Title: New silicate hydrogel with more elasticity as in-situ water diversion system: preparation and investigation of rheological and pugging behaviours

Authors: Dexin Liu; Xingru Wu; Ramadan Ahmed

Addresses: School of Petroleum Engineering, China University of Petroleum, West Road No. 66, Qingdao, Shandong, 266580, China ' Mewbourne School of Petroleum and Geological Engineering, University of Oklahoma, SEC-1210 Sarkeys Energy Center, 100 E. Boyd St., Norman, OK 73019-1003, USA ' Mewbourne School of Petroleum and Geological Engineering, University of Oklahoma, SEC-1210 Sarkeys Energy Center, 100 E. Boyd St., Norman, OK 73019-1003, USA

Abstract: Silicate-based gels are used in water diversion treatments for its low cost and environmental safety. In this paper, a new hydrogel with an interpenetrating network is developed based on three components, sodium silicate (Na₂O.mSi₂O), hydrolysed polyacrylamide (HPAM) and an activator. The interpenetrating network of Na₂O.mSi₂O-HPAM-activator is proposed. In the presence of an activator, Na₂O.mSi₂Oformsa brittle sodium silicate gel, while Na₂O.mSi₂O and HPAM forms an elastic gel resembling a polyacrylamide gel. In the Na₂O.mSi₂O-HPAM-activator system, the sodium silicate hydrogel may be weakly bound by hydrostatic forces to the polyacrylamide molecules. Polyacrylamide tends to wrap around the silicate hydrogel due to these hydrostatic forces, and produces an inorganic-organic interpenetrating network. The gelation time and the gel strength of this new silicate hydrogel system depend on the component concentrations. Furthermore, the rheological and plugging behaviours of this system with inorganic-organic interpenetrating network are investigated. The new three-component hydrogel features at unable gelation time, stronger gel strength, viscoelasticity, low cost and low environmental impact, which can be widely applied as in-depth water diverting agent in injection profile control. [Received: January 23, 2013; Accepted: June 26, 2013]

Keywords: silicate hydrogel; interpenetrating networks; viscoelasticity; plugging behaviour; activators; water diversion; rheology; sodium silicate; hydrolysed polyacrylamide; HPAM; gelation time; gel strength; environmental impact.

DOI: 10.1504/IJOGCT.2014.060091

International Journal of Oil, Gas and Coal Technology, 2014 Vol.7 No.3, pp.263 - 274

Received: 26 Jan 2013
Accepted: 25 Jun 2013
Published online: 24 May 2014 *

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