Large Diameter Reverse Circulation

The demand for quality large diameter RC tools is steadily growing.

The water resource industry focuses on extracting ground water for multiple purposes including municipal wells, industrial consumption, and wells for Agri-Irrigation. It is boosted by population growth trends in Sunbelt states and an increasing number of acres devoted to agriculture.

Environmental considerations continue to increase when drilling water wells in urban areas and has seen a strong trend to the use of RC drilling as it enables effective control of the cutting and drilling fluids. It is essentially a closed loop system that safely contains the cuttings and minimizes potential contamination in environmentally sensitive areas.

The mining industry also uses large diameter RC tools for large diameter wells to process ore and to dewater areas adjacent to open pit mines.

Large diameter wells are a significant and progressive investment meaning the larger and deeper you drill, the larger the investment. The scope of the operation, equipment, and dedicated personnel are considerable in drilling large diameter wells. This means tooling reliability and performance are a drilling contractor’s top requirement.

Matrix RC tooling is second to none in durability. Matrix large diameter RC rods feature some unique design aspects that set them apart from the competition including a double shoulder thread profile for enhanced strength and sealing and the use of vibration dampers between the inner and outer tubes effectively isolating the inner tubes from the forces and stresses of drilling. Additionally, the use of high strength Microalloyed steel and Plasma Arc welding technology allow us to manufacture RC dual tube assemblies that significantly outlast our competitors.

Matrix RC drill rod is engineered for optimal performance. Before our products leave the shop our engineering team implements a rigorous program of 3D CAD simulation testing including finite element analysis (FEA) and Computational Fluid Design (CFD) testing.

Product range is offered in OD’s 5.5” – 6″ – 7″ – 9 5/8″ – 10 3/4″. Lengths up to 40’. Custom sizing is available on request.

Matrix supports their RC tooling with a complete array of purpose specific drill string accessories – Interchanges – Rock Bit Adaptors – Subs – Drill Collars – Transition Rods – Swivels – Hoisting / Lowering -Shrouded Rock Bits –  Fishing Tools and more too good to be true – just ask our customers.

Large Diameter Reverse Circulation Dual Tube Drill Rod

Matrix’s dual tube drill rods feature a wide range of standard and custom sizes making our product adaptable to nearly any rig or drilling program. Sizes range up to a 7” ID inner tube.


Sizes range from 6 5/8 in. to 24 in. for dual rotary rigs. Left hand or right hand threading options are available. Multi-start threading options are used for high torque applications.

Drill Collars

Matrix Drill Collars are used to achieve the correct weight on bit (WOB) to maximize penetration rates and prevent drilling in compression. Matrix Drill Collars are machined from high grade alloy steel corresponding to AISI 4145. Each collar undergoes rigorous quality control procedures during manufacture. Matrix offers a DI-22 thread form and a stress relief groove in the pin tool joint connection. By running Matrix Drill Collars, failures in the drill string will be reduced to a minimum resulting in less cost per foot for the driller.

Transition Rods

The Transition Rod effectively absorbs drill string torsional and lateral stresses associated with deep hole RC drilling. The redistribution of stresses will increase drill string life and minimize failures making the Transition Rod a prudent addition to your drill string. The Transition Rod is positioned strategically between the Drill Collars and the Dual Tube Drill Rod. Matrix Transition rods are machined from high grade alloy steel. Adaptable to any combination of drill collar and RC drill rod sizing.


Stabilizers are used to assist in providing smooth, supported rotation of the drill string. Many times a formation may be subject to significant erosion, causing the borehole wall to be unstable. Stabilizers help to support the lower end of the drill string. In addition to providing supported drill string rotation, stabilizers enhance production as they keep the drill string aligned with the drill bit. Matrix offers milled spiral stabilizers are available up to 48″ long and to 20″ OD. Straight blade stabilizers are available up to 72″ long and 20″ OD.

Side Discharge Swivels

A Matrix specialty product. Allows drillers with smaller rigs to be able to drill with larger sized Matrix dual tube rods by discharging the cuttings below the top head. Features replaceable chrome wear rings for easy maintenance.

Shrouded Rock Bits

Matrix offers a full range of shrouded Tricone bits providing top end protection to the Tricone bit body while maintaining a constant annulus. Our shrouds are designed to release the compressed air into the borehole close to the face of the bit for the most efficient clearing of cuttings.

Side Entry Swivels

Placed below the top head, this product directs compressed air into the annular area of the Matrix dual tube rods while allowing a continuous discharge of cuttings through the top head of the rig.

