Fluidization structures in produced by upward injection of sand through a sealing lithology

Andrew Hurst, J. Cartwright, Davide Duranti

Research output: Chapter in Book/Report/Conference proceedingChapter

64 Citations (Scopus)

Abstract

Subsurface and outcrop data are used to describe sand injectites, a group of genetically related features that includes sandstone dykes and sills, but also structures within depositional sand bodies. Fluidization is identified as the process by which sand is injected but we draw attention to the lack of constraints regarding fluidization velocity and fluid viscosity. Injectites are shown to develop between <10 m and 500 m below the seafloor. No relationship between depth of generation and injection geometry is found. Liquefaction of sand may produce sufficient excess pore fluid to create small sand injections during shallow burial. Large injectite bodies are identified on seismic data that may exceed 4 x 10(7) m(3) are unlikely to be related to sand liquefaction. The general validity of hydraulic fracture as the mechanism for seal failure and propagation of injections is questioned. The association between the formation of polygonal faults and sand injection provides one of several alternative mechanisms for seal failure. Multi-phase intrusion is proposed as a likely mechanism for the formation of large sand intrusions, both because of the cyclical nature of most of the process invoked in their formation, and the author's own observations. Many of the processes of sand injection remain poorly constrained.

Original languageEnglish
Title of host publicationIn: Subsurface sediment mobilization (eds. Van Rensbergen,P.;Hillis,R.;Maltman,A. J.;Morley,C.K.), Geological Society Of London, London
Place of PublicationIn: Subsurface sediment mobilization (eds. Van Rensbergen,P.;Hillis,R.;Maltman,A. J.;Morley,C.K.), Geological Society Of London, London
Pages123-137
Number of pages14
DOIs
Publication statusPublished - 2003

Keywords

  • RESERVOIR GEOMETRIES
  • ESCAPE STRUCTURES
  • FLUID EXPULSION
  • ALBA FIELD
  • NORTH-SEA
  • SEDIMENTS
  • DEFORMATION
  • BASIN
  • UKCS
  • LIQUEFACTION

Cite this

Hurst, A., Cartwright, J., & Duranti, D. (2003). Fluidization structures in produced by upward injection of sand through a sealing lithology. In In: Subsurface sediment mobilization (eds. Van Rensbergen,P.;Hillis,R.;Maltman,A. J.;Morley,C.K.), Geological Society Of London, London (pp. 123-137). https://doi.org/10.1144/GSL.SP.2003.216.01.09