The Siberian Federal University, together with the Novosibirsk State University, developed a model for the extraction of oil with a nano liquid from microporous materials.
Results showed that the efficiency rating of extracting oil is considerably higher if nano particles are added to the oil being extracted – rather than water. As demonstrated by the scientists, the water moves through the material saturated in oil in the form of separate streams at the same time that the nano liquid extracts the oil with a homogeneous front.
What is more, a large share of all known world oil reserves are located in sand formations and the extraction method involves flooding the stratum concerned. The liquid used in this process is water or solutions of surfactants — substances which tend to reduce the surface tension of a liquid in which they are dissolved. And the efficiency rate of extraction in this process is 25-40 %.
Oil industry experts also use methods like a steam thermal effect on the stratum, combustion within the stratum, extraction with hot water, removal of air from within the stratum and others. All of these, however, may not prove to be efficient enough.
“We used for our model experimental measured readings of interfacial tension and the wetting angle on the edge of the oil -rock formation-nano liquid. As a nano liquid we used a water suspension with nano particles of silicon oxide – with an average size of five nanometres. The concentration of nano particles varied from 0 to 1 MAC %. For example, a nano suspension of 1 Mac. % SiO2 with a size of five nanometres more than doubled the coefficient when compared with ordinary water. And this occurred solely because of an improved process of wetting the rock formation,” said Vladimir Zhigarev, co-author of the research and a laboratory researcher for physics-chemistry technologies involving difficult of access hydrocarbon reserves.
The nano liquid moves on the porous material on a single, homogeneous front throughout the entire estimated surface area. And if the water comes through to the edge of the estimated area at approximately one second from the beginning of the flowing process of the stratum, the nano liquid with a concentration of particles of 1 Mac. 5 makes that burst occur over the course of approximately 1.8 seconds, the researchers said.
“As a result of the use of the nano liquid, a considerably larger volume of porous rock is collected through the extraction movement. It therefore follows that a greater amount of oil is washed out from the rock. This research confirms the good prospects for the use of nano particles for developing current and planned deposits,” Zhigarev said.