Emulsion type determined from conductivity

The American Petroleum Institute recommends conducting acid sludge test API RP 42 before performing acidizing jobs in the field [39], These tests are used to determine the type and concentration of the surfactant (nonionic or anionic) needed to break acid-in-oil emulsions in a reasonable period of time. It is very important to perform the tests using live and spent acids at reservoir temperature. Spent acid should be prepared in the lab using formation rock. The live and spent acids should include acid additives as per field formula. The crude oil sample should be fresh, and free from water and oilfield chemicals (e.g., scale inhibitors, demulsifiers, etc.). 

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