Study On The Sand Body Configuration Of Yangxia Formation-Kizilnuer Formation In Tugelming Area,Kuqa Depression

The Middle and Lower Jurassic in the Tugelming area of the Kuqa Depression in the Tarim Basin has good prospects for oil and gas exploration,but the sand thickness in the coal measures is thin and the lateral changes are fast.Based on field outcrop survey,core observation,thin section identification and logging logging data in the study area,combined with theoretical knowledge such as sedimentology and sequence stratigraphy,the reservoir sand body in the study area was analyzed.The reservoir sedimentary facies in the study area is braided river delta facies,which can be further divided into two subfacies of braided river delta plain and leading edge.Sand bodies are widely developed,mainly composed of underwater distributary channel sand bodies.According to the analytic hierarchy process,it is concluded that the Kyzyrenur and Yangxia Formations in this block have 9 petrographic facies,4 vertical superimposed patterns,4 laterally distributed patterns and 4 structural unit combinations.According to the principle of division of the configuration interface of Miall,the main research objects are the interbeds of the sand-mud interlayer of the Kizilnuer Formation and the conglomerate section of the Yangxia Formation in the field outcrop area.Identify,divide out the 5-level interface,and establish a configuration diagram of the sand body configuration corresponding to the underwater distributary channel.In summary,there are four kinds of spatial vertical stacking patterns(discrete type,vertical stacking type,lateral stacking type and composite stacking type)in underwater distributary channel sand bodies;four types of lateral distribution of sand bodies in underwater distributary channels(even Slice type,bevel type,docking type and isolated type)and 4 types of combined unit mode: Type A: sandy channel-sand bottom shape-sand channel combination;Type B: gravel channel-large front accumulation — Side accretion sand body — Stripe accretion sand layer — Sandy channel;Type C: Gravel channel — Large pre-accumulation layer — Side accretion sand body — Stripe accretion layer — Overbank deposit — Sandy channel;Type D:Shallow lake mudstone—estuary dam and distant sand dam—gravel channel.