Description

SJ Double-Way Shock Absorber

Oilfield Downhole Shock Absorber for Axial Shock and Torsional Vibration Control

The SJ Double-Way Shock Absorber from SGPE helps control axial shock, torsional vibration, stick-slip, BHA whirl, and bit bounce during oil and gas drilling. It protects the drill bit, drill string, and bottom hole assembly from sudden impact loads, unstable torque, and harmful downhole vibration.

In many wellbore sections, the drill bit meets hard formations, changing rock layers, uneven weight on bit, and torque fluctuation. These conditions can cause cutter damage, tool fatigue, poor drilling stability, lower drilling efficiency, and higher operating cost. The SJ Type double-way shock absorber absorbs impact energy and helps the drill string run more smoothly.

SGPE builds this oilfield downhole shock absorber with a strong mechanical structure, hydraulic damping system, and torsional-to-axial conversion mechanism. Operators use it in oil wells, gas wells, deep wells, directional wells, horizontal wells, hard formations, interbedded formations, and high-vibration drilling sections.

Send SGPE your hole size, connection type, expected WOB, torque requirement, and drilling condition. Our team will help you select a suitable SJ model for your drilling program.

Quick Product Overview

Item	Details
Product Name	SJ Double-Way Shock Absorber
Product Type	Oilfield downhole shock absorber
Main Function	Controls axial shock and torsional vibration
Common Problems Solved	Stick-slip, BHA whirl, bit bounce, torque fluctuation, vibration damage
Main Applications	Oil well drilling, gas well drilling, directional drilling, horizontal drilling, hard formation drilling
O.D. Range	121 mm to 241 mm
Max. Torque	10 kN·m to 20 kN·m
Max. Bit Weight	200 kN to 540 kN
Temperature Range	-40°C to 150°C
Connection Options	NC38, NC46, NC50, 6 5/8 REG, 7 5/8 REG
Suitable Customers	Drilling contractors, oilfield service companies, petroleum equipment distributors

What Is an SJ Double-Way Shock Absorber?

The SJ Double-Way Shock Absorber is a downhole drilling tool used in the drill string or bottom hole assembly. It controls vibration from two directions:

Axial / vertical shock from bit impact, uneven WOB, formation changes, drill string bounce, and unstable drilling load.
Torsional / horizontal vibration from torque fluctuation, stick-slip, bit resistance, rotary instability, and BHA whirl.

A single-way shock absorber mainly handles vertical impact. However, oil and gas drilling often creates axial shock and torsional vibration at the same time. The SJ Type double-way design controls both problems in one tool.

This makes it a strong choice for high-load drilling, hard formations, interbedded formations, unstable wellbore sections, high-torque drilling, and vibration-sensitive BHA designs.

Key Benefits for Oilfield Drilling

Protect Drill Bits and BHA Tools

The SJ shock absorber reduces sudden shock loads on the drill bit, drill collar, stabilizer, downhole motor, MWD tools, LWD tools, and other BHA components. This helps extend tool life and reduce vibration-related failures.

Improve Torque Stability

Stick-slip can damage cutters, connections, motors, and drill string components. The SJ Double-Way Shock Absorber reduces torsional impact and helps the drill string maintain more stable rotation in high-load and high-friction drilling sections.

Reduce BHA Whirl and Lateral Vibration

BHA whirl can create severe side loads and unstable bit movement. The SJ shock absorber controls axial and torsional energy together, so the bottom hole assembly can run more steadily.

Support Smoother Drilling Performance

Stable drilling helps the bit stay in better contact with the formation. The tool reduces bit bounce, vibration spikes, and impact load, which supports smoother drilling and more consistent performance.

Lower Vibration-Related Drilling Cost

Bit damage, BHA failure, frequent tripping, and non-productive time can increase drilling cost quickly. The SJ Series helps drilling teams reduce these risks in demanding downhole conditions.

Drilling Problems This Tool Helps Solve

The SJ Double-Way Shock Absorber gives drilling teams a practical solution when vibration starts to affect bit life, BHA stability, or drilling efficiency. It helps control several common downhole problems:

Bit bounce: Reduces repeated vertical impact between the bit and formation.
Stick-slip: Helps control torque fluctuation and sudden energy release in the drill string.
BHA whirl: Reduces unstable lateral motion and helps the BHA run more smoothly.
High tool vibration: Helps protect downhole tools from shock-related damage.
Fast bit wear: Supports better bit contact and more stable cutting action.
Poor weight transfer: Helps drilling teams maintain more stable downhole performance.
Vibration-related NPT: Reduces the risk of tool failure, tripping, and drilling interruption.

