Lubricant compositions having two base oil stocks

A method for producing a circulating oil composition, the method comprising:

• optionally, preparing a base oil for a circulating oil composition by blending a first oil base stock for the base oil and a second oil base stock for the base oil, thereby forming the base oil, the base oil comprising:
• about 70 wt % to about 99.99 wt % of a first oil base stock, wherein the first oil base stock comprises an API Group II extra heavy oil base stock, the API Group II extra heavy oil base stock having:
• a kinematic viscosity (ASTM D445, 40° C.) of about 320 cSt to about 520 cSt,
• a kinematic viscosity (ASTM D445, 100° C.) of about 22 cSt to about 36 cSt,
• a viscosity index (ASTM D2270) of about 80 to about 119,
• a pour point (ASTM D97) of about −6° C. or less, and
• a saturate content (ASTM D7419) of about 90 wt % or greater;
• and
• about 0 wt % to about 30 wt % of a second oil base stock, wherein the second oil base stock comprises an API Group I oil base stock, the API Group I oil base stock having:
• a kinematic viscosity (ASTM D445, 100° C.) of about 2 cSt to about 15 cSt;
• providing the base oil;
• optionally, providing an R&O additive package, a pour point depressant, and/or an anti-foam additive;
• and
• optionally, blending the base oil with the R&O additive package, the pour point depressant, and/or the anti-foam additive.