The Efficiency of Local Bentonite as an Extender in Well Cementation

Nigerian local Bentonite has been in use since 2003 but has not gained wide acceptance in the petroleum industry because of its effects on most of the cement properties. However these effects have not been properly studied and modeled. This study involved the experimental and economic evaluation of some Nigerian local bentonite on fresh and salt water cement slurry properties. These properties were compared with those of the more traditional foreign bentonite.The Nigerian bentonite was beneficiated because of its natural state. Both bentonite proved effective in fresh water cement slurries and can mostly be used interchangeably except in cases where high rheology are required. For salt water slurry design local bentonite proved to respond better in rheology and free fluid test evaluation. Therefore with proper beneficiation and further research Nigerian local bentonite could be more efficient and cost effective as an extender in cement slurries.