A Study Of The Seismic Facies And Sedimentary Facies Of The Upper Jurassic Suining Formation In Luodai Gas Field

Luodai gas field is located with Luodai town in the eastern suburb longquanyi district of Chengdu in Sichuan province,is located in the slope zone in eastern Sichuan basin in west Sichuan depression.Due to los with shallow gas reservoir development position and abundant,gas field exploration and development of the economic benefit is remarkable.With the deepening of exploration and development,how to take effective measures to keep the stable production of gas field is the most important problem at present.In order to help solve the problem of Luodai gas field stable production further,we carried out the fine characterization of sedimentary microfacies to define the sedimentary facies characteristics of advantageous facies belts.This paper,taking the advantage of Suining Formation reservoir Jsn₁² sand group as an example,through tectonic characteristics analysis,single well facies classification,correlation between well seismic and well associated sedimentation,seismic phase calibration near the well,seismic facies division,combining with the well research and earthquake research,prepare the floor plan of sedimentary facies.Finally,comprehensive evaluation was carried out according to the structural characteristics and sedimentary facies distribution characteristics,and favorable areas were selected.The research mainly achieved the following results and understandings:?1?According to the results of stratigraphic calibration based on synthetic seismic records,time-depth conversion and structural mapping are carried out.Results showed that the study area is a closed a smaller nose low amplitude anticlinal,common development 5 structural high position,and shall be provided by the well LS35D,LS65D,LS29D,LS68D,LS10D.Hence well block of control and the rest 4are visible in high position in the construction of the relatively small.It can be seen from the structural profile that there are 5 distinct grooves with uniform azimuth distribution.?2?According to sedimentary facies recognition marks,the logging curve characteristics of single well facies classification,sedimentary,even well log facies mainly include bell-shaped curve type,funnel-shaped,box,finger,tooth profile.The sedimentary microfacies types include distributary channel,far sand dam,sheet sand,distributary bay and crevasse fan.The well facies shows that the sand body of the river is developed in the direction of southwest and east north.?3?Establish the borehole seismic response model,and divide the types of seismic phases according to the internal reflection structure of seismic phase units.Which are parallel strong amplitude low-frequency continuous seismic phase,sub-parallel medium amplitude medium-frequency continuous seismic phase,low-amplitude discrete local seismic phase,low-amplitude low-frequency chaotic seismic phase.According to the research results of seismic attributes,the seismic phase and sedimentary phase transformation model is established,and the seismic phase plan is combined with the external reflection form of seismic profile to divide three kinds of seismic facies.They are knoll seismic phase,lenticular seismic phase and compound filling seismic phase.?4?To establish a gas reservoir comprehensive evaluation standard,carries on the optimization of benefit,the study were divided into four types of target zone,respectively?class is enrichment region at?1??2??3??4??5?river channels,?class is adva-ntageous area at?1??2??3??5??7?river channels,?class is advantageous area at?1??2??3??4??5??6??7?river channels,,?class is sand body development zone.It is mainly developed in the sedimentary microfacies of the crevasse fan and the estuary sand dam far from the main river channel.