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Core Barrels -

Core Barrels

We supply a very broad range of Core Drilling Equipment in accordance with both Metric, DCDMA and Wireline Standards. We also offer Core Barrels designed for special applications such as air-flush drilling and for sampling in very loose sandy, materials. If you do not know exactly which tools are best for your application then see our Core Drilling Equipment Selection Guide. This gives you some helpful hints and takes you through the decision steps necessary to make a proper product selection.

Conventional Core Barrels:

B type single tube core barrels are suitable for drilling when no core examination is required (e.g. the drilling of grout holes). XB type are suitable for extended concrete coring.

Whereas the B type core barrel is of fixed length, the XB core barrel is easily extendable during drilling by adding additional metric casing tubes between the core barrel head and reaming shell. In both series, the core lifter fits into the the taper on the inside of the core bit so a core lifter case is not required.

Available in 9 different diameters for metric (millimetre) hole sizes between 46 – 146 mm.

Advantages:
  • Saves cost when no core examination is required
  • Easily extendable in length when coring through thick concrete.

Technical Data

Key to Main Parts of B and XB Core Barrel Assemblies

Complete core barrel consists of:

1. Core Barrel Head

2. Sample Tube 0.5m, 1.0m, 1.5m or 3.0m long

3. Reaming Shell (Blank)

4. Core Lifter

TT core barrels are conventional double tube core barrels with an ultra-thin wall. They are designed for coring in medium hard to very hard homogenous rock in conjunction with water flushing. These core barrels are most frequently used for underground mining operations.

Available in metric (millimetre) hole sizes 46 and 56 mm

Advantages:
  • A high rate of penetration due to small cutting area of the core bit
  • Use of lower pressure and torque minimizes the wear on equipment
  • Lower costs for core bits

Technical Data

Key to Main Parts of TT Core Barrel Assembly

Complete core barrel consists of:

1. Core Barrel Head

2. Inner Tube 1.5m or 3.0m

3. Outer Tube 1.5m or 3.0m

4. Extension Tube

5. Core Lifter

6. Core lifter Case

T2 Series Double Tube Core Barrels

Thin wall conventional core barrels designed for coring in medium hard to very hard homogenous and slightly broken formations with water flushing or polymer. They are designed as double tube core barrels but most can be converted to triple tube by incorporating PVC coreliners. Available in 6 different diameters for metric (millimetre) hole sizes between 46 -101 mm.

Advantages:
  • Fast penetration
  • Large core relative to hole size
  • Good for coring in hard rock formations using impregnated bits

Technical Data

Key to Main Parts of T2 Core Barrel Assembly

Complete core barrel consists of:

1. Core Barrel Head

2. Inner Tube 1.5m or 3.0m long

3. Outer Tube 1.5m or 3.0m long

4. Extension Tube

5. Core Lifter

6. Core lifter Case

T6 Series Double Tube Core Barrels

General purpose conventional core barrels designed for coring in soft to hard homogenous and slightly broken formations with water, mud, polymer or air flushing. Although designed as double tube core barrels, all can be converted to triple tube by incorporating PVC coreliners. Available in 6 different diameters for metric (millimetre) hole sizes between 101 – 146 mm. Also available is the T6H which produces H size hole.

Advantages:
  • Fast penetration compared with thicker wall core barrels (e.g. DCDMA types WF, WG etc)
  • A general purpose core barrel suitable for soft to hard rock formations.
  • In addition to water and polymer, mud and air can be used for flushing

Technical Data

Key to Main Parts of T6 Core Barrel Assembly

Complete core barrel consists of:

1. Core Barrel Head

2. Inner Tube 1.5m or 3.0m

3. Outer Tube 1.5m or 3.0m

4. Extension Tube (T6-116, T6-131 and T6-146 only)

5. Core Lifter

6. Core lifter Case

T6S Series Double Split Tube Core Barrels

The T6S series core barrels are designed for applications such as soil sampling and site investigation in very loose formations. The core barrel is a double tube conventional type but incorporates an aluminium split inner tube making it easy to inspect the core immediately after taking the sample.

A sturdy type of core barrel suitable for mud and air flushing. It is recommended that face discharge core bits be used in order to minimize sample disturbance caused by the flush.

