The Experts below are selected from a list of 39 Experts worldwide ranked by ideXlab platform

Luis Ayala F H - One of the best experts on this subject based on the ideXlab platform.

  • on the pressure saturation path in infinite acting unconventional liquid rich gas Reservoirs
    Journal of Natural Gas Science and Engineering, 2016
    Co-Authors: Matthew D Becker, Miao Zhang, Luis Ayala F H
    Abstract:

    Abstract Unconventional liquid rich natural gas Reservoirs exhibit a number of unique technical challenges, including ultra-low rock permeability, which can lead to prolonged periods of Infinite-Acting flow. Despite this, traditional production data analysis techniques often assume boundary-dominated conditions, which may not be experienced by unconventional systems for very long stretches in their productive life. Analysis of two-phase flow and well production often relies on the use of two-phase pseudo-variables calculations for which the fluid saturation-pressure relationship must be estimated a priori . The de-facto assumption is that such a priori Reservoir saturation-pressure dependency can be acquired from available constant volume depletion (CVD) or constant composition expansion (CCE) laboratory test results. As a result, the influence of Reservoir characteristics or drawdown conditions on saturation-pressure path has not been rigorously investigated in general; and even less for the particular case of Infinite-Acting Reservoir systems under linear flow regime, which is the most commonly observed flow regime in multi-fractured horizontal wells. In the present work, a recently developed semi-analytical solution for the multiphase black-oil formulation, which considers both pressure and liquid saturation as independent variables, is employed to investigate the influence of Reservoir and well conditions on saturation-pressure path in linear Infinite-Acting liquid rich gas systems. Here, the effects of constant bottomhole flowing pressure, initial Reservoir pressure, and relative permeability characteristics on pressure-saturation path are explored in a Reservoir system. Results are compared to constant composition expansion (CCE) and constant volume depletion (CVD) tests, which are routinely invoked to estimate saturation-pressure path, and it is demonstrated that these tests provide very poor estimations of saturation-pressure path for all cases considered. In addition, saturation-pressure paths exhibit significant sensitivity to the parameters investigated, as a result of the significant interplay between liquid dropout and phase mobility. Finally, following the results of the sensitivity study, we use the concept of the compositionally-extended black-oil formulation to further study the physical mechanisms that control saturation-pressure path behavior, which are elucidated through an investigation of the in situ and flowing compositions of surface gas and surface oil pseudocomponents. The results of this paper indicate that traditional methods for estimation of the saturation-pressure path in liquid-rich unconventional systems cannot account for the influence of system parameters on liquid-phase dropout and condensate accumulation. Furthermore, production data analysis techniques must account for these dependencies to develop reliable Reservoir forecasts and reserve estimations.

Amanat U. Chaudhry - One of the best experts on this subject based on the ideXlab platform.

  • Gas Well Testing Handbook - Chapter 6 – Fundamentals of Pressure Buildup Analysis Methods
    Gas Well Testing Handbook, 2020
    Co-Authors: Amanat U. Chaudhry
    Abstract:

    This chapter discusses pressure buildup test. It is the simplest test that can be run on a gas well. If the effects of wellbore storage can be determined, much useful information can be obtained. This information includes permeability, “k”, apparent skin factor, s′, and average Reservoir pressure, ¯P R . The test consists of flowing the well at a constant rate, q sc for a period of time, t p , shutting the well in (at Δt = 0), and measuring wellbore pressure increase with shut-in time, Δt. Horner developed the test, and this method of analysis is generally considered the best. Other conventional methods of analysis include the Horner plot, the Miller-Dyes-Hutchinso plot, and the Muskat plot. Horne showed that a plot of the shut-in pressure, p ws versus log (t p + Δt)/Δt results in a straight line for an Infinite-Acting Reservoir. In the buildup tests, “t” refers to the drawdown period prior to a buildup and Δt refers to the shut-in or buildup time. Matthews, Brons, and Hazebroek (MBH), extended the application of the Horner plot to finite Reservoirs. A buildup test is always preceded by a drawdown, and the buildup data are directly affected by this drawdown. Usually, the drawdown starts from a stabilized Reservoir condition represented by the stabilized Reservoir pressure.

