scholarly journals Experimental assessment of pore fluid distribution and geomechanical changes in saline sandstone reservoirs during and after CO 2 injection

2017 ◽  
Vol 63 ◽  
pp. 356-369 ◽  
Author(s):  
Ismael Falcon-Suarez ◽  
Héctor Marín-Moreno ◽  
Fraser Browning ◽  
Anna Lichtschlag ◽  
Katleen Robert ◽  
...  
Keyword(s):  
Pore Fluid ◽  
Fluid Distribution ◽  
Experimental Assessment ◽  
Sandstone Reservoirs

scholarly journals Poroelastic property analysis of seismic low-frequency shadows associated with gas reservoirs

2020 ◽  
Vol 17 (3) ◽  
pp. 463-474
Author(s):  
Shengjie Li ◽  
Ying Rao
Keyword(s):  
Mode Conversion ◽  
Low Frequency ◽  
Simulation Method ◽  
Wave Mode ◽  
Pore Fluid ◽  
Fluid Distribution ◽  
Gas Reservoirs ◽  
Tight Sandstone ◽  
Reservoir Properties ◽  
Gas Bearing

Abstract Seismic low-frequency amplitude shadows have been widely used as a hydrocarbon indicator. This study investigates the effect of reservoir properties and seismic wave mode conversion on the characteristics of the low-frequency amplitude shadows in gas-bearing reservoirs. The target gas reservoirs are typically related to the lithology of tight sandstone with strong heterogeneity. Pore-fluid distribution within the reservoirs presents patchy saturation in the vertical and horizontal directions, and this patchy saturation easily induces low-frequency shadows beneath gas-bearing reservoirs. These low-frequency shadows are validated by using a poroelastic simulation method. The results of our field case-based study indicate that pore-fluid property, plus the thickness and heterogeneity of reservoirs are the key elements in the generation of low-frequency shadows. The results also indicate that the poroelastic simulation method can be used to effectively predict the spatial distribution of gas-bearing reservoirs, by directly verifying the low-frequency shadow phenomenon existing in the seismic data.

The Three-State Model Of Pore Fluid Distribution

1996 ◽  
Author(s):  
Yongsheng Chen ◽  
Zhenyu Liu ◽  
Fu Dewu
Keyword(s):  
Pore Fluid ◽  
State Model ◽  
Fluid Distribution ◽  
Three State Model

Seismic signatures of reservoir transport properties and pore fluid distribution

Geophysics ◽  
1994 ◽  
Vol 59 (8) ◽  
pp. 1222-1236 ◽  
Author(s):  
Nabil Akbar ◽  
Gary Mavko ◽  
Amos Nur ◽  
Jack Dvorkin
Keyword(s):  
Bulk Modulus ◽  
Solid Phase ◽  
Low Frequency ◽  
Pore Fluid ◽  
Fluid Distribution ◽  
Geometrical Factor ◽  
Velocity Versus ◽  
Frequency Limit ◽  
Local Flow ◽  
Wave Induced

We investigate the effects of permeability, frequency, and fluid distribution on the viscoelastic behavior of rock. The viscoelastic response of rock to seismic waves depends on the relative motion of pore fluid with respect to the solid phase. Fluid motion depends, in part, on the internal wave‐induced pore pressure distribution that relates to the pore micro‐structure of rock and the scales of saturation. We consider wave‐induced squirt fluid flow at two scales: (1) local microscopic flow at the smallest scale of saturation heterogeneity (e.g., within a single pore) and (2) macroscopic flow at a larger scale of fluid‐saturated and dry patches. We explore the circumstances under which each of these mechanisms prevails. We examine such flows under the conditions of uniform confining (bulk) compression and obtain the effective dynamic bulk modulus of rock. The solutions are formulated in terms of generalized frequencies that depend on frequency, saturation, fluid and gas properties, and on the macroscopic properties of rock such as permeability, porosity, and dry bulk modulus. The study includes the whole range of saturation and frequency; therefore, we provide the missing link between the low‐frequency limit (Gassmann’s formula) and the high‐frequency limit given by Mavko and Jizba. Further, we compare our model with Biot’s theory and introduce a geometrical factor whose numeric value gives an indication as to whether local fluid squirt or global (squirt and/or Biot’s) mechanisms dominate the viscoelastic properties of porous materials. The important results of our theoretical modeling are: (1) a hysteresis of acoustic velocity versus saturation resulting from variations in fluid distributions, and (2) two peaks of acoustic wave attenuation—one at low frequency (caused by global squirt‐flow) and another at higher frequency (caused by local flow). Both theoretical results are compared with experimental data.

