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Method Statement 3.13 - Directional Drilling

Document Information

Field Value
Document Reference MS 3.13
Issue Number 2
Issue Date 1 June 2026
Next Review 1 June 2027
Prepared By Sean Ashton
Approved By Aaron Mason, Director
Task No Task PPE to be worn Plant required Reference is made to the Team Pack risk assessment
3.13 Directional Drilling As defined by on-site risk assessment. Works vehicle and hand tools. Directional drilling rig, Waste water bowser, pipe trailer and pump. N/A

Hazards

  • Manual Handling
  • Stored Energy in the Pipe
  • Defective Plant and Equipment
  • Towing Techniques
  • Incorrect Loading
  • Insufficient Space

Environmental Impacts

  • Noise
  • Dust
  • Light From Night working

Customer Impacts

  • Noise
  • Dust
  • Access

Training Required

As Per specific contract training matrix

Additional Plant and Equipment

  • Winch/Tractor Winch
  • Pipe Bursting/Slip Lining Rig
  • Mechanical Excavator

Permits Required

As Per specific contract specifications and Client requirements.

COSHH Assessment Required

  • 2 Stroke Oil
  • Diesel/Petrol
  • Line Marker Spray
  • Lubricating Spray

Sequence of Operations and Control Methods

Job Planning

  • Obtain Utility Plans for area to be drilled.
  • Trace and mark out all utilities on site using spray paint.
  • Check there are no SSSI sites where drilling lubricant could contaminate.
  • Check if there are water courses nearby.

Pipe Preparation

  • Where pipe coils are utilised they will be transported to site on a road worthy and sufficiently sized pipe coil trailer.
  • Pipe sticks shall be transported to site, stored in a secured area and prepared for welding prior to installation.

Pilot Bore

  • Launch and receive pits shall be identified and marked.
  • Marked pits shall be saw-cut and excavated. Where there are existing services hand digging will be implemented.
  • Consideration will be given to the locations of AVs, FHs, SVs and other fittings prior to excavating pits, fittings will be incorporated into launch and receive pits where possible to minimise excavations required.
  • Drill operator shall ensure earth spike is correctly connected.
  • Prior to pipe installation a pilot bore shall be drilled using a track mounted steerable percussive directional drilling unit. The drill unit is surface mounted and hydraulically operates to push & rotate rods into the ground.
  • The drill rods shall be launched first at an angle for depth. It shall then be steered horizontally beneath the surface to emerge within the receive pit at the other end of the proposed bore.
  • For straight line drilling, the slanted head on the first rod shall be continually rotated. To make alterations to the line or level the rotation shall be stopped at the correct rotary angle and the drill head pushed forward via the rod. Once the bias on the slanted head has steered the rods in the required direction, rotation shall recommence.
  • The position of the drill head shall be monitored at all times by tracking the signal emitted from the sonde, which is mounted on the drill head. The tracking information shall include alignment, depth and tilt angle. All details will be recorded on site at 5m intervals with the information documented on a drill log data sheet.

Admixtures

  • Admixtures shall be used, where deemed necessary by the drilling operative. Admixtures shall help assist keeping the bore open when back-reaming, acting as a lubricant/coolant for the drill rods and liquidizing the clay to enabling it to flow back to the reception pit.
  • The specific admixture, typically 'bentonite' or 'easy-mud', shall be prepared by mixing with water. Water will be stored within the tanks on board the rig. As the drilling operation commences the admixtures shall be injected via the drill pumping system, through the rods to the drill head. The waste fluid generated by the process shall be classed as inert and will be disposed of to a site registered to receive. Waste transfer documentation must be completed for disposal.

Pipe Installation - Directional Drilling

  • After pilot bore completion, the bore head shall be replaced by a suitably sized back reamer and towing head.
  • The coil or welded pipe string shall be attached to the towing head. The rods shall then be hydraulically pulled back towards the original launch pit.
  • This process shall be repeated in at least 100m sections until the required installation length is achieved.
  • The pipe line shall be jointed within the launch/receive pits using Electro-Fusion collars.
  • When jointing coils, two collars and a section of stick will be used along with clamps in order to gain correct alignment and reduce joint errors caused by oval pipes created by coiling.
  • Location and number of collars will be marked on the ground for record purposes.
  • Fittings shall be installed as per construction drawings.