Font Size: a A A

The Reservoir Evaluation Of The Chang-6 Member Of The Yanchang Formation In Zhenjing Oil Field, Ordos Basin

Posted on:2010-11-23Degree:MasterType:Thesis
Country:ChinaCandidate:P K LiuFull Text:PDF
GTID:2120360278460688Subject:Oil and gas field development geology
Abstract/Summary:PDF Full Text Request
Ordos Basin is the second largest inland sedimentation basin with prolific in oil and gas resources, so it has a better exploration and development prospect.Base on the further study of sedimentary system and reservoir Characteristics of chang-6 member in Zhenjing Oilfield, Ordos Basin,and re-recognize the sedimentary facies of main oil layer such as chang-62-2 and chang-63-1,the distribution of sand bodies and oil layer, reservoir Characteristics in chang-62-2 and chang-63-1 is clear .This provide geological theory basis for further reservoir evaluation and development of oil and field late.Base on the core observation,logging analysis and previous research results,using the high-resolution sequence stratigraphy theory, taking the key wells for centralization and lake transgression mudstone as the marker bed,the chang-6 member is re-devided and re-comparison.Then,use logging curves to classify logging facies based on the lithology-electric property relation. the sedimentary facies is determined to be the front-delta deposition of braided river delta deposits.There is a large thickness,good lamellosity and continuous sandbody,which have good reservoir quality,while the mouthbar is deposited barely. The depositional characterisytics and the structure of microfacies types in sections are discussed, and the lateral distribution of the sedimental facies are predicted.On the base of physical analysis, mercury injection date, slice observation,the average porosity of chang- 6 is 12.1% ,average permeability is 0.26? 10-3|m 2 , average pore radius is 16.1|m,average throat radius is 0.15|m in chang - 6 member ,so it is considered after the comprehensive reservoir evaluation that it belongs to the type of reservoirs with low porosity and super-low permeability,the middle pore-fine throat,the poor sorting and pore connectivity.The four properties ' relations shows that the physical properties get better and the daily oil production raises with the increasing of average grain size of sandstone,it?s oil-bearing degree also improved.Both of the territorial empirical formulas of the shale content,porosity, permeability and water saturation and the oil water stratum identification model in Zhenjing Oilfield are conclude by lots of experiments for theoretical basis of the reservoir evaluation and good perforation interval in future.The grain-size variation internal of coring sandstone tells that it is mainly presents composite and reverse rhythm in chang-6 member. The types of interlayers are argillaceous and calcareous. Frequency and density of the interlayers have a increasing raise from the main channel sand body to river channel flank.Statistical analysis of the permeability showa that the permeability variation coefficient raised and mutation coefficient decreased from chang-62-2 to chang-63-1.The porosity come from log interpretation is better in western and center of study aera in chang-62-2,and in western and eastern in chang-63-1.After the research on the heterogeneity of the reservoir sandstones, it can be concluded that the heterogeneity resulted from sedimentary environment and diagenesis interaction.the middle of the river channel has poor heterogeneity,and river channel strong.The controlling effect on reservoir by the sedimentary micro-facies is strong.Both the thickness of sandbody and diagenesis are important influenceing factors of reservoir except structure background. The lower limit of reservoir parameters and classification evaluation standard whach can be classified as four types of the Chang-6 member in this oilfield is determined in the paper by considering multivariate factors.The high-quality reservoir is distributed in the central near north(type-â… ) and sourthwest(type-â…¡) of study area in chang-62-2,and the central (type-â…¡)and sourth(type-â…¢) in chang-63-1.
Keywords/Search Tags:Zhenjing Oilfield, the Chang-6 member of the Yanchang formation, Sedimentary facies, heterogeneity, Reservoir characteristics
PDF Full Text Request
Related items