NORSOK STANDARD DRILLING & WELL OPERATIONS

NORSOK STANDARD DRILLING & WELL OPERATIONS D-010

This NORSOK standard is developed by NTS with broad industry participation. Please note that whilst every effort has been made to ensure the accuracy of this standard, neither OLF nor TBL or any of their members will assume liability for any use thereof. NTS is responsible for the administration and publication of this standard. Norwegian Technology Standards Institution Oscarsgt. 20, Postboks 7072 Majorstua N-0306 Oslo, NORWAY Telephone: + 47 22 59 01 00 Fax: + 47 22 59 01 29 Email: norsok@nts.no Website: http://www.nts.no/norsok Copyrights reserved

CONTENTS FOREWORD INTRODUCTION 1 SCOPE 4 2 NORMATIVE REFERENCES 4 3 DEFINITIONS AND ABBREVIATIONS 7 3.1 Definitions 7 3.2 Abbreviations 8 4 GENERAL REQUIREMENT 9 4.1 Well Classification 9 4.2 Well Design 9 4.3 Well Data Acquisition 11 4.4 Blow-out Contingencies or Relief Well Drilling 12 4.5 Barrier Philosophy 13 4.6 Operations 15 4.7 Preparation of Programme 15 4.8 Risk Analyses 18 4.9 Emergency Preparedness Analysis 19 4.10 Application of Consents, Permits, Approvals 20 4.11 Simultaneous Operations 21 4.12 Personnel Qualification & Training 22 4.13 HSE Management System 23 4.14 Safety Drills 25 4.15 Reporting to the NPD 25 4.16 Experience Transfer 25 4.17 Documentation 25 5 OPERATION 27 5.1 Drilling 27 5.2 Completion or workover 37 5.3 Testing 39 5.4 Well Intervention 42 5.5 Pressure Controlled Drilling 45 NORSOK standard Page 1 of 55

ATTACHMENT 5.2 BARRIER TESTING, STATUS AND AVAILABILITY FOR WELL COMPLETION OPERATIONS (INFORMATIVE) 51 ATTACHMENT 5.3 BARRIER TESTING, STATUS AND AVAILABILITY FOR WELL TESTING OPERATIONS (INFORMATIVE) 52 ATTACHMENT 5.4.1 BARRIER TESTING, STATUS AND AVAILABILITY FOR SNUBBING OPERATIONS (INFORMATIVE) 53 ATTACHMENT 5.4.2 BARRIER TESTING, STATUS AND AVAILABILITY FOR COILED TUBING OPERATIONS (INFORMATIVE) 54 ATTACHMENT 5.4.3 BARRIER TESTING, STATUS AND AVAILABILITY FOR WIRELINE OR TRACTOR OPERATIONS (INFORMATIVE) 55 NORSOK standard Page 2 of 55

FOREWORD NORSOK (The competitive standing of the Norwegian offshore sector) is the industry initiative to add value, reduce cost and lead time and eliminate unnecessary activities in offshore field developments and operations. The NORSOK standards are developed by the Norwegian petroleum industry as a part of the NORSOK initiative and supported by OLF (The Norwegian Oil Industry Association) and TBL (Federation of Norwegian Engineering Industries). NORSOK standards are administered and issued by NTS (Norwegian Technology Standards Institution). The purpose of NORSOK standards is to contribute to meet the NORSOK goals, e.g. by replacing individual oil company specifications and other industry guidelines and documents for use in existing and future petroleum industry developments. The NORSOK standards make extensive references to international standards. Where relevant, the contents of a NORSOK standard will be used to provide input to the international standardisation process. Subject to implementation into international standards, the NORSOK standard will be withdrawn. INTRODUCTION The main objective of this NORSOK Standard is to contribute to an optimisation of the drilling & well operations with respect to gaining operational efficiency and to stipulate an acceptable safety level. Revision 2 of this Standard is an overall improvement and expansion of the former D-010, especially on well intervention and pressure control drilling. NORSOK standard Page 3 of 55

1 SCOPE This NORSOK standard defines functional and performance oriented requirements for well design and planning and execution of safe and efficient drilling and well operations in Norwegian waters. 2 NORMATIVE REFERENCES The following standards include provisions which, though reference in this text, constitute provisions of this NORSOK standard. Latest issue of the references shall be used unless otherwise agreed. Other recognised standards may be used provided it can be shown that they meet or exceed the requirements of the standards referenced below. NORSOK M-702 Drill string components NORSOK S-002 Working Environment NORSOK S-003 Environmental Care NORSOK Z 015 Temporary Equipment NORSOK D-001 Drilling Facilities NORSOK D-CR-003 Surface Christmas Tree, Rev. 1 Jan. 1995 NORSOK D-SR-005 Coiled tubing equipment, Rev 1, Jan. 1996 NORSOK D-SR-006 Snubbing equipment, Rev. 1, Jan. 1996 NORSOK D-SR-007 Well testing system, Rev. 1, Jan. 1996 NORSOK D-SR-008 Wireline equipment Rev. 1, Oct. 1996 BS 6755: Part 1: 1986 (1991) = ISO 5208 Specification for production pressure testing requirements NACE MR0175 NPD Sulphide Stress Cracking Resistant Metallic Materials for Oilfield Equipment, 1997 Acts, Regulations and Provisions for the Petroleum Activity ANIS/ASME B31.3 Process Piping, 1996 ISO 10407 ISO 10417 ISO 10423 ISO 10432 Petroleum and Natural Gas Industries Drilling and Production Equipment Drill Storm Design and Operating Limits First Edition, 1993 Petroleum and Natural Gas Industries Subsurface Safety Valve Systems Design Installation, Operation and Repair First Edition, 1993 Petroleum and Natural Gas Industries Drilling and Production Equipment Specification for Valves, Wellhead and Christmas Tree Equipment First Edition, 1994 Petroleum and Natural Gas Industries Subsurface Safety Equipment Specification First Edition, 1993 NORSOK standard Page 4 of 55

