Fast permeability measurements of tight and sorptive gas reservoirs using a radial-flow transient technique

2020 ◽  
Vol 84 ◽  
pp. 103673
Author(s):  
Ruimin Feng ◽  
Jun Liu ◽  
Yongming He ◽  
Shengnan Chen
Keyword(s):  
Radial Flow ◽  
Gas Reservoirs ◽  
Transient Technique

Welltest analysis of hydraulically fractured tight gas reservoirs: a field example from Perth Basin, Western Australia

2012 ◽  
Vol 52 (1) ◽  
pp. 587 ◽  
Author(s):  
Hassan Bahrami ◽  
Vineeth Jayan ◽  
Reza Rezaee ◽  
Dr Mofazzal Hossain
Keyword(s):  
Radial Flow ◽  
Second Derivative ◽  
Tight Gas ◽  
Transient Pressure ◽  
Gas Reservoirs ◽  
Type Curves ◽  
Tight Gas Reservoirs ◽  
Diagnostic Plots ◽  
Reservoir Permeability ◽  
Reservoir Flow

Welltest interpretation requires the diagnosis of reservoir flow regimes to determine basic reservoir characteristics. In hydraulically fractured tight gas reservoirs, the reservoir flow regimes may not clearly be revealed on diagnostic plots of transient pressure and its derivative due to extensive wellbore storage effect, fracture characteristics, heterogeneity, and complexity of reservoir. Thus, the use of conventional welltest analysis in interpreting the limited acquired data may fail to provide reliable results, causing erroneous outcomes. To overcome such issues, the second derivative of transient pressure may help eliminate a number of uncertainties associated with welltest analysis and provide a better estimate of the reservoir dynamic parameters. This paper describes a new approach regarding welltest interpretation for hydraulically fractured tight gas reservoirs—using the second derivative of transient pressure. Reservoir simulations are run for several cases of non-fractured and hydraulically fractured wells to generate different type curves of pressure second derivative, and for use in welltest analysis. A field example from a Western Australian hydraulically fractured tight gas welltest analysis is shown, in which the radial flow regime could not be identified using standard pressure build-up diagnostic plots; therefore, it was not possible to have a reliable estimate of reservoir permeability. The proposed second derivative of pressure approach was used to predict the radial flow regime trend based on the generated type curves by reservoir simulation, to estimate the reservoir permeability and skin factor. Using this analysis approach, the permeability derived from the welltest was in good agreement with the average core permeability in the well, thus confirming the methodology’s reliability.

The Combined Effect of Near-Critical Relative Permeability and Non-Darcy Flow on Well Impairment by Condensate Drop Out

1998 ◽  
Vol 1 (05) ◽  
pp. 421-429 ◽  
Author(s):  
Saskia M.P. Blom ◽  
Jacques Hagoort
Keyword(s):  
Steady State ◽  
Gas Phase ◽  
Relative Permeability ◽  
Capillary Number ◽  
Radial Flow ◽  
Drop Out ◽  
Darcy Flow ◽  
Gas Reservoirs ◽  
Strongly Coupled ◽  
Original Manuscript

This paper (SPE 51367) was revised for publication from paper SPE 39976, first presented at the 1998 SPE Gas Technology Symposium, Calgary, 15-18 March. Original manuscript received for review 19 March 1998. Revised manuscript received 8 July 1998. Paper peer approved 13 July 1998. Summary We present a comprehensive numerical method to calculate well impairment based on steady-state radial flow. The method incorporate near-critical relative permeability and saturation-dependent inertial resistance. Example calculations show that near-critical relative permeability, which depends on the capillary number, and non-Darcy flow are strongly coupled. Inertial resistance gives rise to a higher capillary number. In its turn, the improved mobility of the gas phase caused by a higher capillary number enhances the importance of the inertial resistance. The effect of non-Darcy flow is much more pronounced in gas condensate reservoirs than in dry gas reservoirs. Well impairment may be grossly overestimated if the dependence of relative permeability on the capillary number is ignored. P. 421

