Xu Z.Q.,Chengdu University of Technology |
Xu Z.Q.,Key Laboratory of Earth Exploration and Information Technology of the Ministry of Education |
Song H.,Chengdu University of Technology |
Zhang C.J.,Key Laboratory of Nuclear Techniques in Geosciences of Sichuan Province
Advanced Materials Research | Year: 2013
Xigeda Formation layer, which is widely distributed in Panzhihua area, is researched by the method of γ spectrum measurement. Qinglongshan Xigeda Formation profile is measured by the low-background multi-channelγenergy spectrometer in Panzhihua, the change rules of radioactive elements, including URa, Th, K, Ir and Ira on the profile are analyzed in detail. The characteristics and palaeoenvironmental significance of the sediment layer on the profile is researched by combining the geological features. The results show that the contents of radioactive elements in Xigeda Formation profile reduce obviously from the old to the new layer and change regularly and the radioactive characteristics are consistent to the sediment geological features. All these show that the γ spectrum method is a good one for the study of lake sediment and palaeoenvironment. © (2013) Trans Tech Publications, Switzerland.
Cheng B.,State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation |
Cheng B.,Key Laboratory of Earth Exploration and Information Technology of the Ministry of Education |
Xu T.,Sinopec |
Liang Q.,State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation |
And 2 more authors.
Shiyou Diqiu Wuli Kantan/Oil Geophysical Prospecting | Year: 2014
By using joint inversion of shear wave (S wave) and compressional wave (P wave) and iterated computation to process 3D3C seismic data, we can obtain multi-waves velocity ratio parameters, including S/P wave velocity ratio, S/C wave velocity ratio, C/P wave velocity ratio, and other parameters such as velocity ratio derivative which are derived from multi-wave velocity ratio parameters. Based on the mathematical analysis between Poisson's ratio and wave velocity ratio, we get S/C wave velocity ratio, C/P wave velocity ratio, the first order derivative of C/P wave velocity ratio to P wave, and the first order derivative of C/P wave velocity ratio to Poisson's ratio by using the propagation characters of P and C wave. All of these new parameters are sensitive to lithologic and gas characters which are very useful for gas prediction. Using these new parameters in gas detection of low permeated-tight fractured reservoir in the deep Xujiahe Formation in Western Sichuan Basin, we found that well-developed fractures with high multi-wave ratios are good gas reservoirs, which means multi-wave velocity ratio parameters can be new indicators in gas reservoir identification.