Design method of converted wave-highlighted VSP observation system

Abstract

The invention provides a design method of a converted wave-highlighted VSP observation system, and belongs to the field of seismic exploration in the petroleum industry. The design method comprises the following steps: (1) according to physical parameters of an exploration target layer, solving a Zoeppritz equation to obtain relationships between a P wave reflecting coefficient and a PSV wave reflecting coefficient of the target layer and incident angles; according to change rules of the reflecting coefficients, determining the effective incident angle theta P1-theta P2 of the P wave and the effective incident angle theta S1-theta S2 of the PSV wave of the target layer; (2) according to conditions of an exploration task and a VSP acquisition device, determining arrangement depths the of wave detectors in a well and intervals between the wave detectors; (3) for each CCP surface element, tracing and calculating a ray in a PSV wave receiving point-CCP-shot point direction according to the superposition times required by the task, and calculating a shot point position at which the incident angle is within the effective incident angle theta S1-theta S2 of the PSV wave to generate a density figure at the shot point position of the PSV wave.

Description

Technical field [0001] The invention belongs to the field of seismic exploration in the petroleum industry, and specifically relates to a design method of a VSP observation system that highlights converted waves. Background technique [0002] Three-dimensional three-component seismic exploration, because it provides more abundant information than conventional P-wave exploration, has attracted much attention in recent years. Because P waves and PSV waves have different propagation laws, how to design an observation system that takes both P waves and PSV waves into consideration has always been a difficult problem to solve. In three-dimensional VSP exploration, construction volume and cost control are factors that must be considered when designing an observation system. It is usually required to complete the reception and acquisition of P waves and PSV waves (the converted waves refer to PSV waves) in one operation. The conventional VSP observation system design is first designed ...

AI Technical Summary

Problems solved by technology

Therefore, in the actual three-dimensional three-component VSP data acquisition, it is extremely difficult to use the same observation system scheme to complete the field data acquisition of P wave and PSV wave at the same time through one shot

The actual result is often that the energy of the PSV wave is relatively weak, and it is impossible to complete the exploration task

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