Product Overview
The Combination Mill (Flat Blade Milling Shoe) is a multi-function flat blade combination milling tool specially developed for coiled tubing downhole ball seat, crossover plug milling and casing/tubing inner wall scraping & cleaning remedial workover operations.
The outer cylindrical surface of the main combination mill body is fully welded with hard alloy carbide overlay layer; the wear-resistant carbide layer realizes dual functional effects: on one hand, it can scrape and trim irregular deformed inner wall of casing or tubing during the milling process to smooth the wellbore inner wall; on the other hand, the hard carbide overlay forms a high-wear-resistance protective barrier on the tool outer diameter, effectively reducing abrasive wear of the tool OD caused by contact with casing/tubing inner wall during long-term downhole reciprocating operations.
Each flat blade section of the milling shoe can be equipped with multiple interchangeable cutting hard alloy chip layout schemes: three optional cutting structures including standard crushed carbide grains, piranha serrated cutting chips and additional high-performance integral cutting inserts are available for free selection. The high-performance hard alloy cutting particles provide strong penetrating cutting force for downhole ball seats, crossover plugs and other plug-type obstacles, significantly improving overall milling penetration efficiency and extending the service life of the blade cutting structure.
The applicable outer diameter size range of the combination flat blade milling shoe covers 2-7/8" to 5-1/2", with complete outer diameter specification series to match different wellbore inner diameter constraint conditions and different downhole plug milling construction demands.
The Combination Mill has no complex internal movable friction components, spring energy storage assemblies or differential pressure release mechanisms, with extremely simplified wellsite operation flow and low maintenance cost; construction crews only need to run the combination flat blade milling shoe down along the wellbore until the flat blade cutting face contacts the target ball seat / crossover plug, apply rotary torque and continuous circulating well fluid to realize simultaneous dual operations of casing/tubing inner wall scraping & trimming and plug milling cutting, no additional auxiliary operation steps such as drop ball delivery or shear pin impact jarring are needed, shortening wellsite operation time and reducing human error risks.
Complete Technical Specification Table
| PN Part Number | Outer Diameter OD | Make-Up Length | Working Condition Grade | Bottom Connection Thread |
|---|---|---|---|---|
| Custom PN Series | 2-7/8" | Custom Length | STD Standard | Custom Coiled Tubing Thread |
| Custom PN Series | 3-1/2" | Custom Length | STD Standard | Custom Coiled Tubing Thread |
| Custom PN Series | 4" | Custom Length | STD Standard | Custom Coiled Tubing Thread |
| Custom PN Series | 5-1/2" | Custom Length | STD Standard | Custom Coiled Tubing Thread |
Note: Custom outer diameter, flat blade cutting hard alloy chip layout scheme and base material corrosion resistance grade modification combination flat blade milling shoes are available via engineering consultation. Two working condition grades (STD standard carbon steel / H₂S sour service anti-corrosion alloy) are optional for each outer diameter size, and the working condition grade needs to be clearly confirmed according to the downhole wellbore fluid H₂S concentration corrosive environment during order placement; multiple cutting chip types (crushed carbide / piranha chip / high-performance cutting insert) can be freely matched on flat blades according to downhole plug milling penetration efficiency demands.
Core Features & Advantages
Outer OD Hard Carbide Overlay Protective Layer Welded Body Design: High-hardness wear-resistant hard alloy carbide overlay is continuously welded on the full outer cylindrical surface of the combination mill main body, realizing two core functional effects at the same time: the carbide layer can scrape and trim irregular deformed inner wall of casing or tubing during the milling process to smooth the wellbore inner wall; the hard carbide overlay forms a high-wear-resistance protective barrier on the tool outer diameter, effectively reducing abrasive wear of the tool OD caused by contact with casing/tubing inner wall during long-term downhole reciprocating operations.
