Description
ZSJ/ZXJ Hydraulic Mechanical Two-Piece Drilling Jar for Oil & Gas Drilling
The ZSJ/ZXJ Hydraulic Mechanical Two-Piece Drilling Jar from SGPE helps drilling crews release stuck drill strings in oil and gas wells. It connects with the drill string and delivers upward and downward jarring force when the bottom hole assembly meets tight hole sections, high drag, differential sticking, key seating, cuttings build-up, poor hole cleaning, or other downhole sticking problems.
Stuck pipe can stop drilling, increase rig cost, damage downhole tools, and lead to fishing or sidetracking. For this reason, drilling contractors, oilfield service companies, and petroleum operators often run a suitable downhole jarring tool in the BHA when the well plan shows a high sticking risk.
The SGPE ZSJ/ZXJ system includes two sections: the ZSJ hydraulic up jar and the ZXJ mechanical down jar. Operators can run both sections together as a complete hydraulic mechanical drilling jar, or use one section alone according to BHA design, connection type, well trajectory, and downhole condition.
This two-piece jarring tool fits oil wells, gas wells, directional wells, high-deviation wells, extended-reach wells, complicated wellbores, and deep petroleum wells. SGPE offers multiple models with different O.D., I.D., API connections, tensile load ratings, torque ratings, strokes, release force ranges, and weights, helping buyers select the right tool for the drill string, hole size, working depth, and project requirements.
Key Product Highlights
- Combines hydraulic up jarring and mechanical down jarring in one two-piece system
- Helps release stuck drill strings in oil and gas drilling operations
- Supports BHA jarring, stuck pipe recovery, and oilfield fishing support
- Fits oil wells, gas wells, directional wells, high-deviation wells, extended-reach wells, complex wells, and deep wells
- Allows combined use or separate use of the ZSJ up jar and ZXJ down jar
- Covers multiple O.D. options from 121 mm to 241 mm
- Provides maximum tensile load up to 2800 kN
- Supports maximum working torque up to 22 × 10³ N·m
- Offers common API connections, including REG, NC, and FH types
- Supports model selection according to hole size, BHA design, load, torque, connection, and required jarring force
Designed for Stuck Pipe Recovery in Demanding Oilfield Conditions
Oil and gas wells often involve high load, high torque, vibration, side force, friction, and difficult wellbore contact. As drilling depth increases or the well trajectory becomes more complex, the risk of sticking also rises. Directional drilling, extended-reach drilling, deep drilling, and high-deviation wells can place heavy demands on the drill string and bottom hole assembly.
The SGPE ZSJ/ZXJ Hydraulic Mechanical Two-Piece Drilling Jar gives the crew two impact directions. When the crew needs upward impact, they can activate the hydraulic up jar by applying tension. When the well condition calls for downward impact, they can use the mechanical down jar after preset adjustment. This design gives operators more recovery options instead of relying on only one jarring direction.
In directional and high-deviation wells, this downhole impact tool helps the drilling assembly overcome tight spots, key seats, and high drag zones. In deep oil and gas wells, it supports BHA designs that require high tensile capacity and stable jarring performance. In complicated formations, it gives the rig crew another practical option when normal drill string movement becomes difficult.
For drilling contractors and oilfield service companies, a reliable jar can help protect drilling progress, reduce downtime, and lower the chance of long fishing operations.
How the ZSJ/ZXJ Hydraulic Mechanical Drilling Jar Works
The ZSJ/ZXJ jar stores energy in the drill string and releases that energy as a sharp downhole impact. When the drill string becomes stuck, the rig crew applies tension or compression through the string. The tool delays movement until the load reaches the release condition. Then it fires through its stroke and sends impact energy toward the stuck point.
ZSJ Hydraulic Up Jar
The ZSJ hydraulic up jar creates upward jarring force. The operator pulls on the drill string, while the hydraulic system controls the delay and release process. As the pulling load increases, the tool prepares to fire. Once it reaches the release condition, it moves through its stroke and delivers a strong upward blow.
The hydraulic design allows the crew to adjust the up jarring force through the tool elevation load. This gives operators better control during the job. However, the crew must always keep the jarring force within the rated load of both the tool and the drill string.
