scholarly journals Estimation of reservoir fluid saturation from seismic data: amplitude analysis and impedance inversion as a function of noise

2015 ◽  
Vol 2015 (1) ◽  
pp. 1-4
Author(s):  
Rafael Souza ◽  
David Lumley
Keyword(s):  
Seismic Data ◽  
Amplitude Analysis ◽  
Fluid Saturation ◽  
Reservoir Fluid ◽  
Impedance Inversion

Stochastic inversion of pressure and saturation changes from time-lapse AVO data

Geophysics ◽  
2006 ◽  
Vol 71 (5) ◽  
pp. C81-C92 ◽  
Author(s):  
Helene Hafslund Veire ◽  
Hilde Grude Borgos ◽  
Martin Landrø
Keyword(s):  
Stochastic Model ◽  
Seismic Data ◽  
Synthetic Data ◽  
Time Lapse ◽  
Bayesian Framework ◽  
Reservoir Modeling ◽  
Data Set ◽  
The North ◽  
Fluid Saturation ◽  
Likelihood Model

Effects of pressure and fluid saturation can have the same degree of impact on seismic amplitudes and differential traveltimes in the reservoir interval; thus, they are often inseparable by analysis of a single stacked seismic data set. In such cases, time-lapse AVO analysis offers an opportunity to discriminate between the two effects. We quantify the uncertainty in estimations to utilize information about pressure- and saturation-related changes in reservoir modeling and simulation. One way of analyzing uncertainties is to formulate the problem in a Bayesian framework. Here, the solution of the problem will be represented by a probability density function (PDF), providing estimations of uncertainties as well as direct estimations of the properties. A stochastic model for estimation of pressure and saturation changes from time-lapse seismic AVO data is investigated within a Bayesian framework. Well-known rock physical relationships are used to set up a prior stochastic model. PP reflection coefficient differences are used to establish a likelihood model for linking reservoir variables and time-lapse seismic data. The methodology incorporates correlation between different variables of the model as well as spatial dependencies for each of the variables. In addition, information about possible bottlenecks causing large uncertainties in the estimations can be identified through sensitivity analysis of the system. The method has been tested on 1D synthetic data and on field time-lapse seismic AVO data from the Gullfaks Field in the North Sea.

Deepwater reservoir prediction using broadband seismic-driven impedance inversion and seismic sedimentology in the South China Sea

2018 ◽  
Vol 6 (4) ◽  
pp. SO17-SO29 ◽  
Author(s):  
Yaneng Luo ◽  
Handong Huang ◽  
Yadi Yang ◽  
Qixin Li ◽  
Sheng Zhang ◽  
...  
Keyword(s):  
South China Sea ◽  
South China ◽  
Seismic Data ◽  
Seismic Velocity ◽  
The South China Sea ◽  
Hydrocarbon Exploration ◽  
The South ◽  
Low Frequencies ◽  
China Sea ◽  
Impedance Inversion

In recent years, many important discoveries have been made in the marine deepwater hydrocarbon exploration in the South China Sea, which indicates the huge exploration potential of this area. However, the seismic prediction of deepwater reservoirs is very challenging because of the complex sedimentation, the ghost problem, and the low exploration level with sparse wells in deepwater areas. Conventional impedance inversion methods interpolate the low frequencies from well-log data with the constraints of interpreted horizons to fill in the frequency gap between the seismic velocity and seismic data and thereby recover the absolute impedance values that may be inaccurate and cause biased inversion results if wells are sparse and geology is complex. The variable-depth streamer seismic data contain the missing low frequencies and provide a new opportunity to remove the need to estimate the low-frequency components from well-log data. Therefore, we first developed a broadband seismic-driven impedance inversion approach using the seismic velocity as initial low-frequency model based on the Bayesian framework. The synthetic data example demonstrates that our broadband impedance inversion approach is of high resolution and it can automatically balance between the inversion resolution and stability. Then, we perform seismic sedimentology stratal slices on the broadband seismic data to analyze the depositional evolution history of the deepwater reservoirs. Finally, we combine the broadband amplitude stratal slices with the impedance inversion results to comprehensively predict the distribution of deepwater reservoirs. Real data application results in the South China Sea verify the feasibility and effectiveness of our method, which can provide a guidance for the future deepwater hydrocarbon exploration in this area.

scholarly journals Comparison study between the elevation and datum statics in NC 210, western Libya

2021 ◽  
Author(s):  
Riyadh Alhajni
Keyword(s):  
Conventional Method ◽  
Seismic Data ◽  
Seismic Velocity ◽  
Sand Dunes ◽  
Angle Of Repose ◽  
Amplitude Analysis ◽  
Reflected Waves ◽  
Geometric Spreading ◽  
Amplitude Compensation ◽  
Seismic Lines

Abstract This research compares the results of each method to solve problems caused by sand dunes, In the southwestern region of Libya, the Murzuq basin is covered with sand dunes, which are a significant source of noise in land seismic data, which caused issues in seismic processing, also sand dunes cause increases of travel time of reflected events in seismic data, procuring false structures this problem caused by residual static errors. The presence of extensive sand dunes causes logistic and technical difficulties for seismic reflection prospecting, Due to the steep angle of repose of the sand dunes faces and the low seismic velocity within them, which causes significant time delay to the reflected waves. In this research, three seismic lines (202, 207, 209), of total length 12 km, have been completely reprocessed at Western Geco processing center (Tripoli) using omega software. the methods of gain corrections: time function gain and geometric spreading. Spreading amplitude compensation, has been proceed the results will be compared to another method of gain corrections called residual amplitude analysis compensation (RAAC) which is has better results for static problems the conventional method of computing field statics has been implemented and the result is compared with elevation static. It is obtained by using uphole method (conventional method) yielded a significant improvement over the elevation method.

scholarly journals Time-Lapse Seismic Monitoring of Onshore Reservoirs in Niger Delta, Field ‘K’ as a Case Study

2017 ◽  
Vol 1 (1) ◽  
pp. 23-27 ◽  
Author(s):  
A. Ogbamikhumi ◽  
T. Tralagba ◽  
E. E. Osagiede
Keyword(s):  
Seismic Data ◽  
Acoustic Impedance ◽  
Niger Delta ◽  
Rock Physics ◽  
Time Lapse ◽  
Seismic Survey ◽  
Impedance Change ◽  
Data Set ◽  
Reservoir Fluid ◽  
4D Seismic

Field ‘K’ is a mature field in the coastal swamp onshore Niger delta, which has been producing since 1960. As a huge producing field with some potential for further sustainable production, field monitoring is therefore important in the identification of areas of unproduced hydrocarbon. This can be achieved by comparing production data with the corresponding changes in acoustic impedance observed in the maps generated from base survey (initial 3D seismic) and monitor seismic survey (4D seismic) across the field. This will enable the 4D seismic data set to be used for mapping reservoir details such as advancing water front and un-swept zones. The availability of good quality onshore time-lapse seismic data for Field ‘K’ acquired in 1987 and 2002 provided the opportunity to evaluate the effect of changes in reservoir fluid saturations on time-lapse amplitudes. Rock physics modelling and fluid substitution studies on well logs were carried out, and acoustic impedance change in the reservoir was estimated to be in the range of 0.25% to about 8%. Changes in reservoir fluid saturations were confirmed with time-lapse amplitudes within the crest area of the reservoir structure where reservoir porosity is 0.25%. In this paper, we demonstrated the use of repeat Seismic to delineate swept zones and areas hit with water override in a producing onshore reservoir.

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