Seismic Prediction Of The High-quality Reservoir Of Volcanic Rock In The Yongtan 1 Block Of Southwest Sichuan

Volcanic rock oil and gas reservoirs are widely distributed.With the intensification of global and domestic energy shortages,volcanic rock exploration has achieved breakthroughs in many areas in recent years.The study of methods for seismic prediction of volcanic rock oil and gas reservoirs has become an important part of reservoir prediction a hot spot is also a difficult point.Internationally,a large number of volcanic rock oil and gas reservoirs have been discovered in the United States,Germany,Russia,Argentina,Mexico and other places.In China,volcanic rock oil and gas layers have also been discovered in the Junggar Basin,Tarim Basin,Songliao Basin,Bohai Bay,Huanghua Depression,Jiangsu Oilfield and Erlian Basin in Inner Mongolia.Recently,it has achieved industrial breakthroughs in southwestern Sichuan,demonstrating good exploration prospects.However,the volcanic rocks in southwestern Sichuan have very special and complex gas reservoir characteristics,such as rapid lithology and lithofacies changes,very complex geological conditions,strong heterogeneity,poor physical properties,and relatively developed reservoir micro-fractures.In addition,the surface conditions are complex,the quality of seismic data and imaging effects are poor,so the exploration and seismic reservoir prediction of volcanic gas reservoirs in southwestern Sichuan are facing many technical challenges.The purpose of this paper is to study key scientific and technical issues such as poor quality of seismic data in the volcanic rock section of southwestern Sichuan,unsatisfactory imaging results,unclear reflection characteristics of the inner volcanic rock,and unclear distribution of volcanic structures and volcanic facies.The research mainly starts with the internal structure and external morphology of seismic reflections of volcanic rock reservoirs,forms a method for dividing volcanic structures,and establishes targeted technical processes and methods for seismic prediction of volcanic facies.On this basis,key technologies for seismic prediction of high-quality volcanic rock storage are formed to address volcanic rock Key seismic issues in exploration,and have seen practical results in production.This paper first fully investigates the research status and development trend of volcanic exploration and development at home and abroad,and summarizes the seismic reservoir prediction problems in volcanic rock exploration.Taking the volcanic rocks in the Yongtan 1 block in southwestern Sichuan as the research object,formulating targeted technical procedures.Comprehensive use of logging data,3D seismic data,and volcanic reservoir characteristics analysis,to carry out detailed interpretation of seismic horizons and faults,analysis of volcanic structures and seismic reflection characteristics,volcanic facies identification,and reservoir prediction,and the following research results have been formed:1.According to the guidance of the "source control" theory,the dissection and identification of volcanic structures,volcanic rock bodies,and volcanic facies are carried out step by step,and reservoir prediction studies are carried out on the basis of "facies control" to form volcanic structures and volcanic bodies.,Seismic identification method of volcanic facies.2.Based on petrophysical analysis,combined with attribute analysis,coherence volume and other technologies,using forward simulation of the comprehensive calibration method of well-seismic formation and establishment of five seismic response modes of lithofacies and lithology of volcanic rocks,and clarifying reservoir sensitivity Parameters and seismic attributes;3.Combining geology and logging data,comprehensively using post-stack seismic inversion and seismic attribute analysis methods to predict the spatial distribution of favorable facies belts and favorable volcanic reservoirs.