| According to statistics,the oilfields at the stage of high and ultra-high level accounting for30%of the total number in our country,and the proved reserves,the recoverable reserves and the yield account for a large proportion.At the late stage of oilfield development, there are many factors that influence the distribution of remaining oil,including geological factor and engineering factor.The geological factor is the internal factor and the basis.Therefore,how to predict the geometry,the scale,the superimposition and the flow characteristic of the underground reservoir more accurately is the most important research direction of the oilfield development in geological field.At the early and mid-stages of oilfield development,the accuracy of the study on the underground reservoir mainly is the compound sedimentaty microfacies of layers(such as compound channel).However,while the development goes to the mid and late stages,the distribution of the remaining oil is complicated,its hard to meet the need of the remaining oil prediction and improve the recovery efficiency by this accuracy,especially for the alluvial fan sandy conglomerate reservoir which has a complex deposition construction.The development of reservoir architecture method (Miall,1985) provides a systematic research guideline to the detailed reservoir study and quantitative forecast.Reservoir architecture, also known as the reservoir architectural, structural unit, and means of different levels of the reservoir internal superposition between cell shape, size, direction, and their mutual relations.Reservoir architecture study highlights the level of the reservoir internal sedimentary units and structural, this research has made great progress in fluvial reservoir analysis, and a better application in the underground reservoir. However, the research degree of alluvial fan reservoir architecture is quite limited.In2007,Professor Wu Shenghe etc.in University of Petroleum carried out relevant research work in Karamay,classify the phase belt to determined the grading system and set up a pattern of alluvial fan reservoir architecture.The alluvial fan architecture, has to classify the phase domain on architectural study,then it would be possible to build an ideal architectural pattern.This study adopted two patterns.One is for the fan root architecture.It mainly is the pan communicated sandbody.The architectural elements are actually an entirety which has no visible sub-unit boundaries.So it is more suitable to model on the4architectural element.The other used similar fluvial facies architectural pattern.On account of the water-carried tractive current system and the sediment transporting pathway at the middle part and edge of the fan,this deposition mechanism is more closed to the fluvial facies reservoir,so the architecture is more suitable to use for reference the straight river or the low-sinuosity meandering fluvial architectural pattern.Exactly speaking,it is more closed to braided stream reservoir architecture.Based on this conception,this paper mainly discussed and used the mid-fan braided fluvial belt and the run-off belt at the top of the fan architectural pattern.The paper takes the alluvial fan reservoir in Xinjiang Karamay oilfield triassic Karamay formation (we call it lower Karamay formation for short)as an example, analysis the static and dynamic data of the Eastern zone of dense well in six of the Karamay oilfield, on the basis of previous research, guided by high-resolution sequence stratigraphy and sedimentology,a variety of modeling methods coupled architecture modeling ideas,studies internal architectural element of alluvial fan reservoir quantitative geometrical features and overlay mode, set up to reflect the multi-level architectural interface,3D reservoir architecture modeling,providing a scientific basis for the secondary development in decision-making of glutenite reservoir. Through research the projects,I mainly obtained the following research results:(1)Through study the different modeling methods,found out the modeling methods by analyzed and summarized which are suitable for different alluvial fan architecture.(2) Under the terms of the pattern and each architectural proportion of training image suit the situation,multiple-point simulation method could depict the mid-fan architecture well.Using the principle of multiple-point Geostatistics try to depict the alluvial fan architecture.(3)After concludes by comparing each modeling method,architecture modeling on sealed core wells accurately.The grid size in the plan is10m×10m,and sets a grid every0.125m vertically.It provided an accuracy3D geologic body for3D geologic study and remaining oil study of sealed core wells. |
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