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9-1/2" x 5-1/4" Oil Core Barrel with Safety Joint , Inner Barrel Adjustment Facilities
  • 9-1/2
  • 9-1/2
  • 9-1/2
  • 9-1/2

9-1/2" x 5-1/4" Oil Core Barrel with Safety Joint , Inner Barrel Adjustment Facilities

Place of Origin Germany
Brand Name ROSCHEN
Certification ISO, API
Model Number 9-1/2" x 5-1/4" , 8" x5-1/4"(12-1/4" hole section), 6-5/8" REG, 8", 6-5/8" REG
Product Details
Down The Hole Hammer, DTH Hammer
Down The Hole Drilling, DTH Drilling
Name Item:
Water Well Drilling Equipment
High Manganese Steel
Hydraulic Crawler Drill Rig
Mineral Drilling, Exploration Core Drilling
Down The Hole Drilling Tools
CIR, DHD, QL,SD, Mission, COP Series DTh Hammer
High Light: 

core drilling tools


down hole drilling tools

Payment & Shipping Terms
Minimum Order Quantity
1 sets
Packaging Details
wooden packing box
Supply Ability
10 sets
Product Description


9-1/2" x 5-1/4" Oil Core Barrel with Safety Joint , Inner Barrel Adjustment Facilities



HT and HD Series Core Barrels

The HT and HD heavy-duty core barrels were developed for high torque, long footage coring in highly deviated holes. They cut 2-1/8’ and 5-1/8’ diameter cores, respectively. Solidly constructed of high structural alloy steel tubing, the core barrels feature a safety tool joint upset. HD barrels incorporate double standard outer tube thread connections to enhance the strength of the tool. HD coring barrels are available in standard 30 foot lengths. The HT outer tubes can be joined to form lengths 20 270ft (82m), and the HD outer tubes can be joined to form lengths to 360 ft (110m). These coring systems are fully stabilized by integral stabilizers.

The system uses inner tube Long Distance Adjustment (LDA) system. Wide LDA adjustment range facilitates accurate spacing of the inner tube in relation to the core bit, compensating for thermal expansion of inner tubes.



Features & Benefits


1. Optional safety joint assembly provides a durable threaded connection that can be broken easily on the rig floor to expedite core retrieval. Standard HD barrels have a top sub.

Swivel assembly permits maximum free rotation for maintaining penetration rates and smooth core recovery. Mud flow through the core barrel is optimized to control coring hydraulics and maintain circulation.

Mud lubricated thrust bearing with tempered ball bearings eliminates need for surface lubricating devices. Ball bearings, unaffected by bottom hole temperature or pressure, enable hot hole or high pressure applications.

A pressure relief plug permits the operator to circulate a prescribed volume through the core barrel prior to coring, ensuring a clean inner tube and hole before coring begins.

When seated in the relief plug, the steel drop ball diverts drilling fluids through ports above the inner tube, causing mud flow between inner and outer tubes. This minimizes core contamination and maintains circulation to the bit for proper cleaning and cooling.

Long Distance Adjustment system enables correct positioning of the inner tube above the core head. A wide range of adjustment easily compensates for differential thermal expansion when using aluminum or fiberglass inner tubes.

Inner tube stabilizers provide optimum stabilization and improved stiffness of the inner barrels when long core barrels are configured.

Outer tube stabilizers provide a ribbed sub to reduce core barrel/outer tube contact against the wellbore wall, reducing the risk of differential sticking and preventing premature core barrel wear to extend tool life.

Optional core jam indicator allows immediate detection of jamming core by causing an increase in standpipe. Pressure at the surface, ensuring that cores are not lost due to milling, pilot-type inner tube shoe stabilizers the lower end of the inner tube against the core bit or bit end bearing and serves as a pilot to guide the core into the catcher. Reduction of core jamming is anticipated.

Standard spring core catcher with tungsten carbide grit I.D. provides gripping on consolidated cores. When pulling the string off bottom, the spring catcher will break the core and prevent its loss while retrieving the barrel to the surface.

The HD barrel is designed to be used in motor coring applications in hole inclinations exceeding 90 degrees.





A. Preparing and checking up work before use.

1. Must be sure there are not metal fish or others hard.

2. Checking up about coring barrel.
• The connection thread and friction ring of safety sub should be intact and all sealing O-rings have to be not damaged.

• The Swivel assembly must be turned smoothed.

• There are not deformations and flaws affecting strength of inner or outside barrels which screw thread should be intact.

• The core catcher be used should have proper elasticity. The tungsten carbide grains of welding layer should be of uniform size and the face of layer should be flat.

• The O.D. of stabilizer has not to be greater than coring bit but not to be four millimeters smaller than it.


3. Assembling core barrel


• When core barrel is assembled, the steel ball is not put in it. After the barrel be running at the bottom of well and wash at the same time, put in the ball through inner hole onto seat and then start to drill core.

• Lift up the inner barrel thread to core gripper assembly together with the outside tube thread to lower stabilizer (or difference nipple) at well site by lift nipple. The outside tube is connected to the coring bit and put in well hole like the way tripping in drill collar while it is stuck by safety slips.

• Clamp the inner barrel by chuck. Sit it on the top of the outside barrel and screw off lift nipple. Connect the selected inner barrels and outside barrels each other in order as above way. The inner barrels are screwed on firmly by chain tongs.

• After the safety sub and the swivel assembly on the rig are connected to the top of inner tube, strip chuck and lower the inner barrel to make the thread pin of safety sub be connected to the thread box of the outside barrels.

• The bottom of inner tube shoe pilot type is 8 to 13 mm apart from the inner shoulder of bit, otherwise check out long distance adjustment.