Unsteady Radial Flow of Gas Through Porous Media

1953 ◽  
Vol 20 (2) ◽  
pp. 210-214
Author(s):  
R. Jenkins ◽  
J. S. Aronofsky
Keyword(s):  
Porous Medium ◽  
Porous Media ◽  
Radial Flow ◽  
Transient Flow ◽  
Gas Reservoirs ◽  
Punch Card ◽  
Flow Rates ◽  
Pressure Distributions ◽  
History Of ◽  
Natural Gas Reservoirs

Abstract This paper presents a numerical method for describing the transient flow of gases radially inward or outward through a porous medium in which the initial and terminal pressures and/or rates are specified. Specific examples are worked out which have application in the study of natural-gas reservoirs. The computations were carried out by means of punch-card machines. The pressure distribution as a function of time has been calculated for various ratios of reservoir diameter to well diameter and for various dimensionless flow rates for a well penetrating the center of a homogeneous disk-shaped reservoir. A simple means of predicting the well pressure at any time in the history of such an idealized field has been developed. Flow rates and pressure distributions within the radial reservoir also have been calculated for the case in which the well pressure is suddenly lowered from its initial static value, and then held constant.

scholarly journals Non-circular flows in HIghMass galaxies in a test of the late accretion hypothesis

2021 ◽  
Author(s):  
Dhruv Bisaria ◽  
Kristine Spekkens ◽  
Shan Huang ◽  
Gregory Hallenbeck ◽  
Martha P Haynes
Keyword(s):  
Fourier Transform ◽  
Radial Flow ◽  
Fourier Transform Spectrometer ◽  
Gas Reservoirs ◽  
Outer Disk ◽  
Kinematic Analyses ◽  
Circular Flows ◽  
Atomic Gas ◽  
Weak Constraints ◽  
Gas Accretion

Abstract We present Hα velocity maps for the HIghMass galaxies UGC 7899, UGC 8475, UGC 9037 and UGC 9334, obtained with the SITELLE Imaging Fourier Transform Spectrometer on the Canada-France-Hawaii Telescope, to search for kinematic signatures of late gas accretion to explain their large atomic gas reservoirs. The maps for UGC 7899, UGC 9037, and UGC 9334 are amenable to disk-wide radial flow searches with the DiskFit algorithm, and those for UGC 7899 and UGC 9037 are also amenable to inner-disk kinematic analyses. We find no evidence for outer disk radial flows down to $\bar{V}_r \sim 20 \ \mathrm{km\, s}^{-1}$ in UGC 9037 and UGC 9334, but hints of such flows in UGC 7899. Conversely, we find clear signatures of inner (r ≲ 5 kpc) non-circularities in UGC 7899 and UGC 9037 that can be modelled as either bisymmetric (which could be produced by a bar) or radial flows. Comparing these models to the structure implied by photometric disk-bulge-bar decompositions, we favour inner radial flows in UGC 7899 and an inner bar in UGC 9037. With hints of outer disk radial flows and an outer disk warp, UGC 7899 is the best candidate for late accretion among the galaxies examined, but additional modelling is required to disentangle potential degeneracies between these signatures in H i and Hα velocity maps. Our search provides only weak constraints on hot-mode accretion models that could explain the unusually high H i content of HIghMass galaxies.