This section helps buyers quickly connect the product with their real drilling problems.

How the SJ Double-Way Shock Absorber Works

During drilling, the lower drill string carries axial pressure and rotary torque at the same time. Bit structure, formation hardness, drilling speed, and weight on bit all affect torque at the bottom of the wellbore.

When vibration reaches a critical level, the drill string may develop resonance, bending motion, stick-slip, or BHA whirl. If WOB exceeds the buckling load limit, the drilling tool can lose stability and transfer strong impact loads to the bit and BHA.

The SGPE SJ Double-Way Shock Absorber controls these problems through two key systems.

1. Vertical Damping Unit

The vertical damping unit includes:

Mandrel
Piston assembly
Annular space damping unit
Fluid working chamber
Damping chamber

Inside the working chamber, compressible fluid works like a spring. When the bit receives impact, the fluid compresses and stores part of the vibration energy. When the load changes, the fluid expands and releases energy in a controlled way.

At the same time, non-compressible fluid flows through the damping space. This flow creates friction and heat, which dissipates vibration energy. As a result, the unit reduces vertical impact, lateral vibration, and bit bounce before the full shock load reaches the upper drill string.

2. Piston Change-Over Assembly

The piston change-over assembly controls torsional impact. It converts part of the twisting load into axial movement inside the working chamber.

This assembly includes:

Spline outer barrel
Rectangular spline connection
Piston
Mandrel
Ladder-shaped spiral spline

The spline outer barrel connects with the piston through rectangular splines. The inner surface of the piston connects with the mandrel through ladder-shaped spiral splines. When torsional vibration occurs, this structure changes part of the torsional energy into axial force. Then the hydraulic damping system absorbs and reduces that energy.

This mechanism improves torque stability, protects the BHA, and supports smoother drilling in high-vibration wellbore conditions.

When Should You Use a Downhole Shock Absorber?

A downhole shock absorber becomes useful when drilling conditions create repeated impact, unstable torque, or abnormal BHA movement. Operators often consider the SJ Double-Way Shock Absorber when they notice:

Bit bounce
Stick-slip vibration
Torque fluctuation
BHA whirl
High lateral vibration
Fast bit wear
Cutter damage
Repeated downhole tool failure
Poor weight transfer
Unstable drilling performance
High vibration in directional or horizontal sections

In these conditions, the SJ shock absorber helps protect the bit, stabilize the drill string, and reduce vibration-related downtime.

Oilfield Applications

The SJ Double-Way Shock Absorber works in drilling environments where impact load, torque fluctuation, stick-slip, or BHA instability affects performance.

It suits:

Oil well drilling
Gas well drilling
Deep oil and gas well drilling
Directional drilling
Horizontal well drilling
Hard formation drilling
Interbedded formation drilling
High-torque drilling sections
High-vibration BHA operations
Drill bit protection applications
Stick-slip reduction projects
BHA whirl control
Drill string vibration control
Downhole tool protection
Vibration-related cost reduction

Drilling contractors, oilfield service companies, and petroleum equipment distributors use this tool to protect the bit, stabilize the drill string, and reduce downhole vibration damage.

Product Features

Double-Way Vibration Control Structure

The tool controls both vertical impact and torsional vibration. It offers stronger protection than a single-way shock absorber in complex drilling conditions.

Hydraulic Fluid Damping Chamber

The fluid working chamber and damping chamber absorb and dissipate vibration energy. This design reduces impact load and improves drilling smoothness.

Spiral Spline Conversion Mechanism

The piston change-over assembly changes part of the torsional impact into axial force. This feature helps reduce torque fluctuation and supports stable drill string rotation.

Heavy-Duty Mandrel and Piston Design

SGPE uses a mandrel, piston system, spline outer barrel, and spiral spline structure to support high-load downhole drilling applications.

Wide Model Range for BHA Matching

The SJ Series covers O.D. sizes from 121 mm to 241 mm. Customers can choose different torque ratings, bit weight capacities, tensile loads, connections, and overall lengths according to the drilling program.

Harsh Wellbore Compatibility

The SJ Series supports an ambient temperature range from -40°C to 150°C. It works in demanding oil and gas drilling sections where vibration control matters.

