Reservoir Evaluation And Favorable Area Prediction For Block Hei 69 In Jilin Daqingzijing Oilfield

The Hei 69 block is one of the blocks with large development potential in the Daqingzijing oilfield.Now the parameters of the classification and evaluation standard of the Member K₂qn¹reservoir in study area are low in quality and quantity,and the evaluation results could no longer meet the needs of the present fine development.Therefore,on the basis of sedimentary micro-phase portrayal,focus on the study of reservoir pore space,physical and diagenetic characteristics.Exploring the influence of sedimentation,pore space,and diagenetic features on reservoirs.Preferred multiple parameters for comprehensive multi-reference reservoir evaluation and established evaluation standards.Complete the preferential selection of favorable target areas to provide a scientific basis for later development.Knowledge obtained is as follows:（1）The Member K₂qn¹reservoir in Block Hei69 is mainly developed as a delta front deposit.The sandstone types in Member K₂qn¹are mainly lithic（chalk）feldspathic sandstone with locally developed feldspathic（silt）sandstone.The composition is low in maturity,sub-angular in rounding,moderate to good in sorting,dominated by linear contacts,with calcite and clay minerals dominating the gap fill.（2）The porosity of the K₂qn¹reservoir in study area is distributed from3.1%to 17.8%,with an average of 11.23%;and the permeability is from 0.01 to80.8m D,with an average of 3.14m D,making it a low-porosity,extra-low-permeability reservoir.（3）The pore type is dominated by intergranular pores,with fine throat channels and predominantly micro-throats.The pore structure is relatively complex and the reservoir has a poor percolation capacity.Four types of pore structure are classified in the study area using K-means clustering.Class I and II are the most dominant category.（4）The K₂qn¹reservoir in the study area is in Stage A of the intermediate rock evolutionary stage.The reservoir is mainly subject to compaction,cementation and dissolution.The average compaction porosity reduction（P1）is 50.11%,the average cementation porosity reduction（P2）is 28.87%and the average dissolution porosity increase（P3）is 19.21%.（5）According to the parameters of lithology,physical properties and oil-bearing properties,the reservoirs in Member K₂qn¹of the study area are classified into four categories using hierarchical analysis.Category I reservoir:REI>0.5;Category II:0.5>REI>0.4;Category III:0.4>REI>0.3 and Category IV:0.3>REI.（6）Combined with the results of the comprehensive evaluation of the reservoir and other types of results,the criteria for the division of favourable zones were established.Favourable zones in the area are divided into three categories.And minor layers（7,12 and 14 layers）are delineated.The 12 sub-strata delineate 3 favourable areas of category A,with the largest area of 10.19 km²;the 7 sub-strata delineate 3favourable areas of category A,with the next largest area of 3.36 km²;the 14 sub-strata delineate 3 favourable areas of category A,with the next largest area of 3.36 km²...