ANALYTIC EVALUATION METHOD OF FRACTAL EFFECTIVE STIMULATED RESERVOIR VOLUME FOR FRACTURED WELLS IN UNCONVENTIONAL GAS RESERVOIRS

Fractals ◽  
2018 ◽  
Vol 26 (06) ◽  
pp. 1850097 ◽  
Author(s):  
QI ZHANG ◽  
YULIANG SU ◽  
HUI ZHAO ◽  
WENDONG WANG ◽  
KAIJIE ZHANG ◽  
...  
Keyword(s):  
Shale Gas ◽  
Radial Flow ◽  
Transport Mechanisms ◽  
Gas Reservoirs ◽  
Unconventional Gas ◽  
Stimulated Reservoir Volume ◽  
Reservoir Volume ◽  
Fractal Index ◽  
Unconventional Gas Reservoirs ◽  
Fractured Well

It has been proved that effective stimulated reservoir volume (ESRV) is a significant area dominant to the production of the fractured well in unconventional gas reservoirs. Although ESRV properties can be estimated based on the microseismic technology and the analysis of actual fracturing data, the operations are complicated and results are inaccurate. Due to the complex structure of stimulated reservoir volume (SRV) with fractal and chaotic characteristics, a fractal evaluation model for ESRV (ESRV-FEM) of fractured wells in unconventional gas (both tight and shale gas) reservoirs is developed. Multiple gas transport mechanisms, SRV and unstimulated reservoir volume (USRV) are included. According to the pressure transient analysis (PTA), influences of multiple transport mechanisms on gas transport behaviors in ESRV are conducted. Moreover, the fractal index representing the heterogeneity degree is applied to estimate the ESRV under different inter-porosity flow coefficients and storage ratio conditions based on the ESRV-FEM. In addition, the presented ESRV-FEM is validated by an actual field case. The results show that gas adsorption has a significant effect on the radial flow duration time in SRV, and the heterogeneity makes the radial flow on PTA curves no longer show a horizontal line with the value of 0.5. Calculated ESRV sizes are compared with the assumed ones under different fractal indexes. The stronger the heterogeneity, the smaller ESRV is. The ESRV size of a fractured well in shale gas reservoirs is only 52.11% of SRV size when the fractal index equals to 0.6. The ESRV-FEM presented in this paper is expected to provide an effective method for the evaluation of the ESRV of fractured wells in unconventional gas reservoirs.

Linear vs. Radial Boundary-Dominated Flow: Implications for Gas-Well-Decline Analysis

SPE Journal ◽  
2015 ◽  
Vol 20 (05) ◽  
pp. 1053-1066 ◽  
Author(s):  
Pichit Vardcharragosad ◽  
Luis F. Ayala ◽  
Miao Zhang
Keyword(s):  
Radial Flow ◽  
Transient Flow ◽  
Transient Behavior ◽  
Late Time ◽  
Gas Reservoirs ◽  
Linear Flow ◽  
Unconventional Resources ◽  
Flow Geometry ◽  
Fast Pace ◽  
The Impact

Summary Linear flow is a fundamental reservoir-flow geometry typically associated with production from unconventional resources stimulated by means of hydraulic fracturing. Recently, linear flow has been intensively studied following the fast pace of development of unconventional resources. Previous studies have mainly focused on early transient behavior and behavior of composite linear-flow systems. In this work, a density-based analysis method is extended to study decline behavior of the linear-flow system in boundary-dominated flow (BDF). In this study, we first discuss traditional approaches used to model linear flow in gas reservoirs. Second, we show the applicability of the density-based method for gas linear flow both analytically and numerically. Next, late-time solutions are discussed, and the analytical forecasting solution that best describes the BDF behavior is selected for long-term decline-behavior studies. Previously reported results on radial flow as well as early transient-flow effect are also incorporated to provide a more complete understanding of decline behavior and the impact of flow geometry. We show that boundary-dominated responses in linear-flow scenarios fully develop at much later stages of reservoir depletion compared with radial-flow scenarios. As a result, and in marked contrast with radial flow, purely hyperbolic decline behavior may be completely lost in linear-flow scenarios during boundary-dominated conditions. It is demonstrated that most of the recoverable hydrocarbons are produced during the early transient period for linear-flow conditions, whereas most of them are recovered during the BDF period for radial flow. These results suggest that the availability of accurate early transient models is much more critical for the formulation of linear-flow-decline models than had been traditionally necessary for radial-flow-decline models.

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