Qingshankou shale(Gulong area,China)exhibits strong acoustic anisotropy characteristics,posing significant challenges to its exploration and development.In this study,the five full elastic constants and multipole resp...Qingshankou shale(Gulong area,China)exhibits strong acoustic anisotropy characteristics,posing significant challenges to its exploration and development.In this study,the five full elastic constants and multipole response law of the Qingshankou shale were studied using experimental measurements.Analyses show that the anisotropy parametersϵandγin the study region are greater than 0.4,whereas the anisotropy parameterδis smaller,generally 0.1.Numerical simulations show that the longitudinal and transverse wave velocities of these strong anisotropic rocks vary significantly with inclination angle,and significant differences in group velocity and phase velocity are also present.Acoustic logging measures the group velocity in dipped boreholes;this differs from the phase velocity to some extent.As the dip angle increases,the longitudinal and SH wave velocities increase accordingly,while the qSV-wave velocity initially increases and then decreases,reaching its maximum value at a dip of approximately 40°.These results provide an effective guide for the correction and modeling of acoustic logging time differences in the region.展开更多
The genus Saurogobio Bleeker (1870) is a group of small sized cyprinids. Saurogobio dabryi Bleeker (1871) is widely distributed in East Asia.On the basis of careful inspection of morphological and meristic ch...The genus Saurogobio Bleeker (1870) is a group of small sized cyprinids. Saurogobio dabryi Bleeker (1871) is widely distributed in East Asia.On the basis of careful inspection of morphological and meristic characters of specimen collected from Chenghai Lake in Yunnan and the opening river systems including Pearl River,Minjiang River,Yangtze River,Liaohe River and Songhuajiang River,the Chenghai Lake population of Saurogobio dabryi is considered to represent a new subspecies, Saurogobio dabryi chenghaiensis . Saurogobio dabryi chenghaiensis is distinguished by the combination of following characters.Rostral cap developed,covering over upper lip,and lips with developed papillae.Body and caudal peduncle very slender,body depth 12 7%-15 0% of standard length(SL),caudal peduncle depth 5 5%-6 1% of SL and 31 8%-39 1% of caudal peduncle length.A longitudinal dark stripe present along the axis on each side of body and 6-11 stick shaped black spots (its widths being 25%-50% of its lengths respectively) occur along the stripe.Distance from pelvic fin origin to anus is more than 50% of pelvic fin length.The length of the shortest caudal fin ray is less than 50% that of the longest one.The new subspecies occurs only in Chenghai Lake,Yunnan,China.展开更多
We introduce the Thomsen anisotropic parameters into the approximate linear reflection coefficient equation for P-SV wave in weakly anisotropic HTI media. From this we get a new, more effective, and practical reflecti...We introduce the Thomsen anisotropic parameters into the approximate linear reflection coefficient equation for P-SV wave in weakly anisotropic HTI media. From this we get a new, more effective, and practical reflection coefficient equation. We performed forward modeling to AVO attributes, obtaining excellent results. The combined AVO attribute analysis of PP and PS reflection data can greatly reduce ambiguity, obtain better petrophysical parameters, and improve parameter accuracy.展开更多
基金supported by Major Science and Technology Special Project of China National Petroleum Corporation"Research on Large scale Storage and Production Increase and Exploration and Development Technology of Continental Shale Oil"(2023ZZ15)。
文摘Qingshankou shale(Gulong area,China)exhibits strong acoustic anisotropy characteristics,posing significant challenges to its exploration and development.In this study,the five full elastic constants and multipole response law of the Qingshankou shale were studied using experimental measurements.Analyses show that the anisotropy parametersϵandγin the study region are greater than 0.4,whereas the anisotropy parameterδis smaller,generally 0.1.Numerical simulations show that the longitudinal and transverse wave velocities of these strong anisotropic rocks vary significantly with inclination angle,and significant differences in group velocity and phase velocity are also present.Acoustic logging measures the group velocity in dipped boreholes;this differs from the phase velocity to some extent.As the dip angle increases,the longitudinal and SH wave velocities increase accordingly,while the qSV-wave velocity initially increases and then decreases,reaching its maximum value at a dip of approximately 40°.These results provide an effective guide for the correction and modeling of acoustic logging time differences in the region.
文摘The genus Saurogobio Bleeker (1870) is a group of small sized cyprinids. Saurogobio dabryi Bleeker (1871) is widely distributed in East Asia.On the basis of careful inspection of morphological and meristic characters of specimen collected from Chenghai Lake in Yunnan and the opening river systems including Pearl River,Minjiang River,Yangtze River,Liaohe River and Songhuajiang River,the Chenghai Lake population of Saurogobio dabryi is considered to represent a new subspecies, Saurogobio dabryi chenghaiensis . Saurogobio dabryi chenghaiensis is distinguished by the combination of following characters.Rostral cap developed,covering over upper lip,and lips with developed papillae.Body and caudal peduncle very slender,body depth 12 7%-15 0% of standard length(SL),caudal peduncle depth 5 5%-6 1% of SL and 31 8%-39 1% of caudal peduncle length.A longitudinal dark stripe present along the axis on each side of body and 6-11 stick shaped black spots (its widths being 25%-50% of its lengths respectively) occur along the stripe.Distance from pelvic fin origin to anus is more than 50% of pelvic fin length.The length of the shortest caudal fin ray is less than 50% that of the longest one.The new subspecies occurs only in Chenghai Lake,Yunnan,China.
基金the National "973" Project (No.2007CB209603) the "863" Project (No.2006AA06Z108)
文摘We introduce the Thomsen anisotropic parameters into the approximate linear reflection coefficient equation for P-SV wave in weakly anisotropic HTI media. From this we get a new, more effective, and practical reflection coefficient equation. We performed forward modeling to AVO attributes, obtaining excellent results. The combined AVO attribute analysis of PP and PS reflection data can greatly reduce ambiguity, obtain better petrophysical parameters, and improve parameter accuracy.
