Finite-difference wave migration of initial seismograms of a common point of explosion in the time domain

V.N. Pilipenko, A. O. Verpakhovskaya, V. V. Gnevush
2012 Geofizicheskiy Zhurnal  
Ïîñòóïèëà 6 ÿíâàðÿ 2012 ã. Ïðåäñòàâëåíî ÷ëåíîì ðåäêîëëåãèè Â. Ä. Îìåëü÷åíêî Çàêëþ÷íîþ ïðîöåäóðîþ ñòàíäàðòíî¿ âèðîáíè÷î¿ îáðîáêè òà ³íòåðïðåòàö³¿ äàíèõ ñåéñ-ìîðîçâ³äêè º ì³ãðàö³ÿ ï³ñëÿ ï³äñóìîâóâàííÿ òðàñ ìåòîäîì ñï³ëüíî¿ ãëèáèííî¿ òî÷êè (CÃÒ). Îäíàê, ÿê ïîêàçóº ïðàêòèêà, ³íôîðìàòèâí³øå çîáðàaeåííÿ ãëèáèííîãî ðîçð³çó äຠì³ãðàö³ÿ äî ï³äñóìîâóâàííÿ çà âèõ³äíèìè ñåéñìîãðàìàìè. Ðîçãëÿíóòî àêòóàëüíó çàäà÷ó îáðîáêè òà ³íòåðïðåòàö³¿ ñïîñòåðåaeåíîãî õâèëüîâîãî ïîëÿ ç îòðèìàííÿì çîáðàaeåííÿ áóäîâè
more » ... aeåííÿ áóäîâè ñåðåäîâèùà áåç çàñòîñóâàííÿ ïðîöåäóðè ï³äñóìîâóâàííÿ òðàñ ìåòîäîì ÑÃÒ. Òàêèé ðîçâÿçîê ðåà-ë³çîâàíî çà äîïîìîãîþ íîâîãî âàð³àíòà ñê³í÷åííîð³çíèöåâî¿ ì³ãðàö³¿ âèõ³äíèõ çàïèñ³â, âèáðàíèõ çà çàãàëüíèì ïóíêòîì çáóäaeåííÿ, ó ÷àñîâ³é îáëàñò³. Ïåðåâàãè òà ìîaeëèâîñò³ çàñòîñóâàííÿ çàïðîïîíîâàíîãî ìåòîäó ïîêàçàíî íà ìîäåëüíèõ ³ ðåàëüíèõ ïðèêëàäàõ. The final procedure of the standard production processing and interpretation of seismic data is the post-stack migration by the central deep point method (CDP). However, in practice, a more informative image of the deep section is given by the pre-stack migration according to initial seismograms. The actual task of processing and interpretation of the observed wave field to produce the image of the deep structure without the procedure of the CDP stack is presented. This solution is implemented using a new version of the finite-difference pre-stack migration of the shot record in time domain. The advantages and possibilities of applications of this method are shown in model and real examples. Ââåäåíèå. Ìåòîäû ìèãðàöèè ïðèíÿòî äåëèòü íà äâà îñíîâíûõ òèïà : äî ïðèìåíåíèÿ ïðîöåäóðû ñóììèðîâàíèÿ òðàññ ìåòîäîì ÎÃÒ è ïîñëå åå ïðèìåíåíèÿ (â çàðóáåaeíîé ëèòåðàòóðå pre-stack è post-stack migration ñîîòâåòñòâåííî). Íà ïðàêòèêå äîëãîå âðåìÿ ëèäèðóþùèå ïîçèöèè çàíèìàåò èìåííî ìèãðàöèÿ ïîñëå ñóììèðîâàíèÿ ìåòîäîì ÎÃÒ, êîòîðàÿ âûïîëíÿåòñÿ íà çàêëþ÷èòåëüíîì ýòàïå îáðàáîòêè è ïîçâîëÿåò ïîëó÷èòü îáùóþ èíôîðìàöèþ î ãëóáèííîì ñòðîåíèè ðàéîíà èññëåäîâàíèé. Îäíàêî â ïîñëåäíåå âðåìÿ âñå ÷àùå ïðè îáðàáîòêå íåîáõîäèìî âûäåëèòü îòäåëüíûå äåòàëè ñòðîåíèÿ ãðàíèö è îïðåäåëèòü êîíòóðû êîíêðåòíûõ îáúåêòîâ ñåéñìîðàçâåäêè. Äëÿ ýòîé öåëè áîëåå ïîäõîäèò ìèãðàöèÿ äî ñóììèðîâàíèÿ ïî èñõîäíûì ñåéñìîãðàììàì, êîòîðàÿ äàåò áîëåå ïîëíîå ïðåäñòàâëåíèå î ñòðóêòóðíûõ îñîáåííîñòÿõ ðàçðåçà è òàêèì îáðàçîì çíà÷èòåëüíî óïðîùàåò äàëüíåéøèé ýòàï èíòåðïðåòàöèè íàáëþäåííûõ äàííûõ. Ïî ïîäõîäó ê ðåøåíèþ âîëíîâîãî óðàâíåíèÿ ìåòîäû ìèãðàöèè ïîäðàçäåëÿåòñÿ íà òðè îñíîâíûõ âèäà: ìèãðàöèÿ Êèðõãîôôà, ìèãðàöèÿ â ñïåêòðàëüíîé îáëàñòè è êîíå÷íî-ðàçíîñòíàÿ ìèãðàöèÿ. Ïîñêîëüêó êîíå÷íî-ðàçíîñòíîå ðåøåíèå âîëíîâîãî óðàâíåíèÿ ÿâëÿåòñÿ íàèáîëåå êîððåêòíûì è òî÷íûì [Êëàåðáîóò, 1989; Han, 1998 ], â äàëüíåéøåì áóäåì ðàññìàòðèâàòü èìåííî ýòîò âèä ìèãðàöèè. Åñëè ðàññìàòðèâàòü èçâåñòíûå ìåòîäû ìèãðàöèè ïî èñõîäíûì ñåéñìîãðàììàì, òî äëÿ èõ âûïîëíåíèÿ ïðåäâàðèòåëüíî äåëàþò âûáîðêó èç îáùåãî ïðîôèëÿ íàáëþäåíèé îïðåäåëåí-
doi:10.24028/gzh.0203-3100.v34i3.2012.116636 fatcat:r4tewokeh5bv7deverlarob77m