List of released wells and availability of digital well-log data for Atlantic, Pacific and Alaska OCS regions through December 31, 1985

1986 ◽  
Author(s):  
S.E. Prensky
Keyword(s):  
Well Log ◽  
Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 804
Author(s):  
Lin Liu ◽  
Xiumei Zhang ◽  
Xiuming Wang

Natural gas hydrate is a new clean energy source in the 21st century, which has become a research point of the exploration and development technology. Acoustic well logs are one of the most important assets in gas hydrate studies. In this paper, an improved Carcione–Leclaire model is proposed by introducing the expressions of frame bulk modulus, shear modulus and friction coefficient between solid phases. On this basis, the sensitivities of the velocities and attenuations of the first kind of compressional (P1) and shear (S1) waves to relevant physical parameters are explored. In particular, we perform numerical modeling to investigate the effects of frequency, gas hydrate saturation and clay on the phase velocities and attenuations of the above five waves. The analyses demonstrate that, the velocities and attenuations of P1 and S1 are more sensitive to gas hydrate saturation than other parameters. The larger the gas hydrate saturation, the more reliable P1 velocity. Besides, the attenuations of P1 and S1 are more sensitive than velocity to gas hydrate saturation. Further, P1 and S1 are almost nondispersive while their phase velocities increase with the increase of gas hydrate saturation. The second compressional (P2) and shear (S2) waves and the third kind of compressional wave (P3) are dispersive in the seismic band, and the attenuations of them are significant. Moreover, in the case of clay in the solid grain frame, gas hydrate-bearing sediments exhibit lower P1 and S1 velocities. Clay decreases the attenuation of P1, and the attenuations of S1, P2, S2 and P3 exhibit little effect on clay content. We compared the velocity of P1 predicted by the model with the well log data from the Ocean Drilling Program (ODP) Leg 164 Site 995B to verify the applicability of the model. The results of the model agree well with the well log data. Finally, we estimate the hydrate layer at ODP Leg 204 Site 1247B is about 100–130 m below the seafloor, the saturation is between 0–27%, and the average saturation is 7.2%.


Author(s):  
Mohammad Farsi ◽  
Nima Mohamadian ◽  
Hamzeh Ghorbani ◽  
David A. Wood ◽  
Shadfar Davoodi ◽  
...  

Geophysics ◽  
2005 ◽  
Vol 70 (3) ◽  
pp. B1-B9 ◽  
Author(s):  
John D. Skalbeck ◽  
Robert E. Karlin ◽  
Lisa Shevenell ◽  
Michael C. Widmer

The concurrent development of the Steamboat Hills geothermal area for power production and the adjacent alluvial aquifers for drinking water in Washoe County, Nevada, necessitates a good understanding of the hydrogeologic connection between these water resources. The problem is that adequate characterization of the subsurface geologic structure is not possible with existing geologic data. This need prompted us to construct a detailed 3D representation of the subsurface geologic structure based on 2.75D forward modeling of 11 gravity and aeromagnetic profiles constrained by geologic data and physical (density, magnetic susceptibility, remanent magnetic) properties. Potential-fields modeling results provided greater definition of the alluvial basins, and when combined with well-log data, yield an overall basin volume surrounding Steamboat Hills that is 64% greater than the volume derived from well-log data alone. A representation of the geothermal reservoir, consisting of altered granodiorite and metamorphic rocks, illustrates that the flow of thermal water is fault controlled. The model also suggests that thermal water may upflow along an unexplored fault flanking western Steamboat Hills. North-trending faults that conduct thermal water from the geothermal system to the alluvial aquifer appear to be zones of altered volcanics that produce subtle aeromagnetic anomalies.


2012 ◽  
Vol 44 (8) ◽  
pp. 901-928 ◽  
Author(s):  
E. Chandrasekhar ◽  
V. Eswara Rao
Keyword(s):  
Well Log ◽  

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