ZXJ Mechanical Down Jar
The ZXJ mechanical down jar creates downward impact. Operators preset the down jarring release force mechanically before running the tool into the well. During operation, the crew applies compression through the drill string. When the compression reaches the preset value, the tool releases and sends downward impact energy toward the stuck assembly.
The mechanical friction mechanism gives the down jar stable release behavior. This section works well when the stuck point needs a downward strike or when the drilling program requires both upward and downward recovery options.
Flexible Two-Piece Operation
The ZSJ and ZXJ sections can run together or separately. This design gives drilling engineers more freedom when building the BHA. For wells with high stuck pipe risk, the crew can run the complete hydraulic mechanical drilling jar. For jobs that only need one impact direction, they can run the up jar or down jar alone.
This flexible structure makes the ZSJ/ZXJ jar a practical choice for conventional oil wells, directional wells, deep gas wells, high-deviation wells, extended-reach wells, and complex petroleum drilling projects.
Main Advantages of SGPE ZSJ/ZXJ Drilling Jar
Dual-Direction Jarring Capability
Not every stuck pipe event responds in the same way. Some downhole conditions need upward impact, while others respond better to downward impact. The ZSJ/ZXJ two-piece structure gives the crew both options in one jarring system, so operators can choose the response that fits the actual well condition.
Strong Support for Stuck Pipe Recovery
The tool helps crews handle common stuck pipe causes, including differential sticking, key seating, tight hole sections, cuttings beds, unstable formations, poor hole cleaning, and high drag in directional wellbores. It gives the rig team a controlled way to apply impact force before the operation moves into more expensive recovery work.
Adjustable Hydraulic Up Jarring
The ZSJ up jar uses a hydraulic system that allows adjustment through elevation load. This helps the crew control the upward impact according to the working condition while staying within the safe operating range of the tool and drill string.
Preset Mechanical Down Jarring
The ZXJ down jar uses a mechanical friction mechanism. Operators set the downward release force before running the tool. This design gives the down jar predictable field performance and makes it suitable for planned down jarring operations.
Better BHA Flexibility
Different wells need different BHA designs. The ZSJ and ZXJ sections can run as one complete tool or as separate jarring sections. This allows drilling engineers to match the tool with hole size, connection type, torque requirement, expected overpull, compression load, and stuck pipe risk.
Wide Model Range for Oilfield Projects
SGPE provides models with O.D. from 121 mm to 241 mm, maximum tensile load from 1400 kN to 2800 kN, and maximum working torque up to 22 × 10³ N·m. This range supports many drilling programs, from smaller hole sections to heavy-duty deep well assemblies.
Reduced Non-Productive Time
Stuck pipe can quickly increase rig time and project cost. A reliable drilling jar gives the crew a direct way to apply controlled impact downhole. When operators use the right model and follow the approved drilling procedure, the tool can help restore drill string movement and support a faster return to drilling.
Oilfield Applications
The SGPE ZSJ/ZXJ Hydraulic Mechanical Two-Piece Drilling Jar suits petroleum drilling operations where the drill string may face sticking, drag, or difficult movement. Operators use it in oil wells, gas wells, petroleum exploration wells, development wells, directional wells, high-deviation wells, extended-reach wells, deep wells, and complicated wellbores.
It also supports drilling intervals with differential sticking risk, key seating risk, poor hole cleaning, cuttings accumulation, tight formations, high torque and drag, or unstable borehole conditions. In oilfield fishing support work, the jar can help create repeated impact force for stuck drill string recovery.
When engineers place the jar correctly in the BHA and keep operating loads within the tool rating, it can improve the crew’s ability to respond to stuck string events in demanding downhole environments.
Product Structure: ZSJ Hydraulic Up Jar and ZXJ Mechanical Down Jar
ZSJ Hydraulic Drilling Up Jar
The ZSJ section provides upward jarring impact. It uses a hydraulic system to control release behavior. The operator applies upward load through the drill string. As the load increases, the hydraulic mechanism delays movement until the release condition appears. Then the tool fires upward and creates impact force.
