Pressure Transient Testing

Lee, John; Rollins, J B; Spivey, J.P.

doi:10.2118/9781555630997

Cited by 182 publications

(28 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Because of its flexibility in matching many different pressure responses, this model is often used even when there is no external information to justify its use. Geologically, the most direct rectangular reservoir model applies to wells in fault blocks which are limited by sealing faults [14,15]. The rectangular reservoir model also finds applications in fluvial channels, point bars, and offshore bar deposits where the end of the reservoir affects the test response.…”

Section: Rectangulermentioning

confidence: 99%

Determining Reservoir Model Based on Welltest Analysis for Production Forecasting

Sulistyarso¹

2021

AJSET

View full text Add to dashboard Cite

Welltest analysis is basically an analysis of fluid flow behavior in porous rocks, both in oil reservoirs and gas reservoirs that aim to obtain reservoir characteristics. Welltest analysis is not only limited to get reservoir characteristics and well productivity, but to determine the reservoir and boundary models that are close to the real situation. Until now, to determine the reservoir and boundary models are usually assisted by using a simulator, which is called modeling. However, to determine the reservoir and boundary models has its own challenges, because there are no specific methods or equations that can know for certain the model of a reservoir. Choosing the right type of model also requires some consideration, such as seismic data, geological data, log data, and information provided from other wells drilled into the same formation. From the determination of this model can be used as supporting information for a reservoir, which is then used to be a predictive model and renewal of its geological model, as well as allowing engineers to simulate production estimates. In this paper, we will present an analysis of determining the right reservoir model based on welltest analysis, which selected model is used to simulate production estimates. Case example is taken from an oil well named "HBR-05", which has been carried out a pressure build-up test on one productive layer that until now has not been produced or closed since the well testing was carried out. From the determination of the reservoir model based on welltest analysis, obtained heterogeneous anisotropic reservoir model and rectangular-no flow boundary model. The selected reservoir model is used to simulate the estimated production of the "HBR-05" well if it is produced from this layer. Production forecasting results for 48 months (4 years) the "HBR-05" well, the cumulative production is 107.8 Mbbl. In addition, the results of forecasting show that the reservoir pressure is already below the bubble point pressure in the 22nd month of forecasting.

show abstract

Section: Rectangulermentioning

confidence: 99%

Determining Reservoir Model Based on Welltest Analysis for Production Forecasting

Sulistyarso¹

2021

AJSET

View full text Add to dashboard Cite

show abstract

“…O'Sullivan 6 demonstrated that the nonlinear PDEs that govern fluid flow in geothermal reservoirs can be collapsed to a set of ODEs by introducing the similarity variable η = r / Boltzmann's similarity variable. An equivalent and common choice in classical well-testing theory is the use of the transformationη = r 2 / t , which leads more neatly to the classical exponential integral solution in the case of single-phase equations. − For the case of gas-condensate reservoirs, the introduction of the similarity variable η = r / in eq 3a yields or Following the same procedure, eq 6a can be rewritten as Equations 9 and 10 represent the system of ODEs that governs the flow of fluids in gas-condensate reservoirs, expressed in terms of the similarity variable. If one chooses pressure ( p ) and mass flux ( F ) as the dependent variables, this system of ODEs can be expressed as At this point, it is clear that the similarity method does collapse the original system of PDEs into a set of first-order ODEs in terms of a single independent variablethe similarity variable, η.…”

Section: Implementing the Similarity Variablementioning

confidence: 99%

“…For such conditions, the ODE system would be written as where the porous medium has been considered to be incompressible and k rg = 1 ( S g = 1) and k ro = 0 ( S o = 0). In order to obtain an analytical solution, the governing equations above are linearized by introducing the concept of pseudo-pressure, defined below: When the real gas law and the concepts of pseudo-pressure and gas isothermal compressibility ( c g ) are introduced, the above set of ODEs is recast in the following form: An analytical expression for the mass flux ( F ) can thus be obtained, by neglecting the remaining (usually weak) nonlinearity μ g c g its value being evaluated at initial conditionsand assuming that the porous medium is homogeneous: An alternative approach for the handling of the nonlinearity introduced by the term “μ g c g ” is to define an additional pseudo-variable (“pseudo-time”), − which can be necessary at low-pressure operating conditions when compressibility variations with pressure can be significant. When eq 15a and the previous result are utilized, the classical exponential integral solution that governs the flow of a real gas through a porous medium is readily obtained: where E i is the exponential integral function.…”

