Abstract:We achieve a traveltime inversion technique for simultaneously estimating velocity and depth in the undulate medium in which velocity varies laterally. The inversion technique involves the following essentials. ·The medium is divided into layers which are represented by different-size nets; ·Velocity between net points is expressed by linear function; ·Reflector consists of smooth cubic spline function; ·Theoretical traveltime is calculated using fast ray tracing; ·Inversion algorithm is based on an iterative damping least square method; ·Self-adaptively revised damping factor is used to improve iteration effect; ·Regional and point restrictions are applied to achieving sole solution. Theoretical and practical estimations show that this inversion brings good iteration effect, high accuracy and stable operation, and hence applies to any undulate medium where velocity shows laterally gradient variation.
顾汉明, 赵树元. 横向变速起伏介质走时反演[J]. 石油地球物理勘探, 1993, 28(5): 556-566.
Gu Hanming, Zhao Shuyuan. Traveltime inversion in the medium in which velocity varies laterally. OGP, 1993, 28(5): 556-566.