Study On Characteristics And Classification Of Low Porosity And Low Permeability Reservoirs Of Sha-4 Oil Layer Group In Yi 176,Bonan Oilfield

With the development of petroleum exploration theory,some progress has been made in the exploration and development of low permeability reservoirs in recent years.In view of the low capacity in the Sha-4 Reservoir group of Yi176 area,strong heterogeneity,poor physical property,poor regularity,comprehensive utilization of sedimentary characteristics,diagenetic characteristics,physical characteristics,microscopic characteristics has carried on the detailed description of low permeability reservoir,and describes the plane spreading of different types of reservoirs,through reviewing the study area of low permeability sandstone reservoir are analyzed in detail,and obtained as follows: the reservoir sedimentation,the main study area for the typical fan delta sedimentary bodies,among them,the distributary channel microfacies is distributed in a bifurcated strip,and the microfacies of the estuarine dam is distributed in a lenticular shape.,and the sedimentary microfacies distribution map of the research area was drawn;reservoir property and diagenesis,the study shows that the reservoir rocks in the study area are mainly feldspathic sandstone and lithic argillaceous sandstone,with the characteristics of low component maturity,the average porosity of the reservoir in the study area was 10.6%,and the distribution interval of horizontal permeability was between0.1×10-3?m2 and 1×10-3?m2,generally poor physical properties,and draw the plane distribution of poroperm characteristics of the layer,the basic types of main diagenesis in the study area include mechanical compaction,cementation and dissolution,and are in phase A of the middle diagenetic stage;reservoir microscopic characteristics: this paper divides the pore and microfracture type,the development and distribution of pore throat were studied and microscopic classification was carried out;reservoir oil content: the main control factors were analyzed from the two aspects of sedimentation and micropore throat structure,and a well logging identification template was established;finally comprehensive classification of low permeability reservoirs in the research area was carried out.and divided into four categories,two classes,among them,the development of class I reservoir is relatively mature,which is the main exploration and development direction in the future.