ISO 10433 Petroleum and Natural Gas Industries Drilling and Production Equipment Specification for Wellhead Surface Safety Valves and Underwater Safety Valves for Offshore Service First Edition, 1994 API Bull 6AR Recommended Practice for Repair and Remanufacture of Wellhead and Christmas Tree Equipment, 1994 API Spec 6FA Specification for Fire Test for Valves, 1994 API Bull 6FI Bulletin on Performance of API and ANSI End Connections in a Fire Test According to API Specification 6FA, 1994 API Bull 6F2 Bulletin on Fire Resistance Improvements for API Flangas, 1994 API RP2K Bruk av stigerør API Bull 2J Stigerørsanalyse API Spec 10 Specification for Materials and Testing for Well Cements, 1990 API Spec 10D Specification for Bow-Spring Casing Centralises, 1995 API RP 10E Recommended Practice for Application of Cement Lining to Steel Tubular Goods, Handling, Installation and Joining Third Edition; ISO 10409, 1994 API Spec 13A Specification for Drilling Fluid Materials, 1993 API RP 138-1 Recommended Practice Standard Procedure for Field Testing Water-Based Drilling Fluids, 1990 API RP 138-2 Recommended Practice Standard Procedure for Field Testing Oil-Based Drilling Fluids, 1991 API RP 13C Recommended Practice for Drilling Fluid Processing Systems Evaluation, 1996 API RP 13D Recommended Practice on the Rheology and Hydraulics of Oil-Well Drilling Fluids, 1995 API RP 13E Recommended Practice for Shale Shaker Screen Cloth Designation, 1993 API RP 13G Recommended Practice Standard Procedure for Drilling Mud Report Form, 1991 API RP 13I Recommended Practice Standard Procedure for Laboratory Testing Drilling Fluids, 1995 API RP 13J Testing of Heavy Brines, 1996 API RP 14B API Spec 14D API RP 14H API RP 17A API RP 53 Design, Installation, Repair and Operation of Subsurface Safety Valve Systems Fourth Edition; ISO 10417; Errata 1996, 1994 Specification for Wellhead Surface Safety Valves and Underwater Safety Valves for Offshore Service, 1994 Recommended Practice for Installation, Maintenance and Repair of Surface Safety Valves and Underwater Safety Valves Offshore Fourth Edition; ISO 10419, 1994 Recommended Practice for Design and Operation of Subsea Production Systems, 1996 Blow-out Prevention Equipment Systems for Drilling Wells Third Edition, 1997 NORSOK standard Page 5 of 55

API Spec 5CT Specification for Casing and Tubing (Metric Units) Fifth Edition, 1995 API Spec 5D Specification for Drill Pipe, 1992 API Spec 5B Specification for Threading, Gauging and Thread Inspection of Casing, Tubing and Line Pipe Threads (U.S. Customary Units), 1996 API Spec 5L Specification for Line Pipe, 1995 API Spec 5LC Specification for CRA Line Pipe, 1995 API Bull 5A2 Bulletin on Thread Compounds for Casing, Tubing and Line Pipe Sixth Edition; Superseded by RP5A3, 1988 API Bull 5C2 Bulletin on Performance Properties of Casing, Tubing and Drill Pipe, 1987 API Bull 5C3 Bulletin on Formulas and Calculations for Casing, Tubing, Drill Pipe and Line Pipe Properties, 1994 API Bull 5C4 Bulletin on Round Thread Casing Joint Pressure and Bending, 1987 API RP 5A5 Recommended Practice for Field Inspection of New Casing, Tubing and Plain-End Drill Pipe, 1993 API RP 5B1 Gauging and Inspection of Casing, Tubing and Line Pipe Treads Fourth Edition, 1996 API RP 5C1 Recommended Practice for Care and Use of Casing and Tubing, 1994 API RP 5C5 Evaluation Procedures for Casing and Tubing Connections API Spec 6D Specification for Pipeline Valves (Gate, Plug, Ball and Check Valves), 1994 API Spec 6FB API Specification for Fire Test for End Connections, 1992 API Spec 6FC Specification for Fire Test for Valves with Automatic Backseats, 1994 API Spec 16A Specification for Drill Through Equipment, 1986 (replace with ISO 13533 when issued) API Spec 14A Specification for Wellhead Surface Safety Valves and Underwater Safety Valves for Offshore Service First Edition, 1994 API RP 14B Design, Installation, Operation and Repair First Edition, 1993 API RP 14E Recommended Practice for Design and Installation of Offshore Production Platform Piping Systems, 1991 API STD 607 Fire Test for Soft-Seated Quarter Turn Valves, 1993 API Spec 16D Specification for Control Systems for Drilling Well Control Equipment, 1993 API Spec 7 Specification for Rotary Drill Stem Elements Thirty Eight Edition; Errata 1994 (replace with ISO 10424 when issued) API Spec 7F Specification for Oil-Field Chain and Sprockets, 1993 API RP 7G Drill Stern Design and Operating Limits First Edition, 1993 API Spec 8C Specification for Drilling and Production Hoisting Equipment (PSL 1 and PSL 2), 1992 (replace with ISO 13535 when issued) NORSOK standard Page 6 of 55

