A Fully Coupled Numerical Poroelastic Model To Investigate Interaction Between Induced Hydraulic Fracture and Pre existing Natural Fracture in a Naturally Fractured Reservoir: Potential Application in Tight Gas and Geothermal Reservoirs
- Mohammad Mustafizur Rahman (U. of New South Wales)
- Document ID
- Society of Petroleum Engineers
- SPE Annual Technical Conference and Exhibition, 4-7 October, New Orleans, Louisiana
- Publication Date
- Document Type
- Conference Paper
- 2009. Society of Petroleum Engineers
- 5.8.7 Carbonate Reservoir, 5.8.1 Tight Gas, 4.6 Natural Gas, 3 Production and Well Operations, 1.2.2 Geomechanics, 5.8.6 Naturally Fractured Reservoir, 5.8.2 Shale Gas, 2.5.1 Fracture design and containment, 5.1.2 Faults and Fracture Characterisation, 3.2.3 Hydraulic Fracturing Design, Implementation and Optimisation, 4.1.2 Separation and Treating, 5.9.2 Geothermal Resources, 1.8 Formation Damage, 4.3.1 Hydrates
- 2 in the last 30 days
- 929 since 2007
- Show more detail
- View rights & permissions
|SPE Member Price:||USD 8.50|
|SPE Non-Member Price:||USD 25.00|
This paper investigates interaction of induced and pre-existing fracture by coupling wellbore, induced fracture and natural fracture in a poroelastic reservoir. Possibilities of fracture crossing, bending, arrest and shear dilation for various angles of approach are investigated under different scenarios: in-situ stress state, reservoir rock and fluid properties and characteristics of natural fracture.
The fully coupled poroelastic model and results of this study in particular have a beneficial application in the design and optimization of hydraulic fracture treatments in naturally fractured reservoirs, therefore tight gas reservoirs and enhanced geothermal systems. The model can be extended to design stimulation of naturally fractured reservoirs based on shear dilation (high pressure low injection rate).
In this paper we have demonstrated that natural fractures, faults and other discontinuities severely restrict propagation of an induced fracture. In-situ stress state, orientation and shear strength of pre-existing fracture prove to be most significant factors that influence the fracture propagation trajectory:
- Because of the poro-elastic formulation it was possible to investigate the change in stress state ahead of the fracture tip and evaluate whether the fracture is going to be attracted or rejected by the interface. It was observed that high leak off influences dilation of natural fracture ahead of the arrival of the induced fracture tip.
- Possibilities of fracture arrest increases with increase in high differential stress state and shear strength of pre-existing fractures.
- Fracture crossing is another dominating behaviour for natural fracture with small aperture while fracture dilating for natural fracture with larger aperture.
Fully coupled poroelastic modelling allowed us to gain new knowledge on interaction between induced and pre-existing fractures. This methodology and knowledge base will significantly improve our current approach to design and implement hydraulic fracture treatment in naturally fractured reservoirs.
Keywords: Hydraulic fracturing; Fracture interaction; Fracture geometry; In-situ stresses; Fracture orientation; Stress regime; In-situ stress; Coupled fluid and poroelastic medium.
|File Size||707 KB||Number of Pages||10|