Research On Mico-pore Structure And Production Performance Analyze Of Different Diagenesis Facies In Niuquanhu Area,Santanghu

The micro-pore structure of Xishanyao formation is completed in Niuquanhu area,Santanghu basin,which heterogeneity is much strong.Based on the diagenetic facies,the paper analyzes the petrological characteristics,micro-pore structure,movable fuild characteristics and production dynamic characteristics in different diagenetic facies.We get the following main results:(1)The rock types of X2 section in study area are mainly fine-medium sandstone and little coarse sandstone gravel,which lithology is mainly feldspar lithic sandstone.The reservoir property is poor as a whole,which average porosity is 12.4%and average permeability is 3.24×10-3?m2.As a whole,the compositional maturity,textural maturity,interstitial material content and physical properties in the South are the best,than the East is poorer,the North is just the reverse of the South.(2)The diagenesis facies types experienced in the X2 section of the study area are diverse,which is in a stage the diagenetic stage A.Combined with cementation type,pore type and face rate,we can divided Xishanyao formation of the study area into 6 types of diagenetic facies,the mainly advantaged respectively kaolinite and illite cementation-integranular pore and feldspar dissolved pore facies,kaolinite and chlorite cementation-integranular pore and tuffaceous dissolved pore facies,kaolinite and illite cementation-integranular pore and tuffaceous dissolved pore facies.(3)There are obvious differences in the microscopic pore structure of different diagenetic facies reservoirs,especially on the throat.The pore throat radius of kaolinite and illite cementation-integranular pore and feldspar dissolved pore facies is the lowest of all the facies(58.17),which coordination number is highest.The pore throat radius of kaolinite and carbonate cementation-feldspar dissolved pore and tuffaceous dissolved pore facies is the highest(305.07)and its coordination number is the least.(4)There are differences in the saturation of movable fluid in different facies reservoir.The NMR experiment results show that pore throat connectivity of kaolinite and illite cementation-integranular pore and feldspar dissolved pore facies is much better,which movable fluid is highest(50.96%).The movable fluid of Kaolinite and carbonate cementation-feldspar dissolved pore and tuffaceous is the lowest(36.83%),which pore throat connectivity is strongly poor.(5)Physical properties are one of the most important factors influencing the fluid saturation of different diagenetic facies,especislly permeability.And the micro-pore structure is the decisive factor leading to the internal difference of reservoir,especially main throat radius,effective pore volume and the ratio of pore and throat.The movable fluid will be decreased with the clay minerrals.(6)There are much differences in the production of diagenetic facies reservoirs.kaolinite and chlorite cementation-integranular pore and tuffaceous dissolved pore facies daily oil production is the highest,which water-cut increased rapidly and stable production cycle is much longer.kaolinite and illite cementation-integranular pore and feldspar dissolved pore facies daily oil production and daily fluid are higher,which water-cut sustained stable and stable production cycle long.Kaolinite and illite cementation-integranular pore and tuffaceous dissolved pore facies daily oil production is the lowest,which water-cut is the highest and stable production cycle is short.