This section works well when the stuck drill string needs upward movement to break free from the sticking point.
ZXJ Mechanical Drilling Down Jar
The ZXJ section provides downward jarring impact. It uses a mechanical friction system. Before downhole operation, the operator sets the release force mechanically. During the job, the crew applies compression through the drill string. When the compression reaches the preset value, the tool releases and delivers downward impact.
This section works well when the stuck assembly needs a downward strike or when the drilling program requires a two-direction jarring plan.
Combined or Separate Use
Operators can run the ZSJ hydraulic up jar and ZXJ mechanical down jar together as a complete two-piece drilling jar. They can also use one section alone. This structure helps drilling engineers build a BHA that matches the well plan, hole size, drill string connection, and downhole risk.
Technical Specifications
| Parameter / Model | ZSJ94B / ZXJ94B | ZSJ90B / ZXJ90B | ZSJ80B / ZXJ80B | ZSJ76B / ZXJ76B | ZSJ70B / ZXJ70B | ZSJ66B / ZXJ66B | ZSJ64B / ZXJ64B | ZSJ62B / ZXJ62B | ZSJ56B / ZXJ56B | ZSJ46B / ZXJ46B |
|---|---|---|---|---|---|---|---|---|---|---|
| O.D. mm | 241 | 229 | 203 | 197 | 178 | 172 | 165 | 160 | 146 | 121 |
| I.D. mm | 76 | 76 | 71.4 | 71.4 | 70 | 63.5 | 57 | 57 | 57 | 47 |
| Up Overall Length mm | 5450 | 5450 | 5515 | 5515 | 5424 | 5452 | 5360 | 5360 | 5730 | 5300 |
| Down Overall Length mm | 5550 | 5550 | 5250 | 5250 | 5215 | 5098 | 5215 | 5215 | 5000 | 4760 |
| Up Stroke mm | 343 | 343 | 368 | 368 | 344 | 344 | 344 | 344 | 332 | 305 |
| Down Stroke mm | 254 | 254 | 181 | 181 | 178 | 178 | 178 | 178 | 180 | 178 |
| API Connection | 7 5/8 REG | 7 5/8 REG | 6 5/8 REG | 6 5/8 REG | NC50 | NC50 | NC50 | NC46 | 4 1/2 FH | NC38 |
| Max. Tensile Load kN | 2800 | 2800 | 2500 | 2500 | 2300 | 2200 | 2200 | 2200 | 2000 | 1400 |
| Max. Working Torque N·m | 22 × 10³ | 22 × 10³ | 20 × 10³ | 18 × 10³ | 15 × 10³ | 15 × 10³ | 15 × 10³ | 15 × 10³ | 15 × 10³ | 13 × 10³ |
| Rated Release Force for Up Jar kN | 500–700 | 500–700 | 400–600 | 400–600 | 350–550 | 350–550 | 300–450 | 300–450 | 200–350 | 150–250 |
| Max. Up Jarring Released Force kN | 1000 | 1000 | 750 | 750 | 700 | 700 | 550 | 550 | 450 | 270 |
| Max. Down Jarring Release Force kN | 650 | 650 | 600 | 600 | 550 | 550 | 500 | 500 | 400 | 250 |
| Weight kg | 3000 | 2600 | 2124 | 1950 | 1350 | 1280 | 1200 | 1090 | 870 | 650 |
Model Selection Guide
Choosing the right drilling jar model helps improve safety, impact performance, and stuck pipe response. Engineers should match the tool with the hole size, drill string design, API connection, tensile load, working torque, expected jarring force, well depth, and downhole risk.
For heavy-duty drilling assemblies, ZSJ94B/ZXJ94B and ZSJ90B/ZXJ90B offer larger O.D., higher tensile capacity, stronger torque capacity, and higher release force. These models suit demanding well programs where the BHA needs strong impact performance.
For medium and deep oil and gas wells, ZSJ80B/ZXJ80B, ZSJ76B/ZXJ76B, ZSJ70B/ZXJ70B, and ZSJ66B/ZXJ66B provide a balanced combination of size, strength, stroke, and release force. These models work well in many directional wells, complicated oil wells, and deep drilling applications.
