SEABED SURVEYS AND PIPELINE SPAN RECTIFICATION Doc. No. CPOC-GS-PL-0003 Rev. 0 Date 19/04/13 Page 2 of 2 CPOC TABLE OF CONTENTS 1.0 SCOPE 4 2.0 REFERENCES 5 2.1 Industry Codes and Standards 5 2.2 CPOC Wellhead General Specifications 5 3.0 GENERAL 6 3.1 Definitions 6 3.2 Abbreviations 7 4.0 GENERAL REQUIREMENTS 10 4.1 Health, Safety and Environment 10 4.2 Quality Assurance 10 4.2.1 General 10 4.2.2 Inspection and Test Plan (ITP) 10 4.2.3 Inspection and Test Procedures 10 4.2.4 Quality Records 10 4.2.5 Marking and Identification 11 4.2.6 Traceability 11 5.0 SEABED INTERVENTION PHILOSOPHY 12 5.1 General 12 5.2 Permissible Span Lengths and Stresses 12 5.3 Pre-lay Intervention Survey and Analysis 12 5.3.1 Pre-lay Intervention Survey 12 5.3.2 Analysis 12 5.3.3 Criteria for Pre-Lay Intervention 13 5.3.4 Criteria for Post-Lay Intervention 13 5.4 Pre-Lay Intervention Work 13 5.5 Post-Lay Survey and Analysis 13 5.5.1 Post-Lay Survey 13 5.5.2 Analysis 13 5.6 Post-Lay Intervention Work 14 6.0 ENGINEERING 15 6.1 General 15 6.2 Calculations 15 6.3 Drawings 16
SEABED SURVEYS AND PIPELINE SPAN RECTIFICATION Doc. No. CPOC-GS-PL-0003 Rev. 0 Date 19/04/13 Page 3 of 3 CPOC 7.0 POSITIONING SYSTEMS 18 8.0 SPAN RECTIFICATION 19 8.1 General 19 8.2 Span Rectification 19 8.3 Span Rectification Procedures 19 8.4 Freespan Reduction 20 9.0 EQUIPMENT 21 9.1 General 21 9.2 Mobilisation 21 9.3 Acceptance Trials 21 10.0 SURVEYS 22 11.0 DOCUMENTATION 23 12.0 TECHNICAL QUERIES / NON-CONFORMANCE REPORTS 24 ATTACHMENT 1 FLOWCHART OF SEABED INTERVENTION PHILOSOPHY ATTACHMENT 2 GEOPHYSICAL SURVEY FOR OFFSHORE PIPELINE INSTALLATION
SEABED SURVEYS AND PIPELINE SPAN RECTIFICATION Doc. No. CPOC-GS-PL-0003 Rev. 0 Date 19/04/13 Page 4 of 4 CPOC 1.0 SCOPE This Specification defines the minimum technical requirements for the identification and rectification of unsupported pipeline spans on sea bottom. The intent of this Specification is to provide a minimum standard for span correction based on industry practice and COMPANY’s requirements for the pipeline installation.