API RP 8B Recommended Practice for Procedures for Inspection, Maintenance, Repair and Remanufacture of Hoisting Equipment, 1992 API Spec 9A Specification for Wire Rope, 1995 API RP 9B Recommended Practice on Application, Care and Use of Wire Rope for Oil Field Service, 1986 API RP 10E Recommended Practice for Application of Cement Lining to Steel Tubular Goods, Handling, Installation and Joining Third Edition; ISO 10409, 1994 API RP 5C7 Coiled Tubing Operations in Oil and Gas Well Service First Edition, 1996 3 DEFINITIONS AND ABBREVIATIONS 3.1 Definitions Barrier: One or several dependent barrier elements, which are designed to prevent unintentional flow of formation fluid. A barrier is an envelope preventing hydrocarbons from flowing unintentionally from the formation, into another formation or, to surface. Barrier elements that make up the Primary barrier are those elements, which are or might be in direct contact with well pressure during normal operation. These elements provide the initial and inner envelope preventing unintentional flow of reservoir fluid to surface, or another zone. Barrier elements that make up the Secondary barrier are those, which are or might be exposed to contact with well pressure should any of the elements described as a Primary barrier element fail. These elements provide an envelope outside the Primary barrier envelope providing a second barrier preventing unintentional flow of reservoir fluid to surface, or another zone. HPHT well: Well drilled in a formation with expected shut-in wellhead pressure greater than 690 bar and/or bottom hole temperature in excess of 150 C. NORSOK: Norsk Sokkels Konkurranseposisjon, the Competitive standing of the Norwegian Offshore Sector, the Norwegian initiative to reduce cost on offshore projects. Shall: Verbal form used to indicate requirements strictly to be followed in order to conform to the standard and from which no deviation is permitted, unless accepted by the Operator. Should: Verbal form used to indicate that among several possibilities one is recommended as particularly suitable, without mentioning or excluding others, or that a certain course of action is preferred but not necessarily required. Simultaneous operations: Two or more major activities being in process parallel in time. Tested barrier: Barrier tested and qualified to withstand maximum expected pressure. NORSOK standard Page 7 of 55

Pressure controlled drilling: A well drilled under the conditions that the effective pore pressure in the formation is greater than the static/effective circulating downhole pressure, of a drilling fluid (flow drilling). 3.2 Abbreviations AFE Approval for Expenditure BHA Bottom Hole Assembly BOP Blow Out Preventer BPV Back Pressure Valve CDRS Common Drilling Reporting System CT Coiled Tubing CTD Coiled Tubing Drilling DSHA Defined Situations of Hazard and Accidents ECD Equivalent Circulating Density ESD Emergency Shut Down HMV Hand Manual Valve HPHT High Pressure High Temperature HSE Health, Safety and Environment HXT Horizontal x-mas tree IADC format International Association of Drilling Contractors IBOP Internal Blow Out Preventer IT Information Technology IWCF International Well Control Forum JPD Jointed Pipe Drilling LCC Life Cycle Cost LMRP Lower Marine Riser Package LRP Lower Riser Package LWD Logging while Drilling MSL Mean Sea Level MUT Make up Torque MWD Measurement while Drilling NMCE & R Norwegian Ministry of Church, Education and Research NMD Norwegian Maritime Directorate NPD Norwegian Petroleum Directorate OD Outer Diameter PCD Pressure Control Drilling? PL Production Licensee PSD Production Shut Down QRA Quantitative Risk Assessment RKB Rotary Kelly Bushing ROV Remote Operated Vehicle SAM Regulation relating to systematic follow-up of the working environment (Deleted!) SCSSV Surface Controlled Subsurface Safety Valve SEPREA Specific Emergency Preparedness Requirements for the Activity SFT Surface Flow Tree SJA Safe Job Analysis SPCA State Pollution Control Agency (Statens Forurensingstilsyn) NORSOK standard Page 8 of 55

SSTT TKV TLP WHP WL X-mas tree Sub Sea Test Tree Tubing Kill Valve Tension Leg Platform Well Head Pressure? Wire Line Production Control and Safety Valve Arrangement 4 GENERAL REQUIREMENT 4.1 Well Classification Registration number, well identification and classification or reclassification shall be obtained from the NPD for each well before any operations commence. 4.2 Well Design 4.2.1 Formation Data The well design shall be based on the following: Geological prognosis * Expected stratigraphy and lithology * At least two interpreted deep seismic cross section views through the field or planned well path * Geological description of all prospects * Geological uncertainties * Site survey Fluid contact prognosis Requirements to zonal isolation Temperature, pore pressure and formation strength prognosis Well path and target requirements Potential well collosion risks Hole cleaning and hole stability requirements Production or injection requirements Design life requirements 4.2.2 Well Design Process Prior to commencing the detailed well design process, the following considerations should be part of a conceptual plan: Outline Well * Define well type * Define total lifecycle of well * Policies, procedures, standards and controls in place and adequate Rig suitability Review offset data * Obtain and analyse offset data, identify areas requiring more detailed follow up Evaluate risk for shallow gas and hydrates Wellpath design NORSOK standard Page 9 of 55

