Ray-based stochastic inversion of prestack seismic data for improved reservoir characterization

Geophysics ◽  
2009 ◽  
Vol 74 (5) ◽  
pp. R85-R97 ◽  
Author(s):  
Dennis van der Burg ◽  
Arie Verdel ◽  
Kees Wapenaar
Keyword(s):  
Seismic Data ◽  
Reservoir Characterization ◽  
Normal Incidence ◽  
New Method ◽  
Parameter Estimates ◽  
Lateral Velocity ◽  
Stochastic Inversion ◽  
Reservoir Parameter ◽  
Inversion Techniques ◽  
Amplitude Versus

Trace inversion for reservoir parameters is affected by angle averaging of seismic data and wavelet distortion on the migration image. In an alternative approach to stochastic trace inversion, the data are inverted prestack before migration using 3D dynamic ray tracing. This choice makes it possible to interweave trace inversion with Kirchhoff migration. The new method, called ray-based stochastic inversion, is a generalization of current amplitude versus offset/amplitude versus angle (AVO/AVA) inversion techniques. The new method outperforms standard stochastic inversion techniques in cases of reservoir parameter estimation in a structurally complex subsurface with substantial lateral velocity variations and significant reflector dips. A simplification of the method inverts the normal-incidence response from reservoirs with approximately planar layering at the subsurface target locations selected for inversion. It operates along raypaths perpendicular to the reflectors, the direction that offers optimal resolution to discern layering in a reservoir. In a test on field data from the Gulf of Mexico, reservoir parameter estimates obtained with the simplified method, the estimates found by conventional stochastic inversion, and the actual values at a well drilled after the inversion are compared. Although the new method uses only 2% of the prestack data, the result indicates it improves accuracy on the dipping part of the reservoir, where conventional stochastic inversion suffers from wavelet stretch caused by migration.

scholarly journals An integrated petrophysical-based wedge modeling and thin bed AVO analysis for improved reservoir characterization of Zhujiang Formation, Huizhou sub-basin, China: A case study

2020 ◽  
Vol 12 (1) ◽  
pp. 256-274
Author(s):  
Wasif Saeed ◽  
Hongbing Zhang ◽  
Qiang Guo ◽  
Aamir Ali ◽  
Tahir Azeem ◽  
...  
Keyword(s):  
Seismic Data ◽  
Reservoir Characterization ◽  
Dominant Frequency ◽  
Well Logs ◽  
Amplitude Versus Offset ◽  
Avo Attributes ◽  
Thin Reservoir ◽  
Amplitude Versus

AbstractThe main reservoir in Huizhou sub-basin is Zhujiang Formation of early Miocene age. The petrophysical analysis shows that the Zhujiang Formation contains thin carbonate intervals, which have good hydrocarbon potential. However, the accurate interpretation of thin carbonate intervals is always challenging as conventional seismic interpretation techniques do not provide much success in such cases. In this study, well logs, three-layer forward amplitude versus offset (AVO) model and the wedge model are integrated to analyze the effect of tuning thickness on AVO responses. It is observed that zones having a thickness greater than or equal to 15 m can be delineated with seismic data having a dominant frequency of more than 45 Hz. The results are also successfully verified by analyzing AVO attributes, i.e., intercept and gradient. The study will be helpful to enhance the characterization of thin reservoir intervals and minimize the risk of exploration in the Huizhou sub-basin, China.

Workflow for improvement of 3D anisotropic CSEM resistivity inversion and integration with seismic using cross-gradient constraint to reduce exploration risk in a complex fold-thrust belt in offshore northwest Borneo

2018 ◽  
Vol 6 (3) ◽  
pp. SG49-SG57 ◽  
Author(s):  
Max A. Meju ◽  
Ahmad Shahir Saleh ◽  
Randall L. Mackie ◽  
Federico Miorelli ◽  
Roger V. Miller ◽  
...  
Keyword(s):  
Reservoir Characterization ◽  
Three Dimensional ◽  
Structural Complexity ◽  
Hydrocarbon Exploration ◽  
Parameter Estimates ◽  
Thrust Belt ◽  
Exploration Risk ◽  
Resistivity Logs ◽  
Geologic Interpretation ◽  
Reservoir Parameter

The focus of hydrocarbon exploration has now moved into frontier regions where structural complexity, heterogeneous overburden, and hydrocarbon system fundamentals are significant challenges requiring an integrated exploration approach. Three-dimensional controlled-source electromagnetic (CSEM) anisotropic resistivity imaging is emerging as a technique to combine with seismic imaging in such regions. However, the typically reconstructed horizontal resistivity [Formula: see text] and vertical resistivity [Formula: see text] models often have conflicting depth structures that are difficult to explain in terms of subsurface geology. It is highly desirable to reduce ambiguity or subjectivity in depth interpretation of [Formula: see text] and [Formula: see text] models and also achieve comparability with other coincidentally located subsurface models. We have developed a workflow for integrating information from seismic well-based inversion, interpreted seismic horizons, and resistivity well logs in a cross-gradient-guided simultaneous 3D CSEM inversion for geologically realistic [Formula: see text] and [Formula: see text] models whose parameter estimates for a selected reservoir interval can then be better optimized to aid reservoir characterization. We developed our workflow using exploration data from a complex fold-thrust belt. We found that the integrated cross-gradient approach led to [Formula: see text] and [Formula: see text] models that have a common depth structure, are consistent with seismic and resistivity logs, and are hence less ambiguous for geologic interpretation and reservoir parameter estimation.

Integrated Stochastic Inversion Approach Assessing Thin Reservoirs Full Potential in the Prolific Oil-Prone Periphery of Hassi Messaoud Field, Algeria

2021 ◽  
Author(s):  
Mohamed Samy Tawfik ◽  
Medjdouba Nasrine ◽  
Sabiha Annou ◽  
Aiouna Ahcene ◽  
Abderaouf Haddouche ◽  
...  
Keyword(s):  
Seismic Data ◽  
Reservoir Characterization ◽  
Rock Physics ◽  
Full Potential ◽  
Reservoir Properties ◽  
Stochastic Inversion ◽  
Area Of Interest ◽  
Characterization Study ◽  
Reservoir Potentiality ◽  
Saharan Platform

Abstract Nowadays it become harder, risker and more expensive understanding the reservoir potentiality and design the optimum development plan for challenging thin reservoirs. In a geological complex area, integrated seismic reservoir characterization approach was crucial to unlock the potentiality for the study area, which is located at Oued Mya basin, SE Saharan platform Algeria. Seismic data analysis is one of the key procedures for characterizing reservoirs and monitoring subsurface properties. Integration of seismic stochastic inversion and geological model will help to demonstrate the link between seismic and reservoir properties more quantitative. The seismic data of region were challenging, with around 30 wells drilled over 400 Km2. To overcome the challenges, the available geological and geophysical data were integrated to construct the reservoir characterization study and reduce drilling uncertainty. Ensure the reservoir characterization process was constrained by a robust workflow and consistent with the available geophysical, geological, and petrophysical data. Petrophysical interpretation, seismic interpretation, rock physics analysis and Stochastic Inversion processes were carried out. These processes were integrated to characterize the lateral and vertical extent of the lithofacies in five stacked reservoirs across the area of interest to identify the potential delineation of thin reservoirs of nine-meter thickness.

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