SEABED SURVEYS AND PIPELINE SPAN RECTIFICATION Doc. No. CPOC-GS-PL-0003 Rev. 0 Date 19/04/13 Page 5 of 5 CPOC 2.0 REFERENCES The reference documents listed below, including Industry Codes and Standards and COMPANY specifications, form an integral part of this General Specification. Unless otherwise stipulated, the applicable version of these documents, including relevant appendices and supplements, is the latest revision published on the effective date of the contract. The overall order of precedence of the applicable documents shall be: 1) Government Laws, Rules and Regulations 2) Purchase Order/ Service Order/ Contract Documents 3) Project Particular Specification (PPS) 4) Present General Specification 5) Codes and Standards in reference Any conflict between any of the Contract Documents, or between this specification and any other Contract Document, shall be reported to the COMPANY for decision. In such a case, and unless otherwise agreed or decided by the COMPANY, it is understood that the more stringent requirement shall apply. Exceptions to, or deviations from this specification are not permitted unless previously accepted in writing by the COMPANY. For this purpose, requests for substitutions or changes of any kind shall be complete with all pertinent information required for COMPANY assessment. COMPANY’s approval, nevertheless, will not, in any way, relieve the responsibility of the Contractor to meet the requirements of the industry Codes and Standards referred to an amended herein, in the event of conflict. 2.1 Industry Codes and Standards Reference Title ASME B31.8 Gas Transmission and Distribution Piping Systems ASME B31.4 Pipeline Transportation Systems for Liquid Hydrocarbons and Other Liquids API RP 1111 Design, Construction, Operation and Maintenance of Offshore Hydrocarbon Pipelines (Limit State Design) API RP 5L1 Railroad Transportation of Line pipe API RP 5LW Transportation of Line pipe on Barges and Marine Vessels DNV OS F101 Submarine Pipeline Systems DNV RP F105 Free Spanning Pipelines 2.2 CPOC Wellhead General Specifications Reference Title CPOC-GS-PL-0011 Installation of Submarine Pipelines
SEABED SURVEYS AND PIPELINE SPAN RECTIFICATION Doc. No. CPOC-GS-PL-0003 Rev. 0 Date 19/04/13 Page 6 of 6 CPOC 3.0 GENERAL 3.1 Definitions Reference Description Approval The authorisation in writing given by the COMPANY to the Contractor on a procedure or to proceed with the performance of a specific part of the work without releasing in any way the Contractor from any of his obligations to conform with the technical specifications, requisitions, etc. The words “Approve”, “Approved” and “Approval” shall be construed accordingly COMPANY Carigali-PTTEPI Operating Company Sdn. Bhd. (CPOC) Contract Documents The material requisitions, material specifications, etc. issued by the COMPANY and attached to the Contract or the Purchase Order Contractor Any company CPOC has signed a contract with for the Engineering, Procurement, Construction and Installation of a part of a project Manufacturer The company or its sub-contractors selected by the COMPANY or the Supplier (as applicable) as the Manufacturer of the said materials PPS Designates Project Particular Specification detailing the additional tests and requirements or the possible modifications to the present specification, based on the particular design conditions of the project Shall Used to indicate that a provision is mandatory Should Used to indicate that a provision is not mandatory but is recommended as good practice May Used to indicate that a provision is optional
SEABED SURVEYS AND PIPELINE SPAN RECTIFICATION Doc. No. CPOC-GS-PL-0003 Rev. 0 Date 19/04/13 Page 7 of 7 CPOC 3.2 Abbreviations Reference Description AHT Anchor Handling Tug API American Petroleum Institute BATHYSYSTEM ROV System coupling digiquartz pressure sensor and sounder CCTV Closed-Circuit Television CD Chart Datum C-O Calculated minus Observed correction CP Cathodic Protection CTD Conductivity Temperature Depth sensor DCC Distance Cross Course DGPS Differential Global Positioning System, which uses corrections from known reference stations DHSS Dual Head Scanning Sonar DNV Det Norske Veritas DP Dynamic Positioning DVD Digital Video Disc DVL Doppler Velocity Log EF Extra High Frequency EPCI Engineering, Procurement, Construction and Installation FMEA Failure Modes and Effects Analysis FPSO Floating Production Storage and Offloading FPU Floating Production (semi-submersible) Unit FSO Floating Storage and Offloading GcGPS Globally corrected GPS based on high accuracy clock, trajectory and propagation delay corrections HF High Frequency HSE Health Safety and Environment ILT T-shaped pipeline INS Inertial Navigation System IOM Inspection and Operation Manual ITP Inspection and Test Plan ITRF International Terrestrial Reference Frame KP Kilometre Post
