Fault Seal Analysis

RMSFaultseal allows geologists and reservoir engineers to quickly and easily analyse sealing effects occurring in fault regions. Data representing the degree of sealing can be generated and used as basis for seal analysis or as input to a fl ow simulator. Uncertainty in fault sealing effects is properly handled and can be integrated into overall workfl ows. Characterization of sealing effects can signifi cantly improve the quality and speed of a simulation history match.

Powerful Fault Seal Analysis

Faults are typically included in reservoir models with a geometrical description, including displacement and fault juxtaposition. Fault sealing effects caused by shale smear or fault gouge are more often neglected, or simply handled manually as transmissibility multipliers by the reservoir engineer in a history matching process.

As shown in the fi gure below this is frequently inadequate and the engineer is then required to modify these by trial and error to improve the history match. Through the application of fault seal analysis techniques, both the quality of the reservoir model and the history match can be dramatically improved.

Faults can signifi cantly impact fl uid fl ow within the reservoir and the correct fault fl uid fl ow characterization is often critical to getting a good history match. Fault transmissibility multipliers areone of the factors which have historically been applied by reservoir engineers in an often slow process to get a history match. The history matching process can be signifi cantly speeded up and improved on many reservoirs through the use of Roxar’s fault seal analysis.

Faults also play an important part in the ultimate recovery and sweep effi ciency within the reservoir. Accurate characterization of fault properties ensures that the fi eld development plan and well locations are optimized for recovery and sweep effi ciency.

POOR HISTORY MATCH GOOD HISTORY MATCH

Simple Transmissibility multipliers Fauls seal analysis derived

transmissibility multipliers

Example taken from Svedrup et al. (2003)

RMSFaultseal is part of the RMS workfl ow which has been designed as a truly integrated reservoir interpretation and modeling solution. No other single application brings this degree of integration across so much of the reservoir characterization workfl ow. Multiple disciplines are not just using shared data but also sharing a single application.

IN SUMMARY

• Prediction of fault sealing effects with industry standard models

• Generates fault transmissibility multipliers

• SGR curves from fault property databases can be used as input

• Advanced visualisation of fault zone properties

• Results can be exported to external fl ow simulators or used in integrated streamline or black oil simulations.

• Truly integrated and easy to use

ROXAR AS, GAMLE FORUSVEI 17, PO BOX 112, 4065 STAVANGER, NORWAY TELEPHONE +47 51 81 8800 FAX +47 51 81 8801 WWW.ROXAR.COM

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2014

Fault Seal Analysis

Choice of Fault Zone Permeability Algorithms

RMSFaultseal allows the user to choose the most appropriate fault zone permeability equation for their fi eld and data.Manzocchi et al. (1999)logKFZ = -4SGR – 1⁄4 log(D) * (1 – SGR)5Sperrevik et al. (2002)KFZ = a1*exp{-[a2SGR + a3*Zmax + (a4*Zf + a5)(1 - SGR)7]}

Shale Gouge Ratio (yellow) and Fault Permeability (blue) vizualized on fault faces

SGR Curves from Fault Property Databases

As an alternative to the pre-defi ned equations for fault zone permeability, information from fault property databases can be used where available. This offers the opportunity to use directly measured or analogue data, improving the quality of the results over standard published relationships.

Advanced Visualisation

All fault zone properties can be visualised on the faulted cell faces. These are easily displayed and can be fi ltered to show only the faults of interest. The results for all cells and part cells can be displayed for both hanging wall and footwall cell faces (as shown in the fi gure above).

Accurate Grid Based Calculations

RMS maintains a close link between the structural model and the 3D grid, and this can be utilised in the fault seal modelling. Geometric calculations involved in the fault seal modelling are performed using the structural model, giving a highly accurate result for all types of faults. Fault properties are calculated for all grid cells adjacent to user-selected faults.

Multiple fault seal jobs can be defi ned and executed, containing data set-up for individual or multiple faults. The jobs can be executed in workfl ows, where uncertainty in input parameters can also be investigated.

Flexible Output

The primary output for reservoir simulation is the fault transmissibility multipliers. Additional information such as transmissibility, shale gouge ratio and fault zone permeability can also be generated for QC and analysis.

RMSStream and RMSFlowsim

Results from fault seal analysis can be used directly in Roxar’s integrated simulation and streamlines solutions, RMSFlowsim & RMSStream. This allows the impact of the results to be quickly analysed and used directly within the model for development planning and recovery optimisation.

Export to Industry Simulators

Results can be easily exported to common industry simulators, ensuring seamless integration into your existing workfl ows. Finalresults from simulation can also be imported for further analysis and visualization, alongside the original reservoir model.

To learn more please visit www.roxarsoftware.com or emailus on rss.marketing@emerson.com.

References

Manzocchi, T., Walsh, J. J., Nell, P. & Yielding, G. 1999. Fault transmissibility multipliers

for fl ow simulation models. Petroleum Geoscience 5, 53-63.

Sverdrup E., Helgesen J., & Vold J. 2003. Sealing properties of faults and their infl uence on

water alternating-gas injection effi ciency in the Snorre fi eld, northern North

Sea. AAPG Bulletin, v. 87 (9), pp. 1437-1458.