| The upper Karamay Formation in the centre and eastern of Seven area of Karamay Oildfield is a monocline fault block reservoir, it is divided by internal fault into three development unit, which is the Central region of seven area, the Eastern1region of seven area and East2region of seven area. The Stratum can be divided into five sand group, which is S1, S2, S3, S4, S5, the sand group S2only exist in the seven East2area. The reservoir was found in the late nineteen fifties, and explored in the nineteen sixties. Experienced Productivity construction, High speed stability mining. Decrement, three main development stages. At present, the reservoir well loss is severe, the development of profile is uneven, formation pressure distribution is not uniform, Severe flooding water channeling, Injection production contradiction, Residual oil distribution in complex. Preliminary understanding of reservoir geology has been unable to meet the development needs of reservoir adjustment. This paper is guided by Sedimentology theory, Using multiple factors analysis,by the use of new drilling, coring well data and a large number of pass by formation of well data, the reservoir sedimentary facies, reservoir heterogeneity, reservoir layer microscopic heterogeneity are described, and analies the reservoir and reservoir physical property distribution, provide the basis for the adjustment and tapping the potential of residual oil.A total of292new wells stratigraphic correlation has been completed in this project study, and deep sedimentary facies and reservoir heterogeneity has been studied, There are76figures of various types of sedimentary facies and reservoir heterogeneity parameters has been drawed. the study get the following understanding.1. The rock types in the centre and east of Seven area of Karamay mainly include conglomerate, fine conglomerates, breccia, small coarse sandstone, sandstone, fine sandstone, siltstone, mudstone and transitional types of rock, according to the rock structure and the formation of the hydrodynamic environment can be divided into the conglomerate facies, fine conglomerate facies, sand, fine sandstone facies, facies in silty sand and mudstone facies are six categories; according to different facies vertical combination features can be divided into four types, respectively is the gravel lithofacies and fine-conglomerate phase thin layer of mudstone, siltstone facies facies, small fine gravel and coarse facies lithofacies; fine conglomerate facies, coarse facies and mudstone and powder the sandstone layers to each other; gravelly coarse sandstone facies and facies in fine sand and silt mudstone facies and the layers to each other; mudstone and siltstone phase thin layer of fine sandstone facies.2. The principle of stratification divition in the centre and east of Seven area of Karamay Oilfield has been established, Using lithology, electric property characteristic as the basis. by method of cycle contrast, one by one single well stratified in section, completed292new wells stratigraphic correlation, built research division to the isochronous stratigraphic framework. 3. The Sedimentary type of the upper karamay formation in the centre and east of Seven area of Karamay is piedmont alluvial fan-fluvial deposition. S52-2, S52-1, S51-2group layer developed top fan microfacies, scale is larger, and controls the region from50%to100%oil-bearing area. S51-1, S42-2layer top fan trough microfacies development scale has been reduced in different degree in the seven or seven East1well area, the period and S42-1, S41-2, S41-1layer mainly developed in braided stream, fan braided stream facies sand island, their large size and scope control main oil-bearing area. S32, S31, S12, S11layer is formed at the front end of the transitional development of alluvial fan and flood plain facies braided river facies, channel deposits are relatively large scale and scope, channel microfacies control area58%～100%oil-bearing area.4. The upper Karamay Formation in the centre and east of Seven area of Karamay, is a middle-strong heterogeneous conglomerate reservoir, the heterogeneity of the inner layer, interlayer, plane and microscopic pore structure are strong in the study area. The monolayer layer average permeability variation coefficient in upper karamay formation is1.8～3.3, interlayer permeability changes in the6×10-3μ,2～220×10-3μm2, plane with different phase permeability in the range of15～214, reservoir pore diameter of45μm～450μm, the throat diameter0.14μm～4.4μm, pore throat with a number of0～5, belong to strong heterogeneous glutenite reservoir.5ã€The control of Sedimentary facies of reservoir to the heterogeneity is obvious Reservoir permeability in the plane change is the main effected by the distribution of sedimentary facies, and the next factor is the relationship to the mainstream line orientation. Generally from top fan to fan or fan to fan by the intermediate zone, permeability decreased; the permeability of primary and side edge groove, groove beaches microfacies is the largest in top fan subfacies, braided stream of fan middle phase is the highest permeability fluvial microfacies. Conglomerate reservoir, in the same phase in band, permeability parallel to the mainstream line is higher than the vertical direction. |
