Abstract

"Simultaneous water and gas" (SWAG) injection is the effective method of enhanced oil recovery. However, until recently the effect of SWAG in the development of heavy oil fields has been studied insufficiently.

In the present study laboratory researches have confirmed that SWAG injection when 25% gas content in the mixture significantly increases the displacement efficiency of heavy oil with the viscosity 217 mPa*s of Russkoye deposit, compared with water flooding. It has allowed extending the effective application of SWAG as a non-thermal method of enhanced oil recovery more than twice.

According to the results of laboratory experiments to pre-extracted and not extracted core material, it was found that the degree of hydrophobic pore surface, which depends on the adsorption of polar components of oil, significantly affect the oil displacement efficiency when SWAG implementing.

It was established that SWAG at the optimum gas content is effective for both hydrophilic and hydrophobic environments. The values of the heavy oil displacement efficiency for the hydrophilic core material of Russkoye field are about 1.8 times higher than for hydrophobic.

The technology for SWAG injection from the use of mono-block multistage pump-ejecting systems has been developed. The technology can significantly improve the systems efficiency and the process of water-gas mixtures delivering into injection wells.

The obtained results allow creating non-thermal energy-efficient methods for developing and improving oil recovery of heavy oil fields.

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