A new look at the statistical assessment of approximate and rigorous methods for the estimation of stabilized formation temperatures in geothermal and petroleum wells

Espinoza-Ojeda, Orlando Miguel; Santoyo, E.; Andaverde, Jorge

doi:10.1088/1742-2132/8/2/010

Cited by 22 publications

(14 citation statements)

References 45 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As for the regression models, results showed that SFT values estimated by using an ordinary linear regression model were less than those by the quadratic regression model in Figure 5. This observation was also reported in other literature [16,17].…”

Section: Applications In the Case Of A Small Number Of Data Pointssupporting

confidence: 91%

See 1 more Smart Citation

Static Formation Temperature Prediction Based on Bottom Hole Temperature

Liu

Chen

et al. 2016

Energies

View full text Add to dashboard Cite

Static formation temperature (SFT) is required to determine the thermophysical properties and production parameters in geothermal and oil reservoirs. However, it is not easy to determine SFT by both experimental and physical methods. In this paper, a mathematical approach to predicting SFT, based on a new model describing the relationship between bottom hole temperature (BHT) and shut-in time, has been proposed. The unknown coefficients of the model were derived from the least squares fit by the particle swarm optimization (PSO) algorithm. Additionally, the ability to predict SFT using a few BHT data points (such as the first three, four, or five points of a data set) was evaluated. The accuracy of the proposed method to predict SFT was confirmed by a deviation percentage less than ±4% and a high regression coefficient R 2 (>0.98). The proposed method could be used as a practical tool to predict SFT in both geothermal and oil wells.

show abstract

Section: Applications In the Case Of A Small Number Of Data Pointssupporting

confidence: 91%

“…The general equation of the OLD model is: y = a + bx , where a and b are the intercept and the slope of the fitted straight line [16], while that for the QR model is given by: y = a + bx + cx 2 , where a, b, and c represent the polynomial coefficients [16].…”

Section: Selection Of the Regression Modelsmentioning

confidence: 99%

Static Formation Temperature Prediction Based on Bottom Hole Temperature

Liu

Chen

et al. 2016

Energies

View full text Add to dashboard Cite

show abstract

“…This well had a depth of 50 m, with purely conductive thermal behavior ( Figure 5). For an estimation of the natural geothermal gradient, the bottom-hole temperature (BHT) versus time measurements to different depths was registered after a borehole drilling operation [18,19], and the Horner-plot method (Equation (1)) was used to estimate the static formation temperature (SFT) to a 50-m depth. This method suggests a linear relationship between BHT measurements and the dimensionless Horner time that corresponds to the logarithmic function of the following equation: For the present study, W1 (Figures 4 and 5) was used as a low-enthalpy geothermal energy source for heating water up to 55 °C in a U-tube heat exchanger (HE).…”

Section: Geothermal Source Modelingmentioning

confidence: 99%

“…For an estimation of the natural geothermal gradient, the bottom-hole temperature (BHT) versus time measurements to different depths was registered after a borehole drilling operation [18,19], and the Horner-plot method (Equation (1)) was used to estimate the static formation temperature (SFT) to a 50-m depth. This method suggests a linear relationship between BHT measurements and the dimensionless Horner time that corresponds to the logarithmic function of the following equation: For an estimation of the natural geothermal gradient, the bottom-hole temperature (BHT) versus time measurements to different depths was registered after a borehole drilling operation [18,19], and the Horner-plot method (Equation (1)) was used to estimate the static formation temperature (SFT) to a 50-m depth. This method suggests a linear relationship between BHT measurements and the dimensionless Horner time that corresponds to the logarithmic function of the following equation:…”

Section: Geothermal Source Modelingmentioning

confidence: 99%

Thermodynamic Analysis of a Half-Effect Absorption Cooling System Powered by a Low-Enthalpy Geothermal Source

et al. 2019

View full text Add to dashboard Cite

A thermodynamic analysis of a half-effect absorption cooling system powered by a low-enthalpy geothermal source was carried out. This paper presents modeling of the half-effect absorption cooling system operating with an ammonia/lithium nitrate mixture and based on the first and second laws of thermodynamics, using as energy inputs real data from two geothermal wells located at Las Tres Vírgenes volcanic complex, Baja California Sur, México. Plots of coefficients of performance and exergy efficiency against condenser, evaporator, and generator temperatures are presented for the half-effect cooling system. The results showed that the system was able to operate at generation temperatures between 56 and 70 °C, which were supplied by the geothermal wells in order to produce cooling at temperatures as low as −16 °C, achieving coefficients of performance between 0.10 and 0.36, while the exergy efficiency varied from 0.15 to 0.40 depending on the system operating temperatures.

show abstract

“…Andaverde et al (2005) and Espinoza‐Ojeda et al (2011) estimate equilibrium formation temperatures from measured BHTs by linear and quadratic regression modelling. Both studies find that in a majority of the analysed cases, the relationship between the BHT data and the formation temperature is non‐linear.…”

Section: Theorymentioning

confidence: 99%

Estimation of the equilibrium formation temperature in the presence of bore fluid invasion

Poulsen

Nielsen

Balling

2012

Geophysical Journal International

View full text Add to dashboard Cite

SUMMARY Bottom hole temperatures (BHTs) measured during drilling operations are thermally disturbed by the drilling process. This paper presents a method, CSMI (Cylindrical Source Model with Invasion of bore mud filtrate), for estimating equilibrium formation temperatures with probability distributions from BHT measurements in the presence of bore fluid invasion. The scheme is based on finite element analysis in conjunction with Markov chain Monte Carlo inversion. The axisymmetric forward model assumes a cylindrical source of finite radius and contrasting thermal parameters, which includes the possibility of invasion (advection) of mud filtrate into the formation. In a synthetic example, it is demonstrated that given bore fluid invasion and a low and high temperature of the bore mud and formation, respectively, the equilibrium formation temperature and the uncertainty hereon is underestimated by correction schemes based on purely conductive models. The influence of the borehole radius and fluid invasion on the temperature measured at the borehole axis attenuates over time. It is further demonstrated that the invasion radius and the matrix thermal conductivity cannot be estimated simultaneously with the CSMI scheme. The analysis of five BHT records measured onshore Denmark, for which the equilibrium formation temperature is known, shows that CSMI temperatures based on single datum records are highly uncertain because of a strong negative coupling between the temperature of the mud filtrate and the equilibrium formation temperature. For records with multiple temperature measurements, the CSMI scheme matches statistically the measured equilibrium formation temperatures. It is further shown that additional negative bias is added to Horner plot temperatures if bore fluid invasion has occurred. Allowing for bore fluid invasion in addition to a borehole of finite radius and contrasting thermal parameters, increases temperature estimates by 5 per cent (4–7 per cent) on average given that invasion is indicated and that the bore fluid is significantly colder than the formation. Indications of bore fluid invasion from CSMI analysis are confirmed in two examples by analysing corresponding caliper logs.

show abstract

A new look at the statistical assessment of approximate and rigorous methods for the estimation of stabilized formation temperatures in geothermal and petroleum wells

Cited by 22 publications

References 45 publications

Static Formation Temperature Prediction Based on Bottom Hole Temperature

Static Formation Temperature Prediction Based on Bottom Hole Temperature

Thermodynamic Analysis of a Half-Effect Absorption Cooling System Powered by a Low-Enthalpy Geothermal Source

Estimation of the equilibrium formation temperature in the presence of bore fluid invasion

Contact Info

Product

Resources

About