Product Overview
The Torque Thru Knuckle Joint, also known as torque transmissible downhole universal joint, is a specialized flexible downhole accessory independently developed for coiled tubing fishing, coiled tubing drilling and torque transmission required well intervention operations. It can work in coordination with downhole drilling motors and other torque-generating downhole tools, stably transferring torque from upper tool string to lower working equipment while preventing drilling motors and vulnerable downhole tools from torque impact damage.
This torque thru knuckle joint features a dual functional design: torque transmission and angular deflection. It allows maximum 15° angular deviation to adapt irregular wellbore trajectories, effectively centralizing fallen fish during fishing operations. For ultra-long downhole tool string assemblies, multiple torque thru knuckle joints can be connected in series to greatly enhance the overall flexibility of the tool string, reducing friction resistance between rigid tool string and borehole wall and lowering stuck pipe risks in deviated and horizontal wells.
All standard torque thru knuckle joint models adopt STD standard carbon steel as base material, with complete outer diameter specifications ranging from 1-11/16" to 2-7/8". Each size corresponds to standardized internal through bore and assembly length, equipped with three mainstream oilfield connection thread standards: 1" AMMT, 1-1/2" AMMT and 2-3/8" PAC. The integral sealed structure eliminates fragile internal wearing components, delivering stable long-term downhole service performance and minimal daily maintenance workload.
Complete Technical Specification Table
| PN Part Number | Outer Diameter OD | Internal Through Bore ID | Overall Make-Up Length | Working Condition Grade | Connection Thread |
|---|---|---|---|---|---|
| L4041690120 | 1-11/16" | 0.33" | 12" | STD Standard Carbon Steel | 1" AMMT |
| L4041750120 | 1-3/4" | 0.33" | 12" | STD Standard Carbon Steel | 1" AMMT |
| L4042125120 | 2-1/8" | 0.5" | 13.4" | STD Standard Carbon Steel | 1-1/2" AMMT |
| L4042250120 | 2-1/4" | 0.55" | 13.4" | STD Standard Carbon Steel | 1-1/2" AMMT |
| L4042500120 | 2-1/2" | 0.67" | 13.3" | STD Standard Carbon Steel | 1-1/2" AMMT |
| L4042875120 | 2-7/8" | 0.94" | 15.3" | STD Standard Carbon Steel | 2-3/8" PAC |
Core Features & Advantages
Unique Torque Thru Transmission Capability Different from conventional flexible knuckle joints without torque transfer function, this torque thru knuckle joint adopts special internal transmission structure, which can stably transmit rotary torque generated by drilling motors and upper coiled tubing string to lower fishing or drilling tools. It avoids torque accumulation, torsion deformation and structural damage of downhole working tools, greatly improving safety and stability of torque-bearing coiled tubing operations.
Max 15° Angular Deflection for Complex Well Trajectory Adaptation The joint body supports maximum 15° free angular deflection, which can compensate angle changes of deviated and horizontal well boreholes, adjust tool string running angle in real time, and accurately centralize fallen fish inside the wellbore during fishing operations, greatly improving fishing success rate and construction efficiency.
Series Connection Design to Boost Long Tool String Flexibility When assembling extra-long downhole tool strings, multiple torque thru knuckle joints can be connected in series. Each joint independently provides flexible deflection performance, cumulatively increasing the overall bending flexibility of the entire tool string. This design effectively reduces rigid collision and friction between long tool strings and irregular borehole walls, lowering stuck pipe risk for deep, deviated and horizontal well intervention.
Full-Size Standard Thread Matching System The complete torque thru knuckle joint product line is configured with standardized oilfield connection threads corresponding to different outer diameter sizes. Small OD models match 1" AMMT thread, medium OD models adopt 1-1/2" AMMT thread, and large-size models support 2-3/8" PAC thread. All thread sizes follow unified industry precision machining standards, enabling direct plug-and-play assembly with coiled tubing strings, weight bars, drilling motors and fishing tool assemblies without secondary modification or extra adapter conversion.
Fully Sealed Integral Structure, Stable Downhole Service Performance The internal torque transmission and deflection moving components are wrapped by high-performance integrated sealing assembly, effectively isolating downhole formation fluid, completion brine and solid sand debris from internal transmission parts. It avoids internal component corrosion, sand jamming, torque transmission failure and deflection jamming under long-term downhole torque-bearing working conditions, greatly extending the service cycle of the torque thru knuckle joint and reducing on-site tool replacement frequency.
Low Maintenance & Simple On-Site Assembly Operation There are no fragile spring parts or easily worn sealing components inside the torque thru knuckle joint main body. The overall forging structure is sturdy and impact-resistant, capable of enduring long-term downhole torque and compression loads. On-site assembly only requires standard torque tightening of upper and lower connection threads, which greatly shortens tool string pre-assembly time before well operation. After finishing downhole service, only simple surface cleaning and appearance inspection are needed, cutting down after-sales maintenance labor cost and spare parts inventory pressure.
Application Scenarios
1. Conventional onshore and offshore oil & gas well coiled tubing fishing operations, including fallen tubing, perforating gun, downhole tool fish centralization and retrieval construction.
2. Coiled tubing drilling operations matched with downhole drilling motors, stably transferring rotary torque and protecting drilling motors and vulnerable downhole tools from torque impact damage.
3. Long coiled tubing tool string assembly for deep, highly deviated and horizontal well intervention jobs, multiple torque thru knuckle joints connected in series to increase overall tool string flexibility and reduce borehole friction resistance.