Casing design * Review formations, pore pressures, formation strengths and temperature gradients * Prepare preliminary design * Check design for shallow hazard implications Completion * Review completion equipment with respect to artificial lift requirements, packers, plugs etc. * Testing pressure Formation Evaluation HPHT Evaluation Cold Climate Evaluation Tubing design * Test pressure * Materials selection * Packer envelope Well test requirements Manning or training Logistics and materials HSE * Identify environmental sensitivities * Hazard or risk identification and handling Review design Approve design 4.2.3 Drilling Location A site survey including an assessment of sea bed conditions, water depths, boulders, subsidence, seabed features, possible obstructions, cables, pipelines, anchor holding demands, sea traffic, etc. of concern shall be performed and thoroughly interpreted. The survey shall also cover possible surface locations for relief wells. The seismic lines shall have a penetration covering the geological sequence to the setting depth for casings for the blowout preventer. Connecting seismic lines to neighbouring wells shall be established if practically possible. 4.2.4 Site Specific Considerations Orientation and protection of the facilities should be optimised with regard to prevailing meteorological and oceanographic conditions and with due regard to emergency preparedness. Efforts should be made to eliminate the need to place anchors closer than 500 m off other platforms or subsea installations, and 200 m off pipelines and cables, assuming direction of pull is away from these facilities. Any deployment of anchor or anchorline closer than these distances requires special safety considerations and clarifications to be undertaken if the other Owners or Operators and NPD has consented to the precautions being taken. Increased distances or clearances and additional safety precautions are required where direction of pull is towards other installations or pipelines or cables. Prior to start planning of these operations, operators of exposed platforms, sub sea installations or pipelines and cables shall be notified. NORSOK standard Page 10 of 55

When drilling a well close to a lease line, the position uncertainties for well path or surface location should be taken into account in order not to compromise the lease line. When drilling adjacent to boarder lines to neighbouring countries, international agreements must be observed. For floating units the station keeping capabilities must be verified to be within set criteria (with due consideration to possible anchoring or positioning failure), and it is mandatory to be able to immediately move off location in a shallow gas emergency. For other DSHA the SEPREA's and procedures defined by the operator will apply. 4.3 Well Data Acquisition 4.3.1 General During operations data related to geology, reservoir and drilling shall be collected or recorded in order to facilitate evaluation of geology and prospects, operational control or optimisation and experience transfer. An evaluation of the data acquisition programme shall be done prior to every specific drilling operation in order to comply with the purpose of and requirements for the well. In order to optimise the value and use of data, quality assurance, storage, media, availability etc. should be focused. For a drilling operation the following minimum requirements shall apply: 4.3.2 Geological and reservoir technical Data Requirements Drill Cuttings Unwashed (1 kg) and washed and dried (10-20 g). Min. 10 m intervals, 3 m intervals in expl wells in HC bearing zones. Cores Exploration wells: Min. 1 core in all HC bearing zones and cores from potential source rocks and reservoir rocks. Appraisal wells: Complete reservoir section in selected wells Production wells: A representative selection of wells from the reservoir and source rocks. Side wall cores Optional Fluid, gas and res. formation water samples From individual test intervals. Surface sampling: Pressure, temperature and flow rate to be recorded. Bottom hole sampling: 2 corresponding samples. Pressure, temperature and flow rate to be recorded. Surface samples may be sufficient if recombination gives correct fluid composition Logs/LWD Drilling: Min. to facilitate evaluation of lithology, porosity, water saturation, Formation test: Min. to establish pressure gradient, type of fluids, productivity and temperature. NORSOK standard Page 11 of 55

4.3.3 Drilling Data Requirements Well integrity Data for verification of integrity of well barriers i.e. BOP s, wellhead, casings, cement jobs etc. Directional Continuous (for every stand drilled) registration of inclination and azimuth. Formation pressure All necessary data to be recorded after installation of conductor or surface casing. Formation strength LOT/FIT after casings have been drilled out. Operational Rig data aq. system, Mud data, Mud Logs, MWD logs etc. Ref. also NORSOK Standard D-001, Drilling. An evaluation of the data acquisition requirements shall be identified for each individual well. 4.4 Blow-out Contingencies or Relief Well Drilling 4.4.1 General The blowout contingency plan shall be developed to meet the NPD legislation as well as Operator internal requirements. The document shall be regularly updated to assure that relevant information is available in case of well control. It shall contain the following: Mobilisation of necessary emergency equipment, personnel, services Kill methods in the case of a blowout occurrence. Description of suitable locations for drilling a relief well Measures for limiting the amount of the damage from the hazard or accident Guidelines for normalisation of the operation 4.4.2 Relief Well If a surface intervention cannot be performed on the blowing well the blowing shall be killed or plugged via a relief well. The objective of a relief well is to enter or get communication to dynamically kill and stabilise a blowing well. The following items shall as a minimum be covered for a relief well design: Mapping of suitable drilling locations if appropriate including shallow seismic interpretation of the top section Evaluation of blow-out scenarios and kill methods Requirements to facilities for relief drilling and well killing Evaluation of relevant well profiles and casing programme Estimation of necessary pumping capacity Updated list of available equipment and time critical activities, including possible rigs or facilities for well intervention options as appropriate. Initiation of relief drilling at a relevant location shall commence no later than 12 days after the option is declared. NORSOK standard Page 12 of 55

