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Research And Application Of Reservoir Seismic Reflection Characteristics Based On Forward Modeling

Posted on:2015-09-21Degree:MasterType:Thesis
Country:ChinaCandidate:X Z ZhangFull Text:PDF
GTID:2180330503955869Subject:Earth Exploration and Information Technology
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Forward modeling plays a more and more important role in seismic acquisition, processing and interpretation. In seismic acquisition, the influences on actual seismic acquisition from observing system and excitation means are studied through forward modeling. During seismic processing, the effectiveness of stack and migration, and amplitude-preservation characteristics are both verified through building the forward model. While in seismic interpretation, the forward modeling profiles are compared with the real ones to guide the interpretation of real seismic data. With the development of exploration and exploitation, the time-lapse seismic is gradually widely-applied in oil field. But it is expensive to prospect only for the purpose of time-lapse seismic research. So it is significant to study the deployment of oil wells and the distribution of oil residual through building the forward model by using the data from rolling development, and by changing the reservoir parameters to simulate the exploitation of oil and gas reservoir.The first part of this paper introduces the foundation of rock physics, and estimates the shear wave velocity with well-logging materials that lack shear wave velocity based on the theory of rock physics. Then the influences of reservoir parameters including water saturation, porosity and shale content on both the reflection coefficient and ratio of compressional wave and shear wave velocity are studied and elaborated. The second part firstly builds single-well models and well tie models based on well data and seismic interpretation data, and get the forward modeling data using varying grid wave equation. The results from forward modeling are compared with the real seismic data. Secondly, based on a typical dimensional model, a three dimensional one is built, and the forward data for the three dimensional model in a preliminary process is then analyzed. And also this paper studies the advantage of 3D imaging on dynamic monitoring by multiple shot forwarding and poststack migrating. Finally, the time-lapse seismic tectonic models are built with the consideration of typical geologic characteristics including fault, pinch-out, thin interbed of oil and gas reservoir. And then the transformation of seismic reflection characteristics are studied by changing the reservoir parameters. The third part introduces the processing for model data and real seismic data. Firstly, the influence factors on the seismic reflection character are studied, including the thickness of reservoir, formation lithology, wavelet frequency. And then the reservoir thickness of theoretical model are predicted by using the wave impedance inversion and reflection character analyses. Then these two methods mentioned are used to explain the stratum pinch-out line in working area of a western oil field, and to further determine the prospective lithologic trap. Finally the impact effect of bearing calibration are studied by making the cross equalization for the model data, and nonconforming processing is carried out for the real three dimensional seismic data of an eastern researching area by using cross equalization method, which decreases the variation from non-reservoir effect between monitoring data and original data.The study of deep thin reservoir model is beneficial for the exploration of lithologic hydrocarbon reservoir in western area to find the objective area. The study of time-lapse seismic does good for rolling development and distribution of oil residual. This paper predicts the thickness of reservoir in a certain western oil field, and through the processing of real data in eastern researching area cripples the seismic data anomalies from the change of nonreservoir effect, which makes the monitoring for the exploration and exploitation of oil field more accurate.
Keywords/Search Tags:deep thin reservoir, time-lapse seismic, forward modeling, prediction of reservoir, cross equalization
PDF Full Text Request
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