Available in metric (millimetre) hole sizes 101 and 131 mm, with effective length 1.5 metre only

Advantages:
  • Ideal for direct inspection and rapid logging of the sample when coring loose formations
  • Large annulus between inner and outer tube allows heavy muds or air to be used for flushing

Technical Data

Key to Main Parts of T6S Core Barrel Assembly

Complete core barrel consists of:

1. Core Barrel Head

2. Aluminium Split Inner Tube (1.5m only)

3. Outer Tube (1.5m only)

4. Core Lifter Case

5. Core Lifter

WG and WF Series Double Tube Core Barrels

WG and WF series double tube core barrels are sturdily designed for coring soft to medium rocks using water, polymer or mud flush. The WF series utilize core bits with face discharge flushing ports to prevent core erosion in soft soils and soft rocks. The WG series utilize core bits with internal discharge flushing and are designed for slightly harder formations.

These core barrels are intended for use in conjunction with DCDMA drill rods and casing.

Advantages:
  • ISimple sturdy design
  • Can be used when DCDMA hole sizes N, H, P and S are required.

Technical Data

Key to Main Parts of WG and WF Core Barrel Assembly

Complete core barrel consists of:

1. Core Barrel Head

2. Inner Tube 1.5m or 3.0m long

3. Outer Tube 1.5m or 3.0m long

4. Ferrule / Inner Tube Extension Piece (only required for WF series)

5. Core Lifter

6. Core lifter Case (not required for WG series)

Wireline Core Barrels:

Wireline Double Tube Core Barrels

Wireline core barrels are used when coring to greater depths, mainly because they eliminate the need to couple and uncouple the rod string each time the core is retrieved. An overshot device is dropped on a cable and directly couples onto the inner tube assembly, allowing fast retrieval of the core after each core run. Available in DCDMA sizes B, N, H. and P.

Advantages:
  • Faster coring at greater depths
  • Good stability due to constant diameter of the drill string
  • Excellent hydraulics
  • Good core recovery

Technical Data

Key to Main Parts of W/L Core Barrel Assembly

Complete core barrel consists of:

1. Core Barrel Head
2. Inner Tube 1.5m or 3.0m

3. Stop Ring

4.Core Lifter

5. Core Lifter Case

6. Locking Coupling

7. Adapter Coupling

8. Landing Ring

9. Outer Tube 1.5m or 3.0m

10. Inner Tube Stabilizer

11. Thread Protector

Wireline Triple Tube Core Barrels

Wireline core barrels are used when coring to greater depths, mainly because they eliminate the need to couple and uncouple the rod string each time the core is retrieved. An overshot device is dropped on a cable and directly couples onto the inner tube assembly, allowing fast retrieval of the core after each core run.

The double tube wireline core barrel is converted to triple tube by incorporating a split steel tube inside the inner tube. In addition, a piston and pump-out adaptor is provided for pumping out the split steel tube when it is full of rock core. The stop ring, core lifter case and core lifter also differ from the standard double tube core barrel, being slightly smaller in diameter in order to accept and retain the slightly smaller core.

An alternative method of converting the double tube to triple tube is by incorporating a clear, semi-rigid PVC coreliner inside the inner tube instead of the split steel tube.

Available in DCDMA sizes B, N, H. and P.

Advantages:
  • Faster coring at greater depths
  • Good stability due to constant diameter of the drill string
  • Excellent hydraulics
  • Good core recovery even in highly broken formations.

Technical Data

Key to Main Parts of W/L3 Core Barrel Assembly

Complete core barrel consists of:

1. Core Barrel Head
2. Pump-out Adaptor 3/4″ NPT

3. Piston Plug

4. O Ring

5. Core Ejection Piston

6. Split Inner Tube 1.5m or 3.0m

7. Inner Tube 1.5m or 3.0m

8. Stop Ring

9. Core Lifter

10. Core Lifter Case

11. Locking Coupling

12. Adaptor Coupling

13. Landing Ring

14. Outer Tube 1.5m or 3.0m

15. Inner Tube Stabilizer

16. Thread Protector

GBS Large Diameter Geotechnical Wireline Core Barrel

This highly versatile core barrel system is used widely in geotechnical works to obtain large diameter cores in a wide range of geological formations.

GBS is particularly effective when high quality cores are required in clay, sand or loose, weak formations. The standard core of 102mm is completely retained in a clear PVC Coreliner and is easily extracted in one piece after each core run.

The inner tube assembly latches inside the outer core barrel and is lifted to the surface by a overshot device connected to a wireline cable. The wireline retrieval method greatly improves production rates compared to conventional coring method but also leaves the borehole fully cased at all times ensuring borehole stability in sensitive geology.

There are several different methods of using this core barrel:

Method 1: For coring medium to hard formations. The bit setting is 146mm OD x 102mm ID. TC or diamond bits can be used depending on geology.

Method 2:For coring in soft formations. TC bits are mainly used which consist of two parts – pilot and reamer. The reamer OD is 150mm and pilot ID is 102mm.

Method 3: For coring in very soft or loose formations. The bits are the same as method 2 but a special extended core lifter case runs 25mm in front of the bit.

