The Relationship Between Acoustic Properties and the Petrographic Character of Carbonate Rocks

Rafavich, E.; Kendall, C. H. St. C.; Todd, Terry

doi:10.1071/eg984193

Cited by 10 publications

(18 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Figure 2 shows that the compressional-and shear-wave velocities of the fluid-saturated rocks decrease with increasing porosity. This observation is consistent with results obtained for sandstones by Tosaya and Nur (1982), Han, Nur and Morgan (1986) and Klimentos (1991), and for limestones by Rafavich et al (1984) and Velocity of P-and S-waves in limestones 5 Wilkens et al (1984). The linear regression relationships between the compressional-and shear-wave velocities (in m/s) and porosity f (%) for the fully water-saturated limestones are V p 5317 À 89f; R 2 0:46;…”

Section: R E S U Lt Ssupporting

confidence: 89%

“…Figure 11 shows a plot of the ratio V p /V s versus porosity for limestones from this study and from that of Rafavich et al (1984). The data of Rafavich et al (1984) were obtained at 40 MPa (6000 psi) effective hydrostatic pressure on fully brine-saturated carbonate rocks (limestones and dolomites). Figure 11 shows that the ratio V p /V s for water-saturated limestones is independent of porosity with a mean value for V p /V s of 1.9.…”

Section: Velocity Of P-and S-waves In Limestonesmentioning

confidence: 86%

“…10 shows that the shear moduli of the rocks are reduced significantly by the introduction of pore water. Figure 11 shows a plot of the ratio V p /V s versus porosity for limestones from this study and from that of Rafavich et al (1984). The data of Rafavich et al (1984) were obtained at 40 MPa (6000 psi) effective hydrostatic pressure on fully brine-saturated carbonate rocks (limestones and dolomites).…”

Section: Velocity Of P-and S-waves In Limestonesmentioning

confidence: 98%

“…The fact that the ratio of the compressionalwave velocity to the shear-wave velocity, V p /V s , is about 1.9 for pure limestones, which is significantly different from that for quartzose sandstones (1.5±1.7), means that the proportion of pure limestone and quartzose sandstone in, for example, calcareous sandstone or siliceous limestone can be predicted if the porosities of the rocks are known. This was demonstrated by Wilkens et al (1984) and Rafavich et al (1984). This paper presents further compressional-and shear-wave velocity data for limestones and attempts to establish relationships between the velocities and the petrophysical and textural properties.…”

Section: Introductionmentioning

confidence: 94%

“…These complexities make the relationships between the petrophysical properties and the seismic properties of limestones rather complicated. However, integrated studies of seismic, petrophysical and petrological properties by Rafavich, Kendall and Todd (1984) and Wilkens, Simmons and Caruso (1984) have demonstrated that useful relationships between these properties can be obtained. The fact that the ratio of the compressionalwave velocity to the shear-wave velocity, V p /V s , is about 1.9 for pure limestones, which is significantly different from that for quartzose sandstones (1.5±1.7), means that the proportion of pure limestone and quartzose sandstone in, for example, calcareous sandstone or siliceous limestone can be predicted if the porosities of the rocks are known.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Velocities of compressional and shear waves in limestones