4.5 Barrier Philosophy 4.5.1 Primary Requirements All Operators shall establish and implement a barrier philosophy to meet the NPD legislation s, which shall be adapted also by companies or personnel working for or on behalf of the Operator. The operator should take the necessary steps to assure that the barrier philosophy is adapted, understood and used during operations. During drilling or workover operations the fluid column or a plug is normally providing the primary barrier, with a secondary barrier available to be activated (typically BOP pipe ram or shear or blind ram) No single failure of barrier or barrier element, whether caused by operational error or equipment failure, shall lead to loss of well control. Two independent and tested barriers shall be available. The two defined barriers shall to the extent possible be independent of each other without common barrier elements. If common elements exist procedures shall be established to govern operations and/or failure scenarios. If one barrier fails, immediate measure shall be taken in order to monitor an adequate safety level, until at best two independent and tested barriers have been restored. No other activity than reestablishment of the barrier shall be carried out in the well. The barrier element shall be designed such that: Re-establishment of a lost barrier can be done quickly, The position or location and status can be known, It can be pressure tested, or verified by other means, e.g. observation, It is independent of other barriers in conjunction with the same source of influx, It can operate competently in the environment (pressure, temperature, and fluids) that may be encountered during the period it was intended for. The barrier shall be positioned as close as possible to a potential influx. As part of the planning of the operation there shall be prepared graphical barrier diagrams for the main operational stages clearly identifying primary and secondary barriers. 4.5.2 Testing of Barriers Barriers shall as far as possible be tested in the direction of the potential flow. The barrier shall be tested to the maximum anticipated differential pressure. If high-pressure components, such as BOP rams, valves, seals and gaskets are replaced, these components shall be tested to working pressure. NORSOK standard Page 13 of 55

Test pressures shall be specified in the Operations Programme. Fluids acting as a barrier may be qualified as tested barriers when justified on the basis of the fluid specification, observation and stability testing of the fluid. Inflow as tested barrier elements can be qualified as tested barriers. Criteria shall be established to define the acceptance level for the leak rate while pressure or leak testing barrier elements. 4.5.3 Barrier Status The position or status of the barrier or barrier element shall to the extent possible be known at all times. If not achievable, compensating measures shall be established. Identification of the barriers shall be established prior to commencement of the activity by describing the barrier elements, planned location and method of monitoring. All parameters relevant for maintaining the control of the well shall be monitored continuously. Position or status of the barrier or barrier element shall be available through test record, lights or data printout presented to the driller and/or the principal operator of the equipment representing the barrier. 4.5.4 Barrier Availability The availability of barrier elements shall be defined and documented. When planning an activity, situations where barrier elements are not available (i.e. when running drill collars past a shear ram, which is not qualified for cutting) shall be identified. Passive barrier elements that are dependent on energy to be activated shall be equipped with redundant supply, (accumulators, second electrical power source etc.) 4.5.5 Failure Criteria (Well Control Actions) Prior to commencement of an activity, there shall be a plan of corrective action to be taken in case of failure of barrier elements. A description of possible failure that can affect the barrier shall be described together with a contingency plan to re-establish the barrier. Well control actions should regulate the use of shear ram or other cutting tools by identifying various options and use of barrier elements before the work string or wireline or coiled tubing is sheared. Failure criteria for the barriers and barrier elements shall be described through presentation of contingency action flow diagrams representing those scenarios that are considered to potentially occur as a result of equipment or human failure during the activity. NORSOK standard Page 14 of 55

4.6 Operations 4.6.1 Operations Planning In due time before starting on operation, an approved project definition shall be available in writing. All projects or operations shall be planned in accordance with the relevant Regulatory Bodies' rules and regulations and Company s relevant governing documents. Solutions or methods shall be based on specifications given in the project definition, qualified experiences, available technology and cost or benefit analyses. Life cycle cost (LCC) evaluations shall be reflected in the cost or benefit calculations. Information made available for the operational environment shall give operational personnel a basis to make the decisions required for an optimal cost-effective operation, within the framework established by the HSE. This is particularly important during assignments where deviations from the programme or procedures could lead to a critical situation. The information shall provide the basis for selecting the most optimal solutions during normal operations. The planning and approval process shall be documented. 4.6.2 Back-up Equipment Critical spare parts or back-up equipment with long lead-time should be identified and possibly planned to be located offshore or at the shore base. 4.6.3 Equipment Rig-up Proper, formal interface with the rig systems for the offshore facilities must be established. Norsok Standard Z 015 is considered as recognised standard in this context. 4.6.4 Contingency procedures Approved contingency procedures shall have been reviewed prior to the operations phase. Both Company and contractor shall have these procedures available offshore. Specific contingency procedures related to special applications, operations or equipment not covered in the contractors operational manual, shall be described in the work programme. 4.7 Preparation of Programme Operation premises and a detailed description of the planned tasks to be executed shall be included in specific operations programmes for the operation in question. Typical programmes to be developed are: Drilling programme Completion programme Testing programme Plugging programme Work-over programme Well intervention programme NORSOK standard Page 15 of 55

