Study On The Features Of Reservior Of Chang 10₁ Section Of The Triassic Yanchang Formation In Ordos Basin

The Ansai oilfield of Ordos basin is this paper's study area, Chang 101 oil formation of Triassic Yanchang Formation in Ordos basin is elected as the target layer. Using sedimentary petrology, reservoir sedimentology, reservoir physics and the petroleum geology theories to be the concept guidance of paper, on the basis of predecessors'achievements, collecting the field profiles photos,observing drilling cores and sampling description,combination logging curve and logging interpretation data,using thin section identification, SEM,determination of porosity and permeability of sandstone,Mip experimental analysis as main method to study of reservoir sedimentary facies, petrological characteristics, diagenesis, petrophysical property and pore throat structure, etc.The target is to understand the research area reservoir classification and exhibition cloth, finding high-quality reservoir development site, eventually predicting areas favorable for oil and gas accumulation.Sedimentary structure and logging curve shape of that phase marks the research area for delta plain deposits.Sand body is northeast to southwest toward ribbon or flake distribution.Distributary channel is favorable zones for development of the reservoir.Core ordinary chip and scanning electron microscopy (SEM) analysis estimate the type of sand rock mainly be arkose,cementation content have chlorite film, spontaneous quartz feldspar, calcite, turbidity zeolite, etc.Compaction, cementation, medium diagenesis and explaination actions destroy the primary porosity, causing sandstone property be reduced, dissolition improved reservoir physical properties.Dissolition improved reservoir physical properties.Core casting thin sections concluded between the residual solution pore porosity and grain is the main pore types.Average performance for row flooding pressure is a medium to large, median pressure too large, the median radius of pore throat small, pore throat structure belong to holes fine-micro-fine throat way.These factors comprehensive decision the characteristics of study area's reservoir is low permeability and low porosity.Analysis of reservoir pore, permeability test and logging interpretation data.Reference previous reservoir classification standard and classifying reservoir,the research area is Main III and IV classes development of reservoir with localâ…¡class reservoir.Ansai oilfield Chang 101 formation have Rich oil source(Chang 7 source rock),favorable sedimentary facies (distributary channel),good soure-reservior-roof reservoiring control factors,these factors constitute the updip Dense block reservoirs and sandstone reservoirs with pointed out.Through the sand body development zone, high value porosity district and try oil results,optimization out 13 oil and gas accumulation advantageous area in different paragraphs reservoirs of Chang 101 oil formation.Overall Chang 1012 oil-gas accumulation zones obviously better than the Chang 1011 and Chang 1013.