Semi-analytical solution to pumping test data with barrier, wellbore storage, and partial penetration effects

Abstract. Oscillatory pumping test (OPT) is an alternative to constant-head and constant-rate pumping tests for determining aquifer hydraulic parameters without water extraction. There is a large number of analytical models presented for the analyses of OPT. The combined effects of wellbore storage and initial condition regarding the hydraulic head prior to OPT are commonly neglected in the existing models. This study aims to develop a new model for describing the hydraulic head fluctuation induced by OPT in an unconfined aquifer. The model contains a typical flow equation with an initial condition of static water table, inner boundary condition specified at the rim of a finite-radius well for incorporating wellbore storage effect, and linearized free surface equation describing water table movement. The analytical solution of the model is derived by the Laplace transform and finite integral transform. Sensitivity analysis is carried out for exploring head response to the change in each of hydraulic parameters. Results suggest that head fluctuation due to OPT starts from the initial condition and gradually tends to simple harmonic motion (SHM) after a certain pumping time. A criterion for estimating the time to have SHM since OPT is graphically presented. The validity of assuming an infinitesimal well radius without wellbore storage effect is investigated. The present solution agrees well to head fluctuation data observed at the Boise hydrogeophysical research site in southwestern Idaho.

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Parameter Identification Procedures of Pumping Test Data in Confined Aquifers

SOILS AND FOUNDATIONS ◽

10.3208/sandf1972.29.2_159 ◽

1989 ◽

Vol 29 (2) ◽

pp. 159-168 ◽

Cited By ~ 4

Author(s):

Iichiro Kono ◽

Makoto Nishigaki ◽

Yuji Takeshita

Keyword(s):

Parameter Identification ◽

Test Data ◽

Pumping Test ◽

Confined Aquifers ◽

Identification Procedures

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Parameter Estimation Methods for the Determination of Unsaturated Soil Hydraulic Properties from Pumping Test Data in Unconfind Aquifers

SOILS AND FOUNDATIONS ◽

10.3208/sandf1972.30.2_199 ◽

1990 ◽

Vol 30 (2) ◽

pp. 199-210

Author(s):

Yuji Takeshita ◽

Makoto Nishigaki ◽

Iichiro Kono

Keyword(s):

Parameter Estimation ◽

Test Data ◽

Unsaturated Soil ◽

Hydraulic Properties ◽

Pumping Test ◽

Estimation Methods ◽

Soil Hydraulic Properties ◽

Soil Hydraulic ◽

Parameter Estimation Methods

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Explicit Deconvolution of Well Test Data Dominated by Wellbore Storage

Abstract and Applied Analysis ◽

10.1155/2014/912395 ◽

2014 ◽

Vol 2014 ◽

pp. 1-12

Author(s):

K. Razminia ◽

A. Hashemi ◽

A. Razminia ◽

D. Baleanu

Keyword(s):

Test Data ◽

Material Balance ◽

Early Time ◽

Time Behavior ◽

Well Test ◽

Deconvolution Method ◽

Pressure Data ◽

Practical Applications ◽

Wellbore Storage ◽

Storage Effects

This paper addresses some methods for interpretation of oil and gas well test data distorted by wellbore storage effects. Using these techniques, we can deconvolve pressure and rate data from drawdown and buildup tests dominated by wellbore storage. Some of these methods have the advantage of deconvolving the pressure data without rate measurement. The two important methods that are applied in this study are an explicit deconvolution method and a modification of material balance deconvolution method. In cases with no rate measurements, we use a blind deconvolution method to restore the pressure response free of wellbore storage effects. Our techniques detect the afterflow/unloading rate function with explicit deconvolution of the observed pressure data. The presented techniques can unveil the early time behavior of a reservoir system masked by wellbore storage effects and thus provide powerful tools to improve pressure transient test interpretation. Each method has been validated using both synthetic data and field cases and each method should be considered valid for practical applications.

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Estimation of Transmissivity and Permeability in Swedish Bedrock

Hydrology Research ◽

10.2166/nh.1977.0009 ◽

1977 ◽

Vol 8 (2) ◽

pp. 103-116 ◽

Cited By ~ 13

Author(s):

Leif Carlsson ◽

Anders Carlstedt

Keyword(s):

Statistical Analysis ◽

Test Data ◽

Hydraulic Properties ◽

Pumping Test ◽

Crystalline Rocks ◽

Wide Range ◽

Well Loss

Statistical analysis of pumping-test data from wells have been used to calculate average values of transmissivity and permeability in different Swedish rocks. The influence of the well-loss on the calculations is discussed. The highest values of transmissivity and permeability of the investigated rocks are found in the sandstones of Algonkian and Cambrian age. The Archean crystalline rocks show a wide range of results, and of the investigated rocks the gneisses seem to be more permeable than the granites. However, the degree of tectonization affects the hydraulic properties of the rocks considerably.

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A New Method for the Evaluation of Well Rehabilitation from the Early Portion of a Pumping Test

Water ◽

10.3390/w12030744 ◽

2020 ◽

Vol 12 (3) ◽

pp. 744

Author(s):

Daniel Kahuda ◽

Pavel Pech

Keyword(s):

Skin Effect ◽

Pumping Test ◽

Real Space ◽

New Method ◽

Maximum Slope ◽

Skin Factor ◽

Wellbore Storage ◽

Straight Line ◽

Early Portion ◽

Well Rehabilitation

This study analyzes the unsteady groundwater flow to a real well (with wellbore storage and the skin effect) that fully penetrates the confined aquifer. The well is located within an infinite system, so the effect of boundaries is not considered. The Laplace-domain solution for a partial differential equation is used to describe the unsteady radial flow to a well. The real space solution is obtained by means of the numerical inversion of the Laplace transform using the Stehfest algorithm 368. When wellbore storage and the skin effect dominate pumping test data and testing is conducted for long enough, two semilogarithmic straight lines are normally obtained. The first straight line can be identified readily as the line of the maximum slope. The correlation of the dimensionless drawdown for the intersection time of this first straight line, with the log time axis as a function of the dimensionless wellbore storage and the skin factor, is shown. This paper presents a new method for evaluating the skin factor from the early portion of a pumping test. This method can be used to evaluate the skin factor when the well-known Cooper–Jacob semilogarithmic method cannot be used due to the second straight line not being achieved in the semilogarithmic graph drawdown vs. the log time. A field example is presented to evaluate the well rehabilitation in Veselí nad Lužnicí by means of the new correlation.

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