Research On Seismic Prediction Technologies Of Volcanic Reservoir

Aimed at the world-class problem of volcanic rocks reservoir prediction. The paper based on actual requirement of deep volcanic reservoir gas pool exploration in north Songliao basin, focused on volcanic reservoir prediction, started on its characteristic analysis, applied new theories ,new technologies and methods following with thoughts of seismic and geological integrated research, a set of comprehensive 3D seismic structural interpretation and reservoir prediction methods has been established, it depicts the configurations and physical varieties of volcanic reservoir of Yingcheng formation, and provided an effective research method on deep volcanic reservoir exploration.(1)Volcanic rocks structure interpretion:A sets of technology research such as seismic reflection formation fine demarcation, formation tracking and fault interpretation, velocity field analysis and mapping technology, as a result, a new work thought of 3D seismic structure interpretation which combined with point, line, surface and body and velocity field making method on formation controlling are carried out. It develops the structure interpretation technologies on faulting period of Songliao basin.(2)Volcanic reservoir quantitative interpretion:Analysed the volcanic rocks well log and seismic reflection character,built the volcanic reservoir attribute parameters and twelve volcanic rocks reflection character called "Daqing pattern".Through data browsing to lock target. Research residual structure analysis technology.the residual error map results in what the precise structure map minus the area structure trend map. That residual structure analysis technology, combining with other technologies such as formation thickness analysis, formation leveling etc, could predict accurately the location of Volcanic Mechanism. it is an effective method to identify Volcanic Mechanism in Daqing.The cluster analysis technology of seismic waveform studied seismic reflection characteristics when sedimentary facies unit changes, class the seismic signal by NN pattern identify technology, throuhg well marking, carved out distribution of volcanic lithofacies. The technology remedies shortages that caused by using well log only to study distribution of volcanic lithofacies. It is valuable to explore beneficial belt of volcanic reservoir. (3)Volcanic reservoir inversion:The simulation anneal inversion method is based on simulation anneal algorithm, transforming condition to restriction to realize control of inversion process. When solving overall optimizing problems, it can improve precision and convergence velocity by restrict condition. This technology is a effect method when studying volcanic reservoir distribution in area where has less wells.Seismic inversion under the control of well is a kind of seismic reflected impedance inversion technology which is based on seismic model. Using the parameters of well associate with seismic inversion including impedance, density and GR etc, using abundance high frequency and whole low frequency information of log data to supplement the bandwidth of seismic data, then a high resolution parameter inversion profile acquired, it can create advantage for volcanic reservoir fine description and become a important measure for volcanic reservoir quantitative prediction.(4)Gas detection technology:According to the theory that seismic wave energy moves toward low frequency in two facie medium, SDD(seimic data directly hydrocarbon detection) testing method achieves its purpose through the phenomenon of Low frequency resonance, High frequency attenuation on seismic profile.Dividing-frequency Reflection intensity research is that seismic wave scattering and energy absorbing and attenuation shows some variety of frequency when there has gas in a certain geological objective. Through decomposing and analysis of seismic raw data to find concealed weak attenuation response in order to gas prediction. Those two methods provided the technological support to reservoir gas testing by use of post stack seismic data.(5)Volcanic reservoir fracture prediction:Research on seismic frequency attenuation gradient prediction technology, instantaneous dip detect technology, edge detection technology and seismic coherence analysis technology. Seismic frequency attenuation gradient prediction technology can post fracture growing area and fluid domino effect by the absorbing and attenuation function of formations; seismic coherence analysis technology can detect fracture by calculating coherence between seismic adjacent traces. Volcanic reservoir fracture post stack seismic attribute prediction technology has high reliability for great scale fracture.(6)Satisfied geological results: successful prediction of volcanic reservoir in Ying 1 formation and new cognition of gas field distribution law are acquired in faulting central area of Xujiaweizi.obtained natural gas reserves of 200 billion m~3.The exploration and develop of Volcanic reservoir in Daqing show that Among volcanic reservoir prediction technologies have high application value and popularizing application prospects.