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APl Specification 13A 18th Edition, August 2010

Specification for Drilling Fluids-Specifications and Testing




Product : Low-viscosity polyanionic cellulose (PAC-LV)

Grade: Low-viscosity


Product Description:

API Specification 13A-17 1.1

PAC-LV, also referred to as PAC low-viscosity grade, is a water-solube polymer produced only from cellulose chemically reacted with carboxy-methyl (anionic) groups. The product obtained is further purified to significantly increase the active polymer content.

The product is free-flowing and/or granular powder.


API Specification 13A-17 1.2   

PAC-LV is widely used in water-based drilling fluids for a variety of applications, such as filtration control, viscosity and shale inhibition. Although field use can vary, this procedure focuses on filtration control and viscosity characteristics.


Product Physical Requirement:

API Specification 13A-17 1.7   

To obtain the best handling in the field, it is recommended   that the particle size for PAC LV powder be u 0,8 mm (u 20 mesh)


Technical Requirements: API Specification 13A-17 1.1

Product Rejection: It shall not contain any other polysaccharides such as starch, guar or other naturally occurring polymers or their derivatives.

API Specification 13A-17.1. 4   

PAC-LV shall be free of any foreign polymer. Therefore, a qualitative starch determination shall be performed. If starch is found, no further testing should be performed and the sample shall be rejected.


Filtrate Volume:

API Specification 13A-174 1.2 Footnote 13

API standard evaluation base clay is an example of a suitable product available commercially. Requests for clay should be directed to the API which will forward the request to a supplier for further handling. This inform convenience of users of this Internal Standard and does not constitute an endorsement by ISO of this product.


Table 16-PAC-LV physical requriements

Requirement Standard

Presence of starch or starch derivatives


Moisture Content 

Maximum 10%

Apparent Viscosity

Minimum 40cp

Filtrate Volume

Maximum 16ml