4. Conventional low-sulfur oil and gas well maintenance, well plugging, well abandonment and secondary reservoir reconstruction torque-bearing intervention operations.
5. Matching assembly with weight bar, drilling motors, fishing spears, hydraulic setting tools and jetting subs to form complete standardized torque-transmissible coiled tubing downhole tool combination.
6. Slim small-diameter coiled tubing fishing and drilling service jobs for slim hole and compact wellhead oilfield projects.
Standard Delivery Package
Complete pre-assembled integral torque thru knuckle joint unit with factory precision thread finishing and surface anti-rust protective treatment.
Hard plastic thread protective caps and anti-collision packaging accessories for safe transportation and long-term warehouse storage.
Factory full dimensional tolerance inspection report, base material chemical composition analysis report and mechanical property tensile & torque load test certificate.
Official product installation operation guide and series connection tool string matching assembly manual for on-site torque-bearing construction reference.
Optional customized thread precision inspection report and third-party independent material certification for overseas oilfield fishing & drilling project bidding document requirements.
Quality Warranty & After-Sales Service
Warranty Coverage: 12 months after factory shipment or 500 times cumulative downhole tripping & torque transmission operation cycles, whichever condition comes first.
Strict full factory inspection: Every torque thru knuckle joint passes dimensional tolerance detection, thread precision inspection, torque transmission performance test, sealing performance test and surface defect visual inspection before leaving factory.
Free professional global technical support: Tool string matching consultation, series connection quantity selection guidance and working condition material grade recommendation for all overseas and domestic clients.
Long-term stable spare parts supply: Full complete size series inventory supports bulk wholesale order and fast global sea & air delivery arrangement.
Customized engineering service: Support non-standard outer diameter, internal through bore size, assembly length, special connection thread and H₂S anti-sulfide corrosion alloy material torque thru knuckle joint customization according to client technical drawings, field well parameters and actual downhole torque-bearing working conditions.
FAQ
Q1: What is the core difference between torque thru knuckle joint and conventional knuckle joint?
Conventional sealed knuckle joint only provides angular deflection and 360° rotation without torque transmission capability, only applicable to non-rotary coiled tubing operations like bridge plug setting and wellbore cleaning. Torque Thru Knuckle Joint adopts special internal torque transmission structure, it can stably transfer rotary torque from upper tool string to lower drilling or fishing tools while providing maximum 15° angular deflection, specially designed for coiled tubing fishing and coiled tubing drilling operations requiring torque transfer.
Q2: What are the main application scenarios of torque thru knuckle joint?
This torque transmissible universal joint is mainly used for two core oilfield operation types: 1. Coiled tubing fishing operations, the 15° deflection function can centralize fallen fish inside borehole to improve fishing success rate; 2. Coiled tubing drilling operations matched with drilling motors, it transmits torque and protects drilling motors and vulnerable downhole tools from torque impact damage. For ultra-long tool strings, multiple joints can be connected in series to enhance overall flexibility.
Q3: Can multiple torque thru knuckle joints be connected in series? What is the benefit of series connection?
Yes, multiple torque thru knuckle joints support series connection during tool string assembly. The core benefit of series connection is cumulative improvement of overall tool string flexibility. Each independent torque thru knuckle joint provides 15° angular deflection capacity, multiple joints connected in series can greatly reduce rigid friction and collision between long tool strings and irregular borehole walls, effectively lowering stuck pipe risk in deep, deviated and horizontal well intervention jobs.
Q4: What standard connection threads does the torque thru knuckle joint support?
Our full-series torque thru knuckle joints are equipped with three mainstream oilfield standard connection threads matched with different outer diameter sizes: 1" AMMT for small OD models, 1-1/2" AMMT for medium OD models, and 2-3/8" PAC for large OD models. All thread specifications follow unified industry precision machining standards, realizing direct matching with weight bar, drilling motor, fishing tools, coiled tubing string and other downhole intervention tools without extra adapter conversion.
Q5: Do you accept customized non-standard torque thru knuckle joint specifications and anti-sulfide material versions?
Yes, we provide full customized engineering solutions for global clients. We can manufacture non-standard outer diameter, internal through bore size, overall assembly length, special non-standard connection thread torque thru knuckle joints strictly according to client technical drawings and field well parameters. Besides standard STD carbon steel grade, NACE MR0175 compliant H₂S sour service anti-sulfide corrosion alloy versions are available for high-hydrogen-sulfide corrosive downhole environments.
Get Custom Datasheet & Factory Quote
We are a professional OEM & ODM manufacturer specializing in full series oilfield coiled tubing well intervention tools, supplying high-performance torque thru knuckle joints, conventional sealed knuckle joints, solid weight bars, hydraulic setting tools, fishing tools, drilling motor matching accessories and complete sets of supporting downhole service tools for global onshore and offshore oil & gas field fishing and drilling projects. All our products adopt standardized forging and precision machining process with strict multi-stage factory torque load, sealing and dimensional testing, featuring stable long-term downhole torque-bearing working performance and excellent cost performance ratio. Whether you need standard-size STD carbon steel torque thru knuckle joints, multiple series-connected tool string matching solutions or customized H₂S sour service anti-corrosion versions with non-standard specifications, please feel free to contact our professional engineering team. We will provide targeted torque-transmissible tool string matching solutions, complete detailed technical datasheets and competitive factory bulk wholesale quotations within 24 working hours.
