Stimuli-Responsive Rubber in Oil and Gas Application

This paper presents stimuli responsive fillers in rubber composite materials for various Oil and Gas applications. Specially relates to the fly ash to improve filler dispersion and to enhance the effectiveness of load transfer from polymer matrix to the reinforcing filler. The stimuli-responsive rubber composite shows improved mechanical properties (e.g. modulus) when swelled in water. Apart from cost effectiveness, these composites can show stimuli-responsive property. Fly ash (Class C) is a common component of Portland cement which can be used to achieve a stimuli-responsive effect when added to HNBR rubbers as filler. Exposure to the water brines causes the filler to grow in volume and mass and promotes an increase in pH which enables the hydrolysis of HNBR nitrile groups into carboxyl groups, thus, creating an ionomer. This process is followed by neutralization of the new ionomer with metal ions and formation of ionic crosslinks, further improving mechanical properties of the rubber. This paper presents by using certain classes of fly ash as effective reinforcing filler allows to develop swellable seals that can retain or even increase their modulus and stiffness during swelling. Therefore one can avoid the loss of mechanical properties by seals due to swelling and also eliminate the need to create large swellable packing elements that occupy additional space downhole.