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Document Type |
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Article In Journal |
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Document Title |
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Evaluation of Low Resistivity Beds Using Nuclear Magnetic Resonance Log تقويم الطبقات الرملية منخفضة المقاومة الكهربية باستخدام تسجيلات الرنين المغناطيسي |
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Subject |
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Production Engineering |
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Document Language |
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English |
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Abstract |
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The combination of conventional logs such as 'density,
neutron and resistivity logs is proven to be very effective in the
evaluation of normal reservoirs. For low resistivity reservoirs,
however, an accurate determination of the petrophysical
parameters with the conventional logs is very difficult. This paper
presents some cases of low resistivity reservoirs and low contrast
resistivity reservoirs where conventional logs fail to determine the
petrophysical properties of formation. The problems of these
reservoirs are that conventional logging interpretation shows high
water saturation zones, but water free hydrocarbon would be
produced. In case of low resistivity contrast reservoirs it is
difficult to determine oil-water contact with resistivity logs.
Nuclear magnetic resonance (NMR) log has been only available
as a supplement tool to provide additional information on the
producibility of the reservoirs. The main limitations of NMR
logging, however, has been the cost and long time of acquiring
data. This paper shows that, in the case of low resistivity
reservoirs, NMR logging is a very effective tool, which helps to
accurately determine the reservoir rock petrophysical properties.
For the analysis of NMR data, several aspects of NMR technique
have been used; 1) TlfT2 ratio, for fluid identification, 2) the
difference between NMR derived porosity and total porosity, to
determine the types of clay minerals, 3) NMR relaxation
properties, to identify fluids nature and rock properties of low
contrast / low resistivity reservoirs. This paper presents three
examples of low resistivity reservoirs. Analysis of NMR data of
low resistivity zones has helped to identify the producibility of
these reservoirs zones, to determine lithology independent
porosity and to distinguish between bound and free water. In case
of low contrast resistivity reservoirs where there was little
resi.'itivity contrast between water bearing formation and oil bearing formation, NMR has been able to identify the fluid nature
of the two formations and then the height of the oil column. This
was based mainly on high contrast ofNMR relaxation parameters. |
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ISSN |
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1319-1047 |
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Journal Name |
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Engineering Sciences Journal |
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Volume |
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14 |
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Issue Number |
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1 |
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Publishing Year |
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1422-1424 AH
2002-2003 AD |
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Number Of Pages |
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14 |
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Article Type |
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Article |
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Added Date |
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Sunday, October 11, 2009 |
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Researchers
| غريب مصطفى حمادة | G. M. HAMADA | Researcher | | |
| مساعد ناصر العواد | M. N. AL-AWAD | Researcher | | |
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