An Analytical Model for Composite Reservoirs Produced at Either Constant Bottomhole Pressure or Constant Rate

Olarewaju, J.S.; Lee, W.J.

doi:10.2118/16763-ms

Cited by 15 publications

(11 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As discussed above, the Barenblatt et al (1960) and Warren and Root (1963) type models have been used (Camacho-Velazquez et al, 2008;Da Prat et al, 1981;Ozkan et al, 1987;Raghavan and Ohaeri, 1981;Sageev et al, 1985) for rate transient and decline curve analyses. In earlier papers Kuchuk andBiryukov, 2013, 2014), we showed that the Barenblatt et al (1960) and Warren and Root (1963) type models are inappropriate and incomplete for naturally fractured reservoirs.…”

Section: Mathematical Model For Rate Transient Analysis In Fractured mentioning

confidence: 99%

“…A number of papers have been published on the rate transient behavior of naturally fractured (also called two-porosity, double-porosity, dual-porosity, or fissured) reservoirs using Barenblatt et al (1960) and Warren and Root (1963) type models (Camacho-Velazquez et al, 2008;Da Prat et al, 1981;Ozkan et al, 1987;Raghavan and Ohaeri, 1981;Sageev et al, 1985). A few papers are published on the rate transient behavior of triple-porosity (three-porosity) naturally fractured reservoirs (Al-Ahmadi and Wattenbarger, 2011;Ezulike and Dehghanpour, 2013;Tivayanonda et al, 2012).…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Rate Transient and Decline Curve Analyses for Continuously (Dual-Porosity) and Discretely Naturally Fractured Reservoirs

Kuchuk

Biryukov

Fitzpatrick

2014

SPE Annual Technical Conference and Exhibition

View full text Add to dashboard Cite

Forecasting production rates and reserves is important for reservoir management. Analysis of long-term production data has traditionally been performed using the empirical Arps (1945) decline curves to predict future production. Fetkovich (1980) combined Arps decline curves with constant-wellbore pressure solutions to offer a new method for decline-curve analysis. Furthermore, both rate-transient and declinecurve analyses for naturally fractured reservoirs were performed using Arps (1945) decline curves or Warren and Root (1963) dual-porosity-type models. These approaches have yielded unsatisfactory results for naturally fractured reservoirs. Recent studies show that the Warren and Root (1963) dual-porosity-type models, which do not contain fractures, cannot characterize highly diverse transient behaviors of continuously and discretely fractured reservoirs because they are inappropriate and incomplete for most naturally fractured reservoirs. Furthermore, no investigation has been performed on rate-transient behavior of discretely fractured reservoirs.We investigate rate-transient behavior of continuously (dual-porosity) and discretely naturally fractured reservoirs using semianalytical solutions. These fractured reservoirs can contain periodically or arbitrarily distributed finite-and/or infinite-conductivity fractures, of different lengths and orientations. Our results demonstrate that, in terms of rate transients, neither continuously nor discretely fractured reservoirs behave like the Warren and Root (1963) dual-porosity type model. There are many factors that dominate the rate-transient behavior of naturally fractured reservoirs, such as fracture conductivities, dip angles, lengths, and distributions, as well as whether or not fractures intersect the wellbore. Rate transients associated with these factors are shown for a few continuously and discretely fractured reservoirs with different well and fracture configurations.The inverse of the dimensionless pressure (p D ) is not a good approximation for the dimensionless rate (q D ), but for most cases, their derivatives behave similarly, and exhibit same or similar flow regimes. For some cases, they behave very differently. The similarities or variations are true for any type of reservoirs. For any reservoir, Arps' decline curves yield unreasonably high production rates and cumulative productions, except the exponential decline curve. The exponential decline curve should not be used without taking into account the change of the wellbore pressure as a function of time. Arps' decline curves analysis should not be used for both discretely and continuously fractured reservoirs. An integrated interpretation methodology is outlined for rate transient analysis in fractured reservoirs.A few examples for the rate transient behavior of the continuously and discretely fractured fractured reservoirs are presented. They exhibit different flow regimes depending on fracture distribution, intensity, and conductivity. We also compare the rate transient derivatives with pressure...

show abstract

Section: Mathematical Model For Rate Transient Analysis In Fractured mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Rate Transient and Decline Curve Analyses for Continuously (Dual-Porosity) and Discretely Naturally Fractured Reservoirs

Kuchuk

Biryukov

Fitzpatrick

2014

SPE Annual Technical Conference and Exhibition

View full text Add to dashboard Cite

show abstract

“…Olarewaju, J.S. and Yu, J.P. et al completed a series of studies in the composite reservoir model with different types of applications [6][7] . Chu, L. and Yin Hongjun et al studied the pressure transient analysis of production well and injection well in triple and multiple composite reservoir [8][9] .…”

Section: Introductionmentioning

confidence: 99%

Pressure Transient Analysis of the Low Permeability Composite Reservoir with Threshold Pressure Gradient

