Effect of desiccation on shut-in benefits in removing water blockage in tight water-wet cores

Nur Wijaya, James J. Sheng

Research output: Contribution to journalArticle

11 Scopus citations

Abstract

Water blockage is a type of formation damage that occurs because of capillary discontinuity at the interface between high-capillarity matrix and low-capillarity fracture. This water blockage causes a reduction in oil relative permeability and the need for higher drawdown to allow flowback after hydraulic fracturing. To remove this blockage, shut-in is believed to be effective because it dissipates the water blockage from the matrix-fracture interface deeper into the matrix through capillary imbibition. However, field data demonstrates mixed results – Some field data report shut-in as beneficial, whereas others detrimental. This paper investigates desiccation as one of the main reasons for the mixed shut-in implications. From the perspective of multiphase flow in porous media, our history-matched core-scale model reveals that shut-in can offer some benefits in desiccated water-wet cores but cause further damage in non-desiccated ones. Regardless of the desiccation, our simulation results show that immediate flowback can help ensure high oil relative permeability and remove the trapped water at the matrix-fracture interface more quickly. In a desiccated core, both immediate flowback and shut-in result in the same maximum regained oil relative permeability; however, in a non-desiccated core, immediate flowback results in a higher maximum regained oil relative permeability than shut-in.

Original languageEnglish
Pages (from-to)314-323
Number of pages10
JournalFuel
Volume244
DOIs
StatePublished - May 15 2019

Keywords

  • Capillary imbibition
  • Desiccation
  • Flowback
  • Improved oil recovery
  • Shut-in
  • Water blockage

Fingerprint Dive into the research topics of 'Effect of desiccation on shut-in benefits in removing water blockage in tight water-wet cores'. Together they form a unique fingerprint.

  • Cite this