Characterizing the base oil of a drilling mud for compatibility with subsequent subterranean operations

A method comprising:

• providing a drilling fluid that comprises a base oil;
• using the drilling fluid to drill at least a portion of a wellbore penetrating at least a portion of a subterranean formation;
• measuring a compositional characteristic of the base oil using one or more analytical tests;
• determining whether the base oil is a compatible base oil or an incompatible base oil based at least in part on a comparison of the compositional characteristic of the base oil with one or more known compositional characteristic of a known compatible base oil;
• injecting an amount of spacer fluid that comprises an amount of a surfactant into the wellbore, wherein the amount of the surfactant is increased if the base oil is an incompatible base oil;
• and
• injecting one or more cementing or completion fluids into the wellbore.

A method comprising:

• providing a drilling fluid that comprises a base oil;
• using the drilling fluid to drill at least a portion of a wellbore penetrating at least a portion of a subterranean formation;
• measuring a compositional characteristic of the base oil using one or more analytical tests;
• determining whether the base oil is a compatible base oil or an incompatible base oil based at least in part on a comparison of the compositional characteristic of the base oil with one or more known compositional characteristics of a known compatible base oil;
• providing one or more cementing or completion fluids, wherein the one or more cementing or completion fluids comprise a surfactant if the base oil is an incompatible base oil;
• and
• injecting the one or more cementing or completion fluids into the wellbore.