Xiasiwan Oil Field North Ditch 83 Well Chang 2 Reservoir Comprehensive Evaluation

Xiasiwan oilfield 83 wells located in the upper part of the North Ditch in Xiasiwan oilfield,the main oil-bearing intervals for the member 2 of Yan chang formation,the yield change is big,complex relationship between oil and water,the geological understanding.This paper utilizes logging and all kinds of test data,the 2 layers of sedimentary microfacies,reservoir characteristics are studied.Research shows:the Chang 2 oil-bearing formation can be divided into Chang 21,22 and 23 reservoir group three,Chang 22 can be further divided into long 22-1,22-2 and 22-3 three layers,which are long 22-1 at the top of the ancient rivers cut denudation;Chang 2 reservoir top structure overall performance for West monocline,the local development of a plurality of nose shaped uplift structure;2 long sedimentary characteristics of delta front deposits,mainly developed underwater distributary channel,interdistributary bay microfacies;Chang 2 reservoir rock types are mainly light gray to gray fine-grained feldspar sandstone;reservoir porosity 12.4%,permeability of 5.28×10-3?m2;the main pore types are intergranular pore,intragranular dissolved pore,pore throat combination mainly for small,fine throat type;the reservoir plane and layer,the interlayer heterogeneity in weak;According to the method of Erdos basin reservoir evaluation,reservoir of the study area is mainly of class ? reservoir,combined with reservoir properties,pore structure,reservoir heterogeneity,the third class reservoirs are divided into 4 classes selected porosity,permeability,effective thickness,the average radius of pore throat,evaluation the displacement pressure,Kong Hou combined parameters.The selection of class ? reservoirs and ? reservoirs the majority of the long 22-2,22-3 formation as horizon further development plan adjustment.