SEABED SURVEYS AND PIPELINE SPAN RECTIFICATION Doc. No. CPOC-GS-PL-0003 Rev. 0 Date 19/04/13 Page 8 of 8 CPOC LAT Lowest Astronomical Tide LBL Long Base Line System LF Low Frequency MBE Multi-Beam Echosounder to be mounted on ROV MDE Marginally Detectable Error MF Medium Frequency MSL Mean Sea Level NCR Non-Conformance Report OAS Obstacle Avoidance Sonar OOB Oil Offloading Buoy OOS Out-Of-Straightness PDOP Position Dilution of Precision (satellite geometry indicator) PLET Pipe Line End Terminations RGPS Relative Global Positioning System RINEX Receiver Independent Exchange Format ROM Read-Only Memory ROV Remote Operated Vehicle RTCM SC104Format Recommended format for GPS in differential mode. Differential corrections are often referred to as simply RTCM corrections RTCM SC-140 Radio Technical Commission for Maritime Resource Special Committee 104. SBL Short Base Line System SDRL Supplier Data Requirements List SDU Subsea Distribution Unit SI International System of Units SSS Side Scan Sonar to be mounted on ROV SV Sound Velocity TDP Touch Down Point TMS Tug Management System TMS Tether Management System TQ Technical Queries TV Television UHB Up Heaval Buckling UKOOA United Kingdom Offshore Operators Association USBL Ultra Short Baseline System UTC Universal Time Co-ordinated
SEABED SURVEYS AND PIPELINE SPAN RECTIFICATION Doc. No. CPOC-GS-PL-0003 Rev. 0 Date 19/04/13 Page 9 of 9 CPOC UTM Universal Transverse Mercator VHF Very High Frequency VRU Vertical Reference Unit WGS84 World Geodetic System 1984 WIFI Wireless Fidelity
SEABED SURVEYS AND PIPELINE SPAN RECTIFICATION Doc. No. CPOC-GS-PL-0003 Rev. 0 Date 19/04/13 Page 10 of 10 CPOC 4.0 GENERAL REQUIREMENTS 4.1 Health, Safety and Environment COMPANY has set targets for HSE of no accidents or harm to people or environment. To achieve this goal, the following shall be applied: 1) The Contractor shall develop and implement an HSE management system for the works acceptable to COMPANY. 2) The Contractor shall analyze and implement work practices to as low as possible to minimize the risk to people, facilities and environment. This includes hazardous removal/elimination/minimisation and Failure Modes and Effects Analysis (FMEA) including contingency plans to meet emergency needs. 3) All work shall be completed in a safe manner such that no harm can be caused to personnel or facilities during the project execution. 4) Equipment shall be designed to eliminate or reduce emissions to as low as reasonably practical. 4.2 Quality Assurance 4.2.1 General The Contractor shall develop and implement an agreed quality plan within the project quality system to assure the work as agreed. This includes inspection and testing activities, record keeping, traceability etc. The Inspection and tests shall be as defined on the data sheets, Thailand Regulations, this specification, other specifications where referenced in the Contract and codes and standards listed. The requirements of Thailand Regulations shall take precedence. This shall include, but not be limited to physical inspection, testing, repairing and reporting. 4.2.2 Inspection and Test Plan (ITP) The Contractor shall develop an Inspection and Test Plan (ITP) for submission to COMPANY for approval prior to the commencement of physical works. The Contractor shall perform inspection and testing activities in accordance with the requirements of this specification and the approved inspection and test plan(s). 4.2.3 Inspection and Test Procedures The Contractor shall prepare all necessary inspection and test procedures required for the works and submit to COMPANY for review and approval. 4.2.4 Quality Records The Contractor shall generate quality records from the inspection and test activities listed in this specification and in accordance with the approved inspection and test plan(s). Documents and drawings shall be submitted as agreed in the Contractor’s Supplier Data Requirements List (SDRL).
