A Study of Wettability and Permeability Change Caused by Adsorption of Nanometer Structured Polysilicon on the Surface of Porous Media

Abstract

TX 75083-3836, U.S.A., fax 01-972-952-9435. AbstractA nanometer (10 -9 m) structured particle material, generally so defined that the diameter of the particle is no more than 100nm, has some special physical efficacy in its surface, small size and other properties. One kind of polysilicon with sizes ranging from 10~500nm, and considered as nanometer or sub nanometer sized powder, was used in oilfields to enhance water injection by changing wettability of porous media. The mechanism of enhancing water injection is through improving relative permeability of the water-phase by changing wettability induced by adsorption of polysilicon on the porous surface of sandstone. On the other hand, the adsorption on the porous surface and plugging at the small pore throats of the polysilicon may lead to reduction in porosity and absolute permeability (K) of porous media for pore sizes from 100 to 1000,000nm. Thus the degree of success in well treatment is determined by the improvement of effective permeability of the water-phase.In this paper a mathematical model, which was combined with the study of experiments in the laboratory, is presented and a simulator is developed to simulate water injection dynamics under the conditions of polysilicon injection. The simulator can accurately simulate the process of migration and adsorption in the pore bodies and blocking at the pore throat of the polysilicon in the sandstone. A series of numerical simulation runs was conducted to study the effect of a wide range of parameters, such as the sandstone with different permeabilities, concentration of the polysilicon, injection volumes, and others. The effective permeabilities of the waterphase measured by a number of core flooding experiments are matched well by the numerical results. Since April 2000, nine well treatments with solvent slugs of suspended polysilicon particles in several oilfields in China was shown to be successful and the average injection rate increased 5 times after treatments. chemical properties and chemical equilibrium systems for nanometer powder.Analogously, sand rock, which is composed of grains with different sizes, is porous media deposited under the combination of consolidation and compaction throughout a long geological period, and also has large specific surface area. Since the property of the surface of minerals determines the wettablity of porous walls, and the wettability of reservoir rock governs, to a great extent, the location, flow, and distribution of oil, water, and gas in a reservoir, the distributive characteristics, relative permeability of water and oil and flow dynamics of fluids in porous media can be changed by modifying the wettability of porous walls. Accordingly, the process of development of a reservoir can be improved by wettability modification.

Experimental investigation of SiO2 nanoparticles on enhanced oil recovery of carbonate reservoirs

“…These Nanoparticles have a great potential for increasing pore scale displacement efficiency (Ju and Fan 2009;Onyekonwu and Ologo 2010). Application of these Nanoparticles for enhancing oil recovery in water-wet sandstone systems is well documented in the literature (Ju et al 2002(Ju et al , 2006Ju and Fan 2009;Onyekonwu and Ologo 2010;Wang et al 2010). However, from the view of the literature in this field, only few papers address the application of these Nanoparticles in wettability alteration of carbonate systems (Maghzi et al 2011).…”

“…Numerous experimental works have been published discussing the role of chemical agents in wettability alteration of porous media Strand et al 2003;Standnes and Austad 2003;Hognesen et al 2004;Mohan et al 2011;Ravari et al 2011;Tabrizy et al 2011). However, the role of Nanoparticles in this field is still in its infancy and consequently has attracted the attention of many researchersin last decade due to their specific characteristics (Ju et al 2002(Ju et al , 2006Shen and Resasco 2009;Zhang et al 2010;Suleimanov et al 2011). Silicon dioxide (SiO 2 ) Nanoparticles are very promising materials and can be used in the near future for enhanced oil recovery.…”

Application of Nanoparticles in Enhanced Oil Recovery: A Critical Review of Recent Progress

“…Despite the very large effort, by changing the physical properties of media and geometry, it is required to conduct new experiments to estimate the coefficient existed in the mathematical model equations. Moreover, Ju et al [116] presented mathematical models regarding changes in reservoir properties (porosity and absolute permeability) due to adsorption of NPs. However, the mathematical modeling of such processes is still very complex and still requires novel description and solution methods.…”

Numerical investigation of nanoparticles transport in anisotropic porous media

“…The transport of nanoparticles in size interval i is governed by, (Ju et al, 2002, Ju and Fan, 2009, Liu and Civan, 1994, El-Amin et al, 2012a,b, 2013,…”