A Research Of Three-component Digital Seismic Survey Technique In Sulige Area

Sulige gas field is one of the main petro-gas producing areas of China, which has good exploration prospects. But the effective sandstone in this area has following characteristics:strong anisotropy、great lateral variation、thin thickness and dispersive vertical distribution, the main producing formation HE-8is the typical thin formation with low porosity and low permeability, for these reasons, the exploration quality is never well. From the1990s to2006, the P-wave2D seismic exploration had been carried in this area to the upper Paleozoic and lower Paleozoic, although there is progress in doing hydrocarbon detection directly by utilizing the dynamics characteristic of seismic wave, the exploration success rate is still not high. Therefore, the article quotes the3components digital seismic exploration technology, which can improves the accuracy of the lithology and fluid prediction effectively. The article focus on the key technologies as the separation method of the converted wave field、the extraction method of common conversion point、Static correction technology of converted wave、velocity analysis method、P-S wave joint demarcation technology、 joint inversion, resolves the problem of converted wave imaging well, thereby significantly improving the drilling success rate.The article begins with the geophone type. Through the actual data、spectrum analysis、time-frequency analysis and CCP overlay method, contrasting and analyzing the response capabilities of digital geophone and simulated geophone, and gives evaluation to the function and applicability of the geophone. From the research, the digital geophone is best suited to the high-resolution seismic exploration. Next, according to the small sand scale、thin thickness、difficulties of lateral reservoir prediction and reservoir finding in the working area, using small panel observation in the collection process, otherwise, for increasing the effective reflection energy of the target and decreasing interference and noise, choosing the proper cover times to confirm the observation system parameters reasonably. In the processing steps, the article discuss many aspects as wave field separate method、Static correction technology、amplitude compensation、prestack noise removing、deconvolution and velocity analysis, initially forms a processing flow that is suitable for multiwave seismic data processing in Sulige area. In the interpretation, mainly uses P-wave data and S-wave data of VSP seismic log or full wave train acustic logging to demarcate, and then improves the accuracy of the P-S wave joint interpretation.The multiwave collection、processing and interpretation technology involved in the article had been applied initially in Sulige area, the application example indicates that the multiwave technology is effective and feasible in the study area.