The Mechanical Tubing End Locator is a spring-driven mechanical downhole tool specially designed for oilfield completion, workover and stimulation operations, whose core function is to calibrate the accurate depth position of tubing string bottom ends inside wellbores. This tool adopts built-in spring mechanism to keep clamping dogs in permanent open state; the elastic reset structure allows repeated positioning and depth marking operations during one tubing running trip.
Field engineers can adjust the spring pre-tightening force according to actual construction requirements, which modifies the pulling load transmitted to surface weight indicator flexibly. The clamping dogs are detachable sizing components, and different dimension dog sets can be replaced quickly to match different outer and inner diameter specifications of production tubing. This product series provides two independent material grades: STD standard carbon steel for conventional low-corrosion oil and gas wells, and H₂S sour resistant alloy for harsh high hydrogen sulfide corrosive sour gas well environments. The full specification lineup covers two mainstream production tubing ranges including 2-7/8" and 3-1/2"~4-1/2". Each model is pre-processed with industry standard 1-1/2" AMMT or 2-3/8" PAC premium tubing connection threads, supporting direct assembly with standard completion tubing strings without extra transition subs. Custom non-standard outer diameters, assembly lengths, special connection threads and customized high-corrosion resistant alloy materials are available upon engineering technical consultation.
The full product line includes four independent PN model numbers, divided into STD standard carbon steel grade and H₂S sour resistant alloy grade, all parameters listed as below:
PN L4132125120 (STD Grade): Tool OD 2.125", applicable tubing size 2-7/8", make-up length 18", connection thread 1-1/2" AMMT, working condition STD standard carbon steel
PN L4132875120 (STD Grade): Tool OD 2.875", applicable tubing size range 3-1/2"~4-1/2", make-up length 25", connection thread 2-3/8" PAC, working condition STD standard carbon steel
PN L4132125320 (H₂S Grade): Tool OD 2.125", applicable tubing size 2-7/8", make-up length 18", connection thread 1-1/2" AMMT, working condition H₂S sour resistant alloy
PN L4132875320 (H₂S Grade): Tool OD 2.875", applicable tubing size range 3-1/2"~4-1/2", make-up length 25", connection thread 2-3/8" PAC, working condition H₂S sour resistant alloy
Customized non-standard tool outer diameters, modified make-up assembly lengths, special customized connection thread specifications and enhanced anti-corrosion alloy material versions can be developed and manufactured strictly according to clients’ technical drawing documents and field well downhole working condition fluid parameters. The locator can be assembled directly above packers, landing nipples and stimulation downhole tools to realize integrated tubing string depth calibration during completion running operations.
Adjustable Spring Pulling Force for Tunable Surface Indicator:The internal positioning spring adopts adjustable pre-tightening design. By changing the compression degree of the reset spring, field crews can freely adjust the pulling resistance load generated when clamping dogs contact casing inner wall. This adjustable load directly changes the fluctuation amplitude of weight signals displayed on surface indicator, enabling engineers to customize signal sensitivity according to wellbore fluid viscosity, casing inner wall roughness and construction operation habits, effectively eliminating ambiguous signal judgment errors during depth calibration.
Spring Reset Mechanism Supports Multiple Re-Tagging:Built-in constant force spring structure maintains clamping dogs in fully open standby state all the time. After completing one round of tubing end depth marking, lifting the tubing string slightly retracts the dogs under casing inner wall extrusion; lowering the tubing string again will push dogs open automatically by spring elastic force, ready for next positioning cycle. This mechanical reset design realizes dozens of repeated re-tagging operations within one single tubing running trip, eliminating repeated tubing pulling and tripping operations to save rig time and construction cost significantly.
Interchangeable Sizing Dogs Adapt Variable Tubing Sizes:The clamping dogs are independent detachable sizing modules separated from main tool body. Multiple groups of dog sets with different outer contour dimensions are matched for the product series. When switching construction wells with different production tubing inner diameter profiles, field maintenance personnel only need to disassemble and replace corresponding sizing dog sets without replacing the whole locator body, greatly reducing spare part inventory cost and tool preparation time for oilfield service teams.
Dual Working Grade Material Matching Scheme:The full product series provides two complete material grades to adapt different downhole fluid environments: STD standard carbon steel with outstanding cost performance for conventional onshore oil wells with low hydrogen sulfide, moderate temperature-pressure and non-corrosive formation fluid conditions; H₂S sour resistant alloy model fully compliant with international sour service standards, effectively resisting sulfide stress cracking and uniform metal corrosion under harsh high hydrogen sulfide, high chloride corrosive sour gas well downhole fluid environments. Clients can select corresponding grade models according to hydrogen sulfide content of formation fluid in target construction wells.
