Lithologic Trap Identification And Evaluation Of Triassic Halahatang Formation In The East Of 2st Block Of Tahe Oilfield

As the exploration level of oil and gas increasing,looking for a certain size of structural trap reservoirs has been very difficult,concealment reservoirs become the important goal of attention.the exploration degree of lithologic trap in lithologic trap identification and evaluation is relatively low,the study of the lithologic trap identification and evaluation has significant meaning for the development of rolling oil and gas.With the classic sequence stratigraphy,sedimentology,petroleum geology theory as the instruction,according to the characters of core,logging,interface,etc,having established 1 long-term cycle(LSC1),3 middle-term cycle(TMSC1-TMSC3).with the later of the medium-term cycle TMSC1,water level rising,under distributary channel is the mian microfacies,just keep up half cycle of normal graded bed sequence.the early of medium-term cycle TMSC2,affected by the tectonic uplift,water level dropping,the proportion of sand and mud was reduced.in the early of medium-term cycle TMSC3,the water is shallow and sediment near the surface,which lead strong oxidation,deposited a set of district can contrast marker of carbonaceous mudstone formation,its sedimentary system is marsh wetlands.medium-term cycle TMSC3 later period,tectonic uplift abate,lake area and water level increasing,shore shallow lake become its mian sedimentary microfacies.Combining geological with geophysical and more science,research train of thought is dot ? line ? face and body,researching sesimentary facies within the isochronous trellis medium-term cycle.medium-term cycle TMSC1 period,developping underwater distributary channel and distributary bay but the main sedimentary microfacies is underwater distributary.which are same as medium-term cycle TMSC2.TMSC3 period,developping wetland and shallow lake mud swamp sedimentary microfacies.In the halahatang'group,the main sedimentary of medium-term cycle TMSC2 is sandstone,however,sandstone beds are very thin.the research of the seismic attribute comfirmed that relationship between mean absolute amplitude and sand body thickness,which could reveal the charccteristics of sand body distribution.inversion profile of wave impedance can not great to distinguish between sandstone and mudstone.the characteristics of log curve(SP)response can be sensitive to distinguish between sandstone and mudstone.using psedo-sonic inversion can identify moer than 5m of sand body,depicting its space distribution.combining with the result of tectonic interpretation and seimic attribute?pseudo acoustic inversion,identified 12 trap that have 6 structure-lithology trap and 6 lithology trap.from sand body?cap rock plugging?oiloness and oil source connected aspects,to evaluate trap,selected 5 ? trap and 7 ? trap,three of the ? class trap drill oil reservoir,the other two ? kind of trap can be used as the next step of rolling exploration and development goals.