Effect of Wellbore Storage on the Analysis of Multiphase Flow Pressure Data

1994 ◽  
Vol 9 (03) ◽  
pp. 219-227
Author(s):  
D.G. Hatzignatiou ◽  
A.M.M. Peres ◽  
A.C. Reynolds
Keyword(s):  
Multiphase Flow ◽  
Pressure Data ◽  
Wellbore Storage ◽  
Flow Pressure

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.

Effect of Drag-Reducing Agents in Multiphase Flow Pipelines

1998 ◽  
Vol 120 (1) ◽  
pp. 15-19 ◽  
Author(s):  
C. Kang ◽  
R. M. Vancko ◽  
A. S. Green ◽  
H. Kerr ◽  
W. P. Jepson
Keyword(s):  
Multiphase Flow ◽  
Pressure Gradient ◽  
Slug Flow ◽  
Annular Flow ◽  
Flow Regimes ◽  
Reducing Agents ◽  
Pressure Gradients ◽  
Horizontal Pipes ◽  
Flow Pressure ◽  
Inclined Pipes

The effect of drag-reducing agents (DRA) on pressure gradient and flow regime has been studied in horizontal and 2-deg upward inclined pipes. Experiments were conducted for different flow regimes in a 10-cm i.d., 18-m long plexiglass system. The effectiveness of DRA was examined for concentrations ranging from 0 to 75 ppm. Studies were done for superficial liquid velocities between 0.03 and 1.5 m/s and superficial gas velocities between 1 and 14 m/s. The results indicate that DRA was effective in reducing the pressure gradients in single and multiphase flow. The DRA was more effective for lower superficial liquid and gas velocities for both single and multiphase flow. Pressure gradient reductions of up to 42 percent for full pipe flow, 81 percent for stratified flow, and 35 percent for annular flow were achieved in horizontal pipes. In 2 deg upward inclination, the pressure gradient reduction for slug flow, with a concentration of 50 ppm DRA, was found to be 28 and 38 percent at superficial gas velocities of 2 and 6 m/s, respectively. Flow regimes maps with DRA were constructed in horizontal pipes. Transition to slug flow with addition of DRA was observed to occur at higher superficial liquid velocities.

scholarly journals Engineering Simulation Tests on Multiphase Flow in Middle- and High-Yield Slanted Well Bores

Energies ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2591 ◽  
Author(s):  
Dan Qi ◽  
Honglan Zou ◽  
Yunhong Ding ◽  
Wei Luo ◽  
Junzheng Yang
Keyword(s):  
Multiphase Flow ◽  
Prediction Model ◽  
Flow Pattern ◽  
Pipe Flow ◽  
Slug Flow ◽  
High Yield ◽  
Transition Flow ◽  
Liquid Holdup ◽  
Flow Pattern Map ◽  
Flow Pressure

Previous multiphase pipe flow tests have mainly been conducted in horizontal and vertical pipes, with few tests conducted on multiphase pipe flow under different inclined angles. In this study, in light of mid–high yield and highly deviated wells in the Middle East and on the basis of existent multiphase flow pressure research on well bores, multiphase pipe flow tests were conducted under different inclined angles, liquid rates, and gas rates. A pressure prediction model based on Mukherjee model, but with new coefficients and higher accuracy for well bores in the study block, was obtained. It was verified that the newly built pressure drawdown prediction model tallies better with experimental data, with an error of only 11.3%. The effect of inclination, output, and gas rate on the flow pattern, liquid holdup, and friction in the course of multiphase flow were analyzed comprehensively, and six kinds of classical flow regime maps were verified with this model. The results showed that for annular and slug flow, the Mukherjee flow pattern map had a higher accuracy of 100% and 80–100%, respectively. For transition flow, Duns and Ros flow pattern map had a higher accuracy of 46–66%.

scholarly journals Pressure Data Analysis and Multilayer Modeling of a Gas-Condansate Reservoir

2015 ◽  
Vol 2 (1) ◽  
pp. 7-16
Author(s):  
Fatema Akter Happy ◽  
Mohammad Shahedul Hossain ◽  
Arifur Rahman
Keyword(s):  
Cross Flow ◽  
Storage Effect ◽  
Pressure Data ◽  
Reservoir Properties ◽  
Gas Field ◽  
Wet Gas ◽  
Wellbore Storage ◽  
Response Pressure ◽  
Gas Fields ◽  
Skin Storage

