Reservoir Evaluation Of The Sinian Dengying Formation In The Gaomo Area Of ??central Sichuan

Gao shiti-Moxi area locating in the sichuan basin palaeohigh inclined flat tectonic belt with Wei yuan to Long nv si structure group.The simian system dolomite reservoir in this area is typical low porosity and low permeability reservoir.Using geological data and well logging information to synthetically evaluate reservoir characteristics is an important means in reservoir evaluation.On the basis of previous studies,this paper will log,sedimentology,petroleum geology,and other disciplines to combinating for comprehensive study.Meanwile,collecting logging,well logging,petrophysical analysis data and lucubrating the sedimentation,reservoir characteristics and reservoir distribution evaluation of Dengying formation in research area.Combining with basin's sedimentary facies research and the established facies' model,descripe the core in the area;The Dengying formation's sedimentary facies in Gao shiti-Moxi area is carbonatite restricted platform environment,mainly on bioherm beef beach facies,Restricted lagoon facies and plate facies.The reservoir rock's lithology is dolomite and the most favorable reservoir rocks are mainly algal clot dolomite,algal laminated dolomite,algal arene dolomite,which contain bacteria algae.Through the identification and analysis of the core and cuttings conventional thin section,the main reservoir space type are arst cave,intergranular(dissolved)pore and intergranular(dissolved)hole,reservoir type is mainly divided into crack-hole and porosity(hole).Reservoir physical properties show that the main develope reservoirs.in research area is low porosity and low permeability reservoir.Using logging data to evaluate the reservoir of Dengying formation in the study area.Standardizing the logging data and identificating lithology.Using volume model method to calculate the logging reservoir porosity and compositing density,acoustic and neutron to log porosity,comparison with core porosity at the same time.Calculating gas saturation by using the archie formula and using the saturation,which mearured by core capillary pressure,test results and the conventional core's saturation to conduct tests.On the basis of core data,by means of well logging interpretation,based on test results to determine effective thickness standard.Making connected wells' profile by combined with the effective thickness of single well and comprehending the reservoirs' distributed characteristics in the region.