| D20 well area is a potential oil and gas region which was discovered recently in Cainan oilfield.It is located on the east margin of Junggar Basin and the tectonic unit belongs to the Dishuiquan structural belt on the Dinan uplifting which is adjacent to the Kelameili tectonic zone.The target formation is the glutenite reservoir of the Badaowan formation of the lower Jurassic strata above the carboniferous strata.The reservoir is a typical up dip pinch-out reservoir and the boundary of which is controlled by the faults and the lithological boundaries.With the deepening of the degree of rolling exploration and establishing of development well pattern,the emphasis of reservoir research has turned from the determination of the scope of the reservoir and the exploration of oil-water boundary to detailed description of sedimentary characteristics,reservoir heterogeneity study and injection-production contradiction analysis.The thesis was based on the core description,well logging,seismic data,and under the guidance of modern sedimentary geologic model and the experiment simulation.Sedimentary types,sand bodies' distribution characteristics and the modal of interlayer were evaluated comprehensively.That laid the foundation of fully understanding of sedimentary characteristics of Dishuiquan belt and development scheme optimization.The results and conclusions of this thesis were organized as follows:1.Based on the previous investigation for sequence stratigraphy and the strata situation,using the method of high resolution sequence stratigraphy,combined with core and logging data,and adjusting the stratification of all wells,the strata was divided into J1b11,J1b12 and J1b13 three small layer.2.Through the analysis of regional geological data,characterization of core features and well logging curves shape identification,the sedimentary facies type was concluded as the Gibert fan delta.The sedimentary feature in the plane was shown up as with "small plain,big front".The microfacies of delta plain include braided channel and bar.The delta front is composed of underwater distributary channel,braided bar,sheet sand and the fore-delta shale.3.A new classification of interlayer was proposed.In the first,the interlay was divided into barrier interlayer and high permeability interlayer.The term "barrier","high permeability" all reflected the function of interlayer.Meanwhile reference laminated seal degree of injection water to categorize different interlayer;when modeling on different types of interlayer,the inadaptability of single modeling method can be avoided.4.Based on the actual production performance of injection-production well group and the injection-production contradictions analysis,especially for water breakthrough and water injection doesn't work well group focusing on research,from the sand body connectivity,interlayer distribution and development of water injection,a comprehensive analysis think in later development adjustment,in order to comprehensively carry out separate injection and profile control work for reservoir to increase production and improve recovery factor is most important.The depositional characterization and sedimentary facies distribution in the plane of study area were confirmed on the basis of the achievements above.Water breakthrough and water injection failing were summarized as problems often encountered in exploitation.The thought of dynamic and static combined analysis on reservoir research was attempted.The methods and the overall train of thought to optimize development scheme that "layered injection-production,puckering hypertonic layers,limiting the water amount" should be adopted. |
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