The Method For Effective Evaluation Of Tarim Foreland Fractured Sandstone Reservoirs

With in-depth development of oil and gas industry, large bulk high hole high permeability sandstone reservoirs is more and more difficult to find, Many large companies have to turn them attention to cracks-complex lithologic reservoir exploration and development。In recent years, with well logging technology and the development of oil and gas exploration and development technology, many domestic oilfields have been crack-hole type carbonate rock salt and has made a major breakthrough in the exploration of igneous rock reservoir found substantial oil and gas geological reserves. But for sandstone fractured reservoir logging evaluation method and technology is the unsolved problem.Tarim kuqa piedmont region and south-western purpose layer buried depth, high formation temperature and pressure, lithology and complex, mainly for the dense fissured glutenite reservoir, drilling core, well logging data to identify oil and gas layer and fracture effectiveness evaluation is difficult. Tarim piedmont region of reservoir effectiveness model is established and the standard, the correct evaluation of reservoir parameters, is of great significance to exploration and development and geological engineering.Based on complex lithology identification in the region, according to core analysis, conventional well logging, ECS logging data, adopted the neutron-density or neutron-acoustic, M, N conventional crossplot method and ECS logging lithological identification chart is set up two kinds of method to identify lithology. Crossplot technique identification and quantitative calculation of lithological profile is an important foundation work of logging reservoir evaluation, in sand shale formation in the neutron-density or neutron-acoustic and with M-N crossplot identify lithology, well logging interpretation has confirmed that the method has high credibility, by the cross-plot method, we can the qualitative identification of lithology, the region; ECS logging can be accurately measured formation of C, O, Si and Ca element content, application specific oxide closure model technology, in order to get the percentage content of minerals in formation. To measurement of Al, Mg, Na and other elements, through the standardization of closed and measured elements linked with them, then by all sorts of element abundance or concentration of clay mineral, quartz, feldspar, mica and siderite and pyrite such as mineral content, mineral content and rock skeleton density is closely related, so you can received according to the element capture spectroscopy logging framework to calculate rock mineral composition and content value, identify lithology, quantitative identification of the lithology, by ECS can more accurately than crossplot can reflect stratigraphic lithology. By using logging crossplot, ESC elements logging interpretation results figure established lithology recognition method in use in the region, improve the accuracy of the lithology recognition in the region.In lithology recognition, on the basis of the use of conventional log and core data, accurate petrophysical parameter calculation model is established, and by the porosity, permeability intersection chart method, fluid properties index method, flow belt element method for reservoir effectiveness analysis and determine effective reservoir physical property lower limit standard, preliminary formed dense sandstone reservoir comprehensive evaluation standard, in the reservoir matrix porosity lower limit is3.5%, the matrix permeability lower limit value is0.05, the stoneley wave permeability lower limit of0.2. Seepage coefficient method is used, the flow unit method to determine the lower limit of the effectiveness of reservoir in this area, structure of the seepage coefficient of the lower limit of0.02mu m, flow zone index FZI minimum1.1mu m, the fluid characteristic parameters FTI lower limit of0.05. Combined with the stoneley wave permeability and fracture parameters are further divided into the reservoir level.This article research results through piedmont tight sandstone in tarim basin experiment, effect is good, for similar tight sandstone in tarim basin of fracture effectiveness evaluation has strong significance. Therefore, the research achievements of this paper not only has a strong theoretical significance, but also has important practical value.