The same type of oil geochemistry (oil fingerprinting) data used
to assess reservoir
compartmentalization and allocate
commingled production can be used to identify problems with
well completions, such as:
- Tubing string leaks. Using an excellent case study from the
Gulf of Mexico, Hwang and Elsinger, (1995) illustrate the use of
oil geochemistry (gas chromatography) to infer a leak in one string
in a dual tubing string completion. A subsequent work over of this
well confirmed the breach of the tubing string at the point
suggested by the oil geochemistry. The breach evidently resulted
from the omission of a blast joint that should have been installed
at the point of the eventual rupture, but which had inadvertently
been installed one tubing length shallower (R. J. Elsinger,
personal communication to M. McCaffrey). Similar problems have been
identified in other fields using the same approach. For example,
Kaufman et al. (1997) applied the same oil fingerprinting
techniques to identify tubing string leaks in the Greater Bergan
Field, Kuwait.
- Communication between zones behind casing due to poor cement
jobs, and
- Ineffective stimulation of a given interval.
With all of these applications, the relative abundance of
various compounds in the petroleum are used to identify completion
problems by allowing produced fluids to be tied to specific
reservoir intervals. For more information on the technique
described here, or to discuss a specific project, e-mail us at info@oiltracers.com, or call
us at (214) 584-9169.
References
Hwang R. J. and Elsinger R. J. (1995). Detecting production
tubing leak by time resolved geochemical analysis of oils. Society
of Petroleum Engineers, 355-367.
Kaufman, R. L., H. Dashti, C. S. Kabir, J. M. Pederson, M. S. Moon,
R. Quttainah, and H. Al-Wael, 1997, Characterizing the greater
Burgan Field: Use of geochemistry and oil fingerprinting: SPE Paper
No. 37803, p. 385-394.