Liquid Screen: Pickering Emulsion Templating as an Effective Route for Forming Permeable and Mechanically Stable Void-Free Barriers for Hydrocarbon Production in Subterranean Formations

Abstract

Gravel packs, most commonly occurring as sand slurries, are conventionally employed as a permeable solid layer in the annulus between a production screen and walls of the wellbore in weakly consolidated subterranean formations . Gravel packing is a well-known technique for sand control, whereby unconsolidated fines produced from the soft formation are filtered away from the production fluids (Penberthy and Shaughnessy 1992;Saucier 1974;Powell et al. 2006;Tiffin et al. 1998). Unconsolidated fines are highly challenging, as they are expensive to dispose of and can cause erosion of surface equipment, casing failure, clogging of production pipes, and production loss (Penberthy and Shaughnessy 1992; Sparlin and Hagen 1985). However, gravel packs can be problematic. Bridging of sand particles within the gravel pack can create voids, which can result in mechanical failures or significantly reduce the effectiveness of gravel packs to restrain fines from flowing along with the hydrocarbons produced (Suman 1974;Tiffin et al. 1998;Powell et al. 2006).As an alternative, this paper presents a pioneering method to prepare void-free and mechanically sound permeable barriers in subterranean formations as an alternative to gravel packing. The method of preparation involves the curing of Pickering water-in-oil medium-or high-internal-phase emulsions containing monomers in the annular space between a rock formation and pipe. The emulsions were prepared by simply adding low amounts of nonionic surfactant and dispersant to premade Pickering emulsions, which were stabilized by oleic-acid (OA) modified silica particles (Ikem et al. 2008). The resulting solid materials, known as "poly-Pickering-M/HIPE," have a gas permeability of up to 2.6 darcies and are highly interconnected and permeable to hydrocarbons (Ikem et al. 2010b). This paper shows that it is possible to tailor the gas permeability and mechanical performance of the permeable barrier by altering the emulsion internal-phase volume, the volume of Hypermer 2296 added to the premade Pickering emulsion, and the composition and constituents of the continuous monomer phase; styrene, divinylbenzene (DVB), and poly(ethylene glycol) dimethacrylate (PEGDMA) were used in the monomer phase.

Highly permeable macroporous polymers via controlled agitation of emulsion templates

“…This allows for the production of macroporous polymers with desirable properties such as permeability [7,22], surface area [5,23] and mechanical strength [24] that can be tailored for desired tasks. Much work has been done on predicting the droplet size of emulsions produced in agitated vessels [25][26][27][28], it is therefore suggested that the morphology of emulsion templated macroporous polymers can be predicted in a similar fashion.…”