--> ABSTRACT: Well to Seismic Ties Modeling with the Adaptive Log Analysis, by Deshenenkov, Ivan S.; Kozhevnikov, Dmitry A.; Kovalenko, Kazimir V.; #90135 (2011)

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Well to Seismic Ties Modeling with the Adaptive Log Analysis

Deshenenkov, Ivan S.1; Kozhevnikov, Dmitry A.1; Kovalenko, Kazimir V.1
(1)Well Logging, Gubkin Russian State University of Oil and Gas, Moscow, Russian Federation.

Data integration is a key step for accurate seismic interpretation and reservoir characterization. Hydrocarbon reservoirs are characterized by seismic, well-log, and petrophysical information, which is dissimilar in spatial distribution, scale, and relationship to reservoir properties. Acoustic and density logs could be absent in logging suite. In such case several techniques are applied for acoustic and density logs modeling. We propose adaptive model for elastic properties simulation. Developed algorithm is grounded on theoretically proved petrophysical laws and regularities in contrast with elastic properties simulation techniques which are based mainly on empirical relationships between petrophysical parameters.

According to the adaptive technology it is possible to describe a large number of factors that characterizes reservoir sedimentation conditions, mode of occurrence, epigenetic transformation. The base of the adaptive log analysis technology is the petrophysical invariant (normalized effective porosity or dynamic). It could be determined with log data (acoustic log, density log, compensated neutron log, spontaneous potential log and gamma ray log).

The adaptive log analysis technology tunes log analysis algorithms according to the tool response in formation natural occurrence conditions. Slowness and density of the reservoir can be estimated with characteristic values of acoustic and density log responses.

Examples of the acoustic impedance adaptive simulation and synthetic seismograms modeling were carried out for Jurassic reservoirs - sandstones with complex mineral composition. Acoustic impedance was calculated by two ways. First one is product of P-wave velocity and density; the second one is carried out using adaptive model with spontaneous potential (SP) log, gamma-ray (GR) log and compensated neutron log (CNL).

Petrophysical invariant was calculated from acoustic & formation density logs and SP, GR & CNL for determination of simulation model accuracy characteristics. Calculated acoustic impedance was convolved to the synthetic seismogram in both cases. The excellent traces convergence indicates the high accuracy and reliability of the developed technology. The adaptive model is valid for granular reservoir rock (clastic or carbonate) only.

Calculated elastic parameters can be used to obtain wavelets, restore low-frequency component that is absent in seismic data as well as to analyze the seismic inversion results.

 

AAPG Search and Discovery Article #90135©2011 AAPG International Conference and Exhibition, Milan, Italy, 23-26 October 2011.