Fine Interpretation Of Reservoir In Shuang1of Moliqing

Moliqing fault depression as a secondary building unit of Yitong Basin, is a small half graben rift basin,including Yi52well field, Yi6well field and Yi52well field.The area is290km2. The Shuangyang Formation in the Moliqing area developed Member1of Shuangyang Formation,Member2of Shuangyang Formation,Member3of Shuangyang Formation from the bottom to top.The Member1of Shuangyang Formation from the bottom to up developed Ⅱ sand group and Ⅰ sand group.Ⅱ sand group develop3sublayer,2sublayer,1sublayer from the bottom to up. Oil and gas mainly distributed in1sublayer and2sunlayer of Ⅱ sand group.Member1of Shuangyang Formation mainly developed fan delta,sublacustrine fan and lacustrine sedimentary system.Yi52block and Yi6southeastern are mainly the fan delta sand body.Yi47blocks and the northeastern margin of Yi6mainly developed sublacustrine fan sand body.Member1of Shuangyang Formation has good conditions of oil and gas generation, storage,migration and accumulation.But the reservoir forming model and mechanism have been limited due to the series of different logging,diverse lithology,the less corresponding core and laboratory analysis data and complex oil-gas-water distribution.Therefore,studing the main controlling factors of oil and gas reservoir log interpretation method,establishing oil-gas-water identification standards and plate and identifying oil-gas-water correctly are the urgent problems now in this area.On the basis of pretrophysical,this thesis launchs the four-property relationship study of reservoir and clear the logging response characteristics of oil-gas-water layers,study on fine logging interpretation of Member1of Shuangyang Formation in the Moliqing area,effectively identify the lithology and oil-gas-water and further clarify advantage reservoir of Member1of Shuangyang Formation in the study area.Through above research,we can obtain the following results:(1) the study area of Yi52well area in Member1of Shuangyang Formation is low porous and extra-low permeable reservoir.Yi6well area in Member1of Shuangyang Formation is particularly extra-low porous and permeable reservoir, part of it is medium porous and high permeable reservoir. The largest connected pore radius of the pore system is larger,but the pore sorting property is poor.The distribution of throat is lack of concentration.The fine throat occupies a high frequency and heterogeneity is strong,most of which belongs to fine throat type reservoir. Generally reservoir property is poor and natural seepage is weak.(2) establishing the standard of lithology identification:mudstone,85API<GR<115API,RT<9Ω.m;siltstone,55API<GR<85API,17Ω<RT<27Q.m;glutenite,GR<55API, RT>27Ω.m;establishing fluid identification standards in different area and lithology:conglomerate oil layer of Yi52well area,Rt≥26Ω.m,AC≥230μ s/m;siltstone oil layer of Yi52well area, Rt≥20Ω.m,AC≥230μs/m;conglomerate oil layer of Yi6well area,Rt≥25Q.m,AC≥240μs/m;siltstone oil layer of Yi6well area,Rt≥12Q.m,AC≥243μs/m;sandstone gas bearing reservoir of Yi6well area.Rt≥15Q.m,AC≥260μs/m;siltstone gas bearing reservoir of Yi6well area.Rt≥20Ω.m,AC≥295μs/m.(3) The main influential factor of reservoir quality in Member1of Shuangyang Formation is sedimentary facies types, followed by diagenesis. Comprehensiving physical factors,we can summarize that the favorable reservoir is mainly located in the subaqueous distributary channel and braided river channel deposit microfacies of the shallow depth(about1300m) or mid-depth (about2500m) in the area.(4) Through the empirical statistical method, the lower limit of porosity of effective reservoir in Member1of Shuangyang Formation is8%and the lower limit of permeability is0.3×10-3μm2.accuracy rate is up to93.5%by the verification of testing result. The lower limit of the physical property is reliable.(5)The reservoir of the study area can be divided in three types by the lithology, physical property, pore character and sedimentary microfacies. The property of type I reservoir is best.It developed glutenite of the subaqueous distributary channel on fan delta front.The pore type is mainly intergranular emposieu.The most of throat is fine throat.The porosity is higher than15%and permeability is higher than10×10-3μm2.