Society of Petroleum Engineers Norbert P. Szabó and Mihály Dobróka Department of Geophysics University of Miskolc dobroka@uni-miskolc.hu
Foreword Formation Evaluation Using Well-Logging Data Petrophysical Properties of Formations Interval Inversion as New Joint Inversion Procedure Improving Accuracy of Petrophysical Parameters Layer-Thickness and Morphology Determination Textural Parameters of Formations Petrophysical Parameters of Complex Reservoirs 2
Petrophysical Model Model Parameters Φ(S w +S g +S o ) Porosity (POR, POR2, PORT) Water Saturation (SX0, SW) Shale Volume (VSH) Mineral Content (VMA) Derived Quantities (SCHM, SCHR, PERM) Well-Logging Data Spontaneous Potential (SP) Natural Gamma Ray (GR) Spectral Natural Gamma Ray (K, U, TH) Neutron Porosity (CN) Density (DEN) Acoustic Traveltime (AT) Resistivity (RM, RS, RD) V sh sh = V cl cl +V si V ma =ΣV ma,i +V cem 3
Workflow of Inversion No Yes 4
Interval Inversion Depth Dependent Model Response d (CALC) k (z) = g k ( m (z),m (z), K, m (z)) (k : probe types) Model Discretization by Series Expansion 2 M m (z) = i J i j= B (i) j Ψ (z) j (i :petrophysical parameters) Solution of Forward Modeling d (CALC) k (z) = g k (POR ) (POR) (VMA) (VMA) ( z,b, K, B, K, B, K, ) J B J Optimum Search by Subsequent Combination of Linear (WLSQ) and Global Optimization Methods (Simulated Annealing or Genetic Algorithm) M 5
Benefits of Interval Inversion High Data-to to-unknowns Ratio Improvement in Parameter Estimation Introducing New Inversion Unknowns Automatic Estimation of Layer-Boundaries Estimation of Zone Parameters Estimation of Complex Lithologies 6
Synthetic Tests Input Data Set Inversion Results 7
Estimation of Layer-Thicknesses MOL Hungarian Oil and Gas Company Interval Inversion xx75 xx00 8
2D Interval Inversion Layer No. Parameter Value x x - -0.6-0.2 0.2 0.6 - W- -0.6 W-2-0.2 W-3 0.2 W-4 0.6 W-5 W-6 W- W-2 W-3 W-4 W-5 W-6 0 0 2 2 2 POR 0.049 SX0 0.998 VSH 0.82 VSD 0.05 POR 0.30 SX0 0.80 VSH 0.02 VSD 0.63 POR 0.049 z z 4 4 6 6 SX0 0.997 3 VSH 0.096 VSD 0.05 Boundary Coefficient Value B0 3.32 B 0.40 B2-0.5 8 8 B3 0.25 B4-0.5 0 0 2 B20 7.20 B2 2.65 B22-0.59 B23 0.97 B24-0.6 9
Estimation of Textural Parameters MOL Hungarian Oil and Gas Company Interval Inversion 0
Evaluation of Complex Reservoirs MOL Hungarian Oil and Gas Company Interval Inversion
Summary New Alternative to Increase the Potential of Well- Logging Evaluation Methods Joint Inversion of (Multi-) ) Wellbore Data Improvement in Accuracy, Reliability and Robustness Interval Inversion for New Unknowns as Reservoir Parameters Independent Petrophysical Information for Inversion (Shale Volume Determination by Factor Analysis) Developments in the Future (Integrating Factor Analysis Results, More Zone Parameters as Inversion Unknowns, 3D Morphology Determination) 2
Acknowledgments The described work was carried out as part of the TÁMOPT MOP- 4.2..B-0/2/KONV 0/2/KONV-200-000000 project in the framework of the New Hungary Development Plan. The realization of this project is supported by the European Union, co-financed by the European Social Fund Authors Thank the Support of Hungarian Oil and Gas Company for Long-Term Cooperation and Providing Field Data First Author is Grateful for the Support of the János J Bolyai Research Fellowship of the Hungarian Academy of Sciences 3
geofizika@uni-miskolc.hu