Letter to the editor Journal of Petroleum Science and Engineering: Comment on
"Casing influence while measuring in situ reservoir compaction" by P. Macini
et al. [J. Pet. Sci. Eng. 50 (2006), 40-54]
M. Ferronato, G. Gambolati, C. Janna, P. Teatini
Dept. Mathematical Methods and Models for Scientific
Applications, University of Padova, Padova, Italy
ABSTRACT
The paper by Macini et al. (2006) addresses the
problem of the reliability of in situ compaction
measurements made in producing gas/oil reservoirs
with the aid of the Radioactive Marker Technique
(RMT). This is a very important issue as an essential
parameter controlling anthropogenic land subsidence
over gas/oil fields, namely the vertical rock compressibility
cM, is obtained from RMT data. Based on finite element
analyses, we show that
the cM estimates derived from the RMT measurements
are not significantly disturbed by the presence of the steel
casing, and indeed may be quite representative of the
actual geo-mechanical compaction of the gas reservoirs
being developed in the area, thus allowing for a realistic
prediction of the anthropogenic land subsidence
expected to occur over the gas fields of the Northern
Adriatic. As a major consequence, the concerns raised by
Macini et al. (2006) for the correct RMT implementation
in the Northern Adriatic do not appear to be warranted.