Standard AMMT & PAC Premium Tubing Connection Threads:All standard locator models are pre-machined with two widely recognized industry premium tubing connection threads: 1-1/2" AMMT thread matched for 2-7/8" small size tubing range, and 2-3/8" PAC thread applied for 3-1/2"~4-1/2" large tubing size range. All thread machining complies with unified international oilfield precision forging standards, realizing seamless matching with mainstream completion tubing, packer assembly and stimulation tool strings worldwide without additional transition adapter subs.
Pure Mechanical Structure Without Hydraulic Circulation Requirement:Different from hydraulic activated tubing end locators that rely on fluid circulation to drive positioning blocks, this mechanical locator depends entirely on built-in spring elastic force to control opening and retraction of clamping dogs. No surface pump fluid circulation operation is required during positioning construction, simplifying on-site construction operation procedures and reducing supporting fluid circulation equipment configuration requirements for construction teams, which is especially suitable for small-scale workover and completion construction projects with limited rig supporting equipment.
1. Completion tubing running depth calibration operations. The core application for mechanical tubing end locator is depth positioning during production tubing running for oil & gas well completion projects. It accurately marks tubing bottom end depth benchmarks to ensure packers, landing nipples and other completion accessories are installed at target reservoir intervals with precise depth control.
2. Oilfield stimulation & well workover tubing string depth verification. Widely applied in acidizing, fracturing stimulation and routine well workover construction. When running stimulation tubing strings into target treatment zones, the spring mechanical locator completes multiple depth calibration operations in a single trip without fluid circulation, ensuring stimulation tools are positioned accurately at target pay zones with simplified construction operation steps.
3. Sour gas well completion and high sulfur downhole intervention construction. The dedicated H₂S sour resistant alloy grade model adapts harsh high hydrogen sulfide corrosive downhole environments for sour gas field completion tubing running and maintenance workover operations, providing stable positioning performance under corrosive fluid conditions.
4. Conventional onshore oil well low-corrosion completion construction. All STD standard carbon steel grade models are suitable for standard land oil wells with low hydrogen sulfide, moderate temperature and pressure downhole environments, covering vertical, deviated and horizontal well tubing running depth calibration projects.
Fully pre-assembled mechanical tubing end locator main unit with anti-rust passivation treatment on all AMMT and PAC connection thread surfaces
Multiple sets of spare interchangeable sizing clamping dogs, internal positioning reset springs, dog limiting sealing rings and plastic thread protective caps for transportation and long-term storage
Complete factory full batch inspection documents, including dimensional tolerance test report, raw material metal composition certification, spring pulling load adjustable range test record and surface weight signal trigger calibration test report
Multi-language product installation and field operation manual, including tool disassembly maintenance steps, spring pre-tightening pulling force adjustment guidance for surface indicator sensitivity control, and standard tubing running positioning operation procedures for field construction engineers
Optional third-party independent material certification documents and integrated completion tubing string matching scheme files to meet overseas oilfield project bidding supporting technical document requirements
Warranty Policy: 12 full months after factory shipment or 1000 cumulative mechanical positioning & downhole tripping cycles, whichever service condition is reached first
Strict Full-Process Factory Pre-Delivery Inspection: Every finished mechanical tubing end locator passes multiple rounds of rigorous performance testing before leaving factory, including dimensional precision detection, AMMT & PAC thread tensile load inspection, spring fatigue cycle durability test, sizing dog wear resistance test, surface weight signal trigger stability calibration and full surface visual metal defect inspection, guaranteeing consistent stable performance across all production batches
Free Global Professional Oilfield Technical Support: Provide free production tubing size matching consultation, integrated completion tubing string assembly scheme design and spring pulling force parameter adjustment technical guidance for domestic and overseas oilfield service clients
Long-Term Stable Global Spare Parts Supply Chain: All four standard PN model mechanical tubing end locators are kept in factory finished goods inventory to support large volume bulk wholesale orders. Flexible global sea freight and air freight delivery schedules can be arranged according to clients’ oilfield project construction timelines to match rig operation plans.
Customized Professional Engineering Solution Service: Support research, development and production of non-standard specification mechanical tubing end locators and high anti-corrosion alloy customized versions strictly in accordance with clients’ technical drawing documents, field well downhole working condition fluid parameters and special customized completion tubing construction operation requirements
Q1: What core advantage does the adjustable spring pulling force design bring to field depth calibration operations?