Emphasis should be made on the use of explanatory formats and schematics flowcharts. The programme shall have been subject to an inter-discipline check involving the Operator and the main Contractor(s) prior to implementation. The programme may be supplemented by more detailed guidelines and risk analyses. As the operations proceeds, significant deviations from the programme shall be formally identified and recorded, and approved and the NPD informed where applicable. NORSOK standard Page 16 of 55

Programmes Content General Purpose of activity and time schedule x x x x x x Installation/vessel's name, PL number, block, field x x x x x x Well identification, classification x x x x x x Position (geolgraphical and seismic) x Waterdepth (MSL) and depth reference (RKB elevation) x Organisation Organization plan x x x x x x Resp. and com. during normal operation and emengencies x x x x x x List of contractors x x x x x x Geology Geological prognosis/information x Pressure prognosis/information x Plan for geological sampling/logging x Reservoir Reservoir data prognosis/information x x x x Plan for reservoir technical sampling/logging x x x x Perforation intervals, flow/shut-in periods x x x x x Estimated rates, discharges, env. consequences x x Plan for stimulation x x Technical Casing/tubing programme/information x x x x Cementing programme/information x x x x Fluids programme/information x x x x Directional programme/information x x x x Operational Operational constraints and shutdown criterias x x x x x x References to operational procedures and instructions x x x x x x Detailed operational sequence x x x x x x Safety Detailed description of barriers/well contr. eq. for all phases x x x x x x Safety and operational hazards and planned measures x x x x x x Drills related to well safety x x x x x x Deviations from governmental and internal requirements x x x x x x Drilling Programme Formation Test Programme Completion Programme Perforation-/Isolation Programme Intervention programme Plugging Programme NORSOK standard Page 17 of 55

4.8 Risk Analyses 4.8.1 General Prior to every operation and when evaluating the risk situation, a separate risk analysis shall be considered carried out. Risk Analyses shall be carried out to expose the probability and consequence of single failures or sequential failures that may occur during operation. Risk analyses are normally split in two main categories: Installation specific Quantitative Risk Assessment (QRA), and Operational Risk Analyses The risk analysis shall be performed before the operation is started. The risk analysis shall as far as possible incorporate previous experience with similar operations. The analyses shall be carried out with the co-operation of personnel possessing sufficient operational experience as well as personnel possessing documented risk analysis experience to ensure that all relevant factors are taken into account. Relevant factors may include design of installation, available equipment (including barriers), organisational limitations, environment, geology, etc. 4.8.2 QRA The QRA is performed as part of the design. The operator shall review the QRA to ensure that it is in line with all relevant standards and regulations, and that all significant modifications has been incorporated. The QRA shall reflect the conditions expected at the specific location. 4.8.3 Operational Risk Analyses An operational risk analysis shall, when applicable, be performed: for new or non-standard operations for operations in new areas for operations to be performed by new or modified rig or installation for operations using new or modified equipment for operations including contractor(s) not familiar with the rig, area or operation if the operation are considered hazardous (e.g. HPHT or simultaneous operations, dynamic positioning, deep water, cold climate or reduced riser margin) 4.8.4 Task Analysis Regular task analysis (SJA) shall be carried out to review hazards and consequences of operations and failures that may occur so that risk-reducing measures may be taken. Prior to every operation, introduction of new equipment and when evaluating change in premises, a separate analysis shall be considered carried out. A safety meeting should be held to ensure all personnel are aware of the operational limitations applicable in connection with the operation. Specific meetings to be held as often as required for reviewing risk in the activities (SJA). NORSOK standard Page 18 of 55

4.8.5 Methods The assessment shall as a minimum include the following steps: 4. Consequence Analysis 1. Planning of study 2. Breakdown of the activities 3. Hazard I dentification 6. Risk Evaluation 7. Evaluation of Compensating measures 5. Frequency Analysis 1 2 3 4 5 6 7 The planning shall as a minimum include type of method to be used, boundaries of study, and inclusion of relevant personnel. Risk Acceptance criteria shall be established at this stage. In order to ensure an efficient and structured analysis, the various steps of the operation should be broken down and assumptions recorded. The hazard identification shall systematically identify all potential technical, operational and organisational hazards. The consequences of the identified hazards to personnel, environment and economy shall be identified. The frequency of occurrence of each identified hazard shall be determined based on previous experience, standard methods or expert judgements. Based on the estimated consequences and frequency of the identified hazards, the risk can be estimated and compared to the acceptance criteria. Measures to control, reduce or remove the identified risk shall be evaluated. Probability reducing measures shall be given priority over consequence reducing measures. Results from the risk analysis shall be communicated to the employees and shall be used actively in preventive safety efforts. 4.9 Emergency Preparedness Analysis The emergency preparedness analysis shall ensure a systematic evaluation of all technical, operational and organisational measures which prevent a dangerous situation that has occurred from developing into an accidental event, or prevent or reduce the harmful effects of accidental events that have occurred. Based on information obtained from the risk analysis, a set of defined situations of hazard and accident (DSHA) shall be identified, serving as a basis for establishing the emergency preparedness. For each of the DSHA, a set of Emergency Preparedness requirements shall be identified for each phase of the emergency preparedness. This is illustrated below. The analysis shall result in a set of requirements related to the effectiveness of the emergency preparedness measures employed to meet the defined situations of hazard and accident. NORSOK standard Page 19 of 55

