The Application of Nanoparticle Dispersions to Remove Paraffin and Polymer Filter Cake Damage

Abstract

The use of stabilized nanoparticle dispersions (NPDs) containing silica particles between 4-20 nm in diameter have been shown to be effective at removing skin damage associated with paraffin blocks, as well as polymer based treating and stimulation fluids. The arrangement of particles at the three phase interface into structural arrays promotes lifting of the damage from the surface, stimulating the reservoir. Aqueous dispersions of nanoparticles used in conjunction with traditional remedial methods can effectively remove damage near the wellbore to be produced out of the well, instead of dissolution and potential displacement of the damage further into the formation. Many of the declining oil fields around the world owe a significant portion of their decreased production to formation damage. Usually, this damage is indicative of naturally occurring blocks, like paraffin, or as a result of intervention processes that occur over the lifetime of a well during drilling, stimulation, or intermittent remediation treatments. Eventually, the well can become damaged to the point it is no longer economically viable. This paper will show lab and field results that indicate aqueous nanoparticle dispersions are a capable, and efficient additive for stimulating a damaged well by removal of skin from the surface of reservoir rock. This effect is due to a unique force called disjoining pressure, which causes particles at the nanometer-scale to force themselves between organic matter and the substrate at the interface of the treating fluid. This force promotes the separation of an organic phase from a rock surface.