The built-in positioning spring supports adjustable pre-tightening compression degree, which directly modifies the mechanical pulling resistance load generated when clamping dogs contact casing inner wall. Different pulling loads will produce weight fluctuation signals with different amplitude on the surface weight indicator. Field engineers can adjust spring tension according to specific wellbore conditions such as casing inner wall roughness, formation fluid viscosity and tubing string weight, to customize the most sensitive and stable surface signal feedback, avoiding misjudgment caused by weak or ambiguous weight jump signals during tubing end depth marking.
Q2: How does the multiple re-tagging spring reset mechanism improve oilfield construction efficiency?
The constant force spring inside the tool keeps clamping dogs in open standby state all the time. After finishing one round of tubing end depth calibration, slightly lifting the tubing string will squeeze the dogs inward by casing inner wall extrusion force; lowering the tubing string again will push the dogs fully open under spring elastic reset force, ready for the next positioning cycle. This mechanical automatic reset structure allows dozens of repeated depth marking operations within one single tubing running trip, without pulling the entire tubing string out of the wellbore for repositioning. It drastically reduces repeated well tripping times, shortens overall construction cycle and cuts rig rental, fluid circulation and labor operation costs for oilfield service companies.
Q3: What differences exist between STD standard grade and H₂S sour service grade mechanical tubing end locators?
The STD standard grade adopts conventional carbon steel raw material, which features obvious cost advantages and stable mechanical positioning performance under low hydrogen sulfide, moderate temperature-pressure standard downhole environments of conventional onshore oil wells. The H₂S sour service grade uses special anti-sulfur corrosion alloy metal as base material, fully compliant with international sour service industry standards, which effectively resists sulfide stress cracking and uniform metal corrosion under harsh high hydrogen sulfide, high chloride corrosive sour gas well downhole fluid environments. Clients can select corresponding grade model according to the hydrogen sulfide content of downhole formation fluid in their target construction wells.
Q4: What production tubing size ranges and connection thread specifications do standard mechanical tubing end locator models cover?
Our full series standard mechanical tubing end locator product line covers two mainstream production tubing outer diameter ranges widely applied in global oilfield completion projects: single size 2-7/8", and combined range 3-1/2"~4-1/2". The product line provides two industry standard premium tubing connection thread specifications: 1-1/2" AMMT thread matched exclusively for the 2-7/8" small tubing range, and 2-3/8" PAC thread applied for the medium-large 3-1/2"~4-1/2" tubing range. All AMMT and PAC thread machining complies with unified international oilfield precision forging standards, supporting direct seamless assembly with mainstream completion tubing strings worldwide without extra transition adapter subs.
Q5: Can customized non-standard specification mechanical tubing end locators be produced for special oilfield construction requirements?
Yes, we provide comprehensive customized professional engineering solution services for all global oilfield service clients. We can design and manufacture mechanical tubing end locators with non-standard tool outer diameter sizes, modified overall make-up assembly lengths, special customized non-standard connection thread specifications and enhanced high-corrosion resistant alloy material versions strictly in accordance with clients’ technical drawing documents and field well downhole working condition fluid parameters. Besides customized size and thread specifications, we can also adjust internal spring elastic force parameters to adapt ultra-high temperature or ultra-high pressure special downhole well environments for offshore oilfield completion construction projects.
We are a professional integrated OEM & ODM manufacturer focused on independent research & development, precision forging production and global sales of full-series oilfield completion, stimulation and workover downhole intervention tools. We supply high-performance mechanical tubing end locators, hydraulic tubing end locators, mechanical casing collar locators, packer setting tools, tubing running subs, weight bars, completion auxiliary positioning accessories and a full range of matched supporting downhole service tools for global onshore and offshore oil & gas field completion tubing running, reservoir acidizing/fracturing stimulation and routine well workover construction projects. All our oilfield downhole tools adopt standardized metal forging and precision CNC machining production processes, and pass multiple rounds of rigorous factory performance testing including spring cycle fatigue resistance, connection thread tensile load stability and positioning signal sensitivity calibration testing, featuring stable long-term downhole working performance and excellent comprehensive cost performance ratio compared with imported foreign brand equivalent products. Whether you need standard specification STD carbon steel or H₂S sour resistant alloy mechanical tubing end locators matched with mainstream production tubing size ranges, integrated completion tubing string matching design technical solutions for large-scale well completion project bidding, or customized non-standard size high anti-corrosion alloy mechanical tubing end locator versions for harsh sour gas well and offshore ultra-high temperature-pressure downhole construction environments, please feel free to contact our professional oilfield engineering technical support team. We will provide targeted professional spring mechanical tubing end positioning downhole tool matching solutions, complete detailed technical datasheets with full specification parameters and competitive factory bulk wholesale quotation documents within 24 working hours upon receiving your inquiry demand.
