Estimation of Borehole Flow Velocity from Temperature Profiles

Maria Klepikova, Tanguy Le Borgne, Olivier Bour

UMR 6118 CNRS University of Rennes 1, Rennes, France

Introduction Method Analysis Conclusions

Introduction Method Results Conclusions

1. Introduction

2. Method

3. Temperature-depth profiles as precise flowmeter measurements

4. Comparison of temperature estimated flow velocities to flowmeter

measurements

5. Estimation of fracture transmissivity, hydraulic head and connectivity

6. Conclusions

Plan

Introduction Method Results Conclusions

Temperature profiles applications

Determination of heat flow Estimation of groundwater flow

M. Reiter (2001), Using precision temperature logs to estimate horizontal and vertical groundwater flow components, Water Resour. Res,37 (3),663-674

Claude Jaupart et al. (1982) , A detailed study of the distribution of heat flow and radioactivity n New Hampshire (U.S.A.), Earth and Planetary Science Letters, 59, 267-287

Introduction Method Results Conclusions

Vertical borehole flows

Frank Börner, Susann Berthold (2009), Groundwater Geophysics.

Introduction Method Results Conclusions

Vertical borehole flows

Frank Börner, Susann Berthold (2009), Groundwater Geophysics.

Can we use temperature profiles to estimate borehole flows ?

Introduction Method Results Conclusions

Temperature profile monitoring under different flow conditions

The objective is to characterize fracture hydraulic properties and connectivity

Introduction Method Results Conclusions

Borehole scale model for flow and heat transfer

T is the temperature, is the thermal diffusivity of fluid and rock, and v is the borehole flow velocity.

v

Introduction Method Results Conclusions

The numerically obtained temperature profiles for borehole velocities varying from 0.1 mm/s to 1 cm/s, a typical range of borehole flow velocities observed in fractured formations under ambient conditions

Temperature profiles are found to be very sensitive to borehole flow velocities

V

V

Introduction Method Results Conclusions

Temperature profile – inferred velocities for different flow conditions

Measured temperature profile Inferred flow velocities

Introduction Method Results Conclusions

Temperature profile – inferred velocities for different flow conditions

Measured temperature profile Inferred flow velocities

pumping rate Q=125L/min, drawdown s=1.9m

Introduction Method Results Conclusions

Temperature profile – inferred velocities for different flow conditions

Measured temperature profile Inferred flow velocities

pumping rate Q=145L/min, drawdown s=0.6m

Introduction Method Results Conclusions

Temperature profile – inferred velocities for different flow conditions

Direct flow measurements:

Indirect from temperature measurements:

Introduction Method Results Conclusions

Estimation of the hydraulic properties from the temperature profiles

Once the single and cross-borehole temperature profiles have been

converted into flow profiles, the flow profiles can be interpreted to

infer fracture hydraulic properties.

B2-1

B2-3

B2-2

B2-4

We use the flow modelling approach proposed by Paillet

(1998).

Introduction Method Results Conclusions

Conclusions

• We have developed a methodology for characterizing spatially distributed hydraulic

properties based on temperature profile measurement under ambient, single-borehole

and cross-borehole pumping tests

V

• Vertical flow velocities deduced from the inversion of temperature profiles are

in good agreement with direct flowmeter measurements

• Temperature profiles are strongly sensitive to vertical borehole flow