Seismic inversion method and device

Abstract

The invention discloses a seismic inversion method and device. The method comprises the steps that according to wave impedance curves of all drilled wells in a research block, it is judged that inversion is feasible, and a wave impedance value of a while-drilling point is obtained in the process of logging while drilling; according to the wave impedance curves and the wave impedance value of the while-drilling point, statistics is performed on wave impedance probability distribution curves of the research block; inversion is performed according to the wave impedance probability distribution curves to obtain an inversion result; a wave impedance value of a next while-drilling point is obtained, and statistics is continued to be performed on the wave impedance probability distribution curves of the research block until the drilling process is completed. According to the seismic inversion method and device, inversion accuracy can be improved. Furthermore, a hole drift angle is adjusted according to the inversion result, and the drill encounter rate of a reservoir of a horizontal well is increased.

Description

technical field [0001] The invention relates to the technical field of geosteering, in particular to a seismic inversion method and device. Background technique [0002] Seismic inversion refers to the process of imaging the spatial structure and physical properties of underground strata by using seismic data from surface observations and constrained by known geological laws and drilling and logging data. [0003] Existing seismic inversion methods include post-stack sparse pulse seismic inversion technology, conventional logging-while-drilling (LWD, Logging While Drilling) measurement curve change trend discrimination method, resistivity inversion edge-detection built-in logging-while-drilling tool and density imaging techniques. [0004] In the existing inversion methods, for example, post-stack sparse pulse seismic inversion technology, because the inversion technology relies on seismic pure wave data, and the seismic pure wave data with low signal-to-noise ratio will le...

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Problems solved by technology

[0004] In the existing inversion methods, for example, post-stack sparse pulse seismic inversion technology, because the inversion technology relies on seismic pure wave data, and the seismic pure wave data with low signal-to-noise ratio will lead to large errors in seismic inversion results. large, causing misjudgment of formation prediction, and the seismic pure wave data is limited to the seismic frequency band, the vertical resolution of the reservoir is low, and the lateral physical property change of the thin reservoir cannot be accurately predicted

For example, the mudstone layer is only about 2 meters, and the post-stack sparse pulse seismic inversion technology cannot identify the mudstone layer due to the accuracy limitation

Since the wellbore trajectory cannot touch the mudstone layer, if the inversion method used cannot identify the mudstone layer, it is difficult to ensure that the wellbore trajectory does not touch the mudstone layer

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