Multi Optional Cutting Hard Alloy Chip Flat Blade Layout Design: Each flat blade section of the milling shoe can be equipped with three interchangeable cutting hard alloy chip layout schemes for free selection: standard crushed carbide grains, piranha serrated cutting chips and additional high-performance integral cutting inserts, which can flexibly match different downhole plug hardness and milling penetration efficiency construction demands.
High-Performance Cutting Alloy Particle Blade Structure: The high-hardness wear-resistant cutting hard alloy grains adopt optimized layout design, which provides powerful penetrating cutting force for downhole ball seats, crossover plugs and other plug-type obstacles, significantly improving the overall milling penetration efficiency of the tool and extending the service life of the blade cutting structure.
Full Outer Diameter Size Range Coverage: The applicable outer diameter size range of the combination flat blade milling shoe covers 2-7/8" to 5-1/2", with complete outer diameter specification series to match different wellbore inner diameter constraint conditions and different downhole plug milling construction demands.
Ultra-Simplified Wellsite Operation Logic: The combination flat blade milling shoe has no complex internal movable friction components, spring energy storage assemblies or differential pressure release mechanisms, the operation flow is highly streamlined: only need to run the combination flat blade milling shoe down along the wellbore until the flat blade cutting face contacts the target ball seat / crossover plug, apply rotary torque and continuous circulating well fluid to realize simultaneous dual operations of casing/tubing inner wall scraping & trimming and plug milling cutting, no complex auxiliary operation steps such as drop ball delivery or shear pin impact jarring are needed to shorten wellsite operation time and reduce human error risks.
Low Routine Maintenance Design: The integral cylindrical alloy steel tool body eliminates vulnerable split assembly movable wear parts; after each downhole plug milling and casing wall cleaning operation, only simple surface outer diameter carbide overlay debris cleaning and flat blade cutting chip wear inspection are required, no complex disassembly, internal cutting hard alloy chip replacement or spring preload adjustment maintenance procedures, greatly reducing daily maintenance labor and spare parts inventory cost.
Application Scenarios
1. Coiled tubing downhole ball seat, crossover plug milling and casing/tubing inner wall scraping & cleaning heavy-load intervention treatments, including ball seats, crossover plugs and other plug-type downhole obstacles milling cutting, as well as casing/tubing inner wall irregular deformation trimming and debris cleaning remedial workover construction operations
2. Conventional sweet crude oilfield outer OD carbide overlay multi cutting chip flat blade combination milling shoe downhole ball seat / crossover plug milling and casing wall cleaning remedial workover service (STD Standard carbon steel working condition grade)
3. High-sulfur H₂S containing corrosive downhole wellbore construction project downhole ball seat / crossover plug milling and casing/tubing inner wall cleaning heavy workover projects requiring H₂S sour service anti-sulfide stress cracking high-corrosion-resistant alloy material grade
4. Long-term continuous repeated rotary milling cutting load safety protection for coiled tubing bottom-hole assemblies in onshore and offshore oilfield downhole ball seat / crossover plug milling and casing/tubing inner wall cleaning remedial workover intervention projects
Standard Delivery Package
Complete combination flat blade milling shoe integral cylindrical pre-assembled unit including main tool body with full outer diameter hard carbide overlay protective layer and flat blade sections equipped with interchangeable cutting hard alloy chip layout
Spare interchangeable cutting hard alloy chip maintenance kit with three types of cutting chip specifications (standard crushed carbide grains / piranha serrated cutting chips / high-performance integral cutting inserts) for on-site flat blade cutting structure wear replacement
Full factory inspection test report including repeated rotary milling cutting load fatigue resistance test, integral tensile load test, outer diameter hard carbide overlay wear resistance calibration test and flat blade multi-type cutting chip milling penetration efficiency test data
Product dimension drawing and official installation & operation instruction manual, with detailed on-site downhole ball seat / crossover plug milling and casing/tubing inner wall scraping & cleaning operation guidance, with clear reminder to select STD standard carbon steel grade or H₂S sour service anti-corrosion alloy grade according to downhole wellbore fluid H₂S concentration corrosive environment during order placement, and confirm required flat blade cutting hard alloy chip layout scheme according to different downhole plug milling penetration efficiency demands
Quality Warranty & After-Sales Service
Warranty Coverage: 12 months after factory shipment or 2000 cumulative rotary milling cutting load cycles, whichever condition is reached first