Alert Danger Limitation Rescue Evacuation Normalisation Specific Emergency Preparedness Requirements for the Activity (SEPREA) Alert shall be carried out to ensure totally effective mobilisation of all relevant emergency preparedness resources. Measures for danger limitations shall be implemented when a hazardous situation occurs in order to avoid it developing into an accident situation. Rescue measures shall ensure that missing persons are found and that injured persons are given necessary first aid and brought to safe area for treatment. Evacuation on and from the installation shall be carried out in a safe and organised manner in order that all personnel are brought to a safe area. Normalisation measures shall ensure that personnel are brought ashore for treatment and care, the environment is restored to its normal condition and that damage to the installation is stabilised and the reservoir secured. Verification of the emergency preparedness shall be performed to ensure that the Emergency preparedness requirements are met. Requirements to emergency preparedness competence shall be defined for all personnel taking part in the activity concerned. 4.10 Application of Consents, Permits, Approvals The consents necessary shall be obtained from NPD by the Operator, they are activity specific, and are typically related to the use of a particular installation at a certain area over a defined period. The assessments required to support and document the Application for Consent need to be a wellorganised approach, with multi-discipline involvement from the Operator and Contractors. The Operator is responsible towards the authorities, but the process assumes commitments from all parties involved. Any regulatory exemptions, for which the authority concurrence is requested, are typically detailed in the Application for Consent. NORSOK standard Page 20 of 55

Details regarding the subsequent Permits, Approvals and submittal of programmes for specific drilling and well operations are outlined in the NPD s «Regulations for Drilling and Well Activities and Geological Data Collection, etc.». Activity plans, possible regulatory discrepancies and extraordinary HSE aspects should be highlighted by submission of these documents. A Discharge Permit shall be obtained from the SPCA for exploration and field development operations. 4.11 Simultaneous Operations Simultaneous operations shall be thoroughly planned, analysed and performed with the objective of limiting excessive risk imposed by multiple operations at the same time, as opposed to the risk associated with the execution of these operations individually. Relevant procedures for the control of simultaneous or parallel operations shall be developed and validated or assessed prior to commencement of operations. 4.11.1 Definition of Operations and Basic Safety Criteria The following operations are defined as simultaneous operations if two or more of these operations are executed at the same time within the defined area for such activity: Production or Injection Live well operations Pigging operations exposing drilling and well area Running or pulling riser or heavy lifting or heavy construction Skidding rig Hot Work Drilling operations and workover Conductor driving and installation Injection to annulus Repair of change-out of X-mas tree or annulus valves Pumping and flowing through temporary lines A prerequisite for executing simultaneous operations in a safe and prudent manner is emphasising administrative and operational procedures to ensure a systematic and controlled execution of the activities. 4.11.2 Operational Considerations Operational measures to ensure that simultaneous activities are carried out in a safe manner should at least include the following considerations: Ensure that the day-to-day follow-up of simultaneous activities during the operational phase takes place in a co-ordinated and systematic way, and possible deviations are identified and corrected. If during drilling a well deviates within defined minimum distances to completed and perforated wells, correlated for the uncertainty of the position indication, barriers (plugs) shall be introduced below a possible point of contact in the said production or injection wells. If a possible point of contact is located above the SCSSV, closing and testing the SCSSV will be sufficient. The annular space of wells that may be exposed to collision with a well where drilling is in progress, should be brought into an overpressure condition in relation to the well being drilled, and the annular pressure of the wells should be closely monitored. NORSOK standard Page 21 of 55

Restriction in simultaneous operations during heavy lifts if a sudden loss of suspended loads endanger the safety of other concurrently ongoing operations like such heavy lifts can be, but are not limited to: Handling, running and pulling of BOP, X-mas tree etc. above wellhead areas Running and pulling of risers, drill strings, casings and wellhead components in open water Transfer of heavy equipment between supply boats and rig, etc. Activities shall be halted if the gas level in the drilling area exceeds a certain limit set by the operator. Special precautions shall be taken when welding, grinding, cutting and other high-energy work in the wellhead, BOP or drillfloor area in parallel with simultaneous activities are performed. During simultaneous drilling and production, special restrictions shall be implemented for activities that could lead to a reduction of the safety level during drilling through layers containing hydrocarbons. 4.12 Personnel Qualification & Training In accordance with Statutory regulations and operator procedures, requirements to qualifications or training shall have been set out for all job categories with great impact on safety through the various phases of drilling and well operations. Special training should be provided in the case that new equipment or technology is planned to be used. 4.12.1 Qualifications and Training for Offshore Operations The following specific qualifications requirements for drilling and well operations personnel are supplemental to the common requirements for offshore personnel regarding such as health certification, basic safety and contingency training with refreshers. Supervisory personnel shall have training or experience in Norwegian Acts, Regulations and Provisions. Training with respect to work environment factors shall be in accordance with the NPD Regulations relating to systematic follow-up of the working environment. Personnel involved shall have the education and experience required in compliance with Norwegian Regulations, and shall be able to show proven track records for the same. The OLF/NR s Recommendations for Training of Drilling Personnel is considered to represent the industry norm. Documented experiences for the specific offshore positions can be provided through an on-the-jobtraining system compatible with that system recommended or issued by the NR. Requirements to personnel qualifications should also comprise theoretical and practical training when new equipment is introduced. As supplementary standard for personnel qualifications in the area of well service, reference is made to the Education Plan approved by the Norwegian Ministry of Church, Education and Research in respect of Well Service Techniques, detailed within the areas of Wireline Operations and Cementing. Well Control Training and Refreshers are required for the following offshore positions: Drilling Drilling Supervisor, Toolpusher, Tourpusher, Driller, and Assistant Driller. NORSOK standard Page 22 of 55

