Preparation And Hydrophobic Performances Of Hydrophobic Type Quartz Sand

Fracturing and sand control has the double effects of sand control and stimulation as a new technology, it is suitable for medium and high permeability, severe sand processing and pollution formations. The paper is about the hydrophobic transformation on the surface of the quartz in fracturing and sand control, the transformation to reduce liquid water output by changing the oil and water flow state in quartz sand packed layer. First we use cationic surfactants and anionic surfactants to treat quartz surface, research the factors and rules of wettability, use the contact angle as evaluation criteria to study the influence of surfactant concentration, pH value, temperature, inorganic cations and the soaking time to the surface wettability after treated, then measure the surface tension and adsorption capacity. The experiment results show that cationic surfactant has better hydrophobic effect than anionic surfactant, its surface contact angle can reach 73.2° after treated. Then we manufacture hydrophobic type quartz sand by using OTS self-assembly, measure its acid solubility and crushing rate. The treatment decreases the acid solubility. In physical simulation experiment, we introduce the concept of NFRR value to evaluate the hydrophobic effect, the results show that the NFRR value of quartz sand can reach 2.531 after putting it into OTS/Toluene solution for an hour, hydrophobic effect can achieve the best. We compare hydrophobic type quartz sand with untreated quartz sand and CTAB treated quartz sand, find the hydrophobic effect of hydrophobic type quartz sand is obvious, then we conduct continuous displacement of deionized water to hydrophobic type quartz sand, find its permeability is substantially unchanged and surface properties keep stable.