Section: Noncondensing Gases: Analytical Treatmentmentioning

confidence: 99%

“…The importance of the similarity variable theory in reservoir engineering problems cannot be overstated. The field of well-test analysis in petroleum and natural gas engineering has been built around the concept of the exponential integral solution, which is the result of applying the similarity theory to the partial differential equations for single-phase flow in porous media in a radial geometry. − Nevertheless, in the area of reservoir engineering and over the years, the application of the similarity solution theory has been limited to the analysis of relatively simple and linear (or linearized) problems.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

The Similarity Theory Applied to the Analysis of Multiphase Flow in Gas-Condensate Reservoirs

Ayala

Kouassi

2007

Energy Fuels

View full text Add to dashboard Cite

An important part of the world's hydrocarbon reserves is constituted of gas-condensate deposits, and as such, they have been the subject of intensive research over the years. Gas-condensate reservoirs are complex systems, and their performance analysis involves the handling of highly nonlinear partial differential equations and sophisticated thermodynamic models. For the case of noncondensing natural gas reservoirs, analytical solutions based on the exponential integral function are readily available for the analysis of infinite-acting behavior in production and injection wells. No such tool is available for the analysis of infinite-acting behavior in gas-condensate reservoirs, and the associated analysis of well deliverability is a topic of continuous research. This paper investigates the implementation of the similarity variable theory in the context of the analysis of depletion behavior in natural gas reservoirs. The main objective of this work is to present a novel application of the similarity theory for the case of the analysis of complex systems such as gas-condensate reservoirs, without introducing any simplifications to the inherent nonlinearities present in the associated governing equations.

show abstract

“…The diffusivity equation has been solved in dimensionless form [6]. "Chakrabarty with some other researchers provided a quantitative analysis of the effects of neglecting the quadratic gradient term on solving the diffusion equation governing the transient state [7].…”

Section: Introductionmentioning

confidence: 99%

Numerical determination of the production rate and cumulative production in the constant pressure outer boundary condition

Erhunmwun¹,

Hammed²,

Amiolemhen³

2022

FUJECE

View full text Add to dashboard Cite

The flow regime is identified as a steady-state flow if the pressure at every location in the reservoir remains constant. In this work, we have determined the well production rate and cumulative production in a circular reservoir using the Finite Element Method for the condition of constant pressure outer boundary. The reservoir was divided into 4 smaller part known as finite element. These parts were analyzed and later assembled to form the domain 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 results obtained from the production rate analysis shows that the dimensionless production rate decreases significantly and later becomes uniform because the withdrawn fluid has been completely replaced. This condition remains throughout the entire life of the reservoir presumably. Also, the result shows that there is a uniform increase in the dimensionless cumulative production as time increases. The result obtained in this work was compared with the results obtained by previous researcher. The comparison shows a strong positive correlation between the two methods with a maximum percentage error of 0.1711 and 0.1864 and a minimum percentage error of 0.0001 and 0.0122 for dimensionless production rate and dimensionless cumulative production respectively. Also, result from previous researcher only state the production rate and cumulative production of the reservoir at a particular time but this work predicts the production rate and cumulative production in the entire reservoir at the same time.

show abstract

Pressure Transient Testing

Cited by 182 publications

References 0 publications

Determining Reservoir Model Based on Welltest Analysis for Production Forecasting

Determining Reservoir Model Based on Welltest Analysis for Production Forecasting

The Similarity Theory Applied to the Analysis of Multiphase Flow in Gas-Condensate Reservoirs

Numerical determination of the production rate and cumulative production in the constant pressure outer boundary condition

Contact Info

Product

Resources

About