Wyniki wyszukiwania - BazTech

1

Thin interbed AVA inversion based on a fast algorithm for refectivity

Yang Zhen, Lu Jun

Acta Geophysica

|

2020

|

Vol. 68, no. 4

1007--1020

EN

Zoeppritz equations form the theoretical basis of most existing amplitude variation with incident angle (AVA) inversion methods. Assuming that only primary refections exist, that is, the multiples are fully suppressed and the transmission loss and geometric spreading are completely compensated for, Zoeppritz equations can be used to solve for the elastic parameters of strata efectively. However, for thin interbeds, conventional seismic data processing technologies cannot suppress the internal multiples efectively, nor can they compensate for the transmission loss accurately. Therefore, AVA inversion methods based on Zoeppritz equations or their approximations are not applicable to thin interbeds. In this study, we propose a prestack AVA inversion method based on a fast algorithm for refectivity. The fast refectivity method can compute the full-wave responses, including the refection, transmission, mode conversion, and internal multiples, which is benefcial to the seismic inversion of thin interbeds. A further advantage of the fast refectivity method is that the partial derivatives of the refection coefcient with respect to the elastic parameters can be expressed as analytical solutions. Based on the Gauss– Newton method, we construct the objective function and model-updating formula considering sparse constraint, where the Jacobian matrix takes the form of an analytical solution, which can signifcantly accelerate the inversion convergence. We validate our inversion method using numerical examples and feld seismic data. The inversion results demonstrate that the fast refectivity-based inversion method is more efective for thin interbed models in which the wave-propagation efects, such as interval multiples, are difcult to eliminate.

2

A method of directly extracting multiwave angle-domain common-image gathers

Han J., Wang Y.

Acta Geophysica

|

2017

|

Vol. 65, no. 5

1009--1017

EN

Angle-domain common-image gathers (ADCIGs) can provide an effective way for migration velocity analysis and amplitude versus angle analysis in oil-gas seismic exploration. On the basis of multi-component Gaussian beam prestack depth migration (GB-PSDM), an alternative method of directly extracting multiwave ADCIGs is presented in this pa-per. We first introduce multi-component GB-PSDM, where a wavefield separation is proceeded to obtain the separated PP- and PS-wave seismic records before migration imaging for multiwave seismic data. Then, the principle of extracting PP- and PS-ADCIGs using GB-PSDM is pre-sented. The propagation angle can be obtained using the real-value travel time of Gaussian beam in the course of GB-PSDM, which can be used to calculate the incidence and reflection angles. Two kinds of ADCIGs can be extracted for the PS-wave, one of which is P-wave incidence ADCIGs and the other one is S-wave reflection ADCIGs. In this paper, we use the incident angle to plot the ADCIGs for both PP- and PS-waves. Finally, tests of synthetic examples show that the method introduced here is accu-rate and effective.

3

Sprawność kolektora cieczowego w funkcji kąta padania promieniowania słonecznego

Latała H.

Inżynieria Rolnicza

|

2006

|

R. 10, nr 11(86)

299-307

PL

W prezentowanej pracy przedstawiono wyniki przeprowadzonych badań dotyczące określenia sprawności kolektora słonecznego w funkcji kąta padania promieniowania słonecznego. Badania eksperymentalne wykonano na specjalnie przygotowanym stanowisku, które umożliwiało monitorowanie istotnych parametrów oraz ich archiwizację. Analizowano zarówno wartość dostępnego strumienia promieniowania słonecznego jak i temperatury czynnika grzewczego na wejściu i wyjściu układu kolektorów oraz temperaturę otoczenia. Ciepło użyteczne z kolektorów wyznaczono z równania Hottela-Whilliera-Bilissa, które uwzględnia wpływ cech konstrukcyjnych kolektora i warunków jego eksploatacji. Określona na podstawie pomiarów energia promieniowania słonecznego i obliczona ilość ciepła użytecznego była podstawą do wyznaczenia efektywności badanych kolektorów w zależności od kata padania promieniowania słonecznego.

EN

The presented work includes the results of performed tests determining solar collector efficiency as a function of angle of incidence of solar radiation. Experimental tests were performed on a specially prepared test bench, enabling monitoring and archiving of critical parameters. Both the value of the available solar radiation flux and temperatures of heating medium at the input and output of the collector system and ambient temperature were analyzed. Useful heat from collectors was set out from Hottel-Whillier-Biliss equation, which takes into account impact of design features of the collector and its operating conditions. Energy of solar radiation determined based on measurements and calculated amount of useful heat served as a basis for setting out effectiveness of tested collectors depending on the angle of incidence of solar radiation.

4

Angle of incidence influence of abrasive particles on wear magnitude of hard facings metals

Jankura D.

Zeszyty Naukowe Politechniki Rzeszowskiej. Mechanika

|

2002

|

z. 58 [193]

109-114

EN

The contribution presents the results of the research of resistance of hard facing metals in conditions of erosive wear. Two types of hard - surfacing electrodes with different chemical composition were used on creation of three layers hard facing metals. Chemical composition of electrodes determined difference in structure of surface deposit. We investigated the influence of angle of incidence of abrasive particles on wear magnitude of hard facing metals. The results of the experiments showed that intensity of wear is very depended on parameters of wear as well as structure morphology of hard facing metals.