| Here we have studied diagenesis, sequence of diagenesises and diagenetic facies on the basis of normal slice identification, some other technology and means are also used, for example, observation of SEM, X ray diffraction and so on.According to the evolution of clay mineral, vitrinite reflectance and a variety of the orders of the diagenetic phenomen deduced the purpose layers mainly in its middle diagenetic A period. And speculated that the layer experienced two kinds of evolution of diagenetic environment: The first kind of diagenetic evolution took place in the middle of Es3, salt lake basin. And the second kind took place in i the later section of Es3-Es4, freshwater - brackish lake.Based on the study of the reservoir space and the reservoir characterristics.concluded that the reservoir property of pucheng area mainly reversely correlated with content of carbonate. At about 3700m, the early stage carbonate are dissolved into secondary pores,then the abnormal high porosity is produced. the thickness of sand bodies, sedimentary facies are also affect the characteristics of reservoirs.Based on the oil production test data, the lower limit of the porosity in pucheng area is defined as 9%, and the lower limit of permeability is defined as 0.16×10-3μm2. According to mercury curve and the division standards of diagenetic facies, divided the reservoir of Dongpu area into 3 kinds. For the fist kind, the porosity expression 9% and the permeability surpass 0.35×10-3μm2, with the shaly coated diagenetic facies. and the second kind is characteristiced by that, the porosity ranged 7%-11%, the permeability ranged 0.08×10-3μm2-0.18×10-3μm2, mainly in soluble components dissoluted diagenetic facies. The third kind of reservoir is characteristiced by that the porosity ranged 4%-9%, the permeability ranged 0.02×10-3μm2-0.07×10-3μm2, in carbonate compact cemented and fracture diagenetic facies.The first kind and the second kind are identified as the effective reservoirs.
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