Research On Reservoir Characteristis Of Denglouku Group-quan1Section In Xiaochengzi Area, The South Of Songliao Basin

Xiaochengzi area is located at southern Wangfu fault depression, theSoutheastern part of the Song-liao Basin.The years exploration resultshave showed that there have good oil and gasshow in the clastic rock strataof Denglouku group-Quan1section.But the geological research is very low,mainly due to the early exploration targets is volcanic rock reservoirof Huoshiling Fm.By the study of reservoir petrology, Diageneticcharacteristics, types and structure of reservoir space, reservoirphysical property and reservoir heterogeneity,etc,studied the thereservoir characteristis, the law and main controlling factors ofreservoir development,and distributive rules,to provide scientificbasis for estimating reserves accuratelly,selecting favorable reservoirarea,and speeding up the pace of oil and gas exploration and developmentin the study area.According to the exploration demand, the formation of Dengloukugroup-Quan1section is divided into five sedimentary units. By using thedata of drilling, logging, testing and analysis and seismic sections,thecharacteristics of sedimentary reservoir are studied deeply. The resultsshow that,5types sedimentary facies of lacustrine facies, fan deltafacies, sublacustrine fan facies, meandering river facies and braidedriver facies,10types of subfacies,27types of microfacies in this region of Denglouku group-Quan1section are identified.From bottom to top,itdevelops shallow lake lacustrine-fan delta-sublacustrine fan, braidedriver, meandering river sedimentary system.Studies have shown that, the reservoir rocks mainly is lithic arkoseand arkose lithic, diagenesis which have major influences on reservoirinclude compaction, cementation, metasomasis and dissolution,and thetypes of reservoir porosity in Xiaochengzi area can be divided intoprimary intergranular porosity, narrow intergranular porosity and graindissolution porosity, of which the latter two pore types of developmentis relatively wide.Based on mercury intrusion parameters and mainlithologic characteristic, the lever of pore configuration in this areaban be divided into the level Ⅰ, level Ⅱand level Ⅲ，and the main isⅢ,Ⅱ exsists too,Ⅰ exsists only in local area. In contrast, the porestructure of the sand group Ⅰof Denglouku group-Quan1section is betterthan the lower layers.The porosity and permeability characteristics study indicate:thereservoir petrophysical property of Quan1section is better favorablewith low-ultra low porosity and ultro low permeability,and the reservoirpetrophysical property of Denglouku formation is not very favorable withultra low porosity and very low permeability.In this area, the reservoirhas strong intraformational, interformational nonuniformity, and planarnonuniformity due to the effects of Structure, sedimentation anddiagenesis.And the favorable reservoir areas are selected based on thereservoir properties plane distribution characteristics.