Experimental Investigation of the Matching Relationship between Asphalt Particle and Reservoir Pore in Profile Control Process

Abstract EN

Modified sulfonated asphalt particles have a bright application prospect of the profile control of thick reservoirs due to the low cost, extensive sources, and good compatibility with reservoir.

Nevertheless, the matching relationship between asphalt particles and reservoir pore has seldom been investigated till now.

Oversized particles always block the near-wellbore area, which causes high injection pressures, while undersized particles cannot plug large pores.

We designed a core for this experiment which has a high permeability zone in front of it and many pressure measuring points.

We could quantitatively assess the matching relationship by measuring the on-way resistance coefficient, residual resistance factor, and relative change of permeability of man-made cores after injecting asphalt.

Experimental results indicate that asphalt particles with sizes of 0.02 mm, 0.02–0.06 mm, and 0.08–0.1 mm match with reservoir permeability of 500 mD, 1000 mD, and 2000 mD, respectively.

Undersized or oversized particles can reduce the conformance control effect, and the concentration of asphalt particles in the injectant can limit their migration ability.

When the concentration of asphalt particles increases to 3000 mg/L, accumulations of asphalt particles can be caused in the formation, in which a scheme with asphalt particles alternative water injection is proposed to avoid the accumulation.