28 1 2009 3 Vol128 No11 GLOBAL GEOLOGY Mar1 2009 : 1004 5589 (2009) 01 0098 05 P 1, 1, 2, 1 1., 130026; 2., 100027 :,,,, 1%,,, 12187%,, : ; ; ; : P63114 : A Abstract: Error ana lysis of P2wave non2hyperbolic m oveout veloc ity in layered media XU Shan2hui 1, HAN L i2guo 1, L I Pei2pei 2, L IAN Yu2guang 1 1. College of Geoexploration Science and Technology, J ilin U niversity, Changchun 130026, China; 2. China O ffshore O il Corporation R esearch Center, B eijing 100027, China In order to imp rove the p recision of non2hyperbolic anisotrop ic velocity analysis and adap t the ve2 locity analysis to far offset or other comp lex circum stances, the authors confirm the reliability of non2hyperbolic ve2 locity analysis by summarizing the basic step s of velocity parameters estimation of non2hyperbola in layered media and using num erical simulation and resemblable analysis, and the error between inversion result and theoretical val2 ue is about 1%. The error analysis of anisotrop ic parameter indicates it is sensitive to the error, and the error be2 tween inversion result and theoretical value is as high as 12187%, so it is best to p ick directly to increase the p recision of velocity analysis. Key words: non2hyperbolic moveout; layered media; resemblance; error analysis 0,,,,, [ 1 ],,,,, : 2008207202; : 2008211213 : (863 ) (2006AA06Z108)
1 : P 99, [ 2 ] Thom sen P, A lkhalifah,, [ 3 ],,,, 1 P,,, Thom sen, P p 0 [ 4 ], : V p ( ) = V P 0 (1 + sin 2 cos 2 + sin 4 ) (1) : A lkhalifah, TI,, [ 5 ] : = 1 2 V 2 1 = 1 + 2 (2) V hor = V p0 1 + 2 = V 1 + 2 (3) : V hor 1( 3) V hor,, hor, > 0, V hor > V ; = 0, V hor = V ; < 0, V hor <V A lkhalifah [ 3 ] : V 2 2 x 4 V 2 [ t 2 0V 2 + (1 + 2 ) x 2 ] (4),,, x t 0, 1 V hor F ig11 Rela tion sh ip graph of changes w ith V and V hor (3) : V 2 ( V 2 ) x 4 V 2 [ t 2 0V 4 + x 2 ] (5) ( 5 ) V V hor, P hor, V hor ( xϖ ), (5),,, ( 5),, C = 112 [ 7 ], (5) : V 2 ( V 2 ) x 4 V 2 ( t 2 0V 4 + C x 2 ) (6) C = 1 C = 112 ( x m ax / z = 2), ( 013 015 ) VTI x m ax / z 2,, C = 112,, ( 6), C
100 28 2, (6) t 0 V V hor, CMP, CMP (6) t 0, V V hor, V V hor : S ( t 0, V, ) = t 0 +T /2 t 0 = t 0 T /2 x m ax x = x m in F ( x, t) M t 0 +T /2 t 0 = t 0 T /2 x m ax x = x m in F 2 ( x, t) 2 (7) : M, F ( x, t) F 2 ( x, t) t ( t 0, V, V hor, x), t 0 T ; S, S, V 3 A lkhalifah [ 3 ] : (3) (10) g ( i) g ( i 1) ; g (N ) = V 4 (N ) [1 + 8 (N ) ] = V 2 (N ) [4 (N ) 3V 2 (N ) ] (10) (4) g ( i), 2 ( 11) (12) V ( i) hor = V ( i) 1 g ( i) t 0 ( i) g ( i 1) t 0 ( i 1) 4 (V ( i) ) 4 t 0 ( i) t 0 ( i 1) ( i) 1 = 8 (V ( i) ) 4 g ( i) t 0 ( i) g ( i 1) t 0 ( i 1) t 0 ( i) t 0 ( i 1) + 3 4 (11) (V ( i) 4 ) (12) hor ( i) ( i) 4 TI, 1, P0 2P, 3 VTI P t 2 ( x, N ) = t 2 0 (N ) + V 2 (N ) x 2 ( (N ) V 2 (N ) ) x 2 (8) V 2 (N ) t 2 0 (N ) V 4 (N ) + C (N ) x 2 : (1) (8) ( N ) (C = 112), V hor t 0 ; (2) (9) ( i ) ( i) ; (V ( i) ) 2 = V2 ( i) t 0 ( i) V 2 ( i 1) t 0 ( i 1) t 0 ( i) t 0 ( i 1) (9) 2 P F ig12 Hodographs of P2wave
1 : P 101 1 T I Table 1 Ba sic param eters of double VT Im odel Z/km s 1 V p0 /km s 1 1 017 2 0105 0105 2 1 2142 0115 01041 7 3 P F ig13 Resem blance coun tours of P2wave : V (N) V hor (N ) (N ) (8) ( 2), 2,, hor 01095%, 01949% 01406%,, 12178% 9% 454 V V hor 3 2 T IP Table 2 P2wave veloc ity ana lysis results of double VT Im odel V /km s 1 V hor / km s 1 /% /% /% 1 21098 21100 01095 21098 21100 01095 01000 01000 01000 2 21216 21225 01406 21318 21340 01949 01047 01053 12178 V /km s 1 V hor / km s 1 /% /% /% 1 21098 21100 01095 21098 21100 01095 01000 01000 01000 2 21519 21582 11707 21759 21811 11884 01100 01109 91000,, 5 (2), V ( i) V hor ( i), ( i), : = = 1 2 (V hor + V hor ) 2 (V + V ) 2 (V hor ) 2 : : (V ) 2 (13) V hor V = V hor V2 hor V 3 (14) ( 100 m s 1, 5 10 3 ),,, : = V hor + 1 2 2 V2 hor V 3 2 V hor V 3 hor V + 3V2 hor 2 2V 4 (15) ( 2 10 3 ),,
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