API filtration test

Filtration. The API filtration test for oil-base muds usually gives an all-oil filtrate. The test may not indicate downhole filtration, especially in viscous oils. The alternative high-temperature-high-pressure (HT-HP) filtration test will generally indicate a pending mud problem by amount of fluid loss or water in the filtrate. 

If all the parameters on the right side are known with confidence, the porosity can be determined. This method was applied successfully in some field applications. Chin et al. (1986) gave an invasion porosity log that showed both qualitative and quantitative agreement with conventional neutron and density porosity logs. In the paper, the authors determined the asterisked properties of the mud using API filtration tests and obtained q-(t) from standard resistivity... 

Graphene oxide is a good filtration additive in water-based drilling fluids at concentrations as low as 0.2% by carbon content (29). Standard American Petroleum Institute (API) filtration tests were done with pH-adjusted, aqueous dispersions of graphene oxide and xan-than gum. 

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