Sun

Zhang

et al. 2010

2010 Asia-Pacific Power and Energy Engineering Conference

View full text Add to dashboard Cite

Abstract-A mathematical model of effective radius for low velocity non-Darcy flow in low permeability composite reservoir with two different zones is established and the threshold pressure gradients of the two zones in low permeability composite reservoir are taken into consideration. The solution of bottomhole pressure is obtained, the type curves of pressure behavior for low velocity non-Darcy flow in composite reservoir are plotted, and the effects of parameter on the pressure behavior, such as threshold pressure gradients, diffusivity ratio, mobility ratio, and interfacial radius, are discussed. It is shown in the study that the type curve of pressure derivative is no longer horizontal line at the period of radial flow in the inner and outer zones, but it tends to be upward gradually for the effect of threshold pressure gradient. This characteristic is different from the traditional composite reservoir with two zones. The model is used to interpret the actual well test data of low permeability reservoir, and interpretation results are in good accordance with the actual pressure behavior, indicating that it is practical for studying the characteristics of low permeability reservoir.

show abstract

“…Other investigations regarding the composite resevroir model with different types of applications were conducted, such as the effect of phase segragation, mobility contrast and conductivity ratio. Some researchers have mentioned the potential applications of reservoirs with a fluid bank and a burning front [2][3][4][5] .…”

Section: Introductionmentioning

confidence: 99%

Effect of Mobility Ratio on the Pressure and Pressure Derivative of Wells in Closed Composite Reservoirs

Boussalem

Tiab

Escobar

2002

SPE Western Regional/Aapg Pacific Section Joint Meeting

View full text Add to dashboard Cite

The presence of anomalies in a reservoir, such as faults or change in rock and fluid properties significantly affects the wellbore pressure behavior. An accurate reservoir description of heterogeneous reservoirs, such as a closed composite reservoir, is critical for optimizing the hydrocarbon recovery. Well test analysis provides the best technique for determining the permeability of different zones of the composite system, the skin factor, the pore volume of the inner region and the drainage area1. The first type curves generated for a composite reservoir model appared in the literature in the early 1970s. Although these type curves were widely used for a period of time, some difficulties were found in using them. For example, the same match can be obtained on different dimensionless wellbore storage values. However, type curves were used as the basic mathematical model for several developments. Other investigations regarding the composite resevroir model with different types of applications were conducted, such as the effect of phase segragation, mobility contrast and conductivity ratio. Some researchers have mentioned the potential applications of reservoirs with a fluid bank and a burning front2–5. In this paper an analytical model has been developed for a closed composite system. This model was validated by the numerical model already exist in the literature. An extension of conventional method and the Tiab's Direct Synthesis technique6 are presented for a closed composite reservoir on the basis of the proposed analytical model. The effect of the mobility ratio, and radius ratio, on the pressure response has been thoroughly investigated. A dual porosity behavior confirming the sugar-cube model is observed during the transition period for a high mobility contrast. Three important equations are derived and presented in this study:An equation describing the pseudo-steady-state flow regime observed at the fingerprint of dual porosity behavior,An equation describing the starting time of the pseudo-steady-state flow regime observed at the fingerprint of the dual porosity behavior,An equation for the pseudo-steady-state flow regime governing the boundary effect. The formulated interpretation techniques have been tested on field cases and reasonable results have been obtained. Flow Regimes for the Pressure and pressure derivative Responses of a Closed Composite Reservoir The universal equation of pressure at the pseudo-steady-state flow period for any shape factor and mobility ratio inside of closed composite reservoir is given by7:Equation 1 A pressure derivative curve enhances the details of the information that can be obtained from a well test. Therefore, by using pressure derivative plots, the pressure transient analysis of the subject reservoir may be improved. A log-log plot of the pressure derivative, [dPWD1/dln(tD)], versus dimensionless time, tD, may be used to identify the different flow regimes as follows: Case-1 [M=0.2] (Fig. 1)A zero slope line for the early radial flow in the inner region.A zero slope line for the late radial flow in the outer region.A unit slope line for the pseudo-steady state flow period wich reflects the boundary effect. Case-2 [M=5] (Fig. 2)A zero slope line for the early radial flow in the inner region.A unit slope line for the pseudo-steady state flow period wich reflects the mobility changes.

show abstract

An Analytical Model for Composite Reservoirs Produced at Either Constant Bottomhole Pressure or Constant Rate

Cited by 15 publications

References 14 publications

Rate Transient and Decline Curve Analyses for Continuously (Dual-Porosity) and Discretely Naturally Fractured Reservoirs

Rate Transient and Decline Curve Analyses for Continuously (Dual-Porosity) and Discretely Naturally Fractured Reservoirs

Pressure Transient Analysis of the Low Permeability Composite Reservoir with Threshold Pressure Gradient

Effect of Mobility Ratio on the Pressure and Pressure Derivative of Wells in Closed Composite Reservoirs

Contact Info

Product

Resources

About