A new method for correcting temperature log profiles in low-enthalpy plays

Abstract

Temperature logs recorded shortly after drilling operations can be the only temperature information from deep wells. However, these measurements are still influenced by the thermal disturbance caused by drilling and therefore do not represent true rock temperatures. The magnitude of the thermal disturbance is dependent on many factors such as drilling time, logging procedure or mud temperature. However, often old well reports lack this crucial information so that conventional corrections on temperature logs cannot be performed. This impedes the re-evaluation of well data for new exploration purposes, e.g. for geothermal resources. This study presents a new method to correct log temperatures in low-enthalpy play types which only requires a knowledge of the final depth of the well as an input parameter. The method was developed and verified using existing well data from an intracratonic sedimentary basin, the eastern part of the North German Basin. It can be transferred to other basins with little or no adjustment.

Estimation of the Impact of Basement Heterogeneity on Thermal History Reconstruction: The Western Siberian Basin

“…The second is caused by uncertainty with undisturbed temperature measurements, as the temperature readings in a well during drilling or completion do not reflect the equilibrium formation temperature [100,101], and the measured temperature values can be underestimated by up to ~22 • C, with standard deviation σ = 10 • C for depths of 500 to 9000 m [102,103]. Various correction schemes have been presented and discussed in the literature (e.g., [104,105] and references therein); however, the uncertainty is rarely estimated. In [102], the application of corrections improved "a prediction of formation temperatures with an error less than ±10 • C at somewhat deeper depths than the log in several boreholes.…”

Geothermal Geological Characteristics and Genetic Model of the Shunping Area along Eastern Taihang Mountain

“…The knowledge of subsurface geological characteristics and a thermal genetic model plays an essential role in geothermal exploration and resource assessment [4,5]. Exploration of geothermal resources needs comprehensive multidisciplinary (geological, hydrological, geochemical, and geophysical) surveys through the use of traditional methods and innovative techniques for the geothermal potential assessment [6,7].…”