Technical Specifications

Model	SJ46B	SJ62C	SJ64C	SJ70C	SJ80C	SJ90C	SJ94C
O.D. mm	121	160	165	178	203	229	241
I.D. mm	38	47	47	57	64	71	71
Max. Stroke mm	110	120	120	100	120	120	120
Ambient Temperature °C	-40~150	-40~150	-40~150	-40~150	-40~150	-40~150	-40~150
Max. Torque kN·m	10	15	15	15	20	20	20
Max. Bit Weight kN	200	340	340	400	480	540	540
Tensile Load kN	1000	1500	1500	1500	1960	1960	1960
Pull-Down Overall Length mm	4490	5193	5193	5620	5586	5460	5460
Connection	NC38	NC46	NC50	NC50	6 5/8 REG	7 5/8 REG	7 5/8 REG
Weight kg	320	550	600	700	1000	1300	1500

Mobile note: Swipe left or right to view all models on mobile devices.

Model Selection Guide

Choosing the right SJ Double-Way Shock Absorber depends on hole size, BHA design, bit type, WOB, torque requirement, connection type, temperature, and vibration severity.

For smaller hole sizes and lower torque requirements, SJ46B offers a compact structure with 121 mm O.D., 10 kN·m max torque, and NC38 connection.

For medium drilling programs, SJ62C, SJ64C, and SJ70C provide balanced size, torque capacity, and bit weight capacity. These models suit many directional drilling and high-vibration drilling sections.

For larger boreholes and heavy-duty drilling conditions, SJ80C, SJ90C, and SJ94C offer higher load capacity, larger O.D., and stronger tensile load. These models suit applications where BHA stability, bit protection, and vibration control play a critical role.

SGPE can help select the right model after reviewing your well plan and operating parameters.

Information Needed for Selection and Quotation

To recommend the right downhole shock absorber, SGPE usually needs the following details:

Required model or outside diameter
Connection type
Oil well or gas well type
Hole size
Well depth
Drill string design
BHA configuration
Bit type
Formation condition
Expected weight on bit
Torque requirement
Rotary speed, if available
Downhole temperature
Vibration problem to solve
Quantity
Destination port or country

These details help SGPE provide a more accurate model suggestion, quotation, and lead time.

Quality and Customization Support

SGPE supports model selection, connection confirmation, technical communication, and export packing for oilfield customers.

Customers can discuss customized connection requirements according to drill string design, BHA layout, and project needs. For international orders, SGPE can help confirm product details before shipment and prepare export packing for long-distance transportation.

Upon request, customers can also discuss:

Technical drawing confirmation
Thread connection requirements
Dimensional checking
Thread protection
Export wooden case packing
Inspection photos before shipment
OEM supply for oilfield equipment distributors

This support helps drilling contractors, service companies, and equipment distributors confirm the right shock absorber before placing an order.

Why Choose SGPE?

SGPE supplies practical oilfield drilling tools for demanding downhole operations. We focus on stable product performance, clear technical communication, and responsive service.

When you choose SGPE SJ Double-Way Shock Absorber, you get:

Multiple models for different oil and gas drilling programs
Support for model selection based on hole size, WOB, torque, and BHA design
Strong structure for high-load downhole conditions
Standard NC and REG connection options
Customized connection discussion upon request
Export packing support for international oilfield projects
Technical drawing confirmation upon request
OEM discussion for oilfield equipment distributors
Practical solutions for drilling contractors and service companies

SGPE helps customers source dependable downhole tools for drill string vibration control, BHA protection, and oilfield drilling efficiency.

Request a Quote for SJ Double-Way Shock Absorber

Need a reliable oilfield downhole shock absorber for axial shock and torsional vibration control?

Send SGPE your drilling parameters. Our team will help you choose a suitable SJ model for your oil or gas well drilling project.

Please provide the model, O.D., connection type, hole size, well depth, bit type, expected WOB, torque requirement, working temperature, quantity, and destination.

Contact SGPE today for technical support, price, lead time, and customized oilfield drilling Downhole tool solutions.

E-Mail:
info@sgpe.com

FAQ About Oilfield Downhole Shock Absorber

1. What does an SJ Double-Way Shock Absorber do?

The SJ Double-Way Shock Absorber reduces axial shock, torsional vibration, stick-slip, BHA whirl, bit bounce, and drill string vibration during oil and gas drilling.

It protects the drill bit, bottom hole assembly, drill collar, stabilizer, downhole motor, MWD tools, LWD tools, and other downhole drilling tools from sudden impact loads. It also improves drilling stability and helps reduce non-productive time caused by vibration-related tool damage.

2. What is the difference between a single-way shock absorber and a double-way shock absorber?

A single-way shock absorber mainly reduces axial impact or vertical shock. It works well when bit bounce or sudden vertical load creates the main drilling problem.

A double-way shock absorber controls both axial shock and torsional vibration. The SJ Type double-way shock absorber reduces vertical impact, torque fluctuation, stick-slip, and BHA whirl at the same time. This makes it a stronger option for complex downhole conditions.