  • Oil Well Testing Handbook - Chapter 4 – Pressure Drawdown Testing Techniques for Oil Wells
    Oil Well Testing Handbook, 2020
    Co-Authors: Amanat U. Chaudhry
    Abstract:

    A pressure drawdown test is simply a series of bottom-hole pressure measurements made during a period of flow at a constant production rate. The chapter discusses drawdown tests in Infinite-Acting Reservoirs and developed Reservoirs, including two-rate, variable, multiphase, multi-rate drawdown tests. An analysis technique applicable to pressure drawdown tests during each of these periods including other types of tests is also presented. To obtain a meaningful and useable information from variable-rate tests, good flow rate data are much more critical than the conventional constant rate well tests. In this chapter, the n -rate flow test is discussed. The method assumes an Infinite-Acting Reservoir during the entire test period. This chapter deals with the complete analysis of drawdown test including transient, late transient, and semi-steady-state analysis including single, two-rate, variable-rate, Reservoir limit test, and multiphase and multiple-rate testing. This chapter also discusses how superposition may be used when variable rates are involved.

Matthew D Becker - One of the best experts on this subject based on the ideXlab platform.

  • on the pressure saturation path in infinite acting unconventional liquid rich gas Reservoirs
    Journal of Natural Gas Science and Engineering, 2016
    Co-Authors: Matthew D Becker, Miao Zhang, Luis Ayala F H
    Abstract:

    Abstract Unconventional liquid rich natural gas Reservoirs exhibit a number of unique technical challenges, including ultra-low rock permeability, which can lead to prolonged periods of Infinite-Acting flow. Despite this, traditional production data analysis techniques often assume boundary-dominated conditions, which may not be experienced by unconventional systems for very long stretches in their productive life. Analysis of two-phase flow and well production often relies on the use of two-phase pseudo-variables calculations for which the fluid saturation-pressure relationship must be estimated a priori . The de-facto assumption is that such a priori Reservoir saturation-pressure dependency can be acquired from available constant volume depletion (CVD) or constant composition expansion (CCE) laboratory test results. As a result, the influence of Reservoir characteristics or drawdown conditions on saturation-pressure path has not been rigorously investigated in general; and even less for the particular case of Infinite-Acting Reservoir systems under linear flow regime, which is the most commonly observed flow regime in multi-fractured horizontal wells. In the present work, a recently developed semi-analytical solution for the multiphase black-oil formulation, which considers both pressure and liquid saturation as independent variables, is employed to investigate the influence of Reservoir and well conditions on saturation-pressure path in linear Infinite-Acting liquid rich gas systems. Here, the effects of constant bottomhole flowing pressure, initial Reservoir pressure, and relative permeability characteristics on pressure-saturation path are explored in a Reservoir system. Results are compared to constant composition expansion (CCE) and constant volume depletion (CVD) tests, which are routinely invoked to estimate saturation-pressure path, and it is demonstrated that these tests provide very poor estimations of saturation-pressure path for all cases considered. In addition, saturation-pressure paths exhibit significant sensitivity to the parameters investigated, as a result of the significant interplay between liquid dropout and phase mobility. Finally, following the results of the sensitivity study, we use the concept of the compositionally-extended black-oil formulation to further study the physical mechanisms that control saturation-pressure path behavior, which are elucidated through an investigation of the in situ and flowing compositions of surface gas and surface oil pseudocomponents. The results of this paper indicate that traditional methods for estimation of the saturation-pressure path in liquid-rich unconventional systems cannot account for the influence of system parameters on liquid-phase dropout and condensate accumulation. Furthermore, production data analysis techniques must account for these dependencies to develop reliable Reservoir forecasts and reserve estimations.

