![]() As a result, a correspondence exists between the following parameters: volumetric flow rate, pressure gradient, mobility, hydraulic diffusivity coefficient and heat flow rate, temperature gradient, thermal conductivity and thermal diffusivity. Due to the similarity in Darcy's and Fourier's laws, the same differential diffusivity equation describes the transient flow of incompressible fluid in porous media and heat conduction in solids. In petroleum and geothermal reservoir engineering, pressure and flow well tests are routinely conducted to determine these parameters (Earlougher 1977, Lee 1982, Prats 1982, Edwards et al 1982, Sabet 1991, Horne 1995). The forecast of fluid flow rate of production and injection geothermal wells requires estimation of mobility (formation permeability and fluid viscosity ratio), porosity, total formation compressibility, skin factor and initial reservoir pressure (Earlougher 1977, Elder 1981). Knowledge of the thermal properties of formations (Kappelmeyer and Haenel 1974, Somerton 1992, Vosteen and Schellschmidt 2003) and initial formation temperature are needed to evaluate the energy capacity of geothermal reservoirs. Temperature and pressure investigations fall within the domain of the most exploitable physical parameters (Serra 1984, Tittman 1986). Borehole geophysical logging is used to search for various economic minerals, fresh and hot water, tectonic-structural investigations, and environmental and ecological analysis (Gretener 1981, Jorden and Campbell 1984, Bourdarot 1998). It is widely recognized now that borehole geophysical measurements are no less important than ground geophysical observations. A simulated example is presented to demonstrate the data processing procedure. A semi-analytical equation is used to approximate the dimensionless wall temperature of the heater. It is assumed that the volumetric heat capacity of formations is known and the instantaneous heater's wall temperature and time data are available for a cylindrical probe with a constant heat flow rate placed in a borehole. A new technique has been developed for the determination of the formation thermal conductivity, initial temperature, skin factor and contact thermal resistance. It is shown that the mathematical model of pressure well tests based on the presentation of the borehole as an infinitely long linear source with a constant fluid flow rate in an infinite-acting homogeneous reservoir cannot be used in temperature well testing. The similarities and differences in the techniques of pressure and temperature well testing are discussed. The same differential diffusivity equation describes the transient flow of incompressible fluid in porous media and heat conduction in solids. forgetting to keep units consistent (i.e.Temperature and pressure are the most frequently observed physical parameters in boreholes. What would be a common error in this example? The results should look as follows (with units of m-d): The test will run for 1 day, and monitoring will occur approximately every 3 hours. With a pumping rate of 2730 m 3/d, what would be the expected drawdown at a monitoring well 122 m away. The intention of the upcoming pump test is to double check these estimates. They have results from a pump test conducted two decades earlier, indicating a transmissivity of 1250 m 2/d and a storage coefficient of 1.9x10 -4. Your browser does not support inline frames or is currently configured not to display inline frames.Ī consultant is preparing to conduct a pump test at a local well field. T (elapsed time since the start of pumping): The Cooper-Jacob approximation is given by: This calculator is good for anticipating results from pump tests. The Cooper-Jacob calculator presented here estimates the drawdown for a given well location over time. COOPER-JACOB APPROXIMATION An approximation of the Theissian Model for Pumping Test Interpretation Back to CalculatorsĬooper and Jacob (1946) developed an approximation for the Theis equation and a data analysis method which does not require type-curve matching.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |