Well Testing, Methods and Applicability
Författare
Summary, in English
applications, within civil engineering projects, thermal storage and CO2 storage. The overall
testing goal is to verify the productivity from a well and/or for characterization of hydraulic
and thermal properties, as well as the spatial limitations of an aquifer. There are three major
methods for conducting well testing; slug tests, pumping tests and injection tests. The main
objective of this thesis is to compare and evaluate the applicability of the three major well
testing methods, using experiences gained by active participation in several well testing
operations. Testing of shallow and very deep wells as injection tests using a complete tunnel
lining are compared and uniquely presented together in the same work. To compare and
evaluate the applicability of the three well testing methods, several conditions which govern
the selection of hydraulic testing methods are varied and these include, amongst others, the
location, depth and diameter of the well. In addition, technical constraints, such as logistics,
water handling and external power supply for conducting the testing are also considered.
Certain emphasis is also placed on the use and comparison of pneumatic slug testing with
other well testing methods, as pneumatic slug testing often complementary to the more
expensive and logistically demanding pumping and injection tests. A small diameter slug test
equipment was put together for evaluating the applicability of this method and applied in
three different geological environments, namely sedimentary deposits, volcanic deposits and
the crystalline basement.
It was found that knowledge of the applicability of slug tests, pumping tests and injection tests
is essential for selecting the most appropriate method. Two of the methods, namely pumping
tests and injection tests, are logistically demanding while the third one, slug tests, is easy to
execute. Consequently, it is therefore also an inexpensive test method, which is supported by
the fact that several tests can be conducted in different wells during the same day. Slug testing
using pneumatic initiation has also been demonstrated as a good alternative to pumping tests,
obtaining similar transmissivity estimates. An advantage of slug testing is that the
transmissivity is estimated from a series of slug tests and not from one single test, which is
often the case for pumping or injection tests. Slug testing using pneumatic initiation is often
associated with testing in small diameter wells, but in this work it has been shown applicable
in large diameter wells at least up to 12". A major advantage with pneumatic slug testing
compared with the other methods is that it can be used for transmissivity mapping, simplified
by the method’s easy logistics. It is a useful approach if the wells are distributed over a large
area. It is suggested that slug testing using pneumatic initiation should be used as a preinvestigation
method for civil engineering projects. Further work needs to be carried out for
explaining the observed non-linear characteristics in data obtained from some of the slug
tested wells.
It has also been demonstrated that well testing methods are not only restricted to drilled wells.
The methods can also be applied inside a tunnel with injection through the tunnel lining. The
testing was performed as step injection and constant head/pressure tests and, in conjunction,
the response from the testing was measured in observation wells drilled from ground level.
Analytical solutions developed for vertical wells could be used to interpret hydraulic
properties such as transmissivity, using injection tests performed at tunnel level and the
pressure response measured in two of the observation wells. Well development was found to
be of great importance for any type of well testing and, for deep wells, a hydrojetting system
using coiled tubing and simultaneous pumping was found to be applicable, successful and
time efficient.
Avdelning/ar
Publiceringsår
2010
Språk
Engelska
Fulltext
Dokumenttyp
Doktorsavhandling
Förlag
Department of Electrical Measurements, Lund University
Ämne
- Geotechnical Engineering
Nyckelord
- slug tests
- well completion
- re-injection
- Well testing
- pumping tests
- injection tests
- well development
- pneumatic initiation
- hydro-jetting
- coiled tubing
- tunnel lining
- deep wells
Status
Published
Handledare
- Leif Bjelm
- Gerhard Barmen
ISBN/ISSN/Övrigt
- ISBN: 978-91-976848-3-5
Försvarsdatum
4 juni 2010
Försvarstid
13:15
Försvarsplats
Lecture hall B, in the V-building, John Ericssonsv. 1, Lund University Faculty of Engineering, Lund
Opponent
- James J. Jr Butler (PhD)