For smaller hole sections or lighter drill string designs, ZSJ64B/ZXJ64B, ZSJ62B/ZXJ62B, ZSJ56B/ZXJ56B, and ZSJ46B/ZXJ46B provide suitable dimensions and practical jarring capability without adding unnecessary tool size.
Before ordering, customers should review the planned BHA, drill collar size, drill pipe connection, expected overpull, compression load, torque, mud system, well trajectory, stuck pipe risk, and target interval. SGPE can help check these details and recommend a suitable model according to the project requirement.
Need Help Selecting the Right Model?
Send your hole size, API connection, BHA design, working depth, expected tensile load, maximum torque, and preferred jarring force to SGPE. Our team can help confirm a suitable ZSJ/ZXJ drilling jar before quotation and shipment.
Operation Notes for Oil & Gas Wells
Correct tool selection and proper field operation help the jar deliver stable performance. Before running the tool, operators should confirm that the model, O.D., I.D., connection, tensile rating, torque rating, stroke, and release force range match the drilling program.
The crew should inspect threads, shoulders, seals, working surfaces, and connection areas before the tool enters the well. Clean, well-prepared equipment helps reduce operational risk.
Operators should preset the ZXJ mechanical down jar before downhole operation. After the tool enters the well, the crew cannot freely change the down jarring release force. For the ZSJ hydraulic up jar, the crew can control the upward impact through the elevation load, but the load must stay within the tool and drill string rating.
During operation, the crew should avoid excessive torque, excessive tensile load, and uncontrolled jarring. They should also record the tool model, connection, running depth, jar placement, operating load, jarring cycles, and field performance. These records help engineers improve future well planning and tool selection.
Why Choose SGPE as Your Drilling Jar Supplier?
SGPE supplies oilfield drilling tools and equipment for petroleum drilling contractors, oilfield service companies, and oil and gas operators. For drilling jar buyers, SGPE provides clear specifications, practical model selection support, and export-ready service for international projects.
Before quotation and shipment, SGPE helps confirm model size, API connection, load rating, torque capacity, release force range, and application suitability. This support helps buyers avoid wrong model selection and improves procurement efficiency.
SGPE can support single well projects, drilling fleets, oilfield service operations, and bulk procurement programs. Customers can request product information, technical communication, model confirmation, quotation support, product photos, technical documents, export packing details, inspection support, and delivery coordination according to project needs.
Oilfield buyers need more than a product name. They need correct parameters, clear communication, and reliable support before shipment. SGPE helps customers select a hydraulic mechanical drilling jar that matches the drilling environment and project requirement.
Frequently Asked Questions about Hydraulic Mechanical Two-Piece Drilling Jar
1. What is a drilling jar in oil and gas drilling?
A drilling jar is a downhole tool that helps free a stuck drill string in an oil or gas well. It connects with the drill string and creates a sharp impact when the BHA cannot move normally.
Stuck pipe may come from differential sticking, key seating, cuttings build-up, tight hole sections, high drag, or unstable formations. In these situations, the tool gives the crew controlled impact force to restore movement and reduce the chance of major fishing work.
2. What does the ZSJ/ZXJ Hydraulic Mechanical Two-Piece Drilling Jar do?
The SGPE ZSJ/ZXJ system combines a ZSJ hydraulic up jar and a ZXJ mechanical down jar. It helps crews release stuck drill strings by providing upward and downward impact in one two-piece assembly.
This design gives operators more flexibility in directional wells, deep wells, high-deviation wells, complex wellbores, and drilling projects with high sticking risk.
3. What is the difference between a hydraulic up jar and a mechanical down jar?
A hydraulic up jar delivers upward impact when the operator pulls on the drill string. Its hydraulic system controls delay and release, so the crew can adjust the jarring force through elevation load within the rated range.
A mechanical down jar delivers downward impact after the operator presets the release force before running the tool. During operation, compression activates the down jar once the load reaches the preset value.
4. Why use a two-piece drilling jar for stuck pipe release?
A two-piece drilling jar gives the crew both upward and downward recovery options. Some stuck string conditions respond better to upward pulling, while others need downward impact.
