Improving the Properties of Bentonite as Blocking Agent for Heterogeneous Reservoirs

It is well known that blocking agents are used in order to boost up the oil
production in high water cut wells by injecting the corresponding agents into the
wellbore which retard the water influx across the permeable zones. In this project
bentonite has been chosen as the best potential agent for plugging water permeable
routes, as it acts as a water expandable material in drilling fluid solution which can
expand up to several times than its initial size. As a solution for the water production
issue the cheaper and more effective blocking agent will be developed. In order to
improve the behavior of blocking agent and make it feasible for different reservoir
conditions, bentonite was coated with surfactant. The main goal of the project is to
examine the bentonite as potential pore block agent, as well as it intends to evaluate
performance of bentonite coating by using surfactant and to compare performance of
enhanced bentonite with other established blocking agents. The present study reports
the effect of anionic surfactant sodium dodecyl sulfate (SDS, C12H25 OSO3Na)
upon the stability (dispersion) and rheological (viscosity, yield value) properties of
the nanoclay, hydrophilic bentonite in presence of NaCl. The SDS dispersant was
added in different concentrations in the range of 0.01% w/w to 0.40% w/w. The
results show that the viscosity and zeta potential values of bentonite dispersion are
affected by the addition of anionic surfactant.