| The Kumkol Oil Field is located in South Turgai Basin of Kazakhstan. In this area thefaults are well developed, with complex structure rfacturing, which are small anticlinalstructures，complicated by faults. Trap area is small, and the main objective formation is theAryskum Formation that is at the bottom of the Lower Cretaceous.Currently, the major issues and challenges for the development of the field mainly showthat;①moisture content continues to irse, so it is diiffcult to keep a stable production;②theresults of water injection development differ much, and the water-out degree of oil reservoirsvary, so it needs to impress the strength of comprehensive adjustment to improve the effect ofwater injection development;③the studies of this area focus on primary analysis ofstratigraphic correlation and preliminary analysis of sedimentary facies，and the microfacicsstudy has not been deep resesrehed;④as far as thick sandstone reservoir is concerned, moredetailed study of the mobile unit level has not been carried out;⑤the understanding of thedistirbution of remaining oil is unclear, and it requires the use of combining static and dynamicmeans to characterize the enrichment of the residual oil distribution.In this paper, based on abundant drilling cores of this area, logging and analysis oflaboratory data，with the guidance of theoretical methods of reservoir geology, reservoirsedimentology, logging geology, development geology and other related disciplines, we havemade fine stratigraphic divisions and correlation of the Aryskum Formation at the bottom ofthe Lower Cretaceous in the Kumkol Oil Field and have studied its microfacies distributionlaw, division of reservoir flow units, and study on characteirstics of mobile unit planardistirbution were carired out, which plays the key role in the distirbution of remaining oil.1、Themain results and understanding achieved were summarized as follows:According to the logging data, subdivision and contrast of the objective formation (Mformation Cretaceous) was carired out. The M-I-l divided by predecessors was subdividedinto M-I-l-1and M-I-l-2.2、3Dseismic and stratigraphic division of dirlling wells data show that the structuralcharacteirstics of the structural layer of the studied area has a good inheirtance, the mainregion of the oilfield is a large-scale anticline with NW-SE trend, with the west wing more gentle, and the east wing more steep, the structural highs are in the centre of the ifeld. SKOilfield is a long shatf faulted anticline with the NW-SE trend; the small faults show adistribution of lfying geese.3、Basedon core and log data, sand body of the M layer in the studied area wasindentiifed and compared. Sand body of M-l Layer was superposed together by lateralaccretion, with better connectivity. M-II Layer is dominated by thick massive sandstonesedimentation, with high thickness of single sand body and good lateral connectivity.4、Basedon a vairety of deposition signs, well logs and regional geological background,through the study of the types of sedimentary facies of M Layer, the division of subfacies andmicrofacies was carired out. M-I is meandeirng irver depositional system, M-II is a braidedriver system. According to the results of stratigraphic correlation and study on depositionfacies, the planar distribution pattern of sedimentary microfacies of each layer was studied.5、Thereare relatively stable developed insulating layers among each layer, intcrlayersformed by the deposition and diagenesis developed within the sand body. Lithology ofinsulating layer and interlayer are mainly mudstone and silty mudstone.6、Usingporosity, permeability, clay content, lfow zone index(FZI) and other parameters,applying cluster analysis and stepwise discirminant analysis methods, the reservoir lfow unitswere divided, the discirminant function of reservoir flow units of the M Layer was established,and the M Layer was divided into three flow unit type*Mainly developed Type I, II flow units,the distirbution of lfow units is characterized by the phenomenon of the zoning rfom north tosouth, lfow units with poor physical properties of the Class III are mainly distirbuted in thenorthern part of KN*Flat distirbution law of flow units shows，sedimentation is the mostimportant factor that affects the physical property of reservoirs in the studied area. |
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