Description
Mechanical-Hydraulic Drilling Jar for Controlled Upward and Downward Jarring
The JYSZ series combines a mechanical locking structure with hydraulic operating control in a double-acting drilling jar. It is designed to deliver repeated upward or downward impact when the drill string encounters sticking, drag or downhole restriction during drilling operations.
What Is a Mechanical-Hydraulic Drilling Jar?
A mechanical-hydraulic drilling jar is a downhole tool that combines mechanical locking with hydraulic control to store drill-string energy and release it as an impact when sticking occurs. The JYSZ is double acting, allowing both upward and downward jarring. This gives the driller two recovery directions while maintaining a defined release mechanism during normal drilling and jarring operations.
Key Product Advantages
Mechanical-Hydraulic Design
Combines mechanical locking and hydraulic control instead of relying on only one release principle.
Double-Acting Jarring
Provides both upward and downward jarring so the operator can respond to different sticking conditions.
Defined Release Load
Each model has specified up- and down-release load ranges to support predictable tool selection.
Large Size Coverage
Six models cover 121–241 mm OD for a broad range of drill-string and BHA configurations.
NC & REG Connections
Standard connection options include NC38, NC46, NC50, 6-5/8 REG and 7-5/8 REG.
Repeatable Jarring Cycle
The tool can be reset and cycled repeatedly to deliver multiple impacts during a stuck-pipe recovery operation.
Designed for Stuck-Pipe Recovery While Drilling
The JYSZ drilling jar is run as part of the bottom-hole assembly or drill string and remains available during normal drilling. When the string becomes stuck, controlled tensile or compressive loading is applied to activate the appropriate jarring direction.
How the JYSZ Double-Acting Jar Works
Apply Overpull and Release Stored Energy
With the jar reset, upward load is applied through the drill string. The locking and hydraulic control sections resist movement while energy builds in the string. When the release condition is reached, the mandrel accelerates and converts stored elastic energy into an upward impact.
Slack Off to Generate Downward Impact
For downward jarring, compressive load is applied after the jar is reset. Once the specified down-release condition is exceeded, the internal mechanism releases and produces a downward impact. The cycle can then be repeated as required.
JYSZ Mechanical-Hydraulic Drilling Jar Specifications
Select the model primarily by BHA size, connection, load requirement, allowable working tension and torque.
| Parameter | JYSZ121 | JYSZ159 | JYSZ165 | JYSZ178 | JYSZ203 | JYSZ241 |
|---|---|---|---|---|---|---|
| OD, in (mm) | 4 3/4 (121) | 6 1/4 (159) | 6 1/2 (165) | 7 (178) | 8 (203) | 9 1/2 (241) |
| ID, in (mm) | 2 (51) | 2 1/4 (57.2) | 2 1/4 (57.2) | 2 17/32 (64) | 2 13/16 (71.4) | 3 (76.2) |
| Connection | NC38 | NC46 | NC50 | NC50 | 6 5/8 REG | 7 5/8 REG |
| Up Free Stroke, in (mm) | 6 (152) | |||||
| Down Free Stroke, in (mm) | 6 (152) | |||||
| Maximum Jarring Force, kN | 350 | 700 | 700 | 800 | 1000 | 1250 |
| Rated Up Release Load, kN | 200–240 | 400–450 | 400–450 | 400–450 | 450–500 | 450–500 |
| Rated Down Release Load, kN | 80–100 | 180–200 | 180–200 | 180–200 | 190–210 | 200–220 |
| Maximum Tensile Load, kN | 1600 | 3400 | 3400 | 3700 | 4400 | 5400 |
| Allowable Working Tension, kN | 1100 | 2000 | 2000 | 2400 | 2800 | 3500 |
| Maximum Torque, kN·m | 20 | 51 | 51 | 60 | 100 | 129 |
| Working Torque, kN·m | 15 | 25 | 25 | 30 | 35 | 40 |
| Pump-Open Area, cm² | 75.4 | 126.6 | 126.6 | 143.1 | 198.5 | 283.4 |
Technical values above are based on the supplied JYSZ product data. Final connection, release setting and operating configuration should be confirmed against the customer’s drilling program before manufacture and shipment.