SEABED SURVEYS AND PIPELINE SPAN RECTIFICATION Doc. No. CPOC-GS-PL-0003 Rev. 0 Date 19/04/13 Page 11 of 11 CPOC The records shall be compiled and reviewed by the Contractor following the completion of each inspection and test. Quality Records to be included in the As-Built Report are nominated in Table 11.1-1. Those records not nominated for inclusion in the As-Built Report shall be available for COMPANY review throughout the contract period and thereafter retained in accordance with industry standards. Quality records requiring COMPANY review and or endorsement shall be forwarded to COMPANY progressively throughout the contract period. 4.2.5 Marking and Identification The Contractor shall mark items for identification and traceability in accordance with this specification and other project requirements. Items marked to facilitate traceability shall maintain the marking throughout manufacture and fabrication stages. Markings to be covered in final assembly and coating shall be first transferred to as-built traceability quality records. The transfer of markings to traceability quality records may be subject to COMPANY verification. Items marked to permit identification only shall maintain the marking throughout manufacture stages until included in the final assembly. 4.2.6 Traceability Contractor shall mark items and establish documented means of: 1) Locating the item (traceability record) 2) Locating the quality records generated from inspection and testing of the item
SEABED SURVEYS AND PIPELINE SPAN RECTIFICATION Doc. No. CPOC-GS-PL-0003 Rev. 0 Date 19/04/13 Page 12 of 12 CPOC 5.0 SEABED INTERVENTION PHILOSOPHY 5.1 General Contractor shall be responsible for evaluating, engineering, finalising and performing the necessary pre-lay and post-lay route intervention work to ensure that the pipelines are not over-stressed due to spanning and/or permissible span lengths are not exceeded. A flowchart of the seabed intervention philosophy is given in Attachment 1. This Specification gives the acceptance criteria for pipelines spanning and stressing together with procedures for planning, defining and performing the seabed intervention work. 5.2 Permissible Span Lengths and Stresses Maximum permissible span lengths for the pipelines are presented in the project drawings. Contractor may submit his proposal for allowable spans during intermediate stages such as installation and hydrotest with adequate calculations for COMPANY’s review and approval. 5.3 Pre-lay Intervention Survey and Analysis 5.3.1 Pre-lay Intervention Survey The Contractor shall be responsible for defining and performing a pre-lay intervention survey along the lay corridor. 5.3.2 Analysis A freespan/stress analysis predicting the installation, hydrotest and operational configurations of the pipelines when resting on the seabed shall be performed using the prelay intervention survey information. The analysis shall be performed in accordance with Section 6 of this Specification. The analysis method shall conform to the requirements of applicable codes to finalise the extent, location and method of pre-lay intervention work required (see Section 5.4) and to obtain a good definition of post-lay intervention work (see Section 5.6). For this purpose, a spreadsheet shall be implemented, showing out the Project’s reference of the pipeline and for each change in its cross-sectional specification: 1) The steel pipe OD or ID, whatever the constant value, in mm 2) The steel pipe WT, in mm 3) The steel grade in MPa 4) The corrosion coating WT, in mm 5) The concrete coating WT, in mm 6) The maximum span length under hydrotest condition, in m 7) The maximum span length under operating, in m When processing freespan assessment, it shall be demonstrated whether or not the pipe will deflect and gain any intermediate supports under in-service conditions and the location of
SEABED SURVEYS AND PIPELINE SPAN RECTIFICATION Doc. No. CPOC-GS-PL-0003 Rev. 0 Date 19/04/13 Page 13 of 13 CPOC these supports as well as their suitability as permanent supports (integrity, susceptibility to scour, etc.) shall be fully assessed from the pre-survey results. The location of freespan reduction supports, as well as the required pipeline lift-up height shall then be specified so as to optimise the in-service stress/strain behaviour of the pipeline. 5.3.3 Criteria for Pre-Lay Intervention The pre-lay intervention survey profile shall be analysed for the operating, installation and hydrotest conditions. Pre-lay intervention will be required where the stress levels exceed the allowable for the installation condition only. Pre-lay intervention is also required for span lengths exceeding the Temporary phase (installation and hydrotest) limits unless postlay intervention is specified in such a time schedule that cumulative fatigue damage, calculated using realistic environmental data, does not exceed the limits given in DNV RP F105. 5.3.4 Criteria for Post-Lay Intervention The pre-lay intervention survey profile shall be modified to incorporate the pre-lay intervention works required by Section 5.3.2. The modified profile shall be analysed for both the hydrotest and operational conditions to develop a good definition of the extent of post lay intervention required. If the stresses and/or span lengths in the hydrotest condition exceed the allowable, post lay intervention shall be carried out, as soon as possible, within a time frame to be approved by COMPANY but in any case prior to flooding of the pipelines. 5.4 Pre-Lay Intervention Work The Contractor shall be responsible for performing pre-lay intervention work along the pipelines corridor prior to pipelaying to the extent necessary to ensure that the allowable stress and span limits for the temporary phase are not exceeded after pipelaying. The Contractor shall propose methods of pre-lay intervention for COMPANY review and approval. 5.5 Post-Lay Survey and Analysis 5.5.1 Post-Lay Survey The Contractor shall perform a post-lay survey of the empty pipelines (i.e. prior to flooding) in accordance with Contract specifications. 5.5.2 Analysis A freespan/stress analysis predicting the hydrotest and operational configurations of the pipelines when resting on the seabed shall be performed using the post-lay survey information. The analysis shall be performed in accordance with Section 6. The analysis method shall conform to the requirements of DNV RP F105 and applicable pipeline principal design code as shown in Section 2.1.
