Prediction of capillary fluid interfaces during gas or water coning in vertical wells

Russell Taylor Johns, Larry W. Lake, Rafay Z. Ansari, Arnaud M. Delliste

Research output: Contribution to journalArticle

12 Citations (Scopus)

Abstract

Gas and water coning significantly reduce oil production while increasing production costs. Simulation and experimental methods, coupled with simple analytical solutions or correlations, are typically used to identify the oil rate that minimizes coning and maximizes recovery. Current analytical solutions, however, are overly simplified in that they assume negligible capillary pressure, which leads to segregated flow. This paper presents new benchmark analytical solutions that relax this assumption and also allow for simultaneous two-phase flow. The new coning solutions apply to vertical wells where in-situ fl uids are in vertical equilibrium. The development identifies the important dimensionless groups that control the effect of coning on oil recovery and illustrates how simultaneous two-phase flow affects capillary fluid levels in the formation. Dimensionless two-phase production windows are constructed to identify critical rates, the largest oil rate at which water (or gas) will not be produced. From comparisons to simulation, we show that critical flow rate estimates are accurate for aspect ratios greater than approximately 10. For aspect ratios less than 10, the critical rate estimates are always conservative.

Original languageEnglish (US)
Pages (from-to)440-448
Number of pages9
JournalSPE Journal
Volume10
Issue number4
DOIs
StatePublished - Jan 1 2005

Fingerprint

well
Fluids
fluid
prediction
Gases
gas
Two phase flow
two phase flow
Aspect ratio
Water
oil
Recovery
water
Capillarity
critical flow
capillary pressure
production cost
oil production
Flow rate
simulation

All Science Journal Classification (ASJC) codes

  • Energy Engineering and Power Technology
  • Geotechnical Engineering and Engineering Geology

Cite this

Johns, Russell Taylor ; Lake, Larry W. ; Ansari, Rafay Z. ; Delliste, Arnaud M. / Prediction of capillary fluid interfaces during gas or water coning in vertical wells. In: SPE Journal. 2005 ; Vol. 10, No. 4. pp. 440-448.
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Prediction of capillary fluid interfaces during gas or water coning in vertical wells. / Johns, Russell Taylor; Lake, Larry W.; Ansari, Rafay Z.; Delliste, Arnaud M.

In: SPE Journal, Vol. 10, No. 4, 01.01.2005, p. 440-448.

Research output: Contribution to journalArticle

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