Miao Zhang - One of the best experts on this subject based on the ideXlab platform.

  • on the pressure saturation path in infinite acting unconventional liquid rich gas Reservoirs
    Journal of Natural Gas Science and Engineering, 2016
    Co-Authors: Matthew D Becker, Miao Zhang, Luis Ayala F H
    Abstract:

    Abstract Unconventional liquid rich natural gas Reservoirs exhibit a number of unique technical challenges, including ultra-low rock permeability, which can lead to prolonged periods of Infinite-Acting flow. Despite this, traditional production data analysis techniques often assume boundary-dominated conditions, which may not be experienced by unconventional systems for very long stretches in their productive life. Analysis of two-phase flow and well production often relies on the use of two-phase pseudo-variables calculations for which the fluid saturation-pressure relationship must be estimated a priori . The de-facto assumption is that such a priori Reservoir saturation-pressure dependency can be acquired from available constant volume depletion (CVD) or constant composition expansion (CCE) laboratory test results. As a result, the influence of Reservoir characteristics or drawdown conditions on saturation-pressure path has not been rigorously investigated in general; and even less for the particular case of Infinite-Acting Reservoir systems under linear flow regime, which is the most commonly observed flow regime in multi-fractured horizontal wells. In the present work, a recently developed semi-analytical solution for the multiphase black-oil formulation, which considers both pressure and liquid saturation as independent variables, is employed to investigate the influence of Reservoir and well conditions on saturation-pressure path in linear Infinite-Acting liquid rich gas systems. Here, the effects of constant bottomhole flowing pressure, initial Reservoir pressure, and relative permeability characteristics on pressure-saturation path are explored in a Reservoir system. Results are compared to constant composition expansion (CCE) and constant volume depletion (CVD) tests, which are routinely invoked to estimate saturation-pressure path, and it is demonstrated that these tests provide very poor estimations of saturation-pressure path for all cases considered. In addition, saturation-pressure paths exhibit significant sensitivity to the parameters investigated, as a result of the significant interplay between liquid dropout and phase mobility. Finally, following the results of the sensitivity study, we use the concept of the compositionally-extended black-oil formulation to further study the physical mechanisms that control saturation-pressure path behavior, which are elucidated through an investigation of the in situ and flowing compositions of surface gas and surface oil pseudocomponents. The results of this paper indicate that traditional methods for estimation of the saturation-pressure path in liquid-rich unconventional systems cannot account for the influence of system parameters on liquid-phase dropout and condensate accumulation. Furthermore, production data analysis techniques must account for these dependencies to develop reliable Reservoir forecasts and reserve estimations.

Ja Akpobi - One of the best experts on this subject based on the ideXlab platform.

  • ANALYSIS OF PRESSURE VARIATION OF FLUID IN AN INFINITE ACTING Reservoir
    Nigerian Journal of Technology, 2020
    Co-Authors: Id Erhunmwun, Ja Akpobi
    Abstract:

    In this work, we investigate the well pressure distribution in a boundless Reservoir.  This research work seeks to know the pressure variation in a Reservoir whose pressure disturbance caused by the withdrawal of fluid from the wellbore, is yet to be felt at the external boundaries of the Reservoir. The diffusivity equation was used in the analysis. The work covers the transient state where the Reservoir is acting as if it was infinite in size. The finite element technique, using Lagrange quadratic shape elements was employed to carry out the analysis over the cross-section of the Reservoir. The analysis was done with the assumption that before the well begins production, there was uniform distribution of pressure all through the Reservoir. The accuracy of the result was validated by comparing with the results published by Chatas and Lee. The comparison shows a strong positive correlation between the two methods. Also, the results published by Chatas and Lee stated only the pressure at the wellbore at a particular time but this work predicts the pressure variation in the entire Reservoir from the wellbore to the infinite sized external boundary at the same time. http://dx.doi.org/10.4314/njt.v36i1.11