Study On Types And Features Of Pore Structures Of P Oil Groups In D Oilfield

This paper choose the P oil layer of B district of D oilfield as the main study object,through analyzing various materials of the study area, inducing lots of materials aboutslices of the casting, electron microscope, mercury penetration and core data, we havesystematically discussed and analyzed the pore structure characteristics of reservoir,classification, influence factors and its control factors of remaining oil formation.In this article, we collected all the assay materials of cores l in the study area,including core photos of the47wells, scanning electron microscope photos of156samples of16Wells, capillary pressure data about982samples obtained from117Wells;well water flooding and relative permeability data of14wells, sensitivity experimentaldata of2piece of samples from8Wells etc. Observe110samples of14Wells on slices ofthe casting, pictures of520.Synthesizing regular pore structure characteristic parameters and fractal characteristicparameter and sorting parameters, we established classification standard and evaluationbasis, studied the microscopic pore structure, analyzed the relationship betweenmicroscopic pore structure parameters macroscopic physical parameters; Based on this, allthe samples of microscopic pore structure of the study area is divided into five categories,from Ⅰ to Ⅴ pore throat radius decreases gradually, pore throat ratio increased little bylittle; Pore permeability becomes poorer and poorer, filler content increases, the maximumsaturation values of pressure and displacement pressure increases gradually, heterogeneityincreases.Based on the observation of Through the mirror of slices of the casting, this paperanalyzes the main pore types of P oil layer in the study area, the main pore types includereservoir intergranular pore, solution pore and small amounts of crack and throat typesmainly include reducing throat, flake and bent flake throat and bundle throat, etc. Troughmercury penetration experiment data and results, various characteristic parameters of porestructure are analyzed, concluding that medium is given priority to all pore structureparameters of P oil layer; through conventional physical properties and the sensitivity testdata and results, study the physical properties and sensitivity characteristics of P in the studied area reservoir. The results showed that physical property of P oil layer is givenpriority to the medium hole, permeability to the medium permeability, pore structure isgiven priority to Ⅱ type reservoir, reservoir property is good, but different fields or areasis slightly different.Study the degree of different factors on the pore structure in detail, diagenesis on thepore structure is the most detailed, for P oil layer, compaction play the role of damagingthe pore structure; Cementation make the space of primary pore and throat diameternarrowed and complex; the surface of reservoir pore throat become coarse because ofdissolution, and the dissolution of sandstone can happen many times, its cause iscomplicated, secondary dissolution pores can be various,which makes the sandstone porestructure characteristics changes greatly in the late; in addition, feldspar dissolvedhappened in the study area, it also makes the reservoir space improved; and themetasomatism is mainly the transformation of clay minerals.The distribution range of P oil layer is wide, from the deposit, although it belongs toshallow water delta deposits as a whole, in different areas there is still difference of subfacies and microfacies, therefore, different facies belt have different sedimentarycharacteristics, reservoir physical properties will be different. Through differentsedimentary microfacies, from the distributary plain, main channel property is best, thebody thick sand layer take second place, followed by interchannel sand as the main bodythin layer, the none main channel and the none main body interchannel sand, the maindevelopment Ⅰ, Ⅱ, Ⅲ pore structure; for front area in phase, the main river channelproperty is best, the body thick sand layer take second place, followed by interchannelsand as the main body thin layer, the none main channel and the none main bodyinterchannel sand, the main development Ⅲ, Ⅳ pore structure; the outside front phase,main body residual channel property is best, followed by the thick layer of sandsheet,none main body of residual channel sand sheet, the none main body and sheet, porestructure is given priority to with Ⅳ, Ⅴ.