Effect of Drilling Fluid (Water-Based vs Oil-Based) on Phase Trap Damage in Tight Sand Gas Reservoirs.pdf

SPE 154652
Effect of Drilling Fluid (Water-Based vs Oil-Based) on Phase Trap Damage
in Tight Sand Gas Reservoirs
Mitchel Tsar, Hassan Bahrami, Reza Rezaee, Geeno Murickan, Sultan Mehmood, Mohsen Ghasemi,
Abolfazl Ameri, Mahna Mehdizadeh, Curtin University
Copyright 2012, Society of Petroleum Engineers

This paper was prepared for presentation at the EAGE Annual Conference & Exhibition incorporating SPE Europec held in Copenhagen, Denmark, 4–7 June 2012.

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Abstract
Tight gas reservoirs are mainly characterized by low matrix permeability and significant damage. During drilling and
fracturing of tight formations, wellbore liquid invades into tight formation and increases water saturation around wellbore
and eventually reduces permeability near wellbore or adjacent to fracture wings. The damage to permeability caused by
invasion of liquid into tight formation is controlled by capillary pressure and relative permeability curves.
The phase trap damage is one of the main concerns in use of water based drilling or fracturing fluid, since due to high critical
water saturation, strong capillary pressure, and sensitivity of tight sand to water. Therefore, use of oil based mud may be
preferred in drilli