This article is about SAES-L-470 which is about Trenchless Pipelines Construction Requirements and download SAES-L-470 PDF for piping and mechanical engineers, supervisors and project managers. This is saudi aramco standard based on international codes and standards and useful for piping and mechanical engineering knowledge to get job as engineers, QC Supervisors and QC managers, Engineering managers and technicians.
SAES-L-470 PDF Download
SAES-L-470SAES-L-470 Trenchless Pipelines Construction Requirements
SAES-L-460 is a standard developed by Saudi Aramco that specifically focuses on the minimum design and installation requirements for trenchless pipeline construction. Trenchless construction refers to methods of installing pipelines underground without the need for traditional open-cut trenching.
In accordance with SAES-L-460, pipeline design and construction for trenchless methods should adhere to the guidelines provided in SAES-L-410 and SAES-L-450. SAES-L-410 covers the general requirements for pipeline design, while SAES-L-450 provides guidelines for pipeline construction.
However, it is important to note that when it comes to the design of pipelines specifically for road crossings, the requirements outlined in SAES-L-460 take precedence. SAES-L-460 provides the necessary design criteria and installation guidelines specifically tailored to pipeline crossings under roads.
General Requirements
The SAES-L-460 standard outlines several general requirements for trenchless pipeline construction. These requirements ensure that the selection and execution of trenchless techniques are carried out effectively and in accordance with established guidelines. Here are the key points:
- Feasibility of Trenchless Technique: The selection of the trenchless technique should be based on its feasibility considering factors such as drill path length, pipe diameter, and subsurface conditions. Other considerations include underground utilities/equipment, project schedule, and cost.
- Operator Experience: The operator of the trenchless machine must have a minimum of five years of experience. Additionally, the equipment operations manual should be available onsite at all times for reference and guidance.
- Geotechnical Data:
- Geotechnical Report: A geotechnical report must be prepared by an approved geotechnical contractor designated by Saudi Aramco. The report should be based on a minimum of two vertical boreholes drilled at each crossing location. Additional boreholes may be required depending on the drill path length and crossing type.
- Contractor Qualifications: The geotechnical report should be prepared by a contractor listed in the Consulting Services Department’s (CSD) approved Geotechnical Engineering Offices. Boreholes should be conducted by a contractor approved by the Inspection Department’s list of Geotechnical Third Party Testing Laboratories.
- Borehole Depth: The minimum depth of the boreholes should be 15 meters.
- Pipeline Trenchless Package: The pipeline trenchless package must be reviewed by the Consulting Services Department (CSD) and approved by the Project Management Team (PMT) or the operating organization, as applicable. The package should include essential information such as:
- Trenchless Technique: Specification of the selected trenchless technique along with justification for its selection.
- Pipeline Design Parameters: Details of pipeline design parameters including pressure, temperature, size, and material specification.
- Coating Specifications: Proposed coating types for girth welds and overall Abrasion Resistant Overlay (ARO) for the pipeline.
- Geotechnical Report: Inclusion of the geotechnical report as per the requirements in Section 5.3.
- Plan Drawings: Detailed plan drawings of the crossing area, including the pipeline route, and any surface or subsurface equipment or utilities within 20 meters of the proposed drill path.
- Cross-Sectional Elevation Drawing: Drawing depicting the grade profile, underground equipment or utilities, and any relevant details.
- Load Calculations: Operation and installation load calculations, including allowable elastic bending stress, allowable elastic bend angle, allowable external hoop stress of the pipe, and approximate external pressure stress exerted by the drilling mud. For Horizontal Directional Drilling (HDD), the A.G.A/PRCI Report, PR-227-9321 should be used as a design guide.
- Drilling Fluid Design Plan: A comprehensive plan for drilling fluid design, including mixing, storage, pumping, filtration, recycling, etc.
- Reaming Sequence and Sizes: For HDD, the plan should include the reaming sequence and sizes, including the final bore diameter.
- Buoyancy Control Plan: A plan for controlling buoyancy as per the requirements specified in paragraph 6.3.9.1.
- Excavation Plan: A plan outlining the excavation process as per the requirements specified in paragraph 6.4.1.1.
- Drilling Execution Plan: Detailed plan and procedures for drilling execution as per Appendix A.
- Operator Resumes: Resumes of the equipment operators as per the requirements specified in paragraph 5.2.
Trenchless Construction Methods
The SAES-L-460 standard provides guidelines for trenchless construction methods. The following methods are addressed in the document:
- Approval of Non-Addressed Methods: Any trenchless construction method not covered in the document must be approved by the Consulting Services Department (CSD). However, pipe jacking and pipe ramming methods are not permitted for the carrier pipe. Pipe ramming may be used for the casing pipe.
