Study On The Distinguished Channel Identification And Countermeasure Of B21 Well

All the countries in the world of the old oil field after more than ten years water injection of development,on the whole have entered high water cut and recoverystage. In the large pore formation, large pores become the dominant channel of injected water into the range of medium, it is difficult to improve scope. The injected water along the large channels of ineffective circulation so that other parts of a reservoir is hard to be afflictive, serious impact on oil displacement efficiency, resulting in the obvious difference in areal residual oil saturation. The injected water channeling and well premature flooding have seriously restricted the exploitation of crude oil. Moreover, in the process of oil field water injection development, under the influence of reservoir heterogeneity, water oil mobility ratio, injection production imbalance and other factors, the bottom of reservoir is extremely easy to the formation of large pores,injected water forms a short circuit flow along the dominant channel, intensify the contradiction between layers of the reservoir, the seepagewater washing part of dominant channel resistance is smaller and become water injection dominant channel.The late stage of water injection development,the injected water flow along the dominant channel of circulation leads to a large number of invalid water rise, and the weak flow region is formed at the top of the reservoir, also resulting in theenrichment of remaining oil, low producing degree of water flooding.Therefore,the large pores in sandstone reservoir has an important influence on reservoir permeability and injection production process. As the requirement of the rapid development of the national economy of petroleum growth, to improve the developed oil recovery is an important development direction. Therefore, in order to ensure the effectiveness of water injection development, it is necessary to discover and identify the dominant flow channels in reservoirs.There are some problems in the development of Baikouquan reservoir B21well area:reservoir heterogeneity, flat contradiction, dominant channel, water channeling. By the understanding of geological, dynamic data analysis, test data analysis and combined with the experiment, study on thedominant channel of B21well area B1layer, provide a scientific basis for the selection of profile control and water plugging agent type,design of the construction site, evaluationof the effect on adjustment.It has a very important significance improvement of B21well area Baikouquan oilfield development.This paper widely investigates and studys the domestic and abroad literatuer, combining the previous studies, research results are as follows:1. Baikouquan formation with high water district in recent years due to the variation of water injection well conditions, injection rate, injection level low, resulting in plane and profile pressure distribution, potential reservoir producing degree is reduced, water cut rising quickly, decreasing increasing, development effect.2. Dominant channel formation reservoir original layer with high porosity and high permeability layer in the high-pressure water erosion and the driving force is the core mechanism of, the reservoir rock particles adsorbed on the surface of clay minerals and intergranular fillings or cement corrosion, exfoliation, carrying and migration process and make intergranular pore wall surface becomes smooth, pore expansion thickening, and ultimately the formation of higher porosity, permeability distribution with.3. The formation mechanism and genetic types of the advantages of the channel in the actual reservoir exploitation are analyzed.. The factors that affect the formation of the dominant channel include reservoir microstructure, reservoir physical property, sedimentary facies, reservoir heterogeneity and mining method, etc.. The types of dominant channels are: sedimentary microfacies control, micro fracture network connectivity, lithologic sedimentary interface, reservoir transformation, long-term water injection micro particle migration.4. Analysis the dominant channel in Bai21well area B1layer of baikouquan formation conglomerate reservoir distribution.4. Proposed the heterogeneous synthetic index, pore radius, sedimentary rhythm and production (ceiling) intensity of liquid analysis channel advantage, of Baikouquan reservoir water flooding advantage channel are analyzed. First, through the development of production status and liquid producing profile a preliminary evaluation of the dominant channel and through sedimentary rhythm, heterogeneous composite index and pore radius clear advantage channel development level. Finally, the tracer monitoring and testing data to verify the development level of accuracy. The dominant channels of B1layer were mainly concentrated in B12and B13sand groups, and the dominant channels of1020A well group were well developed.5.1020A wells and1133well profile control ideas proposed and developed construction scheme, construction site, after oil production increased15.6t/d, water cut decreased by6.4percentage points, two well group cumulative increased oil3116.1t to verify the accuracy of the recognition results.