Classification And Application Of Reservoir Petrophysical Facies In The West Of Sulige Gas Field

The reservoir of the He 8th of the main gas producing layer in the western area of the Sulige gas field,it is a typical tight sandstone reservoir,and has the characteristics of ultra-low porosity and ultra-low permeability.This thesis makes full use of previous research data to summarize the basic geological characteristics,sedimentary environment,and diagenetic evolution of the study area.At the same time,cooperate with multiple experimental methods to quantitatively describe the physical properties,micropore characteristics and fluid occurrence characteristics of different types of reservoirs from multiple perspectives.Based on the division rules of petrophysical facies,the sedimentary facies and diagenetic facies are superimposed,divided and evaluated the petrophysical facies types of the target layer,and the favorable pore-percolation development zones of the target layer are predicted.The main results of this thesis are as follows:(1)The overall structure of the He 8 reservoir is gentle in the western area of the Sulige gas field,and the sedimentary facies in the upper part of He 8 is the meandering river delta plain facies,and the sedimentary facies in the lower part of He 8 is the braided river delta plain facies.The rock types are mainly lithic quartz sandstone and quartz sandstone,kaolinite content is highest in interstitials,it has strong cementing effect,the average porosity is 7.66%and the average permeability is 0.819×10-3?m2.(2)The diagenesis stage of the He 8 reservoir is in the middle diagenesis stage B,partially entered late diagenesis stage,the reservoir has undergone various diagenetic transformations.According to the physical properties and the types of diagenesis,the diagenetic facies of the He 8 reservoir are divided into four types,and they are:weak kaolinite cemented dissolved pore-intergranular pore phase(diagenetic facies A),medium-kaolinite cemented dissolved pore-intercrystalline pore phase(diagenetic facies B),carbonate cemented dissolved pore-microporous phase(diagenetic facies C),carbonate cemented dense phase(diagenetic facies D),the latter two basically have no reserve capacity,and most of them are dry layers in actual development.(3)The types of pores developed in the reservoir of the He 8 are mainly intergranular pores,lithic pores and intercrystalline pores.The mainly types roaring include tube-shaped roaring channels,sheet roaring channels,etc.Using experimental methods such as high-pressure mercury intrusion,constant velocity mercury intrusion,nuclear magnetic resonance(NMR),and gas-water phase infiltration to evaluation of reservoirs.And divided the reservoir into ????III?IV four types,their physical properties deteriorate in turn.(4)According to the rules of rock physical facies division,focusing on the diagenetic facies,the types of rock physical facies in the target layer are divided into three types:PF1,PF2,and PF3.Each rock physical facies is evaluated by using reservoir quality factor(RQI).It is the main gas-bearing zone;according to the distribution area of favorable rock physical phases,we have gained a new understanding of the distribution of favorable pore-permeability development zones in the study area.