A Joint Inversion Method for Seismic Reflection Slope and Gravity Anomaly Data

Abstract

The present invention relates to a combination method of seismic reflective waveliness and gravity abnormal data, which belongs to the field of seismic and gravity data of geophysical exploration. It includes the following steps: entering seismic observation data and gravity abnormal observation data set; given initial model; use the current model to calculate the seismic, gravity data set; obtain the calculation data set and observation data set residual; establish a combined inversion target function; solve Get speed, density update; update model; terminate iterative output final result. The invention simultaneously utilizes seismic waveliness and gravity abnormal data, with a multi-scale policy iteration to obtain a speed and density difference model, ultimately a speed-density model having similar structures simultaneously. The combined inversion method can effectively reduce the multio-solving problem of single type data inversion, obtain a higher speed-density model of accuracy.

Description

technical field [0001] The invention relates to a joint inversion method of seismic reflection wave slope and gravity anomaly data, which belongs to the field of joint inversion of seismic and gravity data in geophysical exploration. Background technique [0002] There are obvious differences in the velocity and density parameters of different lithologic formations underground, and only a limited understanding of the subsurface structure can be obtained based on a single observation data from seismic inversion or gravity inversion alone, and this understanding is often difficult to withstand. As another test of observational data, a single method has certain one-sidedness and limitations. [0003] The joint inversion of severe earthquakes is the key to solve this problem. In the early joint inversion, the seismic data mainly played the role of controlling the horizon and guiding the separation of the gravity field, using the gravity data to supplement the places where the s...

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Problems solved by technology

In the early joint inversion, the seismic data mainly played the role of controlling the horizon and guiding the separation of the gravity field, using the gravity data to supplement the places where the seismic reflection is unclear, and obtaining the structural distribution characteristics and interface extension information that cannot be determined only by the seismic data , this method is greatly affected by subjective factors; later, the joint inversion of post-stack seismic and gravity data appeared, which will directly introduce the deviation of the post-stack section into the inversion results, and this error is concealed; later developed the The joint inversion of first arrival travel time and gravity data of pre-stack earthquakes, this method only uses the travel time information of earthquakes, cannot well resolve the ambiguity between formation depth and velocity, and the inversion depth is heavily dependent on offset

In addition, the joint inversion of severe earthquakes usually imposes constraints on the physical property relationship. The disadvantage of this method is that the explicit physical property empirical relationship may violate the real situation of the subsurface

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