SEABED SURVEYS AND PIPELINE SPAN RECTIFICATION Doc. No. CPOC-GS-PL-0003 Rev. 0 Date 19/04/13 Page 14 of 14 CPOC The Contractor shall use the analysis results obtained to assess and finalise the extent, location and method of any post-lay intervention work required. The Contractor shall propose methods of post-lay intervention for COMPANY review and approval. 5.6 Post-Lay Intervention Work The Contractor shall be responsible for performing all necessary post-lay intervention work to ensure that the allowable stress and span limits for the permanent phase are not exceeded. The Contractor may elect to perform the post-lay intervention work with the pipelines air-filled or water-filled. Contractor shall perform the post-lay intervention works within the priorities set out for carrying out the post lay intervention works. The definition of the priorities for the post lay intervention work shall be based on fatigue analysis. The time frame for carrying out the post-lay intervention works shall be, based on the priorities, approved by COMPANY. All post-lay intervention work shall be defined as a minimum to satisfy the following objectives: 1) Intervention work shall be scheduled such that any fatigue usage with any span will not exceed the allowable limit given in DNV RP F105, prior to the performance of such work; 2) Intervention work shall be defined to ensure that everywhere along the pipelines route, the permissible limits for the permanent phase are satisfied before hydrotesting.
SEABED SURVEYS AND PIPELINE SPAN RECTIFICATION Doc. No. CPOC-GS-PL-0003 Rev. 0 Date 19/04/13 Page 15 of 15 CPOC 6.0 ENGINEERING 6.1 General COMPANY will provide all available pipelines route survey information including route profiles to the Contractor. All available environmental data is given in the Contract Documents. Proposed pipeline route profiles are also provided with the Contract Documents. The Contractor shall perform engineering to determine the location and extent of intervention work required prior to pipelay (pre-lay intervention) and after pipelay (post-lay intervention). The Contractor shall propose methods of seabed intervention to COMPANY for review and approval. The Contractor shall consider economical methods to rectify unsupported spans including long term safety. The methods could be to locally remove the seabed material and/or supporting pipelines on grout bags or equivalent. The Contractor shall be responsible for evaluating the risk of settlement into seabed and scouring during the operational phase if grout bags are used. COMPANY wishes to minimise the extent of seabed intervention work. The Contractor shall be required to collaborate with COMPANY to achieve this without deviating from the minimum requirement of DNV RP F105 and applicable pipeline principal design code as shown in Section 2.1. As such, the Contractor may, if considered appropriate, propose rerouting of the pipelines within the survey corridor to minimise the extent of pre or post lay seabed intervention work. Details of such re-routing shall be submitted to COMPANY for review and approval prior to implementation. The Contractor shall demonstrate, using established engineering analysis procedures, full scale and/or sample tests and/or field trials to COMPANY the suitability of all proposed methods of intervention. In the case of post-lay intervention, the Contractor shall ensure that the method of intervention does not pose a risk of damage to the pipelines. The Contractor’s procedures shall identify the limiting environmental conditions in which intervention work may be carried out to the accuracy stated on the Contract drawings. 6.2 Calculations Calculations for allowable span length shall be in accordance with the requirements of DNV RP F105 and applicable pipeline principal design code as shown in Section 2.1. Span acceptance screening shall be carried out using a fully validated finite element computer program. Under EPCI or installation scope of work, the outcome of the spanning analysis shall be captured in the “Pipeline Spanning Analysis Report” which includes as a minimum the acceptable span lengths. The EPCI or installation Contractor shall as a minimum update the report and perform the following seabed analysis for span length and stress level acceptance screening based upon route profiles provided by COMPANY for the Installation, Hydrotest and Operational cases: 1) Establish requirements based upon analysis results using COMPANY supplied route profiles for both pre-lay and post-lay intervention work for the temporary and permanent conditions. 2) Perform re-analysis using additional data from the pre-lay intervention survey and finalise pre-lay intervention requirements to avoid over spanning and overstressing in