Assefa¹,

McCann

Sothcott

2003

Geophysical Prospecting

200

View full text Add to dashboard Cite

Carbonate rocks are important hydrocarbon reservoir rocks with complex textures and petrophysical properties (porosity and permeability) mainly resulting from various diagenetic processes (compaction, dissolution, precipitation, cementation, etc.). These complexities make prediction of reservoir characteristics (e.g. porosity and permeability) from their seismic properties very difficult. To explore the relationship between the seismic, petrophysical and geological properties, ultrasonic compressional‐ and shear‐wave velocity measurements were made under a simulated in situ condition of pressure (50 MPa hydrostatic effective pressure) at frequencies of approximately 0.85 MHz and 0.7 MHz, respectively, using a pulse‐echo method. The measurements were made both in vacuum‐dry and fully saturated conditions in oolitic limestones of the Great Oolite Formation of southern England. Some of the rocks were fully saturated with oil. The acoustic measurements were supplemented by porosity and permeability measurements, petrological and pore geometry studies of resin‐impregnated polished thin sections, X‐ray diffraction analyses and scanning electron microscope studies to investigate submicroscopic textures and micropores. It is shown that the compressional‐ and shear‐wave velocities (Vp and Vs, respectively) decrease with increasing porosity and that Vp decreases approximately twice as fast as Vs. The systematic differences in pore structures (e.g. the aspect ratio) of the limestones produce large residuals in the velocity versus porosity relationship. It is demonstrated that the velocity versus porosity relationship can be improved by removing the pore‐structure‐dependent variations from the residuals. The introduction of water into the pore space decreases the shear moduli of the rocks by about 2 GPa, suggesting that there exists a fluid/matrix interaction at grain contacts, which reduces the rigidity. The predicted Biot–Gassmann velocity values are greater than the measured velocity values due to the rock–fluid interaction. This is not accounted for in the Biot–Gassmann velocity models and velocity dispersion due to a local flow mechanism. The velocities predicted by the Raymer and time‐average relationships overestimated the measured velocities even more than the Biot model.

show abstract

Section: R E S U Lt Ssupporting

confidence: 89%

Section: Velocity Of P-and S-waves In Limestonesmentioning

confidence: 86%

Section: Velocity Of P-and S-waves In Limestonesmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 94%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Velocities of compressional and shear waves in limestones

Assefa¹,

McCann

Sothcott

2003

Geophysical Prospecting

200

View full text Add to dashboard Cite

show abstract

Deep crustal structure of the northeastern Gulf of Mexico: Implications for rift evolution and seafloor spreading

et al. 2014

View full text Add to dashboard Cite

We image deep crustal structure using marine seismic refraction data recorded by a linear array of ocean-bottom seismometers in the Gulf of Mexico Basin Opening project (GUMBO Line 3) in order to provide new constraints on the nature of continental and oceanic crust in the northeastern Gulf of Mexico. GUMBO Line 3 extends~524 km from the continental shelf offshore Pensacola, Florida, across the De Soto Canyon and into the central Gulf basin. Travel times from long offset, wide angle reflections and refractions resolve compressional seismic velocities and layer boundaries for sediment, crystalline crust, and upper mantle. We compare our results with coincident multichannel seismic reflection data. Our velocity model recovers shallow seismic velocities (~2.0-4.5 km/s) that we interpret as evaporites and clastic sediments. A Cretaceous carbonate platform is interpreted beneath the De Soto Canyon with seismic velocities >5.0 km/s. Crystalline continental crust thins seaward along GUMBO Line 3 from 23-10 km across the De Soto Canyon. High seismic velocity lower crust (>7.2 km/s) is interpreted as extensive syn-rift magmatism and possibly mafic underplating, common features at volcanic rift margins with high mantle potential temperatures. In the central Gulf basin we interpret thick oceanic crust (>8 km) emplaced at a slow full-spreading rate (~24 mm/yr). We suggest a sustained thermal anomaly during slow seafloor-spreading conditions led to voluminous basalt flows from a spreading ridge that overprinted seafloor magnetic anomalies in the northeastern Gulf of Mexico.

show abstract

The effect of pressure on ultrasonic velocity and attenuation in near‐surface sedimentary rocks

Best

1997

Geophysical Prospecting

View full text Add to dashboard Cite

The Relationship Between Acoustic Properties and the Petrographic Character of Carbonate Rocks

Cited by 10 publications

References 0 publications

Velocities of compressional and shear waves in limestones

Velocities of compressional and shear waves in limestones

Deep crustal structure of the northeastern Gulf of Mexico: Implications for rift evolution and seafloor spreading

The effect of pressure on ultrasonic velocity and attenuation in near‐surface sedimentary rocks

Contact Info

Product

Resources

About