core holders used in drilling and coring applications

1. BY:-
Deepak Agarwal

2.  Core Holder
 Need Of Core Holder
 Tests Performed By Core Holder
 Types Of Core Holders
 Standard Core Holders In Industry
 Hassler Type Core Holder
 Construction
 Working
 Preceding Of The Project So Far…….
 References & Bibliography

3.  A portable apparatus provide on-site permeability
measurements and formation evaluation by a core
sample extracted from an underground reservoir.
 CORE SAMPLE: A cylindrical rock(1-1/8“ to 5-1/4"
diameter and 30 to 60 ft long) sample taken from the
formation for geological analysis to perform laboratory
evaluation of basic properties.

4.  It is usually desirable for both routine and special tests
of core samples to be conducted at pressures
simulating those encountered in the subsurface
geologic formations from which the core samples were
removed.
 The portable apparatus is easily and conveniently
transported to well locations for use on-site, thereby
allowing the core sample to be tested in actual
reservoir conditions.

5.  Gas & Liquid Permeability
 Formation Damage
 Porosity
 Dynamic Filtration
 Compressibility
 Acidization
 Relative Permeability
 Resistivity
 Secondary Water Flooding
 Radial Flooding
 Enhanced Oil Recovery
 Steam Flooding

6.  According to geometry:
-Vertical core holder
-horizontal core holder
 According to test:
-resistivity core holder
-polymer flooding core holder
-acidizing core holder
-Steam Flooding core holder
-Dynamic Filtration core holder
 For Permeability Measurements
-Gas (or Air) permeability measurement core holder
-water (or brine, polymer) permeability measurement core holder

8.  Hassler Type Core Holders
 Biaxial Type Core Holders
 Triaxial Type Core Holders

9. Biaxial Type Core holders
Biaxial type core holders are defined as core holders
that have common radial and axial pressure applied to
the core sample. These core holders are routinely used
for gas and liquid permeability and other core
flooding experiments.

10. Triaxial Type Core Holders
TCH or RCHT Series core holders are triaxial type core holders. A
triaxial type core holder is defined as a core holder in which the axial
and radial pressures are independent of each other and can be varied
during the test.

11.  Hassler type core holders are defined as core holders that
have radial pressure applied to the core sample.
 These core holders are routinely used for gas and liquid
permeability and other core flooding experiments.
 Spacers are provided to accommodate undersized cores.
 The distribution plugs are provided with a single inlet and
outlet.
However, additional ports can be added as required. The
volume of all ports and flow lines are kept to a minimum so
that accurate flow data can be determined.

13.  An elastic rubber sleeve for receipt of a core sample is
disposed in an open-ended, cylindrical cavity of an open-
ended, cylindrical body.
 The ends of the sleeve are fitted over flanged ferrules. A
cylindrical end plug is releasably locked in one end of the
body with one of its ends inserted through the adjacent
ferrule engage one end of the core sample.
 A cylindrical piston housing having a cylindrical cavity is
releasably locked in the other end of the body. A cylindrical
piston is disposed in the cavity of the piston housing with
one of its ends protruding from an open end of the cavity
and inserted through the adjacent ferrule to engage the
other end of the core sample.

14.  Pressurized fluid moves the piston to apply axial force
to the core sample. The sleeve is compressed by
pressurized fluid to apply radial force to the core
sample. Test fluid conduits are provided in the piston
and the end plug.

15. Fluid is forced into one end of a
rock (or soil) specimen under
pressure P, and the amount of
fluid emerging at the other end
per unit time (also called flow
rate q) is measured.
k A p
q
L

16.  With this design, the core holder does not need to be
completely disassembled in order to interchange core
test samples. After the confining pressure has been
released, the end plugs and distribution plugs are
removed and the core sample is easily removed from
the sleeve. The sleeve and end caps remain in place
within the core holder.
 Quick release end plugs and quarter turn end plug
removal allows for easy assembly and disassembly
from one end.

17. 1. Core sample may not be representative of the reservoir rock because
of reservoir heterogeneity.
2. Core recovery may be incomplete.
3. Permeability of the core may be altered when it is cut, or when it is
cleaned and dried in preparation for analysis. This problem is likely to
occur when the rock contains reactive clays.
4. Sampling process may be biased. There is a temptation to select the
best parts of the core for analysis.

18.  Anderson, G. 'Coring and Core analysis
 Handbook,' Tulsa. Petroleum Publishing Co., 1975.
200 p.
 “Drilling Operations Manual” IDT ONGC 1994
 “Reservior Engineering” by TARAK AHMED
 “Methods and apparatus for permeability
measurement” by G. L. HASSLER patented in 1944.