SEABED SURVEYS AND PIPELINE SPAN RECTIFICATION Doc. No. CPOC-GS-PL-0003 Rev. 0 Date 19/04/13 Page 16 of 16 CPOC the temporary air-filled condition. Analysis shall be performed to check the stress and strain state of the pipelines in the temporary water filled condition. If required, additional pre-lay intervention resulting from this analysis may be defined in agreement with the COMPANY. 3) Should spans be allowed to exceed the temporary phase permissible limits after pipelay, perform span fatigue analyses, using route profiles provided by COMPANY, additional data from pre-lay intervention survey and pre-lay intervention work definitions, to establish post-lay intervention work programme (detailing locations, method, extent and schedule of Work). 4) Analysis based upon the post lay survey information to establish unacceptable spans for the temporary condition for which immediate span intervention work is necessary to avoid exceeding cumulative fatigue damage. 5) Analysis based upon the post-lay survey information to establish span intervention work, which is necessary prior to hydrotest, and further intervention work required prior to pipelines operation. In addition to the above span intervention analysis, Contractor’s calculations shall establish the stability and adequacy of span intervention methods as follows: 1) Stability of pre-lay span intervention works 2) Scour of the intervention material due to environmental forces shall be prevented. 3) Adequacy and stability of supports, to the pipelines The Contractor shall also perform post intervention analyses based upon “as installed” intervention work to demonstrate adequacy of completed Work. The Contractor’s seabed analysis for spans and stress levels shall be performed using a fully validated finite element analysis computer program. Details of the analysis methods and program validation shall be provided to COMPANY for review and approval. The Contractor’s span fatigue analysis methodology, details of computer programs and their validation shall also be provided to COMPANY for review and approval. Element lengths and seabed bathymetric nodal positions used in the Contractor’s seabed analysis shall not be greater than 20 % of the allowable span length applicable to the region being analysed or 2 m whichever is the lesser. The Contractor’s seabed analysis for successive sections of the pipelines route shall have sufficient overlap to eliminate local stress/span anomalies due to analysis end conditions. Residual lay tension or bottom tension for the seabed analysis shall be based upon the Contractor’s three-dimensional dynamic pipelay analysis results. 6.3 Drawings The Contractor shall prepare and make available to COMPANY drawings of all span intervention work to be carried out prior to and after pipelines installation that shall include, but not limited to: 1) Details of the proposed installation equipment 2) Vessel positioning when near to an installed pipelines or cable
SEABED SURVEYS AND PIPELINE SPAN RECTIFICATION Doc. No. CPOC-GS-PL-0003 Rev. 0 Date 19/04/13 Page 17 of 17 CPOC 3) Typical configuration for proposed intervention method (such as trenching, grout bagging, rock mound profile for rock dumping method) 4) Location plans for all areas of span intervention work 5) As-built drawings
SEABED SURVEYS AND PIPELINE SPAN RECTIFICATION Doc. No. CPOC-GS-PL-0003 Rev. 0 Date 19/04/13 Page 18 of 18 CPOC 7.0 POSITIONING SYSTEMS The positioning systems for all vessels engaged in the pre-lay and post-lay intervention work shall be as per Attachment 2. The positioning equipment used for intervention works shall be the same as that used for pipelines installation. In areas where it is necessary to reduce pipelay tolerances in order to minimise pre-lay intervention works, the Contractor shall consider the use of transponder arrays to accurately position the pipelines.
