Fine Stratigraphic Division And Reservoir Prediction Of Oil-bearing Sand Body In Xishanyao Formation In Well 9 Of Junggar Basin

Luliang oilfield is located in the centre of Junggar Basin.It is an important exploration and development block of Xinjiang petroleum.The major target of this research is the Lu 9 well-block.which mainly makes study from proceed with the core description,the logging data and seismic section of this tripartite face.By the primary marks of contrast in region,data of reconnaissance in field and interface of sequence stratigraphy,stratum of the oil-containing interval Xishanyao Formation?J₂x?were devised and according to its characteristics the?J₂x₁?stratigraphic framework was set up.The system research discussed the sedimentary structure distribution,reservoir space-time structure,oil production performance data of facies in the study area,and low permeability reservoir.The coupling relationship between diagenesis,reservoir oil-water distribution,injection-production contradictions scientific problems is solved.Predicted the distribution of favorable reservoir for efficient rolling Luliang oilfield development provides the reliable geological basis.The thesis main understanding and the conclusion is as followsUnder the guidance of high-precision sequence stratigraphy,the unconformity surface and boundary analysis were carried out on the well seismic data of the Xishan yao Formation?J₂x?in Lu9 well area,so as to identify that the secondary cycle of the Xishanyao Formation?J₂x?consists of a positive cycle and a reverse cycle.On the basis of the three-level sequence of Xishanyao Formation?J₂x?,the stratigraphic framework with fine division of the four-level and five-level sequences of the oil-sands in the first section of Xishanyao Formation?J₂x₁?is established,and the distribution and development law of the sequence stratigraphy in the first section of Xishanyao Formation?J₂x₁?is studied.On the basis of sequence stratigraphic evolution,the source systems and heavy mineral components of the Xishanyao Formation?J₂x₁?were studied.Aiming at the single well and continuous well profile facies of the first section of Xishanyao Formation?J₂x₁?,the fine comparison of small layers and the distribution analysis of flat surface facies were established to explore the sedimentary evolution law.The logging curve is mainly shaped like a bell,a box and a funnel.Therefore,in the delta sedimentary body of the first section of Xishanyao Formation?J₂x₁?in the study area,two sedimentary subfacies of the delta plain and the delta front,and five sedimentary microfacies of subaqueous channel and subaqueous estuary sandbar are identified.Luliang oilfield the?J₂x₁?from the field lithology is given priority to with fine-medium grained lithic sandstone,with low compositional maturity,but the characteristics of high textural maturity belongs to low porosity and permeability in the reservoir,the reservoir space is limited by the geological genesis,can be divided into the following three aspects:?1?delta reservoir space and pore size are small,primary intergranular pore and secondary pore two classes;Clastic rocks mainly consist of subangular siltstones with overlapping layers and subangular sandstones with medium to fine grained sandstones with mixed structures.?3?diagenesis and cementation make the throat thinner,the mineral composition is dominated by quartz,followed by feldspar,heterogenous and porous calcium cement content is relatively low,so that the reservoir oil and water distribution is uneven,permeability decreased.Based on the study and analysis of the reservoir four relations,combining with the distribution of the reservoir sand body,the types of sedimentary microfacies and the influence of the sand body thickness,carried out the reservoir classification.That will behave of predict the favorable reservoirs in the first section of Xishanyao Formation?J₂x₁?in Lu9 well area.