Study On Reservoir Prediction Of Fluvial Facies Of DongYing Group In Lujiazhuang Area Of Raoyang Sag

Oil and gas exploration field of China is tending to change from looking for structural entraps to seeking litho logic ones in recent years with the development of oil and gas exploration and exploitation. Reservoir prediction technology has been turning into one of the most important and useful methods in oil and gas research field. Seismic data, for its successive character in landscape orientation, and well-logging data, for its high-resolution power in vertical orientation, have been taken into consideration as a whole to predict litho logic reservoirs, which is the leading way in this field at nowadays. Reservoir prediction technique is an technology applied for reservoir or hydrocarbon-bearing pool research, raised from the eighties of20th century in Geophysical circles and developed rapidly, which comprehensively utilizes seismic^geology、well logging and other data to reveal geometric spacial distribution (including reservoir thickness、structural feature of reservoir’s Top Bottom、bearing of trend and thinning out location, etc)of subterranean target(reservoir、hydrocarbon reservoir, etc)and distribution character of reservoir’s microscopic reservoir attribute parameter. So, reservoir prediction technique is a synthetically applied technology. It is a process including matching、transformation and integration between seismic data and well logging data bearing high-re solution, and geological knowledge permeated from beginning to end. Its application greatly improved petroleum geologists’predictive ability.Lujiazhuang area of Rao Yang sag is located in the centre of Rao Yang sag, it’s research area has104square kilometer. The interval of interest is Dongying formation of paleogene system. This area belong to Liuxi broken solt belt and Liuchu anticline between southern excessive area, with the two tectonic belt in taking formed many complex broken small fault blocks group. The research by our predecessors considers that Dongying formation is major fluvial facies sedimentary system, poor property, faults, monolayer thickness thin, generally conventional try oil production is low. Therefore the research of reservoir prediction, analysis favorable sand bodies distribution law, find effective method of channel sand body prediction, and they can realize new breakthrough for further exploration.The method of constrained sparse spike inversion supposes that the reflections coefficients of strata are sparse. A rapid trend-constrained pulse inversion calculation is adopted, using the seismic interpretation horizon and logging-constraint to control the trend and scopeof wave impedance. The pulse calculation can obtain the wide-band result, The inversion result is faithful to seismic data, simultaneously; the constraint of logging and geology can replenish the component of low and high frequencies. The vertical resolution is heightened, comparatively to the conventional seismic data. In order to improve the accuracy of the oil-gas forecasting, the division of the seismic facies is especially important, The accuracy of the seismic facies division will directly affect the reliability of the oil-gas exploration results. Through the analysis of all kinds of basic data, in learning and using the basis of predecessors’achievements, carefully tracking compared to the multi-channel seismic profile of the study area. By using the seismic facies analysis technology, further analysis of its sedimentary environment of Dongying formation, identified the bottom boundary of the stratums and typical seismic facies unit and type. Made to predict the sand body distribution, and Study fluvial seismic stratigraphy, the initial establishment of the river seismic facies model.Seismic reservoir prediction obtains the more and more extended application along with the seismic survey technology progress. Good benefit in exploration has been achieved. The principle and the physical significance of seismic inversion for reservoir prediction also rapidly developed and demonstrated good prospects.Wave impedance inversion technology in seismic exploration has a important position. Seismic inversion mainly included prestack and post-stack inversion. At present post-stack inversion has a widely application, post-stack inversion mainly included seismic trace integration, recursion inversion, model inversion, Geostatistics inversion. This paper analyze the development of inversion technology, and has the further study on Recursive Inversion, Model Inversion, Geostatistics Inversion, discusses some problems on these inversion technology, and compares the advantages and disadvantages of these inversion.In reservoir prediction of Lujiazhuang area of Rao Yang sag, This article take seismic facies analysis technique, Qualitative predict the extension of sand body of Fluvial of Dongying formation in research area; this paper adopted a constraint sparse pulse inversion method, detailedly predict the extension of sand body, and prediction thickness and porosity of reservoir, characteristic of Planar distribution. According to the map of predict thickness of sand body, the map of predict porosity of sand body, the map of wave impedance, then we can draw a conclusion, Ed3formation is medium—high pore porosity reservoirs, and it’s porosity is between16%-25%, and is the main oil reservoir of this set reservoir, Es1and Ed2has a relatively low porosity, and it’s porosity is between10%-23.7%, is the secondary oil reservoir of this set reservoir. compared with individual Wells statistics reservoir thickness, the forecast of the reservoir thickness is coincide with it. The individual well has large inaccuracy, it’s mainly affected by fracture structure. By the contrast of the map of wave impedance of subzone and the map of sedimentary facies of subzone, we can see the sand body that be controlled by well clearly, and the position of sand body that is through predict accord with the regular of sedimentation model, therefore, the inversion results is reliable.Comprehensive analysis shows the result is largely consistent with the result of Sedimentary facies analysis. The location of the prediction of sand body Comply with the law of Sedimentation model, Accuracy and Good Reliability.