Imbibition processes in fractured chalk core plugs with connate water mobilization

C.M. Nielsen, D. Olsen, N. Bech

Research output: Chapter in Book/Report/Conference proceedingConference article in proceedings

5 Citations (Scopus)


A displacement process in a chalk core plug with an induced axial fracture uses the fluid system H 2O-D 2O-n-decane. Initially the plug contains a mixture of D 2O and n-decane with oil saturation equal to 88 %. The plug is flooded with H 2O. The displacement process is monitored by NMR with a chemical shift technique enabling spatial resolution of the H 2O and oil signals. The D 2O component is not directly detected, but is calculated from the difference between the actual signal intensities and the signal intensities in a situation where the pore space is completely saturated with H 2O and oil. H 2O-D 2O-oil constitutes a partly miscible fluid system which is an analogy to the injection water-formation water-oil system of a hydrocarbon reservoir under waterflooding. The injected H 2O traverses the sample as a well-defined front together with capillary uptake from the fracture plane. Ahead of the H 2O front the D 2O of the sample is mobilized and travels as a bank in front of the H 2O. Though the initial concentration of D 2O is only 12 % the D 2O concentration reaches 50 % at the bank. The experiment was simulated by means of ECLIPSE with a fair match of the displacement process. The injected H 2O has only made limited contact with the produced oil of the sample. In case of chemical EOR processes connected to waterflooding of hydrocarbon reservoirs a similar displacement situation could seriously affect the efficiency of the EOR process.

Original languageEnglish
Title of host publicationSPE Annual Technical Conference and Exhibition, 1-4 October, Dallas, Texas
PublisherSociety of Petroleum Engineers
Number of pages10
Publication statusPublished - 2000
EventSPE Annual Technical Conference and Exhibition 2000 - Dallas, Texas, U.S.A.
Duration: 1 Oct 20004 Oct 2000

Publication series

SeriesSPE Reservoir Engineering (Society of Petroleum Engineers)


ConferenceSPE Annual Technical Conference and Exhibition 2000
CityDallas, Texas, U.S.A.

Programme Area

  • Programme Area 3: Energy Resources


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