- Auger Boring: Auger boring is permitted for crossing lengths of less than 50 meters. In areas where alignment precision is required, guided auger boring should be used.
- Horizontal Directional Drilling (HDD):
- Marking Entry and Exit Points: Based on the topographical survey of the crossing site, the entry and exit points of the HDD operation should be clearly marked.
- Design of Drill Path: The design of the drill path should consider the geotechnical data, entry and exit angles, and the minimum bend radius of the pipe. Bends in the drill path should be elastic, with a minimum radius of 100 times the pipe’s nominal diameter (in feet).
- Selection of HDD Drill Rig: The type and size of the HDD drill rig should be selected based on the calculated bore drilling and pipe string pulling loads required for the project.
- Drilling Bits Selection: The selection of drilling bits should be based on the geotechnical report.
- Steering Tools and Tracking: During the drilling of the pilot hole, steering tool systems and drill bit tracking tools should be provided.
- Back Reamers: Only factory-made back reamers suitable for the soil type should be used.
- Drilling Mud: Adequate flow of drilling mud should be pumped during the pilot bore drilling, reaming stages, and pipe pulling.
- Final Bore Diameter: The final bore diameter should be 1.2 to 1.5 times the pipe’s outside diameter. For pipes up to 32 inches, a bore diameter of 1.5 times the pipe diameter may be used, and the value should be reduced for larger diameter pipes.
- Pipe Installation:
- Buoyancy Control Plan: For pipe diameters of 36 inches and larger, a buoyancy control plan should be developed.
- Pipe String Support: The pipe string should be laid over roller supports or held with side booms and cradles. Holding the pipe string using belts through cranes or side booms is not permitted.
- Swivels: A swivel should be attached between the pipe string and the reamer, and a safety break-away swivel should be connected between the pipe pulling head and the rotational swivel. This is to ensure that the pulling force does not exceed the maximum allowed for the pipe string.
- Drilling Mud Filling: Prior to pipe pulling, the entire bore between the exit and entry points should be filled with drilling mud.
- Pipe Pulling Operation: During the pulling operation, the pipe string should be lifted and held at an angle that matches the bore entry angle. The pullback operation should be completed without interruption.
By following these guidelines, trenchless construction methods can be carried out effectively and ensure the successful installation of pipelines. Following article are related to SAES-L-470 PDF Download.
SAES-L-460 PDF Download – Pipeline Crossings under Roads
SAES-L-450 PDF Download – On-Land and Near-Shore Pipelines
SAES-L-440 PDF Download – Anchors for Buried Pipelines
FAQs about SAES-L-470 PDF Download
Q: What does SAES-L-460 define?
A: SAES-L-460 is a standard that defines the minimum design and installation requirements for trenchless pipeline construction.
Q: What factors should be considered in selecting a trenchless technique?
A: The selection of a trenchless technique should be based on factors such as feasibility, underground utilities/equipment, geotechnical data, schedule, and cost. Feasibility is determined by factors like drill path length, pipe diameter, and subsurface conditions.
Q: What experience level is required for the operator of a trenchless machine?
A: The operator of the trenchless machine is required to have a minimum of five years’ experience. Additionally, the equipment operations manual should be available onsite at all times.
Q: What are the requirements for geotechnical data in trenchless construction?
A: A geotechnical report must be prepared by an approved geotechnical contractor, based on a minimum of two vertical boreholes drilled at each crossing location. Additional boreholes may be necessary depending on the length of the drill path and the type of crossing. The depth of the boreholes should be a minimum of 15 meters.
Q: What should be included in the pipeline trenchless package for review and approval?
A: The pipeline trenchless package should include information such as the type of trenchless technique with selection justification, pipeline design parameters, proposed coating types, geotechnical report, plan drawing showing the pipeline route and nearby surface/subsurface equipment, load calculations, drilling fluid design plan, reaming sequence and sizes, buoyancy control plan, excavation plan, drilling execution plan, and equipment operator’s resumes.
Q: Are there limitations on trenchless construction methods?
A: Yes, the standard states that trenchless construction methods not addressed in SAES-L-460 must be approved by the Consulting Services Department (CSD). Pipe jacking and pipe ramming methods are not allowed for the carrier pipe, but pipe ramming may be used for the casing pipe.
Q: What are the requirements for Horizontal Directional Drilling (HDD)?
A: The design of the drill path should consider geotechnical data, entry and exit angles, and a minimum bend radius for the pipe. The HDD drill rig should be selected based on the required bore drilling and pipe string pulling loads. Suitable drilling bits, steering tools, and back reamers should be used. Adequate flow of drilling mud is necessary during drilling stages. The final bore diameter should be 1.2 to 1.5 times the pipe’s outside diameter.