The ZSJ/ZXJ design supports hydraulic up jarring, mechanical down jarring, or combined use. This makes it useful for directional oil wells, deep gas wells, extended-reach wells, and intervals with high torque and drag.
5. Which wells need a hydraulic mechanical drilling jar?
A hydraulic mechanical drilling jar works well in oil and gas wells with high sticking risk. Typical applications include directional wells, deep petroleum wells, high-deviation wells, complicated wellbores, extended-reach wells, and wells with high torque and drag.
It also helps in wells with differential sticking risk, key seating risk, heavy cuttings accumulation, unstable borehole contact, or oilfield fishing support needs.
6. What causes stuck pipe during oil and gas drilling?
Common causes include differential sticking, key seating, tight hole sections, cuttings beds, poor hole cleaning, wellbore instability, high dogleg severity, hole collapse, and excessive torque and drag.
Directional and high-deviation wells often increase the risk because cuttings can settle on the low side of the borehole. Deep wells and permeable formations may also create sticking problems because of higher loads and pressure difference.
7. How do operators choose the right drilling jar model?
Operators should match the jar with the well plan, hole size, BHA layout, drill collar size, API connection, tensile load, torque requirement, stroke, release force range, and expected sticking risk.
Before ordering, customers can share hole size, connection type, BHA design, working depth, expected overpull, torque requirement, and preferred jarring direction with SGPE. This information helps confirm a suitable ZSJ/ZXJ model.
8. Where should a drilling jar be placed in the BHA?
Jar placement depends on the well plan, BHA design, jar type, drill collar arrangement, and expected stuck point. Engineers usually place the tool where it can transfer impact force effectively and stay within the load rating of nearby tools.
The jar also needs enough free drill string above it to store energy and create useful impact. Operators should confirm final placement with the drilling engineer, tool provider, and approved drilling program.
9. Can the ZSJ up jar and ZXJ down jar work separately?
Yes. Operators can run the ZSJ hydraulic up jar and ZXJ mechanical down jar together or separately.
For high-risk wells, the crew can run the complete two-piece tool. For jobs that only need upward impact, they can use the ZSJ up jar. For jobs that only need downward impact, they can use the ZXJ down jar.
10. What information should customers provide before requesting a quotation?
Customers should provide the required model or preferred outside diameter, hole size, well type, oil well or gas well application, and whether the well is vertical, directional, high-deviation, extended-reach, or deep.
They should also share the BHA design, API connection, working depth, expected tensile load, maximum torque, required up jarring force, required down jarring force, order quantity, and delivery requirement. These details help SGPE check model suitability and prepare an accurate quotation.
11. How does the ZSJ/ZXJ jar help reduce non-productive time?
Stuck pipe can lead to fishing, sidetracking, tool replacement, and long rig delays. The ZSJ/ZXJ system helps reduce this risk by giving the crew a controlled way to apply impact force downhole.
The hydraulic up jar provides upward impact, while the mechanical down jar provides downward impact. This dual-direction capability helps the crew respond faster when the drill string becomes stuck.
12. Why choose SGPE as a drilling jar supplier?
SGPE supplies drilling tools and oilfield equipment for petroleum drilling contractors, oilfield service companies, and oil and gas operators. For drilling jar buyers, SGPE provides product specifications, model selection support, and export-ready service.
SGPE can help confirm model size, connection type, tensile load, torque rating, release force range, and application suitability before quotation and shipment. For single well projects, drilling fleets, and oilfield procurement programs, SGPE helps customers choose a hydraulic mechanical drilling jar that fits the drilling environment.
Request a Quote from SGPE
Need a reliable hydraulic mechanical two-piece drilling jar for oil and gas drilling? SGPE can help you select a suitable ZSJ/ZXJ model according to your well condition, drill string design, connection type, working depth, torque requirement, and expected jarring force.
Please send your required model, hole size, API connection, BHA design, working depth, expected tensile load, maximum working torque, required up jarring force, required down jarring force, quantity, and delivery requirement. Our team will review your project details and provide technical support, model confirmation, and a competitive quotation.
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