Need Help Selecting a JYSZ Model?
Send us your BHA size, connection, expected tensile load, required jarring direction and operating conditions.
How to Select the Correct JYSZ Drilling Jar
1. Match Tool OD to the BHA
Select an outside diameter that is compatible with the drill-string and wellbore clearance.
2. Confirm the Connection
Match NC or REG connections to adjacent drill-string components without introducing unnecessary crossovers.
3. Check Release Load
Compare the rated up/down release range with the planned drill-string operating loads and jarring program.
4. Check Tension & Torque
Allowable working tension and working torque must be compatible with the expected BHA loads.
5. Confirm Well Conditions
Provide hole size, well trajectory, drilling-fluid system and expected operating temperature before final selection.
6. Review Jar Placement
Final placement should be determined from the BHA design and expected sticking mechanism, not from tool OD alone.
Mechanical-Hydraulic vs Hydraulic vs Mechanical Drilling Jars
The JYSZ is intended for buyers who want a hybrid operating concept rather than a purely hydraulic or purely mechanical jar.
| Selection Factor | JYSZ Mechanical-Hydraulic | Full Hydraulic Jar | Mechanical Jar |
|---|---|---|---|
| Operating concept | Mechanical locking + hydraulic control | Hydraulic delay/release | Mechanical release |
| Jarring direction | Up + Down | Model dependent | Model dependent |
| Best fit | Programs requiring a hybrid double-acting jar | Programs prioritizing hydraulic control | Programs prioritizing a fully mechanical release system |
| Shangshanpetro option | JYSZ Series | QY Hydraulic Drilling Jar | QJZ Mechanical Drilling Jar |
Engineering and Procurement Considerations
A drilling jar should not be selected only by nominal outside diameter. The release setting, tensile capacity, working torque, connection and BHA placement must be reviewed together. For procurement teams, this also means the quoted model should correspond to the actual drill-string program rather than a generic size request.
If your application uses a specific drill collar or adjacent heavy BHA component, also review our API drill collar specifications when checking connection and load compatibility.
Information to Send for a Technical Quotation
Send these details through Contact Us for a Quote.
Frequently Asked Questions
What is the main difference between the JYSZ and a full hydraulic drilling jar?
The JYSZ uses a combined mechanical-hydraulic operating concept, while a full hydraulic jar relies primarily on hydraulic delay and release. The choice should be based on the required release behavior, BHA design and operating program.
Can the JYSZ jar both upward and downward?
Yes. The JYSZ is a double-acting drilling jar and is designed to deliver both upward and downward jarring.
What sizes are available?
The standard series shown here includes JYSZ121, JYSZ159, JYSZ165, JYSZ178, JYSZ203 and JYSZ241, covering 121 mm to 241 mm outside diameter.
Which connections are available?
The listed standard connections are NC38, NC46, NC50, 6-5/8 REG and 7-5/8 REG depending on model. Connection requirements should be confirmed against the adjacent BHA components before ordering.
How should I choose the release-load range?
Release load should be evaluated together with drill-string tensile capacity, planned operating load, jar placement and expected sticking condition. Send the BHA information to Shangshanpetro for model confirmation.
Should a jar be selected only according to hole size?
No. Hole size is only one selection factor. Tool OD, connection, tensile load, torque, release load, BHA position, well trajectory and operating conditions should all be reviewed.
What information is needed before ordering?
Provide the required model or OD, connection, BHA, hole size, working loads, jarring direction, drilling-fluid system, maximum downhole temperature, quantity and any inspection or documentation requirements.
Related Drilling Tools
Request a JYSZ Drilling Jar Technical Quote
Tell us the required size, connection, BHA and operating loads. We will confirm the suitable JYSZ configuration for your drilling program.
