SPE Reservoir Evaluation & Engineering
Volume 12, Number 3, June 2009, pp. 427-432

SPE-113460-PA

A New Polymer Application for North Sea Reservoirs

View full textPDF ( 625 KB )

DOI  More information 10.2118/113460-PA http://dx.doi.org/10.2118/113460-PA

Citation

  • Spildo, K., Skauge, A., Aarra, M.G., and Tweheyo, M.T. 2009. A New Polymer Application for North Sea Reservoirs. SPE Res Eval & Eng  12 (3): 427-432. SPE-113460-PA. doi: 10.2118/113460-PA.

Discipline Categories

  • 6 Reservoir Description and Dynamics
  • 6.4 Primary and Enhanced Recovery Processes
  • 6.4.6 Chemical Flooding Methods Methods (e.g., Polymer, Solvent, Nitrogen, Immiscible CO2, Surfactant, Vapex)

Summary

Field trials have demonstrated increased oil recovery by injection of colloidal dispersion gels (CDG). Characteristics of these trials include reservoirs characterized by high permeability heterogeneity and low injection water salinities. The enhanced oil recovery (EOR) has been attributed to improved waterflood sweep in the rather heterogeneous reservoirs where this method has been applied. This study presents an investigation of the applicability of CDG at higher salinity, and particularly sandstone North Sea oil reservoir applications.

Earlier laboratory work and field trials involving CDG have involved relatively low reservoir temperatures and low injection water salinity (~5000 μg/g). This study involves experiments at high temperature (85°C) and salinity (~35 000 μg/g). When crosslinking is complete, the CDG solutions have slightly lower viscosities than the corresponding polymer solutions, and they also appear to be more stable at high temperatures.

In preparation for a field pilot, several coreflood experiments have been conducted. Significant increase in oil recovery resulting from CDG injection has increased the interest for a field trial in a North Sea oil field. On average, 40% of the remaining oil after waterflooding was produced by CDG injection in linear corefloods, and a mechanism of microscopic diversion is proposed to explain these results. Our hypothesis is that CDG injection can contribute as an EOR method, giving both a microscopic diversion and a macroscopic sweep.

© 2009. Society of Petroleum Engineers

View full textPDF ( 625 KB )

History

  • Original manuscript received: 12 February 2008
  • Meeting paper published: 20 April 2008
  • Revised manuscript received: 17 September 2008
  • Manuscript approved: 25 October 2008
  • Published online: 1 June 2009
  • Version of record: 1 June 2009