Open Access

ARTICLE

Experimental Study on the Deep Profile Control and Oil Displacement Technology of Nanoscale Polymer Microspheres

Zhao Hua^1,2, Meiqin Lin^1,2, Zhaoxia Dong^1,2, Zihao Yang^1,2, Mingyuan Li^1,2, Jie Yang^1,2, Xiuling Ji^1,2

1 Enhanced Oil Recovery Research Institute, China University of Petroleum, Beijing 102249, China.
2 Key Laboratory of Enhanced Oil Recovery, CNPC, Beijing, 102249, China.

Structural Longevity 2013, 9(2), 119-129. https://doi.org/10.3970/sl.2013.009.119

Abstract

In this paper, scanning electron microscopy (SEM), dynamic lighting scattering (DLS) and HAAKE rheometer experiments were adopted for investigating on the shape, size and rheological property of nanoscale polymer microspheres. Besides, nuclear-pore film filtration, sand packed tube displacement and core displacement experiments were also adopted to study the mechanism of deep pro- file control and oil displacement of nanoscale polymer microspheres. The results demonstrated that the original shape of the nanoscale polymer microspheres were typically spherical with a size range of 30-60nm. When the microspheres were dispersed in water, the grain diameter of them increased by 3-6 times due to swelling and the poly-dispersed system appeared but the conformation of microspheres still kept spherical. In a certain range of shear rate, the microsphere dispersed system with the concentration of 100-900 mg/L showed apparent shear thickening behavior and would be favorable for increasing the flow resistance of displacing fluid. These microspheres dispersed systems exhibited effective plugging on 0.4µm pore-size nuclear pore film and deep plugging in core and had a higher tendency to form effective plugging to the high permeability layer and drive crude oil of the low permeability layer in parallel sand packed tubes. Cross-linked polymer microspheres could reduce water permeability because microspheres were adsorbed, accumulated and bridged in the pore-throat and the adsorbed layers would be collapsed by pressure and entered into reservoir deeply owing to microspheres’ good deformation property. Meanwhile these microspheres would drive crude oil on and in pores/throats while they transported in porous media and thereby achieved the coordinated and simultaneous effects of deep profile control and oil displacement and the ultimate purpose of improving oil recovery.

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Keywords

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