B. Operation


1. Operate tranquility on trip and forbid sudden force to prevent the tool from swinging violently.

2. Running the tool slowly when it meets the key seat, dogleg or narrow borehole in the course of tripping in. If it is stopped, should ream down borehole again with cone bit.

3. When the tool is stopped by sand plug (or others falling in), should circulate mud and turn drilling tool at the same time to wash down.

4. After the tool running to the bottom of well, circulate mud fully to wash inner barrel and the bottom of well, and then make sensitivity adjustment.
5. Rotating suddenly in the reverse direction is not permit to prevent safety from being screwed off.

C. Coring Operation
Lower drilling string slowly to let coring bit touch the bottom of well. Adopt low limiting speed and low drilling pressure (about 5 KN) to test run. Run the tool smoothly until the bottom of well coincides with the shape of bit and then adjust gradually coring technique parameters to recommended data.


D. Coring Operation

1. Drill ought to feed regularly and drill pressure ought to be increased gradually to avoid oblique-slip.

2. Forbid to run drill string strictly under large drilling pressure.

3. Drill feed ought to be operated by head driller or by special man assigned.

4. Circulating and drilling should not be slopped generally in coring operation while the coring bit does not leave the bottom of well unless an accident.



E. Notice of coring operation 


1. Attention to rotational speed and pump pressure etc in the course of coring operation. When anomalous change occurs, should deal with it resolutely.

2. If pump pressure increases gradually and rotational speed decreases at the same time but pump pressure returns to normal at the time lifting drill string, coring bit is worn torn under general situation and you ought to cut core and then trip out.

3. If pump pressure increases suddenly and rotational speed decreases obviously at the same time, this situation proves that coring bit goes into soft formation and is wrapped by clay and then you ought to adjust drilling pressure.

4. If pump pressure increases and rotational speed does not change but pump pressure does not decreases at the time lifting drill string, the water hole of bit is blocked up at many situations. If this situation is unable to be cleared, ought to cut core and trip out.

5. Pump pressure is big waved while rotational speed is now fast, now slow. The reason is that hard formation is interlaced with soft and so the drilling pressure should be adjusted.

6. Pump pressure become low while rotational speed decreases obviously and coring operation has even no drilling footage.


F. Core Breaking and Single Pipe Connecting


1. Lifting drill sting slowly at the time of core breaking with paying attention to observe weight indicator gage. If hang weight increases from 50 to 150KN and then returns to normal immediately, it is proved that core has been broken. If hang weight increases from 50 to 150 KN and then not return to normal, you should stop lifting drilling string. Keep pull force to core and increases mud flow rate to circulate until core is broken.

2. If hang weight would not increase along with lifting drill string (exceed compressed length), you should trip out immediately.
3. If a single pipe need to be connected, break core and insert stop pin of turnplate to keep drill string motionless. After a single pipe is connected to drill string, lower drill string slowly onto the bottom of well. Then increase drilling weight bigger 10% ~ 50% than before to make remainder core insert into core gripper. After lifting drill string and returning hang weight to before, run turnplate and increase drilling weight gradually to recommended parameters.

Service instruction

1. Check up if or Swivel assembly, inner tube, outside tube, stabilizer, coring bit and the connection thread.
2. Check up the connection thread of Swivel assembly, inner and core gripper etc loosens or not.
3. Bearing

• Must turn smoothed.

• Clearance along axial direction can not exceed five millimeters.


4. Safety joint

• Check up sealing O-ring and change over it damaged.

• Should be cleaned after use and spread antirust grease on the screw thread.


5. Stabilizer ought to be repaired when it is worn and torn until the O.D. of it is smaller four millimetres than bit O.D.

6. Coring tool must be washed cleanly after use. Spread antirust grease on screw threads. Parts and auxiliary tools are place in box.

7. Coring tool can not permit to be ram in the course of shipping as well as loading or unloading and should be lifted and laid smoothly.



When ordering, please specify:


1. Name and part number of assembly

2. Size of core

3. O.D. and I.D. of outer barrel

4. O.D. and I.D. of inner barrel

5. Types and size of stabilizers

6. Top connection


Core Barrel Specifications Core Barrel Specifications

4-3/4' x 2-5/8'

6-3/4' x 4'

8' x 5-1/4'

Core Barrel Length

Multiples of 30ft

Multiples of 30ft

Multiples of 30ft

Outer Tube

4-3/4' x 3-3/4'

6-3/4 x 5-3/8'

8' x 6-5/8'

Inner Tube

3-3/8' x 2-7/8'

4-3/4' x 4-1/4'

6-1/4' x 5-1/2'

Top Connection*

3-1/2' IF

4-1/2' IF

6-5/8' REG.





Steel Ball Size




Core Size O.D.




Recommended Hole Sizes

5-3/4' ~ 7'

8 ~ 9'

9 ~ 12-1/4'

Weight(Gross) Ibs.




Recommended Max.Pull




Yield Torque (ft.Ibs.)




Makeup Torque(ft.Ibs)




Operating Parameters









Fluid Capacity(min/max)

100/210 GPM

200/450 GPM

390/450 GPM




Specification of fiber Inner Tube


Volumic Mass (1000kg/m3)

Coefficient of thermal expansion (-108/℃)

Heat Conduction Coefficient (W/m.℃)

Tensile Strength  (Mpa)

Working Temperature(℃)








Bottom Thread of Outer Tube


Core Barrel

Outer Tube

Threads Per Inch






4-3/4' x 3-3/4'

4-3/4' x 3-3/4'







6-3/4' x 5-3/8'

6-3/4' x 5-3/8'







8' x 6-5/8'

8' x 6-5/8'











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