3. How does the SJ Double-Way Shock Absorber protect the drill bit?

The drill bit often meets hard rock, changing formations, uneven WOB, and unstable torque. These conditions can cause bit bounce, cutter damage, abnormal wear, and lower rate of penetration.

The SJ shock absorber absorbs part of the impact energy before the shock load reaches the bit and upper drill string. It also helps maintain better bit contact with the formation. As a result, the tool protects the bit and improves cutting stability.

4. Can the SJ Double-Way Shock Absorber reduce stick-slip vibration?

Yes. The SJ Type shock absorber reduces stick-slip by controlling torsional impact and torque fluctuation in the drill string.

Stick-slip often occurs when the bit slows down, stops, and then suddenly releases stored torque. This can damage cutters, BHA tools, and drill string connections. The piston change-over assembly converts part of the torsional vibration into axial movement, while the hydraulic damping system absorbs and dissipates the energy.

5. Can this tool help control BHA whirl?

Yes. The SJ Double-Way Shock Absorber helps control harmful BHA vibration and instability, including forward whirl, backward whirl, lateral vibration, and torsional vibration.

BHA whirl can create severe side loads and damage downhole tools. By reducing axial impact and torsional shock together, the SJ shock absorber helps the bottom hole assembly run more smoothly in directional wells, horizontal wells, deep wells, and high-vibration sections.

6. Where should operators install the SJ shock absorber in the drill string?

Operators usually install the SJ Double-Way Shock Absorber in the drill string or BHA according to the drilling program.

The best position depends on bit type, hole size, BHA design, formation condition, WOB, rotary speed, torque requirement, and vibration severity. In many applications, the tool works close to the vibration source to protect the bit and lower BHA. SGPE can review the basic drilling parameters and recommend a suitable model.

7. Is the SJ Double-Way Shock Absorber suitable for directional drilling and horizontal drilling?

Yes. The SJ Double-Way Shock Absorber suits many directional drilling and horizontal well drilling applications.

These wells often face high friction, unstable torque, poor weight transfer, BHA vibration, and stick-slip. The SJ shock absorber reduces axial impact and torsional vibration, so it can support smoother drilling in curved sections, horizontal sections, and high-vibration wellbore conditions.

8. What drilling conditions need a downhole shock absorber?

A downhole shock absorber becomes important when the drilling operation shows bit bounce, stick-slip, torque fluctuation, BHA whirl, high tool vibration, fast bit wear, or repeated downhole tool failure.

The SJ Double-Way Shock Absorber works well in hard formations, interbedded formations, deep well sections, high-torque drilling sections, directional wells, horizontal wells, and severe vibration conditions. It helps drilling teams protect the bit, stabilize the BHA, and reduce vibration-related cost.

9. How do I choose the right SJ Double-Way Shock Absorber model?

To choose the right model, compare your well condition with each model’s O.D., I.D., max stroke, max torque, max bit weight, tensile load, connection type, tool length, and tool weight.

For smaller hole sizes and lower torque needs, SJ46B may fit the application. For medium drilling programs, SJ62C, SJ64C, and SJ70C offer balanced size and load capacity. For larger boreholes, higher WOB, and heavy-duty drilling, SJ80C, SJ90C, and SJ94C provide stronger torque capacity and tensile load.

10. What information should I provide before requesting a quote?

Please provide the required model or O.D., connection type, well type, hole size, well depth, bit type, expected WOB, torque requirement, rotary speed, working temperature, BHA design, quantity, and destination.

With these details, SGPE can check the working condition, suggest a suitable SJ model, and reply with a clearer quotation and lead time.

11. What temperature range and connection types does the SJ Series support?

The SJ Series supports an ambient temperature range from -40°C to 150°C, which suits harsh oilfield downhole conditions.

Standard connection options include NC38, NC46, NC50, 6 5/8 REG, and 7 5/8 REG, depending on the selected model. SGPE can also discuss customized connection requirements according to drill string design, BHA configuration, and project needs.

12. Why should oilfield customers choose SGPE SJ Double-Way Shock Absorber?

SGPE supplies oilfield drilling tools for drilling contractors, oilfield service companies, and petroleum equipment distributors.

The SJ Double-Way Shock Absorber helps customers control drill string vibration, protect expensive BHA components, improve drilling stability, and reduce vibration-related downtime. SGPE can also support model selection, connection discussion, technical communication, export packing, inspection photo discussion, and responsive quotation service for international oilfield projects.

Contact SGPE today for technical support, price, lead time, and customized oilfield drilling tool solutions.