Oligomer oils and their manufacture

A process for the selective production of an oligomer oil having predetermined properties comprising:

• (a) polymerizing a feed comprising one or more C3 to C20 olefins having at least one hydrogen on the 2-carbon atom, at least two hydrogens on the 3-carbon atom and at least one hydrogen on the 4-carbon (if 4 carbon atoms are present in the olefin), in the presence of a catalyst system comprising a bulky ligand transition metal complex of the stoichiometric Formula 1 and an activating quantity of an activator comprising an organoaluminum compound or a hydrocarbylboron compound or a mixture thereof:
• LmMXnX′p Formula 1
• wherein L is the bulky ligand, M is the transition metal, X and X′ may be the same or different and are independently selected from the group consisting of halogen, hydrocarbyl group or hydrocarboxyl group having 1-20 carbon atoms, wherein m is 1-3, n is 0-3, p is 0-3 and the sum of the integers m+n+p corresponds to the transition metal valency, to thereby form a product mixture comprising a distribution of products at least a fraction of which have properties that are outside of a predetermined range therefor, and
• (b) oligomerizing at least a pre-selected fraction of the product mixture formed in step (a) in the presence of an acidic oligomerization catalyst to thereby form the aforesaid oligomer oil;
• wherein the resulting product mixture comprises less than 35% by weight of oligomers that contain two or less monomeric units and at least 60% by weight of oligomers that contain three monomeric units.