Study On Architecture Of Channel Sandbody: High-Resolution Sequence Stratigraphy Of Fy Oil Layer In East 14th Block Of Yushulin Oilfield

In recent years, with the theoretical and technical of oil and gas exploration and development progressing, the theory of sequence stratigraphy applying to the basin-scale classic sequence stratigraphy, culminates in applying to reservoir-scale high-resolution sequence stratigraphy. The different levels sub-base level cycle of the formation corresponds with the division of sand body,which has important significance in exploration and development of oil and gas fields.The study on internal architecture of the continental meandering channel sands, its theoretical model has been formed earlier, model type relatively centralized.The morphological characteristics of most of the meandering river is that its lateral accretion bodys in beach (point bar) are parallel and fixed distribution, because it formed in the balance period which occurred neither filling nor erosion of the river. There are some lateral accretion bodys in point bar of meandering river takes the shape of stair, because it formed in upper stream in the meandering river, where the erosion was relatively strong, river began to swing to the abandoned river course, which gradually increased the angle of lateral accretion formation.Internal architecture of single sand body is not only a new sedimentary research,but also stretching and development of the high-resolution sequence stratigraphy ,and the major geological problems which requires to solve in tertiary recovery stage. This contents of the current research aimed at meandering point bars and braided channel sand dam bodies, mostly focused on ancient outcrop and modern sedimentary, the study on architecture of single sand body within underground oil fields is less. With the modern sedimentary and ancient outcrop studies increasing,more and more genesis types of the architecture of sand body will be established, which wlii be able to guide research better on the architecture of sand body underground oilfield and the three-dimensional geological model, ultimately serve the remaining oil three-dimensional prediction in old fields, improve oil and gas recovery.Through Searching published literature at home and abroad, which can be seen,compared to foreign countries, we pay more attention to the remaining oil prediction. This is closely related to sedimentary characteristics of underground reservoirs. Compared to the complexity of terrestrial sedimentary environments, mostly foreign oil reservoir sedimentary is marine environment, the complexity of the remaining oil is less than China. Taking into account the investment risk, foreign will make full use of natural energy back to the first layer on one round in the exploitation of the reservoir,do not want mining in hard to work hard, so far have not formed a systematic and effective method of remaining oil (Yu Qitai, Gang Qinlin, 1999).Through subdivision of reservoir sequence, this paper analyses and describes the distribution regularity of remaining oil from the single well, reservoir plane and three-dimensional spatial.1. high resolution sequence stratigraphic classificationThrough analysing the sedimentary dynamics of all levels sub-base level cycle and identifying of the interface of which,it explored a set fine-resolution sequence stratigraphic correlation methods for the river - delta system,and for the first time Fuyang reservoir in Yu-East 14th block was divided into a long-term, two medium-term and 34 short-term base level cycle, established a regional unified, fine high-resolution sequence stratigraphic framework.SSC₃^SSC₂2 is a process of large-scale base-level rise, SSC₂3^SSC₂3 is a process of base-level fall slowly,SSC₂3^SSC₃4 also is a process of large-scale base-level rise, constitute two mid-term base level cycle changes in the study area, and SSC₂^SSC₃4 base level is a long-term process of change. SSC₂^SSC₃ short-term cycles channel sands cuting in the vertical is particularly serious,Through single well→plane→three-dimensional gradually realized sand body formation in the study area, it will be subdivided into single channel deposition. The SSC₂, SSC₂, SSC₃ three short-term cycles were respectively subdivided into the two parts, subdivision is SSC₂a, SSC₂b, SSC₂a, SSC₂b, SSC₃a, SSC₃b.2. Fine structure interpretation between sequencesPut forward that "Well sure, earthquake modeling, combined with sand body distribution, well and seismic integrated interpretation "technology, carried out the fine layer structure interpretation. Interpretated a number of small faults which is difficult originally to identify. Re-verified the structural situation of the study area and predicted the location of sand bodies between wells.Layer structure detailed interpretation is ready for the stratigraphic and horizontal wells and its horizontal core's angle adjustment,and take direct the internal architecture of meandering channel sands researching in study area.3. Describing the microfacies of short-term sedimentary cycleWe established fine high-resolution sequence isochronal stratigraphic framework In east 14 well area,on the basis of it,using the earthquake, drilling and logging data,one by one well to identify the single well logging curves characteristic of short-term cycle,obtained log-phase mode of the microfacies, and then determined microfacies types in the single well, the last election according to the sedimentary environment of short-term phase combination of flat sedimentary facies.Completion of the microfacies maps of short-term sedimentary cycle before and after infill -well drilling, and comparison of microfacies change before and after infilling, sum-uped the complexity and regularity of reservoir development in the study area, as to provide some guidance of a clearer understanding the oil reservoir.4. Internal architecture research of single meandering channel sand bodyAfter sedimentary microfacies maps were drawn out in single sand body level, accurately identify the point bar, abandoned meandering river, using the logging and the core datum, identifying lateral interlayer,calculating these parameters,such as direction, dip Angle, density of interlayer. According to the classic internal architecture mode of single sand body,infering its plane and profile river track,and finally establishing internal architecture of single meandering channel sand body in main layer.5. The remaining oil research in reservoirFrom the one-dimensional (single well), two-dimensional (plane of layers), three-dimensional (remaining oil in point bar) to the layers, summed up a series of remaining oil distribution types, and analysed its distribution law. In general use crude oil of low-permeability reservoirs is difficult and less. Based on the above results, establishment low-permeability reservoirs architecture of meandering channel sand body geometry model of remaining oil in Yu-East 14th block, think of breakthrough the low-permeability affection, integrating communication side of the top point bar and flooding oil tend to along the perpendicular to tendency of point bar effect is more reasonable, which solved the contradictions during the oil field development,for oil field development adjusting in the next step has played an important role.Research throughout the paper, forming a set of theoretical methods and techniques using high resolution sequence stratigraphy to guide reservoir study,depositional environment and development for similar levels of other oil fields have very strong guidance and reference. Meanwhile,a more clear understanding of the complexity of the reservoir in study area, and the corresponding will take a more scientific and rational means of field development to develop more efficiently, which makes due contributions in oil field development adjustment and remaining oil redevelopment.