Kailastila gas field located at Golapgonj, Sylhet is one of the largest gas fields in Bangladesh. It produces a high amount of condensate along with natural gas. For the high values of GOR, it may be treated as a wet gas at reservoir condition. Three main sand reservoirs are confirmed in this field (upper, middle & lower).In this study, it has been shown that reservoir parameters of this gas field can be obtained for multilayered rectangular reservoir with formation cross-flow using pressure and their semi log derivative on a set of dimensionless type curve.The effects of the reservoir parameters such as permeability, skin, storage coefficient, and others such as reservoir areal extent and layering on the wellbore response, pressure are investigated.Shut in pressures are used in calculating permeability, skin factor, average reservoir pressure, wellbore storage effect and other reservoir properties. The direction of the formation cross flow is determined, first by the layer permeability and later by the skin factor.Finally, it is recommended to perform diagnostic analysis along with multilayer modeling to extract better results.Reservoir can also be considered as a multilayer cylindrical and can also use these models for other fields.

Analysis of Short-Time Pressure Data Dominated by Wellbore Storage and Skin

1979 ◽  
Vol 31 (05) ◽  
pp. 623-631 ◽  
Author(s):  
J. Garcia-Rivera ◽  
Rajagopal Raghavan
Keyword(s):  
Time Pressure ◽  
Pressure Data ◽  
Wellbore Storage ◽  
Short Time

Fast-Fourier-Transform-Based Deconvolution for Interpretation of Pressure Transient Test Data Dominated by Wellbore Storage

2005 ◽  
Vol 8 (03) ◽  
pp. 224-239 ◽  
Author(s):  
Yueming Cheng ◽  
W. John Lee ◽  
Duane A. McVay
Keyword(s):  
Laplace Transform ◽  
Early Time ◽  
Pressure Response ◽  
Pressure Data ◽  
Reservoir System ◽  
Wellbore Storage ◽  
Constant Rate ◽  
Storage Effects ◽  
Pressure Transient Test ◽  
Deconvolution Techniques

Summary We present a deconvolution technique based on a fast-Fourier-transform (FFT)algorithm. With the new technique, we can deconvolve "noisy" pressure and rate data from drawdown and buildup tests dominated by wellbore storage. The wellbore-storage coefficient can be variable in the general case. In cases with no rate measurements, we use a "blind" deconvolution method to restore the pressure response free of wellbore-storage effects. Our technique detects the afterflow/unloading rate function with Fourier analysis of the observed pressure data. The technique can unveil the early-time behavior of a reservoir system masked by wellbore-storage effects, and it thus provides a powerful tool to improve pressure-transient-test interpretation. It has the advantages of suppressing the noise in the measured data, handling the problem of variable wellbore storage, and deconvolving the pressure data without rate measurement. We demonstrate the applicability of the method with a variety of synthetic and actual field cases for both oil and gas wells. Some of the actual cases include measured sandface rates (which we use only for reference purposes), and others do not. Although this paper is focused on deconvolution of pressure-transient-test data during a specific drawdown/buildup period corresponding to an abrupt change of surface flow rate, the deconvolution method itself is very general and can be extended readily to interpret multirate test data. Introduction In conventional well-test analysis, the pressure response to constant-rate production is essential information that presents the distinct characteristics for a specific type of reservoir system. However, in many cases, it is difficult to acquire sufficient constant-rate pressure-response data. The recorded early-time pressure data are often hidden by wellbore storage(variable sandface rates). In some cases, outer-boundary effects may appear before wellbore-storage effects disappear. Therefore, it is often imperative to restore the early-time pressure response in the absence of wellbore-storage effects to provide a confident well-test interpretation. Deconvolution is a technique used to convert measured pressure and sandface rate data into the constant-rate pressure response of the reservoir. In other words, deconvolution provides the pressure response of a well/reservoir system free of wellbore-storage effects, as if the well were producing at a constant rate. Once the deconvolved pressure is obtained, conventional interpretation methods can be used for reservoir system identification and parameter estimation. However, mathematically, deconvolution is a highly unstable inverse problem because small errors in the data can result in large uncertainties in the deconvolution solution. In the past 40 years, a variety of deconvolution techniques have been proposed in petroleum engineering, such as direct algorithms, constrained deconvolution techniques, and Laplace-transform-based methods, but their application was limited largely because of instability problems. Direct deconvolution is known as a highly unstable procedure. To reduce solution oscillation, various forms of smoothness constraints have been imposed on the solution. Coats et al. presented a linear programming method with sign constraints on the pressure response and its derivatives. Kuchuk et al. used similar constraints and developed a constrained linear least-squares method. Baygun et al. proposed different smoothness constraints to combine with least-squares estimation. The constraints were an autocorrelation constraint on the logarithmic derivative of pressure solution and an energy constraint on the change of logarithmic derivative. Efforts also were made to perform deconvolution in the Laplace domain. Kuchuk and Ayestaran developed a Laplace-transform-based method using exponential and polynomial approximations to measured sandface rate and pressure data, respectively. Methods presented by Roumboutsos and Stewart and Fair and Simmons used piecewise linear approximations to rate and pressure data. All the Laplace-transform-based methods used the Stehfest algorithm to invert the results in the Laplace domain back to the time domain. Although the above methods may give a reasonable pressure solution at a low level of measurement noise, the deconvolution results can become unstable and uninterpretable when the level of noise increases. Furthermore, existing deconvolution techniques require simultaneous measurement of both wellbore pressure and sandface rate. However, it is not always possible to measure rate in actual well testing. Existing techniques are, in general, not suitable for applications without sandface rate measurement.

