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Pre-stack Sensitive Elastic Parameter Inversion And It's Application In Xihu Depression

Posted on:2008-02-11Degree:DoctorType:Dissertation
Country:ChinaCandidate:J L YangFull Text:PDF
GTID:1100360212483630Subject:Mineral prospecting and exploration
Abstract/Summary:PDF Full Text Request
The prospecting of lithology reservoir as well as gas reservoir sometimes requires unconventional seismic inversion technique.Based on the research results of elastic parameters sensitivity (to lithology and fluid) trial, pre-stack sensitive elastic parameters inversion (PSEPI) has been presented in this paper. The basic idea, before pre-stack elastic parameter inversion, elastic parameters sensitivity (to lithology and fluid) trial (using well log data) must be done first in an area, that determine which elastic parameter is the most sensitive to lithology and fluid. PSEPI is conducted using CRP gather data and well log data to get sensitive elastic parameters. These sensitive elastic parameters are used to predict lithology and fluid. A series of techniques has been developed according to the meet of PSEPI.The relationship between incidence angle and the robustness of AVO inversion has been researched based on model data. The optimum strategy of AVO inversion has been presented according to the research results. Large incidence angle (offset) is not necessary unless density is the most sensitive parameter in an area. If density is a key parameter in an area, large incidence angle is necessary. The appropriate angle is about 45°, and the maximum angle is not more than 50°.Multiple attenuation method has been improved. 3D Crossplotting technique between two datasets has been successfully used to determine gas-bearing sand distribution. The prediction of gas-bearing sand has been achieved using PSEPI technique in Xihu depression. In HY area, Poisson's ratio (σ), μ*p and λ/μ, are sensitive to H5 gas-sand. H5 gas-sand distribution has been successfully predicted, and 20km~2 gas-bearing sand has been identified. Based on the results of gas-bearing sand prediction, the designing of appraisal well or prospect well has been made. In Pinghu area, Poisson's ratio (σ) and λ,*ρ have been successfully used to identify four target zones of gas-bearing sand, and the predicted results have been proved by well PH6.
Keywords/Search Tags:AVO inversion, elastic parameters, sensitivity trial, lithology and fluid, prediction
PDF Full Text Request
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