scholarly journals Reservoir fluid substitution effects on seismic profile interpretation: A physical modeling experiment

2010 ◽  
Vol 37 (10) ◽  
pp. n/a-n/a ◽  
Author(s):  
Shangxu Wang ◽  
Xiang-Yang Li ◽  
Bangrang Di ◽  
David Booth
Keyword(s):  
Physical Modeling ◽  
Seismic Profile ◽  
Substitution Effects ◽  
Fluid Substitution ◽  
Reservoir Fluid ◽  
Modeling Experiment

Investigation of fluid effects on seismic responses through a physical modeling experiment

2020 ◽  
pp. 1-38
Author(s):  
Chao Xu ◽  
Pinbo Ding ◽  
Bangrang Di ◽  
Jianxin Wei
Keyword(s):  
Seismic Data ◽  
Physical Modeling ◽  
Seismic Velocity ◽  
Water Saturation ◽  
P Wave ◽  
Seismic Velocities ◽  
Seismic Responses ◽  
Modeling Experiment ◽  
Seismic Reflections ◽  
Tight Rocks

We investigated fluid effects on seismic responses using seismic data from a physical modeling experiment. Eight cubic samples with cavities quantitatively filled with air, oil, and water and sixteen non-fluid samples were set within a physical model. Both pre-stack and post-stack seismic responses of the samples were analyzed to quantitatively investigate the fluid effect on the seismic response. It was indicated that fluids could cause detectable changes in both pre-stack and post-stack seismic responses for tight rocks. At first, fluids filled within samples caused changes in pre-stack seismic responses. Visible differences could be detected between angle gathers of the samples filled with air, oil, and water. For the base reflections, the amplitudes at large angles of the air-filled and oil-filed samples are obviously stronger than those of the water-filled sample. In addition, the presence of fluids within samples led to significant changes in post-stack seismic reflections. For samples with similar P-wave impedances to the background, we found strong seismic reflections for the fluid samples and weak or even no reflections for the non-fluid samples. There was notable interference between the top and base reflections for the fluid samples while there was none for the non-fluid samples. Seismic velocities were estimated using the two-way travel times between the top and base reflections. The estimated seismic velocity gently declined with increasing water saturation until 90%. When the water saturation was more than 90%, the seismic velocity showed a steep increase.

Effects of fluids and dual-pore systems on pressure-dependent velocities and attenuations in carbonates

Geophysics ◽  
2008 ◽  
Vol 73 (5) ◽  
pp. N35-N47 ◽  
Author(s):  
Remy Agersborg ◽  
Tor Arne Johansen ◽  
Morten Jakobsen ◽  
Jeremy Sothcott ◽  
Angus Best
Keyword(s):  
Fluid Flow ◽  
Confining Pressure ◽  
Substitution Effects ◽  
Fluid Substitution ◽  
Pore System ◽  
S Wave ◽  
Low Velocity ◽  
Wave Velocities ◽  
Three Samples ◽  
Local Fluid Flow

The effects of fluid substitution on P- and S-wave velocities in carbonates of complex texture are still not understood fully. The often-used Gassmann equation gives ambiguous results when compared with ultrasonic velocity data. We present theoretical modeling of velocity and attenuation measurements obtained at a frequency of [Formula: see text] for six carbonate samples composed of calcite and saturated with air, brine, and kerosene. Although porosities (2%–14%) and permeabilities [Formula: see text] are relatively low, velocity variations are large. Differences between the highest and lowest P- and S-wave velocities are about 18% and 27% for brine-saturated samples at 60 and [Formula: see text] effective pressure, respectively. S-wave velocities are measured for two orthogonal polarizations; for four of six samples, anisotropy is revealed. TheGassmann model underpredicts fluid-substitution effects by [Formula: see text] for three samples and by as much as 5% for the rest of the six samples. Moreover, when dried, they also show decreasing attenuation with increasing confining pressure. To model this behavior, we examine a pore model made of two pore systems: one constitutes the main and drainable porosity, and the other is made of undrained cracklike pores that can be associated with grain-to-grain contacts. In addition, these dried rock samples are modeled to contain a fluid-filled-pore system of grain-to-grain contacts, potentially causing local fluid flow and attenuation. For the theoretical model, we use an inclusion model based on the [Formula: see text]-matrix approach, which also considers effects of pore texture and geometry, and pore fluid, global- and local-fluid flow. By using a dual-pore system, we establish a realistic physical model consistently describing the measured data.