Full factory inspection: Each finished combination flat blade milling shoe passes integral tensile load test, repeated rotary milling cutting load fatigue test, outer diameter hard carbide overlay wear resistance calibration test and flat blade multi-type cutting chip milling penetration efficiency test before factory delivery
Free professional technical support: Our oilfield downhole tool engineering team provides coiled tubing downhole ball seat / crossover plug milling and casing/tubing inner wall cleaning remedial workover tool string matching, outer diameter & working condition grade (STD / H₂S) selection and flat blade cutting hard alloy chip layout scheme selection consultation free of charge
Long-term spare parts supply: All interchangeable cutting hard alloy chip wear accessories are stocked with competitive factory bulk pricing
Custom development service: Support custom outer diameters, customized flat blade cutting hard alloy chip layout schemes, base material corrosion resistance grade modification, bottom coiled tubing connection thread profiles and special size combination flat blade milling shoes based on customer technical drawings
FAQ
Q1: What is the core function of a Combination Mill (Flat Blade Milling Shoe)?
The Combination Mill (Flat Blade Milling Shoe) is a multi-function flat blade combination milling tool dedicated to coiled tubing downhole ball seat, crossover plug milling and casing/tubing inner wall scraping & cleaning remedial workover operations. The outer cylindrical surface of the main mill body is fully welded with hard alloy carbide overlay layer, the carbide layer can scrape and trim irregular deformed inner wall of casing or tubing during milling, and forms a wear-resistant protective layer to reduce abrasive wear of the tool outer diameter. Each flat blade section can be equipped with three interchangeable cutting hard alloy chip layout schemes: standard crushed carbide grains, piranha serrated cutting chips and additional high-performance integral cutting inserts, the high-performance cutting alloy particles provide powerful penetrating cutting force for downhole ball seats, crossover plugs and other plug-type obstacles to improve milling penetration efficiency. The applicable outer diameter size range covers 2-7/8" to 5-1/2". Two independent working condition material grade options are provided: STD standard carbon steel grade for conventional non-corrosive wellbore environments without high-concentration H₂S corrosive medium; H₂S sour service high-corrosion-resistant alloy grade for high-sulfur H₂S containing corrosive downhole wellbore construction conditions. No complex internal movable friction components or spring assemblies are equipped, operation flow is highly simplified, widely applied for coiled tubing downhole ball seats, crossover plugs and other plug-type downhole obstacles milling cutting and casing/tubing inner wall scraping & cleaning remedial workover construction operations.
Q2: What three core structural advantages does this Combination Mill Flat Blade Milling Shoe own?
1. Outer OD hard carbide overlay protective layer welded body design, high-hardness wear-resistant hard alloy carbide overlay is continuously welded on the full outer cylindrical surface of the combination mill main body, realizing two core functional effects at the same time: the carbide layer can scrape and trim irregular deformed inner wall of casing or tubing during the milling process to smooth the wellbore inner wall; the hard carbide overlay forms a high-wear-resistance protective barrier on the tool outer diameter, effectively reducing abrasive wear of the tool OD caused by contact with casing/tubing inner wall during long-term downhole reciprocating operations; 2. Multi optional cutting hard alloy chip flat blade layout design, each flat blade section of the milling shoe can be equipped with three interchangeable cutting hard alloy chip layout schemes for free selection: standard crushed carbide grains, piranha serrated cutting chips and additional high-performance integral cutting inserts, which can flexibly match different downhole plug hardness and milling penetration efficiency construction demands; 3. Ultra-simplified wellsite operation logic & low routine maintenance design, the combination flat blade milling shoe has no complex internal movable friction components, spring energy storage assemblies or differential pressure release mechanisms, only need to run the combination flat blade milling shoe down along the wellbore until the flat blade cutting face contacts the target ball seat / crossover plug, apply rotary torque and continuous circulating well fluid to realize simultaneous dual operations of casing/tubing inner wall scraping & trimming and plug milling cutting, no complex auxiliary operation steps such as drop ball delivery or shear pin impact jarring are needed to shorten wellsite operation time and reduce human error risks; the product also features full outer diameter size range coverage and integral cylindrical tool body low maintenance design to further optimize on-site construction efficiency and reduce post-operation maintenance workload.
