Seismic velocities in carbonate rocks

Wang, Z.; Hirsche, W. Keith; Sedgwick, G.

doi:10.1016/0148-9062(91)91315-i

Cited by 12 publications

(17 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…600 m). To calculate the thickness and the depth in metres of the seismic units, a range of conservative estimate velocities in carbonate formations (between 2500 and 3000 m/s; Wang et al, 1991) was used as an average for all the sedimentary thickness. These averaged velocities fall in the range of velocities calculated for the southern Karukéra spur sedimentary cover following seismic refraction experiments Kopp et al, 2011).…”

Section: Seismic Interpretation Methodsmentioning

confidence: 99%

Tectonic and sedimentary architecture of the Karukéra spur: A record of the Lesser Antilles fore-arc deformations since the Neogene

et al. 2015

View full text Add to dashboard Cite

Section: Seismic Interpretation Methodsmentioning

confidence: 99%

Tectonic and sedimentary architecture of the Karukéra spur: A record of the Lesser Antilles fore-arc deformations since the Neogene

et al. 2015

View full text Add to dashboard Cite

“…It is also miscible with CO2 under McElroy reservoir conditions. Figure 4 also shows the velocity and bulk modulus of the Carnation oil measured by Wang et al (1991). Both Vp and bulk modulus of FIG. 2.…”

Section: Seismic Propertiesmentioning

confidence: 97%

Seismic monitoring of a CO₂ flood in a carbonate reservoir: A rock physics study

1998

View full text Add to dashboard Cite

A carbon dioxide (CO2) injection pilot project is underway in Section 205 of the McElroy field, West Texas. High-resolution crosswell seismic imaging surveys were conducted before and after CO2 flooding to monitor the CO2 flood process and map the flooded zones. The velocity changes observed by these time-lapse surveys are typically on the order of -6%, with maximum values on the order of -10% in the vicinity of the injection well. These values generally agree with laboratory measurements if the effects of changing pore pressure are included.The observed dramatic compressional (VP) and shear (VS ) velocity changes are considerably greater than we had initially predicted using the Gassmann (1951) fluid substitution analysis (Nolen-Hoeksema et al., 1995) because we had assumed reservoir pressure would not change from survey to survey. However, the post-CO2 reservoir pore fluid pressure was substantially higher than the original pore pressure. In addition, our original petrophysical data for dry and brine-saturated reservoir rocks did not cover the range of pressures actually seen in the field. Therefore, we undertook a rock physics study of CO2 flooding in the laboratory, under the simulated McElroy pressures and temperature.Our results show that the combined effects of pore pressure buildup and fluid substitution caused by CO2

show abstract

“…Several studies have been made (e.g., Raymer et al 1980;Rafavich et al 1984;Wang et al 1991;Anselmetti and Eberli 1993;Anselmetti 1994;Stafleu et al 1994;Kenter and Ivanov 1995;Han et al 1986;Kenter et al 1997aKenter et al , 1997bWoodside et al 1998) that show the primary factors controlling acoustic velocity in nearly pure carbonates are both the amount and type of porosity, diagenetic properties, and mineralogy. The classic velocity transforms, Wyllie's time-average equation (Wyllie et al 1956), and Gardner's empirical relation (Gardner et al 1974), allow the prediction of P-wave velocity from porosity or bulk density in single data sets but fail to account for the variation in velocity at a given porosity value.…”

Section: Introductionmentioning

confidence: 97%

Acoustic Properties of "Young" Carbonate Rocks, ODP Leg 166 and Boreholes Clino and Unda, Western Great Bahama Bank

Kenter¹,

Anselmetti²,

Kramer³

et al. 2002

Journal of Sedimentary Research

View full text Add to dashboard Cite

Acoustic properties determined from logs and discrete measurements along a borehole transect across the slope of the western Great Bahama Bank margin (ODP Leg 166) show a distinct relationship with primary sediment composition and noncarbonate content.Dominant sediment types are alternating cemented and uncompacted calciturbidites with shallow-water derived grains, and poorly to uncemented and compacted periplatform ooze of globigerinid-dominated wackestone to packstone. Comparison of the velocity-porosity variation from logs and discrete measurements reveals that both tend to follow the trend of generally accepted velocity transforms. Primary control on the acoustic velocity is exerted by total porosity, whereas the remaining variation in velocity is explained by differential diagenesis. The less cemented to uncemented and compacted background sediments have velocities that, at a given porosity, fall below the timeaverage equation for calcite. The cemented turbidites, however, have velocities that are higher than those predicted by the time-average equation. Although it is unclear whether the original volume of aragonite or presence of organic matter controlled this difference, it is suggested that the acoustic properties reflect an input signal. The presence of noncarbonate material, some of which is clay, increases basinward and further reduces the acoustic velocities in the background sediment. In contrast, earlier work on the more proximal slope, and nearly pure carbonate, intervals in Clino and Unda cores documents diagenetic differentiation in compositionally similar sediment, resulting in alternating acoustically fast and slow layers. Marginal and nearly pure limestones have a more complex acoustic behavior and hence are difficult to predict.Though both velocity logs and discrete velocity measurements show comparable general trends, logging data show a considerably larger variation at a given porosity value (up to 3.5 km/s) than discrete data, which ranges between 1.0 and 2.5 km/s. To improve the quality of velocity logs it is suggested to groundtruth these data with other logging data, general velocity transforms, and, ideally, discrete measurements on core plugs.

show abstract

Seismic velocities in carbonate rocks

Cited by 12 publications

References 0 publications

Tectonic and sedimentary architecture of the Karukéra spur: A record of the Lesser Antilles fore-arc deformations since the Neogene

Tectonic and sedimentary architecture of the Karukéra spur: A record of the Lesser Antilles fore-arc deformations since the Neogene

Seismic monitoring of a CO₂ flood in a carbonate reservoir: A rock physics study

Acoustic Properties of "Young" Carbonate Rocks, ODP Leg 166 and Boreholes Clino and Unda, Western Great Bahama Bank

Contact Info

Product

Resources

About

Seismic velocities in carbonate rocks

Cited by 12 publications

References 0 publications

Tectonic and sedimentary architecture of the Karukéra spur: A record of the Lesser Antilles fore-arc deformations since the Neogene

Tectonic and sedimentary architecture of the Karukéra spur: A record of the Lesser Antilles fore-arc deformations since the Neogene

Seismic monitoring of a CO2 flood in a carbonate reservoir: A rock physics study

Acoustic Properties of "Young" Carbonate Rocks, ODP Leg 166 and Boreholes Clino and Unda, Western Great Bahama Bank

Contact Info

Product

Resources

About

Seismic monitoring of a CO₂ flood in a carbonate reservoir: A rock physics study