Development and tackling directions of seismic exploration technology for deep and ultra-deep marine carbonate rocks
As Shunbei oil and gas area and Luntan 1 well in the Tarim Basin obtain industrial oil and gas flows at a depth of more than 8200 m,carbonate rock exploration is rapidly moving towards the deep and ultra-deep fields,posing a severe challenge to seismic exploration technology.This article mainly analyzes the research progress and problems faced in the theory of ultra-deep complex wave field seismic imaging.In terms of key technologies for predicting ultra-deep reservoirs,the current status of small fault identification through seismic data structure characterization and quantitative prediction methods for pore structure based on digital cores has been analyzed.From the perspective of geological exploration requirements,this paper proposes the develop-ment trend and key research directions of deep and ultra-deep carbonate reservoir and fluid prediction tech-nology,so as to provide a reference for the theoretical and technical research of marine carbonate rock seismic exploration,and the following understandings are obtained:① For ultra-deep seismic data with low signal-to-noise ratios,Q-stack depth migration and TTI medium RTM technology have achieved certain results in car-bonate reservoir imaging.The key research directions include interlayer multi-wave suppression based on wave theory,anisotropic Q-RTM,least squares Q-RTM,and anisotropic omnidirectional angle domain imaging technology.② The seismic data-based prediction technology of deep and ultra-deep heterogeneous carbonate reservoirs has the problems of weak theoretical methods and low prediction accuracy,so it is urgent to strengthen the exploration of theoretical methods and technical breakthroughs.③ The deep integration of seis-mic petrophysical experiment and reservoir geology,the refined seismic data-based prediction technology of sen-sitive reservoir properties based on the wave characteristics of two-phase media(frequency,dispersion,and at-tenuation),artificially intelligent and quantitative prediction of carbonate reservoirs,and fluid detection tech-nology are important development directions.The development trend of"reliable deep seismic data,multi-dis-ciplinary and high-precision characterization of reservoirs,and deep learning artificial intelligence"is obvious.