Q3: What outer diameter sizes and configurable options do these Combination Mill Flat Blade Milling Shoes support?
Our standard applicable outer diameter size range covers 2-7/8", 3-1/2", 4" and 5-1/2". Each OD size supports two independent working condition material grade versions for free matching selection: STD standard carbon steel working condition grade and H₂S sour service high-corrosion-resistant alloy working condition grade. All models support custom coiled tubing bottom connection threads compatible with global mainstream coiled tubing connector assemblies and other supporting downhole ball seat / crossover plug milling and casing wall cleaning remedial workover tools. Custom flat blade cutting hard alloy chip layout schemes and base material corrosion resistance grade specifications are available upon customer downhole wellbore fluid H₂S concentration corrosive environment and downhole plug milling penetration efficiency construction demands.
Q4: What is the standard production lead time for bulk purchase orders?
All standard PN part numbers are kept in factory inventory, goods can be delivered within 7–15 working days. Customized combination flat blade milling shoes with special outer diameters or customized flat blade cutting hard alloy chip layout schemes, base material corrosion resistance grade specifications & bottom connection thread profiles require 20–35 working days production cycle, subject to total order quantity and customization scope.
Get Custom Datasheet & Factory Quote
We are a professional OEM & ODM manufacturer focused on full series coiled tubing heavy workover and washing downhole service tools, covering combination flat blade milling shoes, five-blade five-wing milling shoes, flat bottom milling shoes, magnetic fishing rods, magnetic junk retrieval magnets, venturi junk baskets, flow activated releasable fishing overshots, flow activated releasable fishing spears, flow activated releasable JDC running/pulling tools, flow activated releasable GS fishing tools, bi-direction mechanical accelerators, bi-direction hydraulic accelerators, bi-direction hydraulic jars, up-stroke hydraulic jars, bi-direction mechanical jars, up-stroke mechanical jars, wireline grabs, wireline spears and all other supporting downhole fishing, jarring, anchoring and washing service tools. Every finished product undergoes strict factory tensile load, repeated rotary milling cutting load fatigue, outer diameter hard carbide overlay wear resistance calibration and flat blade multi-type cutting chip milling penetration efficiency testing, with complete material inspection certification attached to each shipment. Please share your detailed technical requirements, including target outer diameter size, required working condition grade (STD standard carbon steel / H₂S sour service anti-corrosion alloy), required flat blade cutting hard alloy chip layout scheme, downhole wellbore fluid H₂S concentration corrosive environment construction conditions, working environment and all customized specification demands. Our dedicated oilfield downhole tool engineering team will send complete detailed technical datasheets and competitive factory wholesale quotations within 24 business hours, and provide professional on-site downhole ball seat / crossover plug milling and casing/tubing inner wall scraping & cleaning operation guidance, with clear confirmation reminder for working condition grade selection (STD standard carbon steel for non-corrosive well / H₂S sour service anti-corrosion alloy for high-sulfur corrosive well) and flat blade cutting hard alloy chip layout scheme confirmation according to different downhole plug milling penetration efficiency construction demands during order placement.
