Abstract:

Fault seal analysis has been used for a gas condensate field in the Cuu Long Basin to study the fault seal influence on fluid compartmentalization and flow retardation. Fault seal capacity is evaluated based on many factors, including shale gouge ratio (SGR), juxtaposition, fault throw, fault thickness, fault permeability and the effect of diagenesis. The results of such analyses are used as input for calculating the fault transmissibility multiplier (TM), which is used in the simulation model for mimicking the flow retardation effect of faults. The 3D fault model analysis and TM calculation are done using the RMS modeling software. The fault TMs are then validated through history matching on a production simulation model. It has been found that despite having low SGR, low displacement and fault thickness, which imply leaking faults, diagenesis due to great burial depth (>3.5km) has significantly enhanced the sealing potential, leading to most faults having high sealing capacity. The Sperrevik method for estimating fault permeability was found to be the most appropriate in calculating fault TM for the simulation model of reservoirs with high burial depth. Using fault TM calculated from fault seal model help to not only evaluate the fault seal capacity faster and more accurately, but also reduce subjectivity in the evaluation process.