Assessment of Radius of Investigation of Pressure Transient Analysis in Highly Heterogeneous Reservoirs

2021 ◽  
Author(s):  
Murat Zeybek ◽  
Lei Jiang ◽  
Hadrien Dumont

Abstract The radius of investigation (ROI) of pressure transient analyses has been traditionally assessed using analytical formulations with basic reservoir parameters for homogenous systems. Numerous studies aimed to improve ROI formulations to incorporate all reservoir and testing parameters such as gauge resolution and rate for more accurate ROI assessments. However, new generation wireline formation testers aim to improve deep transient tests with significant developments in gauge resolution and increasing rate. Challenges still remain in heterogeneous formations such as shaly sands and carbonate reservoirs. In this study, detailed conceptual high-resolution numerical models are set up, including comprehensive reservoir and measurement parameters, to investigate more realistic ROI assessments in layered heterogeneous systems without and with hydraulic communication. Several conceptual examples are presented in layered systems with permeability contrasts. In addition, deviation from infinite-acting radial flow (IAFR) and pressure propagation in highly heterogeneous layered systems are investigated to detect the presence of geological features, including closed boundary systems and the presence of a fault in the proximity of wellbore.

2010 ◽  
Vol 13 (02) ◽  
pp. 341-358 ◽  
Author(s):  
F.. Medeiros ◽  
E.. Ozkan ◽  
H.. Kazemi

Summary Pressure-transient responses of wells in a heterogeneous reservoir are usually computed with numerical models by using fine gridding and very short timesteps. An exceptions to this practice has been the use of analytical, semianalytical, and boundary-element methods for relatively simpler forms of heterogeneity, such as layering or the existence of natural fractures. This paper presents a semianalytical approach to compute pressure transients for more-complex forms of heterogeneity including composite, layered, and compartmentalized reservoirs. In this approach, the reservoir is divided into blocks corresponding to locally homogeneous substructures, and analytical pressure-transient solutions for adjacent blocks are coupled at the boundaries. This approach is consistent with the averaging effect of pressure transients and provides an alternative to full numerical modeling of pressure-transient responses in heterogeneous formations. The validation of the approach is demonstrated in comparison to the analytical solution for horizontal wells in a homogeneous reservoir. Application examples highlight the physical consistency of the approach and demonstrate its capability to model different types of reservoir heterogeneity.


1999 ◽  
Vol 395 ◽  
pp. 161-180 ◽  
Author(s):  
Y. RUBIN ◽  
A. SUN ◽  
R. MAXWELL ◽  
A. BELLIN

We present a new approach for modelling macrodispersivity in spatially variable velocity fields, such as exist in geologically heterogeneous formations. Considering a spectral representation of the velocity, it is recognized that numerical models usually capture low-wavenumber effects, while the large-wavenumber effects, associated with subgrid block variability, are suppressed. While this suppression is avoidable if the heterogeneity is captured at minute detail, that goal is impossible to achieve in all but the most trivial cases. Representing the effects of the suppressed variability in the models is made possible using the proposed concept of block-effective macrodispersivity. A tensor is developed, which we refer to as the block-effective macrodispersivity tensor, whose terms are functions of the characteristic length scales of heterogeneity, as well as the length scales of the model's homogenized areas, or numerical grid blocks. Closed-form expressions are developed for small variability in the log-conductivity and unidirectional mean flow, and are tested numerically. The use of the block-effective macrodispersivities allows conditioning of the velocity field on the measurements on the one hand, while accounting for the effects of unmodelled heterogeneity on the other, in a numerically reasonable set-up. It is shown that the effects of the grid scale are similar to those of the plume scale in terms of filtering out the effects of portions of the velocity spectrum. Hence it is easy to expand the concept of the block-effective dispersivity to account for the scale of the solute body and the pore-scale dispersion.


2017 ◽  
Author(s):  
M. Ibrahim ◽  
C. Pieprzica ◽  
E. Vosburgh ◽  
A. Dabral ◽  
O. Olayinka ◽  
...  

Author(s):  
Stefan Schmid ◽  
Rudi Kulenovic ◽  
Eckart Laurien

For the validation of empirical models to calculate leakage flow rates in through-wall cracks of piping, reliable experimental data are essential. In this context, the Leakage Flow (LF) test rig was built up at the IKE for measurements of leakage flow rates with reduced pressure (maximum 1 MPA) and temperature (maximum 170 °C) compared to real plant conditions. The design of the test rig enables experimental investigations of through-wall cracks with different geometries and orientations by means of circular blank sheets with integrated cracks which are installed in the tubular test section of the test rig. In the paper, the experimental LF set-up and used measurement techniques are explained in detail. Furthermore, first leakage flow measurement results for one through-wall crack geometry and different imposed fluid pressures at ambient temperature conditions are presented and discussed. As an additional aspect the experimental data are used for the determination of the flow resistance of the investigated leak channel. Finally, the experimental results are compared with numerical results of WinLeck calculations to prove specifically in WinLeck implemented numerical models.


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