Method 4: For coring in very soft or loose formations. The core lifter case is extended to run 60mm in front of the bit. The inner tube is spring loaded so that the core lifter case retracts behind the bit when harder formations are encountered. The bit setting is 146mm OD x 109mm ID

Method 5:Shelby tube sampling of soft or very soft formations. This is an attachment that replaces the inner tube and has at the bottom end a shelby tube which samples ahead of the bit. The bit is same as method 1

Method 6: Full hole drilling assembly, this is an attachment that replaces the inner tube for non-coring purposes. The core bit is same as method 1 and the non-coring bit is 101.6mm diameter. For pilot coring ahead of the GBS barrel, it is possible to attach a smaller diameter core barrel (T6-101 or smaller) in place of the non-coring bit.

Advantages:
  • Large diameter, high-quality core
  • Ability to obtain good recovery in a wide range of geological formations
  • Excellent hydraulics
  • Very versatile system

Technical Data

Special Applications:

412F Airflush Core Barrel

The 412F airflush core barrel is designed for coring in soft to medium hard rocks using air as the flushing medium. It is often used for open-cast coal exploration and general geotechnical coring in situations where it is not desirable to use air as the flushing medium.

The large annular space between the inner and outer tubes, in combination with face-discharge core bit designs, allows a large volume of air to reach the face of the bit . This is essential for cooling the bit and uplifting rock cuttings from the borehole.

This core barrel has proved to be very effective when used with PCD core bits, giving a fast rate of penetration and good core recovery

Advantages:
  • Optimized for the use of air flush

Technical Data

Key to Main Parts of 412F Core Barrel Assembly

Complete core barrel consists of:

1. Core Barrel Head

2. Inner Tube 1.5m or 3.0m

3. Outer Tube 1.5m or 3.0m

4. Inner Tube Extension

5. Core Lifter

6. Core Lifter Case

Mazier Core Barrel

The automatic Mazier core barrel is designed for obtaining undisturbed core samples in very soft soils.

This core barrel has a spring-loaded inner tube assembly. When drilling in soft formations, the core lifter case protrudes up to 50mm in front of the bit, and acts as a cutting shoe. The soft core is protected from the water flush (see Figure a).

When coring in harder materials, the spring loaded inner tube comes under pressure and the inner tube retracts, so now the core lifter case assumes a normal position (see Figure b).

A PVC coreliner is used inside the inner tube to retain the core, and a “basket” catcher can be used to prevent soft materials from slipping out.

This type of core barrel is used widely in some parts of Europe and Australasia and is reported to give 100% recovery in soft formations, such as sands, silts and marls.

It is available in 101mm hole diameter (74mm core) and can be used in conjunction with T2-101 and T6-101 core barrels which are more suited for hard rocks.

The 74 mm diameter core obtained with the mazier is compatible with the commonly used laboratory triaxial testing apparatus. Advantages:
  • Undisturbed core samples from soft soil 0.1MPa
  • Nil wall coefficient

Technical Data

Key to Main Parts of Mazier Core Barrel Assembly

Complete core barrel consists of:

1. Core Barrel Head

2. Outer Tube 1.0m

3. Inner Tube 1.0m

4. PVC Coreliner

5. Basket Core Lifter

6. Cutting Shoe

7. T.C. Core Bit

Coreliner System (Triplex)

Coreliner is a clear, semi-rigid PVC tube that fits inside the inner tube of a core barrel and allows the rapid extraction of cores in their in-situ state. In principle, all double tube core barrels – conventional and wireline – can be quickly and easily converted to triple tube core barrels (sometimes called « Triplex ») – by the addition of a plastic coreliner.

Core barrels that use the coreliner system require a special core bit, core lifter and (in some cases) special core lifter case, with a slightly smaller internal diameter than the standard type. This is because the core must be slightly smaller than usual in order to fit into the PVC coreliner.

This is a very good technique that enhances the quality of core and overall core presentation, especially advantageous when coring sticky, broken and soft formations. It has become the « industry standard » core handling system in those locations where coreliner is readily available.

Coreliner is supplied in standard 10ft (3.05m) lengths which are easily cut down with a hacksaw to 5ft (1.525m) lengths for use in 5ft /1.5m core barrels. Plastic caps are available to seal the ends of the coreliner tubes..

Advantages:
  • Low cost method to convert double tube core barrels to triple tube
  • Cores preserved in their in-situ state
  • No disturbance or damage to cores is possible during core extraction or transportation
  • Major time saving advantage in core removal
  • Reduces wear and damage to core barrels
  • Great technique when coring sticky, soft or broken formations

Technical Data