Databank

Workreport 1997-18

Back

Name:

Kuhmon Romuvaaran kairanreikien RO-KR10 ja RO-KR11 geofysikaalisten reikämittausten tuloskäsittely ja rakennemallin tarkistus

Writer:

Ari Luukkonen; Auli Kuusela-Lahtinen; Kai Front

Language:

Finnish

Page count:

91

Summary:

Working report: INTERPRETATION OF GEOPHYSICAL LOGGING OF BOREHOLES RO-
KR10 AND RO-KR11 AT THE ROMUVAARA SITE AT KUHMO AND
REVISION OF THE BEDROCK MODEL

Luukkonen, A., Kuusela-Lahtinen, A. & Front, K.
VTT/Communities & Infrastructure
Posiva Work Report 97-18

ABSTRACT

The Finnish power companies Teollisuuden Voima Oy and Imatran Voima Oy are
preparing to final disposal of the high-level nuclear fuel waste deep into the bedrock.
The Romuvaara research site at Kuhmo is one of the four candidates selected for the
detailed site characterization. This report describes the processing and interpretation of
standard single hole geophysical borehole logging carried out in the boreholes RO-
KR10 and -KR11 drilled during years 1995 and 1996 at the research site Romuvaara at
Kuhmo, Eastern Finland. Furthermore, the structural bedrock model of the Romuvaara
site was revised according to the hydraulic conductivity measurements, oriented fracture
data of dipmeter and televiewer applied in the large 76 mm diameter borehole KR10,
and according to the reflections obtained by oriented borehole radar and VSP surveys.
Lithological units are relatively well identified and classified by systematic utilisation of
combined natural gamma radiation, density, magnetic susceptibility, and back scattered
neutron flux information. In bedrock fracturing studies fractured sections are mostly
identified by the interpretation of acoustic, density, resistivity, and temperature logs.
Furthermore, temperature, electrical conductivity and difference flow measurements in
the studied boreholes are utilised in fractured section identification. For structural
interpretation of fractured sections fracture orientation, Vertical Seismic Profiling
(VSP), borehole radar and dipmeter measurement results were utilised.
Excluding minor mafic interlayers, drilled profiles are composed mostly of main rock
types of the study area, namely leucotonalite and tonalite. According to bedrock
fracturing studies borehole KR10 contains two intensively fractured sections and
borehole KR11 eight sections, which mostly are hydrologically significant. Considering
structural interpretation studies in borehole KR10 it is proposed certain adjustments for
the fracture zone R18B or optionally a new structure in Romuvaara structural model
connected to the surface lineament RVLF2. Based on structural interpretation studies in
borehole KR11 it is suggested new structures to be attached in the structural model
connected to the surface lineaments RVLF3 and L21.

Key words: Geophysical, structural bedrock model, lithological unit, fracturing,
hydraulic conductivity
INTERPRETATION OF GEOPHYSICAL LOGGING OF BOREHOLES RO-
KR10 AND RO-KR11 AT THE ROMUVAARA SITE AT KUHMO AND
REVISION OF THE BEDROCK MODEL

Luukkonen, A., Kuusela-Lahtinen, A. & Front, K.
VTT/Communities & Infrastructure
Posiva Work Report 97-18

ABSTRACT

The Finnish power companies Teollisuuden Voima Oy and Imatran Voima Oy are
preparing to final disposal of the high-level nuclear fuel waste deep into the bedrock.
The Romuvaara research site at Kuhmo is one of the four candidates selected for the
detailed site characterization. This report describes the processing and interpretation of
standard single hole geophysical borehole logging carried out in the boreholes RO-
KR10 and -KR11 drilled during years 1995 and 1996 at the research site Romuvaara at
Kuhmo, Eastern Finland. Furthermore, the structural bedrock model of the Romuvaara
site was revised according to the hydraulic conductivity measurements, oriented fracture
data of dipmeter and televiewer applied in the large 76 mm diameter borehole KR10,
and according to the reflections obtained by oriented borehole radar and VSP surveys.
Lithological units are relatively well identified and classified by systematic utilisation of
combined natural gamma radiation, density, magnetic susceptibility, and back scattered
neutron flux information. In bedrock fracturing studies fractured sections are mostly
identified by the interpretation of acoustic, density, resistivity, and temperature logs.
Furthermore, temperature, electrical conductivity and difference flow measurements in
the studied boreholes are utilised in fractured section identification. For structural
interpretation of fractured sections fracture orientation, Vertical Seismic Profiling
(VSP), borehole radar and dipmeter measurement results were utilised.
Excluding minor mafic interlayers, drilled profiles are composed mostly of main rock
types of the study area, namely leucotonalite and tonalite. According to bedrock
fracturing studies borehole KR10 contains two intensively fractured sections and
borehole KR11 eight sections, which mostly are hydrologically significant. Considering
structural interpretation studies in borehole KR10 it is proposed certain adjustments for
the fracture zone R18B or optionally a new structure in Romuvaara structural model
connected to the surface lineament RVLF2. Based on structural interpretation studies in
borehole KR11 it is suggested new structures to be attached in the structural model
connected to the surface lineaments RVLF3 and L21.

Key words: Geophysical, structural bedrock model, lithological unit, fracturing,
hydraulic conductivity

Keywords:

Geofysikaalinen; rakennemalli; kivilaji; rikkonaisuus; vedenjohtavuus

File(s):

Kuhmon Romuvaaran kairanreikien RO-KR10 ja RO-KR11 geofysikaalisten reikämittausten tuloskäsittely ja rakennemallin tarkistus (pdf) (3 MB)


Back


Share article:
This website stores cookies on your computer. These cookies are used to improve our website and provide more personalised services to you.
Close

Cookies

To make this site work properly, we sometimes place small data files called cookies on your device. Most big websites do this too.

1. What are cookies?

A cookie is a small text file that a website saves on your computer or mobile device when you visit the site. It enables the website to remember your actions and preferences (such as login, language, font size and other display preferences) over a period of time, so you don’t have to keep re-entering them whenever you come back to the site or browse from one page to another.

2. How do we use cookies?

A number of our pages use cookies to remember your actions and preferences (such as login, language, font size and other display preferences.)

Also, some videos embedded in our pages use a cookie to anonymously gather statistics on how you got there and what videos you visited.

Enabling these cookies is not strictly necessary for the website to work but it will provide you with a better browsing experience. You can delete or block these cookies, but if you do that some features of this site may not work as intended.

The cookie-related information is not used to identify you personally and the pattern data is fully under our control. These cookies are not used for any purpose other than those described here.

3. How to control cookies

You can control and/or delete cookies as you wish – for details, see aboutcookies.org. You can delete all cookies that are already on your computer and you can set most browsers to prevent them from being placed. If you do this, however, you may have to manually adjust some preferences every time you visit a site and some services and functionalities may not work.

Close