time - lapse gravity inversion using genetic algorithm (2 bit)
DESCRIPTION
TIME - LAPSE GRAVITY INVERSION USING GENETIC ALGORITHM (2 BIT). EKO JANUARI WAHYUDI Supervised by: Dr. Wawan Gunawan A Kadir Dr. Hendra Grandis. OUTLINE. INTRODUCTION 4D MICROGRAVITY FLUID SUBSTITUTION GENETIC ALGORITHM PERFORMANCE TEST REAL DATA INVERSION CONCLUSION. - PowerPoint PPT PresentationTRANSCRIPT
TIME-LAPSE GRAVITY INVERSION USING GENETIC ALGORITHM (2 BIT)
EKO JANUARI WAHYUDI
Supervised by:Dr. Wawan Gunawan A Kadir
Dr. Hendra Grandis
• INTRODUCTION• 4D MICROGRAVITY• FLUID SUBSTITUTION• GENETIC ALGORITHM• PERFORMANCE TEST• REAL DATA INVERSION• CONCLUSION
OUTLINE
INSTITUT TEKNOLOGI BANDUNG
INSTITUT TEKNOLOGI BANDUNG
• As technology advance gravimeter also improve in accuracy and give the possibility to monitor pore fluids redistribution in permeable layer.
• Especially in Indonesia, 4D microgravity becomes considerable choice because: (1) relatively cheaper, (2) strong response (in many cases), (3) fast in acquisition, (4) less social and environmental conflict.
• Focus of this study is inversion programming using genetic algorithms (GA's).
• This study was inspired by publication Krahenbuhl & Li (2008). They used binary formulation to inverse borehole and surface gravity data.
INTRODUCTION
INSTITUT TEKNOLOGI BANDUNG
INSTITUT TEKNOLOGI BANDUNG
• Pore fluids (gas, oil, & water) are subject in gravity forces, because they have different densities.
• Mass redistribution will cause changes in the gravity attraction.
4D MICROGRAVITY
INSTITUT TEKNOLOGI BANDUNG
INSTITUT TEKNOLOGI BANDUNG
Δρmax = 00.060 0.297 0.237 (in g/cc)
Assumption:Porosity = 30%Water Density = 1.00 g/ccOil Density = 0.80 g/ccGas Density = 0.01 g/cc
FLUID SUBSTITUTIONINSTITUT TEKNOLOGI BANDUNG
INSTITUT TEKNOLOGI BANDUNG
• GA is optimization method that combines biology genetic concept with optimization function maximize fitness through artificial evolution process
• Genetic algorithm using the principal of survival for the fittest
GENETIC ALGORITHM
INSTITUT TEKNOLOGI BANDUNG
INSTITUT TEKNOLOGI BANDUNG
Krahenbuhl (2005)
• GA does not need any derivatives or curvature information• GA's strongly can handle non-linier inversion and give sharp
characterization of fluid contact movement in permeable layer.
GENETIC ALGORITHM
INSTITUT TEKNOLOGI BANDUNG
INSTITUT TEKNOLOGI BANDUNG
The objective function
GA’s RESULTS
INSTITUT TEKNOLOGI BANDUNG
INSTITUT TEKNOLOGI BANDUNG
Inversion Result
Krahenbuhl & Li (2009)
Data Observation
Inversion Performance
1 BIT, 2 BIT
INSTITUT TEKNOLOGI BANDUNG
INSTITUT TEKNOLOGI BANDUNG
1 bit Inversion
n=2 bit Inversion
PERFORMANCE TEST
INSTITUT TEKNOLOGI BANDUNG
INSTITUT TEKNOLOGI BANDUNG
Inversion ResultSynthetic Model
REAL DATA INVERSION
INSTITUT TEKNOLOGI BANDUNG
INSTITUT TEKNOLOGI BANDUNG
Inversion Result
Data Observation
• Genetic algorithm can be applied in 4D gravity inversion• Using 2 bit GA inversion give the possibility to characterize 3 type
density changes in reservoir• Inversion results from real data show the characterization of mass
increase, mass decrease, and stable zone in permeable layer
CONCLUSION
INSTITUT TEKNOLOGI BANDUNG
INSTITUT TEKNOLOGI BANDUNG
THANKS