Matrix Product Placeholder
Tremie / Grout Pipe

Matrix – Tremie Pipe is a Flush OD Product and is offered in multiple diameters from 3 ½”  OD down to 1 ¾” OD – our Tremie Pipe is built strong to deliver grout material at depth – We use an alloy tool joint that is Plasma Arc welded providing strength and durability – Our Tremie Pipe utilizes a taper lock thread profile that provides a tight seal, and easy make and breakout. Lengths 20 ft and 30 ft – or to customer specification.

Inner Tube Testers

Similar to a thread protector with a hole in it, Matrix Inner Tube Testers screw into the pin end of the RC Drill Rod. Then, by running compressed air into the opposite end of the rod a leak will be revealed if there is air exiting out of the hole in the tester lid. If a leak is discovered replacement of O-rings often fixes the problem. If the leak persists, it can be concluded that the inner tube has been ruptured and it will have to be replaced or scrapped.

Subs and Accessories

Back Reamers (Digout Subs)

The Matrix Back Reamer (Digout Sub) has multiple functions. First, it helps prevent premature wear to the RC DTH Hammer. The second function of the back reamer is to in fact “back ream” the borehole. This is necessary in the event the borehole wall is unstable and experiencing partial collapse and assists the driller in removing the drill string from a tight borehole. The Back Reamer is positioned between the RC DTH hammer and the first RC Drill Rod.  The back reamer consists of an outer body and an inner lift tube. When the inner lift tube of the Back Reamer shows signs of deterioration it can be easily replaced.

Saver Subs

Matrix RC Saver Subs are manufactured from heat treated alloy steel and have exceptional strength and durability. The Saver Sub has an inner tube and an outer body. It is used to connect the swivel or Top Head Adaptor to the first RC drill rod. The saver sub becomes the main makeup and breakout connection, protecting the threads on the swivel or top head.

Blow-Down Subs

The Matrix Blow-down Sub is used to clear blockages in the slots of the interchange, Rock Bit Adaptor, or dual tube drill rod inner tube. Connected at the top of the RC drill string, this product seals the annulus of the dual tube rod and channels the airflow down the RC inner tube. The Blow-down sub is comprised of two components – the Blow-down Sub inner tube and the outer body.

Blow-Up Subs

The Blow-up Sub is positioned at the top of the drill string disconnected from the top drive. It is used to direct the airflow up the inner tube (through the head to the sample collection tube) to clear a blockage. Available for all sizes of Matrix RC tools.

Aerator Subs

The Aerator Sub, in conjunction with the air injector sub, is utilized in dual tube flooded reverse applications. This product assists in initiating lift of the water column in the inner tube to begin circulation in deep hole drilling applications. The Aerator Sub inner tube features two small angled passages that allow a calculated amount of compressed air to be released to the inner tube before reaching the bottom hole assembly.

Air Injector Subs

The Matrix Air Injector is used in dual tube flooded reverse applications to aerate the water column inside the inner tube initiating upward flow. The air injector is the main, high-flow site of aeration found near the bottom of the string.

Interchanges (Crossover Subs)

The Interchange is a 3 piece assembly consisting of an Interchange body, an inner tube, and a top sub. An Interchange is used in conjunction with an RC DTH hammer or Tricone Rock Bit. Its purpose is to direct the cuttings from the bit into the inner tube of the RC drill rod where they flow up the string and are discharged on surface. Jetted style interchanges bleed a controlled amount of compressed air into the return sample stream thus “jetting” the cuttings up the inner tube. The Interchange is positioned in the drill string directly above the DTH Hammer. Matrix interchanges are built tough and available in 1, 2, or 3 slot designs with or without “jetting” and are made to fit each Matrix RC tooling size.

Rock Bit Adaptors

The Rock Bit Adaptor (RBA) is employed in RC drilling with a Tricone Rock Bit. The RBA connects directly to the Tricone Rock Bit and its purpose is to direct the cuttings into the inner tube of the RC drill string.

The Rock Bit Adaptor is an assembly made up of 4 components:

  1. RBA Outer Body
  2. RBA Inner Tube
  3. Wear Sleeve
  4. Bladder

Matrix offers size specific RBA connection options to the tricone bit.

Lowering, Hoisting, & Handling

Matrix manufacturers hoisting plugs equipped with heavy duty bails to allow you to safely hoist and lower your RC drill string.



This rod handling tool is very popular in angular hole applications. The Matrix Clamshell locks around the drill rod tool joints and assists in the angular positioning of the RC rod.  Whether you are adding or removing rod from the drill string, it saves time and makes the task easier.

Not seeing what you need? Call us at (931) 359-6564

Customized Tooling For Your Business

Maximize your drilling equipment with our tooling
  • “Matrix has helped us tremendously over the years. The team at Matrix doesn’t roll its eyes or make excuses when it comes to figuring out a custom drilling solution. They really latch on to this stuff and get excited about solving our problems! To have a supplier like that is huge.”

    Chris DelahuntyVP of Operations, DOSECC Exploration Services