scholarly journals General Solution for Tidal Behavior in Confined and Semiconfined Aquifers Considering Skin and Wellbore Storage Effects

2020 ◽  
Vol 56 (6) ◽  
Author(s):  
Xuhua Gao ◽  
Kozo Sato ◽  
Roland N. Horne
Keyword(s):  
General Solution ◽  
Wellbore Storage ◽  
Storage Effects

Changing Wellbore Storage Effects In Gas Well Testing

1997 ◽  
Author(s):  
S. Al-Haddad ◽  
M. LeFlore ◽  
T. Lacy
Keyword(s):  
Well Testing ◽  
Gas Well ◽  
Wellbore Storage ◽  
Storage Effects

scholarly journals Explicit Deconvolution of Well Test Data Dominated by Wellbore Storage

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.

Formation-Tester Pulse Testing in Tight Formations (Shales and Heavy Oil): Where Wellbore Storage Effects Favor the Determination of Reservoir Pressure

2012 ◽  
Author(s):  
Nishaboori Abdolhamid Hadibeik ◽  
Mark A. Proett ◽  
Dingding Chen ◽  
Abbas Sami Sami Eyuboglu ◽  
Carlos Torres-Verdin ◽  
...  
Keyword(s):  
Heavy Oil ◽  
Reservoir Pressure ◽  
Wellbore Storage ◽  
Pulse Testing ◽  
Storage Effects ◽  
Tight Formations

scholarly journals Wellbore Effects in the Analysis of Two-Phase Geothermal Well Tests

1982 ◽  
Vol 22 (03) ◽  
pp. 309-320 ◽  
Author(s):  
Constance W. Miller ◽  
Sally M. Benson ◽  
Michael J. O'Sullivan ◽  
Karsten Pruess
Keyword(s):  
Water Reservoir ◽  
Hot Water ◽  
Well Test ◽  
Two Phase ◽  
Pressure Transient ◽  
Analysis Techniques ◽  
Wellbore Storage ◽  
Storage Effects ◽  
Transient Data ◽  
Well Tests

Abstract A method of designing and analyzing pressure transient well tests of two-phase (steam/water) reservoirs is given. Wellbore storage is taken into account, and the duration of it is estimated. It is shown that the wellbore flow can dominate the downhole pressure signal completely such that large changes in the downhole pressure that might be expected because of changes in kinematic mobility are not seen. Changes in the flowing enthalpy from the reservoir can interact with the wellbore flow so that a temporary plateau in the downhole transient curve is measured. Application of graphical and nongraphical methods to determine reservoir parameters from drawdown tests is demonstrated. Introduction Pressure transient data analysis is the most common method of obtaining estimates of the in-situ reservoir properties and the wellbore condition. Conventional graphical analysis techniques require that. for a constant flowrate well test in an infinite aquifer, a plot of the downhole pressure vs. log time yields a straight line after wellbore storage effects are over. The slope of that line is inversely proportional to the transmissivity (kh/u) of the reservoir. The extrapolated intercept of this line with the pressure axis at a specified time (1 hour or 1 second depending on the units used) gives the factor 0 Cth(re2), which is used to calculate the skin value of a well. In this study, the effects of a two-phase steam/water mixture in the reservoir and/or the wellbore on pressure transient data have been investigated. There have been a number of attempts to extend conventional testing and analysis techniques to two-phase geothermal reservoirs including drawdown analysis by Garg and Pritchett, Garg, Grant, and Moench and Atkinson. Pressure buildup analysis has been investigated by Sorey et al. To solve the diffusion equation that governs the pressure change in a two-phase reservoir analytically, it is necessary to make a number of simplifying assumptions. One assumption is that the fluid compressibility in the reservoir is initially uniform and remains uniform throughout the test. With this approach, it can be shown that a straight line on a pressure vs. log time plot will be obtained, the slope being inversely proportional to the total kinematic mobility When conducting a field test it is rarely possible to maintain the uniform saturation distribution in the reservoir required for that type of analysis to be applicable. In addition, the very high compressibility of the two-phase fluid creates wellbore storage of very long duration. Since most of the available instrumentation for hot geothermal wells (greater than 200C) can withstand geothermal environments for only limited periods, long-duration wellbore storage further complicates data analysis. Thus numerical simulation techniques must be used to study well tests to determine the best method of testing two-phase reservoirs. This work investigates and defines more thoroughly the well/reservoir system when the reservoir or wellbore is filled with a two-phase fluid. Four examples are considered:a single-phase hot water reservoir connected to a partially two-phase wellbore,a hot water reservoir that becomes two-phase during the test,a two-phase liquid-dominated reservoir, anda two-phase vapor-dominated reservoir. State-of-the-art analysis techniques are applied to pressure transient data after wellbore storage effects have ended. In the first example, a nongraphical method of analysis is discussed, which is applicable at early times when wellbore storage effects still dominate the pressure response. Note that our analysis has been done for a two-phase homogeneous, nonfractured reservoir. Previous studies of well test methods for two-phase reservoirs have been restricted to this case. SPEJ P. 309^

A Noniterative Blind Deconvolution Approach to Unveil Early Time Behavior of Well Testings Contaminated by Wellbore Storage Effects

2012 ◽  
Vol 134 (2) ◽  
Author(s):  
Arash Moaddel Haghighi ◽  
Peyman Pourafshary
Keyword(s):  
Blind Deconvolution ◽  
Storage Period ◽  
Early Time ◽  
Test Duration ◽  
Well Testing ◽  
Time Behavior ◽  
Rate Data ◽  
Deconvolution Method ◽  
Wellbore Storage ◽  
Storage Effects

Deconvolution method is generally used to eliminate wellbore storage dominant period of well testing. Common Deconvolution techniques require knowledge of both pressure and rate variations within test duration. Unfortunately, accurate rate data are not always available. In this case, blind deconvolution method is used. In this work, we present a new approach to improve the ability of blind deconvolution method in well testing. We examined the behavior of rate data by comparing it with a special class of images and employed their common properties to represent gross behavior of extracted rate data. Results of examinations show ability of our developed algorithm to remove the effect of wellbore storage from pressure data. Our Algorithm can deal with different cases where wellbore storage has made two different reservoirs behave identical in pressure response. Even if there is no wellbore effect or after wellbore storage period is passed, proposed algorithm can work routinely without any problem.

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