The Preparation and Performances of Self-Dispersed Nanomicron Emulsified Wax Solid Lubricant Ewax for Drilling Fluids

Abstract

An oil-in-water nanomicron wax emulsion with oil phase content 45 wt% was prepared by using the emulsifying method of surfactant-in-oil. The optimum prepared condition is 85°C, 20 min, and 5 wt% complex emulsifiers. Then the abovementioned nanomicron emulsifying wax was immersed into a special water-soluble polymer in a certain percentage by the semidry technology. At last, a solidified self-dispersed nanomicron emulsified wax named as Ewax, a kind of solid lubricant for water based drilling fluid, was obtained after dried in the special soluble polymer containing emulsifying wax in low temperature. It is shown that the adhesion coefficient reduced rate(ΔKf)is 73.5% and the extreme pressure (E-P) friction coefficient reduced rate(Δf)is 77.6% when the produced Ewax sample was added to fresh water based drilling fluid at dosage 1.0 wt%. In comparison with other normal similar liquid products, Ewax not only has better performances of lubrication, filtration loss control property, heat resistance, and tolerance to salt and is environmentally friendly, but also can solve the problems of freezing in the winter and poor storage stability of liquid wax emulsion in oilfield applications.

Novel Environmentally Friendly Lubricants for Drilling Fluids Applied in Shale Formation

“…The 0.25 wt % GO even increased the reduction rate of adhesion coefficient of WBDF to 93.31%, indicating the excellent lubricating ability of GO to the filter cake. According to corporate standards, when the lubricant can reduce the friction coefficient or adhesion coefficient by more than 50%, it can be used for drilling. , Therefore, 0.1 wt % GO was sufficient to meet the industrial requirements of drilling fluid lubricants. On the other hand, 2 wt % Gly-DES reduced the adhesion coefficient of WBDF by 59.74%, reflecting the potential of Gly-DES as a lubricant for drilling fluids.…”

“…The traditional drilling fluid lubricants such as hydrocarbons, fatty acids, mineral oil, asphalt, graphite powder, etc. generally have problems such as unsatisfactory lubrication effects, poor long-term wear resistance, toxicity, environmental unfriendliness, and serious foaming. − To solve the environmental protection problem, ester lubricants based on natural animal and vegetable oils as raw materials have been widely favored. ,− However, some ester lubricants containing aromatic hydrocarbons still have a certain fluorescence intensity, which brings inconvenience to logging work after drilling . Therefore, it is necessary to find new nontoxic and nonfluorescent materials that can be used as high-performance lubricants.…”