SEABED SURVEYS AND PIPELINE SPAN RECTIFICATION Doc. No. CPOC-GS-PL-0003 Rev. 0 Date 19/04/13 Page 19 of 19 CPOC 8.0 SPAN RECTIFICATION 8.1 General The Contractor shall propose methods of pre- and post pipelay span intervention and methods for maintaining lateral stability if applicable. The construction route shall be cleared of any debris and obstructions assessed as hazards, in order to facilitate the proper and safe installation of the pipelines and dog-legs. Such debris and obstructions shall be cleared and disposed in the respect of Section 4.2, CPOC-GS-PL-0011 requirements. Adequate provision for keeping the route clear of all waste materials and refuse as the works proceed shall be made accordingly. For high temperature pipeline, where upheaval buckling phenomena are anticipated, special attention will be paid to the possible future preparation of the pipeline route. Pre-sweeping and other subsea works to limit pipeline free spanning shall be evaluated. 8.2 Span Rectification Span rectification methods may include pre-sweeping, dredging, trenching, ploughing, minor re-routing or grout bagging. The Contractor shall propose its span rectification methods for COMPANY review and approval. Such proposals shall as a minimum contain the following: 1) Technical details of the intervention method 2) Description of installation vessel and equipment 3) Previous experience with the method and installation equipment 4) Safety of personnel, equipment and pipelines 5) Calculations as required showing the suitability and adequacy of the proposed method The chosen methods of span rectification shall be such that damage does not occur to the pipelines concrete coating and/or corrosion coating. Any pre-lay intervention proposed shall ensure that the pipelines are not supported on sharp seabed features. Where rock dumping is used for span correction after pipelines installation, the Contractor shall demonstrate that rock sizes and fall velocity shall be such that there will be no damage to the pipelines or coatings by impact. 8.3 Span Rectification Procedures The Contractor shall prepare and provide to COMPANY procedures for span intervention operations, which shall include as a minimum: 1) Description/procedures for all intervention operations 2) Method of inspection of intervention zones, prior to and after pipelines installation 3) Contingency and rectification procedures
SEABED SURVEYS AND PIPELINE SPAN RECTIFICATION Doc. No. CPOC-GS-PL-0003 Rev. 0 Date 19/04/13 Page 20 of 20 CPOC 4) Survey procedures 5) Details of monitoring and control equipment and operation 8.4 Freespan Reduction During the pipelaying phase, any new freespans shall be subject to the assessment method presented in previous Section 5.3.2. Temporary free spanning must not induce fatigue damages greater than 5% of the one associated with the overall design life. Then freespan reduction supports shall: 1) Be of either inflatable grout bags or any approved alternative devices 2) Be installed at the assessed locations and shall achieve the required lift-up values 3) Be installed as soon as practicable after laying and always before it is water filled for the hydrostatic test. Bags containing either cement plus sand or sand alone are prohibited. The type of grout bags, cement sand ratio, etc., and all grouting shall fulfill Project requirements. The bearing width of the grout bags across the pipeline should be at least three times the outside diameter of the pipeline Grout bag support shall embed the pipeline over at least one half of the outside pipe diameter. Settlement as well as scouring of the supporting bags in soft seabed shall be accounted for.
