Pm (phenolphthalein alkalinity mud filtrate) Mf (methyl orange end point alkalinity mud filtrate)

Pf represents the alkalinity of the phenolphthalein mud filtrate. Pf is different from Pm, because it tests the affect of bases and salts do. However, Pm includes the effect of both dissolved and undissolved salts and bases in the drilling mud .

 

 

Mf represents the end point of methyl orange alkalinity of the mud filtrate and the definition of alkalinity to methyl orange is the acid amount used to reduce the pH to 4.3 . According to the API test, you'll see Pm, Pf and Mf are displayed in the report of sludge per day and all amounts are expressed in cubic centimeters of 0.02 N sulfuric acid per cubic centimeter of fluid sample drilling.

 

Pf and Mf tests are based mud filtrate that will help us know the ions in the drilling mud.

 

Let me explain each case and what it means as follows;

 

First case: if you see that the Pf and Mf are roughly the same, the ions (hydroxyl ions) is the major contributor to the alkalinity of the mud.

 

Second case: if you have any bicarbonate ions (), The test results indicates that the FP is low but the high Mf.

 

Third case: if you see two numbers (Pf and Mf) are high, it means you have carbonate ions () In the system.