scholarly journals Influences of suspended sediments on the ecosystem in Lake Michigan: a 3-D coupled bio-physical modeling experiment

2002 ◽  
Vol 152 (2-3) ◽  
pp. 169-190 ◽  
Author(s):  
Rubao Ji ◽  
Changsheng Chen ◽  
Judith Wells Budd ◽  
David J. Schwab ◽  
Dmitry Beletsky ◽  
...  
Keyword(s):  
Physical Modeling ◽  
Lake Michigan ◽  
Suspended Sediments ◽  
Modeling Experiment

scholarly journals Reservoir Fluid Substitution Effect in Heterogeneous Seismic Model

2021 ◽  
Vol 06 (03) ◽  
pp. 98-106
Author(s):  
Wei Zhang ◽  
Mingjing Gui ◽  
Qing Zhao ◽  
Mengling Liu ◽  
Xinyue Liu ◽  
...  
Keyword(s):  
Substitution Effect ◽  
Fluid Substitution ◽  
Seismic Model ◽  
Reservoir Fluid

3‐D AVO physical modeling experiment over a simulated fracture medium

1995 ◽  
Author(s):  
Sharma V. Tadepalli ◽  
John A. McDonald ◽  
K. K. Sekharan ◽  
Robert H. Tatham
Keyword(s):  
Physical Modeling ◽  
Fracture Medium ◽  
Modeling Experiment

A physical modeling study of seismic features of karst cave reservoirs in the Tarim Basin, China

Geophysics ◽  
2016 ◽  
Vol 81 (1) ◽  
pp. B31-B41 ◽  
Author(s):  
Chao Xu ◽  
Bangrang Di ◽  
Jianxin Wei
Keyword(s):  
Tarim Basin ◽  
Physical Modeling ◽  
Relative Amplitude ◽  
Seismic Migration ◽  
Distribution Shape ◽  
Bright Spots ◽  
Spatially Distributed ◽  
Modeling Experiment ◽  
Deep Strata ◽  
Seismic Scale

On seismic migration sections, anomalous bright spots, called the string of beads response (SBR), are common features of carbonate karst reservoirs at the seismic scale in the Tarim Basin, China. To understand the SBR features of different karst caves, which is an important issue for local exploration, we conducted a physical modeling experiment. Within the physical model, we included various single caves with different scales, velocities, shapes, and fluids, as well as multiple caves in different spatial distributions. SBRs of all caves were extracted and summarized from the migration sections. First, we investigated effects of the cave scale, velocity, spatial distribution, shape, and fluids on SBRs. The relative amplitude of SBRs increased with the cave width ranging from 25 to 400 m and decreased with the cave velocity. The SBR split into two new SBRs when the cave height was larger than 100 m. Spatially distributed multiple caves resulted in some special SBRs, such as long SBRs, inclined SBRs, waved SBRs, and chaotic SBRs. The cave shape contribution to SBRs could be neglected in deep strata practically. The relative amplitude of SBRs of caves filled with gas and oil was stronger than those filled with water. Then, we established an interpretation chart of the corresponding relationship between six types of SBRs and their potential caves. Short SBRs were the responses of caves with a height of less than 60 m. Long SBRs corresponded to two kinds of cave units: (1) a single cave with a height between 70 and 100 m and (2) two caves (height less than 60 m) vertically distributed with a small distance (less than 60 m). Chop-shaped SBRs indicated caves with a width of more than 100 m. Inclined SBRs, waved SBRs, and chaotic SBRs corresponded to multiple caves spatially distributed in triangles, rhombuses, and clusters, respectively.

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