Patent ID: 8375773

Claim:
A method of determining the wettability of a surface under predetermined conditions, wherein the surface simulates or is a downhole surface for use in an oil or gas operation, the method comprising the steps of: (A) selecting a first fluid wherein the first fluid simulates or is a downhole fluid for use in an oil or gas operation; (B) contacting the surface with the first fluid under first predetermined conditions, (i) wherein the first fluid comprises: (a) a first base fluid, wherein the first base fluid is aqueous, and wherein the first base fluid has one or more reflected, emitted, or excited to be emitted observable properties; and (b) a first marker, (ii) wherein the first marker is soluble in the first base fluid, and wherein the first marker reflects, emits, or is excited to emit a first observable property, (iii) wherein the first observable property is distinguishable from the reflected, emitted, or excited to be emitted observable properties of the first base fluid, and wherein the first observable property is electromagnetic radiation or radioactivity, and (iv) wherein the first predetermined conditions comprise: (a) a shear rate; (b) a time; and (c) a temperature; (C) separating the surface from the first fluid, wherein after the step of separating, a film of the first fluid can remain on the surface; and (D) observing the surface for the presence or absence of the first marker to determine the wettability of the surface.