Deep-target 3D Seismic Data Acquisition Technique In Dongpu Sag

The oil gas resources below 3500m is very rich in Dongpu sag, but it is verydifficult to explore. there are a lot of pitfalls for old deep seismic data:weak reflectionenergy, low S/N ratio, poor continuity , blurred basement reflection. and unclear fault,lower resolution., Dongpu oil gas exploration step has been restricted seriously bythese problem. This paper is for the purpose of conducting the research to the deepreflection signal characteristic, develops suppression of deep noise technology, a set ofacquisition techniques is formed which is suitable for the geologic character ofDongpu sag, at the same time ,which geometry attribute parameter can be optimized.In order to solve the above problem, this paper mainly developed the followingresearch, Firstly, the dynamic range of amplitude for recordable deep seismic signalcan be obtained by using the quantitative evaluation to deep reflection signaldecay ,Secondly, on this basis of thorough analysis the deep main interference typeand the characteristic, by studying the theory and the practical that the geophoneconnection and combination, the different geophone type as well as the burying mode,that adopt the series receiver string and big combination distance, the geophone digswith 20-40cm pits, is considered as the effective method for reducing the effect ofsurface layer absorption, the ambient noise, and improving S/N ratio of deep seismicexploration data, Thirdly, noise wave investigation using box wave test was conductedto test the geophone combination under of many kinds of explosive types and weight,thought the high energy explosive, the small "pin" form and the small diamondcombination receive cause the deep reflection energy to be strongest. The fourth, therate of change distribute characteristic for close together offset has been analyzedunder the same bin, by applying deep geometry system forward modelling and offsetattribute analysis technology, the acquisition problem that quantitative evaluation ofoffset distribution uniform has been solved. It lead to that aforementioned techniquescan resolve some acquisition problem of Dongpu sag, These techniques might providesthe reference to the deep exploration of oil field periphery and the similar work area.