TY  - JOUR
A1  - Amour, Frederic
A1  - Mutti, Maria
A1  - Christ, Nicolas
A1  - Immenhauser, Adrian
A1  - Agar, Susan M.
A1  - Benson, Gregory S.
A1  - Tomas, Sara
A1  - Alway, Robert
A1  - Kabiri, Lachen
T1  - Capturing and modelling metre-scale spatial facies heterogeneity in a Jurassic ramp setting (Central High Atlas, Morocco)
JF  - Sedimentology : the journal of the International Association of Sedimentologists
N2  - Each simulation algorithm, including Truncated Gaussian Simulation, Sequential Indicator Simulation and Indicator Kriging is characterized by different operating modes, which variably influence the facies proportion, distribution and association of digital outcrop models, as shown in clastic sediments. A detailed study of carbonate heterogeneity is then crucial to understanding these differences and providing rules for carbonate modelling. Through a continuous exposure of Bajocian carbonate strata, a study window (320 m long, 190 m wide and 30 m thick) was investigated and metre-scale lithofacies heterogeneity was captured and modelled using closely-spaced sections. Ten lithofacies, deposited in a shallow-water carbonate-dominated ramp, were recognized and their dimensions and associations were documented. Field data, including height sections, were georeferenced and input into the model. Four models were built in the present study. Model A used all sections and Truncated Gaussian Simulation during the stochastic simulation. For the three other models, Model B was generated using Truncated Gaussian Simulation as for Model A, Model C was generated using Sequential Indicator Simulation and Model D was generated using Indicator Kriging. These three additional models were built by removing two out of eight sections from data input. The removal of sections allows direct insights on geological uncertainties at inter-well spacings by comparing modelled and described sections. Other quantitative and qualitative comparisons were carried out between models to understand the advantages/disadvantages of each algorithm. Model A is used as the base case. Indicator Kriging (Model D) simplifies the facies distribution by assigning continuous geological bodies of the most abundant lithofacies to each zone. Sequential Indicator Simulation (Model C) is confident to conserve facies proportion when geological heterogeneity is complex. The use of trend with Truncated Gaussian Simulation is a powerful tool for modelling well-defined spatial facies relationships. However, in shallow-water carbonate, facies can coexist and their association can change through time and space. The present study shows that the scale of modelling (depositional environment or lithofacies) involves specific simulation constraints on shallow-water carbonate modelling methods.
KW  - 3D facies modelling
KW  - carbonate ramp
KW  - facies heterogeneity
KW  - Jurassic
KW  - modelling algorithms
KW  - scale
Y1  - 2012
U6  - https://doi.org/10.1111/j.1365-3091.2011.01299.x
SN  - 0037-0746
VL  - 59
IS  - 4
SP  - 1158
EP  - 1189
PB  - Wiley-Blackwell
CY  - Malden
ER  -