Formulação de óleo de base, uso de um óleo de base leve derivado de fischer-tropsch, e, métodos para melhorar uma propriedade de uma formação de óleo de base e para preparar uma formulação de óleo de base

摘要

Base oil formulation containing a mineral derived base oil and a Fischer-Tropsch derived light base oil. The Fischer-Tropsch oil may be used to upgrade an under- processed mineral oil. The Fischer-Tropsch oil causes less of an increase in volatility than predicted by theory. It may therefore be used to improve a property of a base oil formulation containing a mineral derived base oil, the property being selected from cold flow properties, viscosity profile and oxidative stability, whilst still achieving a target maximum volatility X for the formulation, by adding to the formulation a concentration c of a Fischer-Tropsch derived light base oil, wherein c is higher than the maximum concentration c' of the Fischer-Tropsch derived light base oil which theory would predict could be added without increasing the volatility of the formulation above the target maximum X.