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 testsof core samples to be conducted at pressuressimulating those encountered in the subsurfacegeologic formations from which the core samples wereremoved. The portable apparatus is easily and convenientlytransported to well locations for use on-site, therebyallowing the core sample to be tested in actualreservoir 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 7. Hassler Type Core Holders Biaxial Type Core Holders Triaxial Type Core Holders 8. Biaxial Type Core holdersBiaxial type core holders are defined as core holdersthat have common radial and axial pressure applied tothe core sample. These core holders are routinely usedfor gas and liquid permeability and other coreflooding experiments. 9. Triaxial Type Core HoldersTCH or RCHT Series core holders are triaxial type core holders. Atriaxial type core holder is defined as a core holder in which the axialand radial pressures are independent of each other and can be variedduring the test. 10. Hassler type core holders are defined as core holders thathave radial pressure applied to the core sample. These core holders are routinely used for gas and liquidpermeability and other core flooding experiments. Spacers are provided to accommodate undersized cores. The distribution plugs are provided with a single inlet andoutlet.However, additional ports can be added as required. Thevolume of all ports and flow lines are kept to a minimum sothat accurate flow data can be determined. 11. An elastic rubber sleeve for receipt of a core sample isdisposed in an open-ended, cylindrical cavity of an open-ended, cylindrical body. The ends of the sleeve are fitted over flanged ferrules. Acylindrical end plug is releasably locked in one end of thebody with one of its ends inserted through the adjacentferrule engage one end of the core sample. A cylindrical piston housing having a cylindrical cavity isreleasably locked in the other end of the body. A cylindricalpiston is disposed in the cavity of the piston housing withone of its ends protruding from an open end of the cavityand inserted through the adjacent ferrule to engage theother end of the core sample. 12. 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. 13. Fluid is forced into one end of arock (or soil) specimen underpressure P, and the amount offluid emerging at the other endper unit time (also called flowrate q) is measured. k A pq L 14. With this design, the core holder does not need to becompletely disassembled in order to interchange coretest samples. After the confining pressure has beenreleased, the end plugs and distribution plugs areremoved and the core sample is easily removed fromthe sleeve. The sleeve and end caps remain in placewithin the core holder. Quick release end plugs and quarter turn end plugremoval allows for easy assembly and disassemblyfrom one end. 15. 1. Core sample may not be representative of the reservoir rock becauseof reservoir heterogeneity.2. Core recovery may be incomplete.3. Permeability of the core may be altered when it is cut, or when it iscleaned and dried in preparation for analysis. This problem is likely tooccur when the rock contains reactive clays.4. Sampling process may be biased. There is a temptation to select thebest parts of the core for analysis. 16. 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.