groundwater supply, and several areas were selected to be the potential targets for the Wumishan Formation and the Pre-Paleogene.

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On the importance of rock thermal conductivity and heat flow density in basin and petroleum system modelling

Basin Research ◽

10.1111/bre.12427 ◽

2019 ◽

Vol 32 (5) ◽

pp. 1261-1276 ◽

Cited By ~ 1

Author(s):

Evgeny Chekhonin ◽

Yury Popov ◽

Georgy Peshkov ◽

Mikhail Spasennykh ◽

Evgeny Popov ◽

...

Keyword(s):

Thermal Conductivity ◽

Heat Flow ◽

Petroleum System ◽

Flow Density ◽

System Modelling ◽

Heat Flow Density ◽

Rock Thermal Conductivity

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Heat flow in the Uinta Basin determined from bottom hole temperature (BHT) data

Geophysics ◽

10.1190/1.1441680 ◽

1984 ◽

Vol 49 (4) ◽

pp. 453-466 ◽

Cited By ~ 100

Author(s):

David S. Chapman ◽

T. H. Keho ◽

Michael S. Bauer ◽

M. Dane Picard

Keyword(s):

Thermal Conductivity ◽

Heat Flow ◽

Thermal Resistance ◽

Geothermal Gradient ◽

Surface Heat ◽

Subsurface Temperature ◽

The South ◽

Uinta Basin ◽

Surface Heat Flow ◽

Bottom Hole

The thermal resistance (or Bullard) method is used to judge the utility of petroleum well bottom‐hole temperature data in determining surface heat flow and subsurface temperature patterns in a sedimentary basin. Thermal resistance, defined as the quotient of a depth parameter Δz and thermal conductivity k, governs subsurface temperatures as follows: [Formula: see text] where [Formula: see text] is the temperature at depth z=B, [Formula: see text] is the surface temperature, [Formula: see text] is surface heat flow, and the thermal resistance (Δz/k) is summed for all rock units between the surface and depth B. In practice, bottom‐hole and surface temperatures are combined with a measured or estimated thermal conductivity profile to determine the surface heat flow [Formula: see text] which, in turn, is used for all consequent subsurface temperature computations. The method has been applied to the Tertiary Uinta Basin, northeastern Utah, a basin of intermediate geologic complexity—simple structure but complex facies relationships—where considerable well data are available. Bottom‐hole temperatures were obtained for 97 selected wells where multiple well logs permitted correction of temperatures for drilling effects. Thermal conductivity values, determined for 852 samples from 5 representative wells varying in depth from 670 to 5180 m, together with available geologic data were used to produce conductivity maps for each formation. These maps show intraformational variations across the basin that are associated with lateral facies changes. Formation thicknesses needed for the thermal resistance summation were obtained by utilizing approximately 2000 wells in the WEXPRO Petroleum Information file. Computations were facilitated by describing all formation contacts as fourth‐order polynomial surfaces. Average geothermal gradient and heat flow for the Uinta Basin are [Formula: see text] and [Formula: see text], respectively. Heat flow appears to decrease systematically from 65 to [Formula: see text] from the Duchesne River northward toward the south flank of the Uinta Mountains. This decrease may be the result of refraction of heat into the highly conductive quartzose Precambrian Uinta Mountain Group. More likely, however, it is related to groundwater recharge in late Paleozoic and Mesozoic sandstone and limestone beds that flank the south side of the Uintas. Heat flow values determined for the southeast portion of the basin show some scatter about a mean value of [Formula: see text] but no systematic variation.

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