SEABED SURVEYS AND PIPELINE SPAN RECTIFICATION Doc. No. CPOC-GS-PL-0003 Rev. 0 Date 19/04/13 Page 21 of 21 CPOC 9.0 EQUIPMENT 9.1 General The Contractor shall provide to COMPANY, descriptions and technical information on all proposed construction vessels and equipment. This shall include, but not be limited to the following: 1) Vessel principal dimensions 2) Vessel horizontal positioning system 3) Dynamic positioning equipment 4) ROV survey equipment 5) Construction system 6) Monitoring and control instrumentation 7) Accommodation and services onboard 8) Communication systems onboard 9) Safety systems and precautions 9.2 Mobilisation Mobilisation of any vessels, personnel and equipment shall take place at a port agreed between COMPANY and the Contractor. Prior to the mobilisation of any positioning system on any vessel, the system shall have been checked and calibrated in accordance with calibration requirements as per Attachment 2. The Contractor shall demonstrate to COMPANY all software that it is to be used during the Project using “real” data at least 30 days prior to the commencement of any Work. The Contractor shall make available to COMPANY a time schedule of the mobilisation of any vessel including all necessary testing and calibrations. 9.3 Acceptance Trials All vessels shall be subjected to an acceptance trial prior to the completion of mobilization and the commencement of any Work. The Contractor shall prepare all procedures for performing the vessel acceptance trials, and shall provide them together with all relevant certificates to COMPANY before commencement of vessel mobilisation. The location of the trials shall be agreed between COMPANY and the Contractor and shall be close to the Work location.
SEABED SURVEYS AND PIPELINE SPAN RECTIFICATION Doc. No. CPOC-GS-PL-0003 Rev. 0 Date 19/04/13 Page 22 of 22 CPOC 10.0 SURVEYS Survey work performed, as part of the span intervention activities shall be as per Attachment 2. Contractor shall, as a minimum, perform the following surveys works: 1) Pre-lay intervention survey 2) Post-lay intervention survey 3) Pre-lay survey 4) Post-lay survey
SEABED SURVEYS AND PIPELINE SPAN RECTIFICATION Doc. No. CPOC-GS-PL-0003 Rev. 0 Date 19/04/13 Page 23 of 23 CPOC 11.0 DOCUMENTATION Engineering documentation to be submitted to COMPANY for review and/or approval are summarised in Table 11.1-1. Timing for submission of these documents as well as documents to be included in the As-Built Report is also nominated in Table 11.1-1. Table 11.1-1 Documentation Engineering Documents COMPANY Review Timing* Included in As-Built Report Included in IOM Vessel acceptance trial procedures YES A12 NO YES Intervention analysis procedures YES A12 NO NO Finite element computer program validation YES A12 NO NO Seabed roughness analysis YES A12 NO NO Pre and Post-lay intervention calculations YES A12 NO NO Emergency span correction procedures YES A12 NO YES Support stability calculations YES A12 NO NO Lateral stability calculations if applicable YES A12 NO NO Pre and post pre-lay intervention survey results YES At completion of surveys YES NO Final prelay intervention calculations after pre-prelay survey YES At completion of surveys NO NO For each proposed intervention method: Vessel position drawings YES A12 NO YES Intervention procedures YES A12 NO YES Equipment descriptions and technical information YES A12 NO YES Engineering calculations YES A12 NO NO Positioning system documentation YES A12 YES YES Equipment calibration reports YES A12 YES NO Repair procedures YES A12 NO YES As-Built Drawings YES 2 weeks after completion of intervention works YES NO
SEABED SURVEYS AND PIPELINE SPAN RECTIFICATION Doc. No. CPOC-GS-PL-0003 Rev. 0 Date 19/04/13 Page 24 of 24 CPOC A12 – 12 weeks after effective contract date 12.0 TECHNICAL QUERIES / NON-CONFORMANCE REPORTS 1) Any Contractor’s requests for clarifications or deviations to COMPANY specifications shall be submitted to COMPANY only through Technical Queries (TQ), the format of which shall have prior approval of the COMPANY. A deviation to specification shall not be considered as accepted if it has not been submitted to and accepted by COMPANY through a Technical Query. 2) Approval given by the COMPANY to any Contractor’s work procedures, specifications, equipment, etc. shall not release in any way the Contractor from his obligation to meet the COMPANY specifications. 3) Any work performance or test result which is found, at a later date, not in conformance with COMPANY specifications or agreed procedure shall be subject to a Non-Conformance Report (NCR) to be issued by the Contractor for submission to COMPANY. NCR report shall indicate corrective action intended by the Contractor.