Uncertainty in Fluid Substitution Using Gassmann's Equation and Implication for DHI Analysis and Time-Lapse Monitoring

2012 ◽  
Author(s):  
Okey Ileka
Keyword(s):  
Time Lapse ◽  
Fluid Substitution

Time-lapse well log analysis, fluid substitution, and AVO

2003 ◽  
Vol 22 (6) ◽  
pp. 550-566 ◽  
Author(s):  
Ying Zou ◽  
Laurence R. Bentley
Keyword(s):  
Time Lapse ◽  
Log Analysis ◽  
Fluid Substitution ◽  
Well Log ◽  
Well Log Analysis

scholarly journals TIME-LAPSE POROSITY AND VELOCITY ANALYSIS USING ROCK PHYSICS MODELS IN NIGER DELTA, NIGERIA

2021 ◽  
Vol 5 (2) ◽  
pp. 47-52
Author(s):  
Emmanuel Aniwetalu ◽  
Akudo Ernest ◽  
Juliet Ilechukwu ◽  
Okechukwu Ikegwuonu ◽  
Uzochukwu Omoja
Keyword(s):  
Oil And Gas ◽  
Seismic Velocity ◽  
Water Saturation ◽  
Rock Physics ◽  
Time Lapse ◽  
Fluid Substitution ◽  
Average Value ◽  
Velocity Models ◽  
Fluid Properties ◽  
Average Water

The analysis of 3-D and time-lapse seismic data in Isomu Field has offered the dynamic characterization of the reservoir changes. The changes were analyzed using fluid substitution and seismic velocity models. The results of the initial porosity of the reservoirs was 29.50% with water saturation value of12%.The oil and gas maintained saturation values of 40% and 48% with average compressional and shear wave velocities of 2905m/s and 1634m/s respectfully. However, in fluid substitution modelling, the results reflect a change in fluid properties where average gas and oil saturation assume a new status of 34% and 24% which indicates a decrease by 14% and 16% respectively. The average water saturation increases by 30% with an average value of 42%. The decrease in hydrocarbon saturation and increase in formation water influence the porosity. Thus, porosity decreased by 4.16% which probably arose from the closure of the aspect ratio crack due to pressure increase.

Sensitivity study of rock-physics parameters for modeling time-lapse seismic response of Norne field

Geophysics ◽  
2013 ◽  
Vol 78 (6) ◽  
pp. D511-D523 ◽  
Author(s):  
Amit Suman ◽  
Tapan Mukerji
Keyword(s):  
Seismic Response ◽  
Pore Pressure ◽  
History Matching ◽  
Joint Inversion ◽  
Rock Physics ◽  
Clay Content ◽  
Time Lapse ◽  
Fluid Substitution ◽  
Seismic Modeling ◽  
Sensitive Parameters

Time-lapse seismic modeling is an important step in joint inversion of time-lapse seismic and production data of a field. Rock-physics analysis is the basis for modeling the time-lapse seismic data. However, joint inversion of both types of data for estimation of reservoir parameters is highly nonlinear and complex with uncertainties at each step of the process. So it is essential, before proceeding with large-scale history matching, to investigate sensitive rock-physics parameters in modeling the time-lapse seismic response of a field. We used the data set of the Norne field to investigate sensitive parameters in time-lapse seismic modeling. We first investigated sensitive parameters in the Gassmann’s equation. The investigated parameters include mineral properties, water salinity, pore pressure, and gas-oil ratio. Next, we investigated parameter sensitivity for time-lapse seismic modeling of the Norne field. The investigated rock-physics parameters are clay content, cement fraction, average number of contact grains per sand, pore pressure, and fluid mixing. We observed that the average number of contact grains per sand had the most impact on time-lapse seismic modeling of the Norne field. The clay content was the most sensitive parameter in fluid substitution for calculating seismic velocities of the Norne field. Salinity and pore pressure had minimal impact on fluid substitution for this case. This sensitivity analysis helps to select important parameters for time-lapse (4D) seismic history matching, which is an important aspect of joint inversion of production and time-lapse seismic modeling of a field.

Sign in / Sign up

Export Citation Format

Share Document