scholarly journals Revisão e Implementação de Soluções Analíticas para a Determinação da Pressão em Poços de Petróleo

2020 ◽  
Vol 5 ◽  
pp. 17
Author(s):  
Igor Caetano Cariello ◽  
Paulo de Tarço Honório Junior ◽  
Grazione De Souza ◽  
Helio Pedro Amaral Souto
Keyword(s):  
Laplace Transform ◽  
Analytical Solutions ◽  
Reservoir Engineering ◽  
Well Testing ◽  
Pressure Data ◽  
Test Analysis ◽  
Wellbore Storage ◽  
Reservoir Systems ◽  
The Laplace Transform ◽  
The Time Domain

<p>A Análise de Testes de Poços é um ramo da Engenharia de Reservatórios no qual<br />empregamos dados de pressão de poço a partir de testes de produção/injeção de fluido em conjunto com modelos físico-matemáticos para caracterizar o sistema poço-reservatório, usando problemas inversos. Nessas situações, aplicamos amplamente soluções analíticas e semianalíticas do modelo físico-matemático que descreve o fluxo. Nesse contexto, o objetivo do presente estudo é 1) realizar uma revisão bibliográfica sobre algumas das soluções analíticas clássicas para determinação da pressão no poço produtor e 2) implementar os códigos numéricos para a criação de uma biblioteca computacional, proporcionando as soluções analíticas voltadas para a determinação da pressão em poços produtores de petróleo. Os sistemas poço-reservatório estudados possuem um poço vertical e levam em consideração os efeitos de condições de contorno, a estocagem na coluna de produção do poço, dano à formação, períodos de fluxo e estática, bem como a presença de fraturas naturais. Obtivemos as soluções analíticas usando a transformada de Laplace e uma inversão numérica, utilizando o algoritmo Stehfest, para calcular a variação de pressão ao longo do tempo.</p><p><br /><strong>Palavras-chave</strong>: Soluções Analíticas, Transformada de Laplace Inversa, Tranformada de Laplace, Algoritmo de Stehfest, Análise de Teste de Poço.</p><p>===================================================================</p><p>Well Testing Analysis is a branch of Reservoir Engineering, in which we<br />employ well pressure data from production tests/fluid injection in conjunction with physical-mathematical models to characterize the well-reservoir system, using inverse problems. In these situations, we widely used analytical and semi-analytical solutions of the physical-mathematical model that describes the flow. In this context, the objective of this work is to 1) carry out a bibliographic review on some of the classic analytical solutions for determining the pressure in the producing well and 2) implement the numerical codes for the creation of a computational library, providing the analytical solutions aimed at determining pressure in oil-producing wells. The well-reservoir systems with a vertical well take into account the boundary effects, wellbore storage, formation damage, drawdown and buildup test analysis, and the presence of natural fractures. We obtain the analytical solutions using the Laplace transform and a numerical inversion, using the Stehfest algorithm, to calculate the pressure variation in the time domain.</p><p><br /><strong>Key words</strong>: Analytical Solutions, Inverve Laplace Transform, Laplace Transform, Stehfest Algorithm, Well Testing Analysis.</p>

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