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Workreport 1997-52

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Name:

Syväkairaus HH-KR4 Loviisan Hästholmenilla vuonna 1997

Writer:

Risto Niinimäki

Language:

Finnish

Page count:

392

Summary:

Working report: CORE DRILLING OF DEEP BOREHOLE HH-KR4 AT HÄSTHOLMEN IN LOVIISA

ABSTRACT

At the beginning of the year 1997 Hästholmen in Loviisa was selected
as the fourth investigation site after a feasibility study performed
in 1996. The detailed site investigations will be carried out during
years 1993...2000

As a part of the investigation programme Suomen Malmi Oy (Smoy) core
drilled a 1000,99 m deep borehole with a diameter of 56 mm in autum
1997 at Hästholmen. The identification number of the borehole is HH-
KR4.

A set of control measurements and the sampling of the flushing water
were carried out during the drilling. Both the volume and the
conductivity of the flushing water and the returning water were
recorded as well as the pressure of the fushing water. The objective
of these measurements was to obtain more information from bedrock and
groundwater.

Uranine was used as a label agent in the flushing water. The volume of
the used flushing water was about 350 m³ and the measured volume of
the returning water was about 170 m³. At the end of the work the
borehole was flushed by pumping about 53 m³ of water from the bottom
of the borehole. The deviation of the borehole was measured with the
deviation instruments Reflex - Maxibor and Boremac D2. The
inclinations of the Maxibor measurement have been corrected based on
the inclinations of the Boremac measurement. The results of the
corrected Maxibor measurement indicate that the borehole deviates
30.71 m to the left and 63.89 m up at the depth of 980 m.

Core samples were photographed and they were logged by a geologist at
the site. Uniaxial compressive strength, Young`s modulus and the
Poisson`s ratio were measured from the core samples. The main rock
type is rapakivi granite consisting of various types, of which two
majority are pyterlite and homogenious rapakivi granite. Fractures are
mostly filled or tight. Many fractures are caused by core discing
after the depth of 218 m. The average fracture frequency is 2.9 pcs/m.
The borehole penetrated 36 broken zones. The total length of the
broken zones is 49.97 m, which is 5.2 % of the total core length.

Keywords: core drilling, borehole, rapakivi granite, fracture, control
measurements, elastic parametres, deviation measurements
CORE DRILLING OF DEEP BOREHOLE HH-KR4 AT HÄSTHOLMEN IN LOVIISA

ABSTRACT

At the beginning of the year 1997 Hästholmen in Loviisa was selected
as the fourth investigation site after a feasibility study performed
in 1996. The detailed site investigations will be carried out during
years 1993...2000

As a part of the investigation programme Suomen Malmi Oy (Smoy) core
drilled a 1000,99 m deep borehole with a diameter of 56 mm in autum
1997 at Hästholmen. The identification number of the borehole is HH-
KR4.

A set of control measurements and the sampling of the flushing water
were carried out during the drilling. Both the volume and the
conductivity of the flushing water and the returning water were
recorded as well as the pressure of the fushing water. The objective
of these measurements was to obtain more information from bedrock and
groundwater.

Uranine was used as a label agent in the flushing water. The volume of
the used flushing water was about 350 m³ and the measured volume of
the returning water was about 170 m³. At the end of the work the
borehole was flushed by pumping about 53 m³ of water from the bottom
of the borehole. The deviation of the borehole was measured with the
deviation instruments Reflex - Maxibor and Boremac D2. The
inclinations of the Maxibor measurement have been corrected based on
the inclinations of the Boremac measurement. The results of the
corrected Maxibor measurement indicate that the borehole deviates
30.71 m to the left and 63.89 m up at the depth of 980 m.

Core samples were photographed and they were logged by a geologist at
the site. Uniaxial compressive strength, Young`s modulus and the
Poisson`s ratio were measured from the core samples. The main rock
type is rapakivi granite consisting of various types, of which two
majority are pyterlite and homogenious rapakivi granite. Fractures are
mostly filled or tight. Many fractures are caused by core discing
after the depth of 218 m. The average fracture frequency is 2.9 pcs/m.
The borehole penetrated 36 broken zones. The total length of the
broken zones is 49.97 m, which is 5.2 % of the total core length.

Keywords: core drilling, borehole, rapakivi granite, fracture, control
measurements, elastic parametres, deviation measurements

Keywords:

kairaus; kairanreikä; rapakivigraniitti; rako; tarkkailumittaukset; muodonmuutosominaisuudet; sivusuuntamittaus

File(s):

Syväkairaus HH-KR4 Loviisan Hästholmenilla vuonna 1997 (pdf) (10.6 MB)


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