Nanometer-scale pore fluid distribution and drying damage in preserved clay cores from Belgian clay formations inferred by BIB-cryo-SEM

2014 ◽  
Vol 179 ◽  
pp. 117-131 ◽  
Author(s):  
Guillaume Desbois ◽  
Janos L. Urai ◽  
Susanne Hemes ◽  
Stephane Brassinnes ◽  
Mieke De Craen ◽  
...  
Keyword(s):  
Pore Fluid ◽  
Fluid Distribution ◽  
Nanometer Scale

Effects of fluid saturations on undrained poroelastic constants in layered media

2020 ◽  
Vol 223 (1) ◽  
pp. 366-378
Author(s):  
Shengjie Li
Keyword(s):  
Fluid Phase ◽  
Elastic Parameter ◽  
Pore Fluid ◽  
Fluid Distribution ◽  
Fluid Substitution ◽  
Coarse Scale ◽  
Vertical Stiffness ◽  
Heterogeneous Reservoirs ◽  
Stiffness Constant ◽  
Poroelastic Model

SUMMARY Understanding the fluid dependence of the poroelastic stiffness constants of a layered porous package is of great importance in subsurface exploration and development. While the effects of the pore-fluid distribution caused by coarse-scale heterogeneities within an isotropic medium have been studied for several decades, the role of these heterogeneities on the poroelastic constants of a finely layered package is still largely unexplored. In this study, we apply the poroelastic upscaling methods to estimate the fluid-dependent poroelastic stiffness constants of a layered package at the coarse scale. The numerical results show that the refined Gassmann's fluid substitution formulae presented in this paper is applicable if a single fluid phase is uniformly saturated within a layered package. The stiffness constants (${c_{11}}$ and ${c_{33}}$) of the layered package with patchy saturations are always higher than or equal to those obtained for the medium with homogeneous saturations, the stiffness constants predicted by the refined fluid substitution formulae for the package simultaneously saturated with different fluids fall between them. Experimental results confirm the relationship between the undrained vertical stiffness constant and the effective pore-fluid bulk modulus for the patch saturated package, indicating that a reasonable result can be achieved by properly choosing an effective poroelastic model that accounts both for the fluid hydraulic communication and the anisotropy of the medium. The results improve the understanding of the coarse-scale fluid dependence of the poroelastic stiffness constants of a layered package, and therefore, it can be used to interpret the seismically inverted elastic parameter for the petrophysical properties in heterogeneous reservoirs.

scholarly journals Effect of Vibrations on Pore Fluid Distribution in Porous Media

2006 ◽  
Vol 62 (2) ◽  
pp. 187-204 ◽  
Author(s):  
Ming Xiao ◽  
Lakshmi N. Reddi ◽  
Susan L. Steinberg
Keyword(s):  
Porous Media ◽  
Pore Fluid ◽  
Fluid Distribution

scholarly journals Applying NMR T2 Spectral Parameters in Pore Structure Evaluation—An Example from an Eocene Low-Permeability Sandstone Reservoir

2021 ◽  
Vol 11 (17) ◽  
pp. 8027
Author(s):  
Yan Lu ◽  
Keyu Liu ◽  
Ya Wang
Keyword(s):  
Pore Structure ◽  
Fluid Distribution ◽  
Integrated Analysis ◽  
Low Permeability ◽  
Bohai Bay ◽  
Petrophysical Properties ◽  
Spectral Parameters ◽  
Pore Structures ◽  
Sandstone Reservoirs ◽  
Structure Evaluation

The Eocene low-permeability sandstone reservoirs in the Dongying Depression, Bohai Bay Basin, China host a significant amount of oil reserves. The development of the reservoirs has been hampered by our inability to understand the complex and heterogeneous pore structures of the reservoirs. In this study, the pore systems, pore sizes, pore connectivity, and movable fluid distribution of the Eocene Shahejie Formation (Es4) sandstone reservoirs were investigated using an integrated analysis of optical and scanning electron microscopy (SEM), mercury injection capillary pressure (MICP), and nuclear magnetic resonance (NMR). The full-range pore structures of the Es4 sandstone reservoirs were evaluated by using NMR experiments. Various NMR T2 spectral parameters suitable for describing the pore structures and movable fluid distribution were extracted through morphological and statistical analysis of NMR T2 spectra. In combination with corresponding MICP data and petrophysical properties, we have demonstrated the reliability and robustness of the T2 spectral parameters for pore structure characterization. Four types of pore structures (I, II, III, and IV) were distinguished from the NMR T2 spectral parameters in association with other petrophysical properties and macroscopic behaviors. We have demonstrated the effectiveness of using the NMR T2 spectral parameters to characterize and classify micropore structures, which may be applied to effectively evaluate and predict low-permeability reservoir quality.

Discontinuous Pore Fluid Distribution under Microgravity-KC-135 Flight Investigations

2005 ◽  
Vol 69 (3) ◽  
pp. 593-598 ◽  
Author(s):  
Lakshmi N. Reddi ◽  
Ming Xiao ◽  
Susan L. Steinberg
Keyword(s):  
Pore Fluid ◽  
Fluid Distribution
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