The Seismic Prediction Technology Of Reservoir And Its Application

Reservoir prediction technique can reveal the underground target bed(including reservoir, hydrocarbon reservoir and so on) geometry(including reservoir thickness, structural feature of the top and bottom reservoir, bearing of reservoir trend the position of reservoir wedge out and so on) and micro-storage performance parameter of reservoir distribution features by seismic data, geology data and well data in different exploratory development stage. This combined technique improves petroleum geologist forecasting ability of petroleum resource. Because seismic data are continuous on the horizon, and well data are limited much on the horizontal. What is more, seismic data includes abundant physical property information. Reservoir seismic prediction technique is very important in hydrocarbon exploratory. Reservoir seismic prediction technique studies seismic information as the main object, and combine well logging, well testing, various information such as geology, oil extraction and analysis laboratory results to study reservoir distribution, lithology variation, thickness variation, physical features, fluid and hydrocarbon reservoir characteristics.This article describes the current seismic reservoir prediction techniques in the field of petroleum exploration:the techniques of seismic facies, seismic inversion and seismic attribute. The two techniques of seismic inversion and seismic attribute are the core techniques of seismic reservoir prediction. This article analyses and studies these three techniques, and gives out some application limitations of part techniques.Seismic facies technique analyses primarily sedimentary facies by seismic reflection characteristics on seismic data and inference sedimentary facies. Sedimentary facies analysis can direct reservoir study. Seismic facies technique can determine it is a favorable reservoir by seismic reflection wave on external reflection geometry and internal reflection structure, external reflection geometry and internal reflection structure contain the wave combined information of frequency, amplitude, and continuity, and each geometry and reflection structure reply to one sedimentary environment, which are summed by the predecessors’experience. This technique is primarily observed on the profile through the naked eye and it is a qualitative tool. Now it is moving in a direction of quantitative development, using computer to operate and judge, making it easy to operate, such as cluster analysis of waveforms.Seismic attribute technique development is rapid, and its varieties are too many.it mainly use mathematical formulas to extract some information from the reflected wave, and its physical meaning of reflected wave is not very clear, which results in multiple interpretation of the same attribute. Even though it still is the core technique of reservoir prediction. Practice has proved that it is still representative of certain strata information such as depth, amplitude and so on.Seismic inversion technique is mainly for prediction of lithology, it can reverse sand thickness, wave impedance, porosity and other information. The common inversion is wave impedance inversion. Seismic inversion technique combines effectively seismic and well data and uses mathematical knowledge to fill information in the junction of the two data, such as linear interpolation method between wells and wells,which can make information continuous. Seismic inversion technique of reservoir prediction is also a core technique. Seismic inversion now forms a variety of methodologies based on actual needs. Practical application depends on the specific case.No matter which technique you use, or how to integrated use of technique, all of them are reliably based on seismic interpretation. Seismic interpretation of reservoir prediction is the basis.seismic horizon calibration is the critical step in reservoir prediction, and mainly uses synthetic seismogram is mainly used by VSP data in this article. Calibration results are checked by one well profile and well tie profile calibration, and well tie profile can coordinately modify one well profile calibration results. So that well tie calibration make the best coincident with the phase axis.Zhong Guai-58three dimensional work area in Bai Kouquan in Xinjiang Karamay Bai jiantan is for an example in this article. The structure of this project locates on the thrust belt in the Northwest margin of Junggar basin, and Triassic and Permian formations is studied in this article. Triassic formation is mainly about Bai Kouquan formation, and lithology is mainly the green and grey conglomerate, glutinite with few brown mud-stone. Permian stratigraphy is divided into four groups, from top to bottom are:Shang Wuerhe group, Xia Wuerhe group, Xa Zijie group and Feng Cheng group, which composed of consists of grey glutinite and is unconformity contact with up Triassic formation. Reservoir seismic prediction technique are main applied to these formation.Studing on reservoir seismic prediction technique, this article combining Zhong Guai-58three dimensional work areas’practical application introduct details about wave impedance of seismic inversion technique, as well as seismic properties and spectrum decomposition of seismic attribute technique in the work area of the application. Seismic prediction technique is based on a precise calibration and tectonic interpretation of the Formation. Boundaries of a favorable reservoir is depicted more clearly by using seismic inversion and seismic attributes techniques, reservoir is predicted by integrating structures, sediment and other information.Three representative reservoirs are picked out in this article:KE81Eastern favorable reservoir, KE303wells Triassic favorable reservoir and KE201well area favorable reservoir, and how to use these techniques of seismic facies, seismic attributes and seismic inversion to predict these reservoirs is detailed. KE81Eastern favorable reservoir is predicted mainly through seismic reflection geometry, as well as internal reflection structure on seismic profile, For example, foreset reflection structure can help sedimentary facies analyse sedimentary environment of work areas, and then find possible petroleum reservoir in horizontal position and vertical position, through the sedimentary facies analysis, sedimentary source analysis, conditions of petroleum reservoir analysis. Then check it whether it coordinates with the predecessor summary of seismic facies features on the seismic profile.lt can be verified by seismic attribute technique if it is the same as predecessors’. KE303Triassic favorable reservoir is mainly in the old oil field. Old oil wells in this region will be reviewed, and the seismic profiles will be interpreted to redetermine the possible reservoir range, at last seismic attribute technique will be used to validate it, focusing on using spectral decomposition technology. The spectral decomposition is mainly used for thin-layer spectrum analysis. The result of the spectral decomposition has been expected. Seismic inversion was mainly used for KE201area favorable reservoir. This reservoir’s conditions meet the basic inversion conditions. There are more wells around it, and they distributed more evenly. The inversion method for specific situations should be selected after having these initial conditions. Well logging-constrained inversion method based on model is mainly selected. The wave impedance inversion method gets the desired results. Of course other methods still are needed to analyze this reservoir such as seismic attribute technique.