Well Intervention Wireline and Coils Tubing personnel are missing under well control training and refreshers requirements. The following wording is suggested: The Operator Company s Leader for Well Operations and Intervention. All supervisory personnel for wireline, coiled tubing and snubbing operations, such as: Superintendent, Supervisor and relevant 3 rd part equipment suppliers. Equipment operators that operate the unit, such as: Wireline winch operator, Coiled tubing cabin operator, Snubbing jack operator and Choke operator. Basic well control training and subsequent refresher courses shall be completed in accordance with US-MMS, UK-HSE or International Well Control Forum (IWCF) certification standards. The Operator can carry out mandatory control by requesting the Contractors to confirm there is consistence in personnel qualifications requirements by detailed references to existing regulations and standards, and to present any discrepancies and the existing training schedule for personnel involved. 4.13 HSE Management System Health, safety and environmental protection (HSE) shall receive particular attention through operations planning. An HSE Management system shall be implemented to meet regulatory requirements, and should be compatible with the E&P Forum s «Guidelines for the Development and Application of Health, Safety and Environmental Management Systems». Evidence on shortcomings in HSE performance should result in special measures or support or monitoring as agreed between the Operator and Contractor concerned. 4.13.1 Working Environment & Occupational Health Work areas should be subject to regular evaluation or charting against the NPD s «Regulations relating to systematic follow-up of the working environment, etc.», NORSOK standard S-002 Working Environment and/or against OLF/NR s «Recommended Guidelines for systematic followup of the working environment on Mobile Units, etc.». For operations with mobile units designated for drilling and well operations, the Drilling Contractor can be assigned the role as Principal Enterprise according to the OLF/NR s «Standard Agreement concerning Principal Enterprise responsibilities» for co-ordination and follow-up of the working environment onboard. On fixed installations, this role will typically rests with the Operator or Owner. Working environment and occupational health factors with high potential for changes between various wells should receive extra focus, like the changes imposed by the use of chemicals, drilling and completion fluids and additives. Before start of the operations the workforce shall receive relevant information concerning health hazards related to their work and measures to prevent harmful exposure. Including possible training in correct use of personnel protective equipment and with emphasis on risk and preventative measures associated with non-routine operations, tasks, methods, materials and chemicals. Systems should be properly implemented for the reporting of accidents, work related diseases, unsafe acts and conditions. A safety delegate system shall be implemented for the drilling and well NORSOK standard Page 23 of 55

operations area, and the system shall also include representatives to serve the interests of the Well Service Contractors. 4.13.2 Environmental Protection Appropriate systems for protection of the environment should be in accordance with the operative parts of the NORSOK S-003 standard for «Environmental Care». Chemicals, which are discharged to the water or emitted to the air, shall cause as little harm as possible to the environment. Selection of chemicals should be based on an overall evaluation of efficiency, environmental data, safety data and economic criteria. The total evaluation of the product should also address the quantity and concentration of emissions. All fluids and chemicals (also for emergencies, detergent and thread dope) shall have been tested in accordance with SPCA s guidelines. Chemicals on SPCA s list A and B should be as clean as possible. Chemicals which are included in the Paris Convention s Annex A part I or contain alkylfenol or alkylfenol-connections shall not be discharged. An assessment of measures for reduced fuel or energy demands and steps to reduce the consumption of chemicals and use of chemicals with better environmental characteristics shall be part of the continuous improvement process. The technology available for reducing discharges to the sea and emissions to the air shall be continuously evaluated. There shall be systems in place for handling waste and keeping track of chemicals or substances onboard and discharges. All chemicals used during the course of the work shall have Material Safety Data Sheets conforming to quality requirements issued by the OLF. Data sheets with details about composition, personnel safety data, toxicity, bioaccumulation and biodegradability shall be available for all products. An inventory of explosives and radioactive materials onboard shall be kept up to date at all times. The use of thread dope with heavy metal content should be avoided for tubular. The use of heavy metal containing dope should only be used if demanded by technical or safety reasons. Concerning well testing, other methods than burning shall be considered, including collecting oil. Use of special vessels for collecting oil should be considered, and this evaluation shall be documented. Effective burning must be provided for, both technically and operationally. Wellbore fluid in the transition between the water or diesel column and the perforations shall not be routed directly over the burners, but may be routed to production or be produced to a storage tank system onboard for subsequent handling. All discharges shall be recorded and reported via the Operator to the SPCA according to mandatory provisions. NORSOK standard Page 24 of 55

The need for documenting an environmental risk assessment is much dependent of the area or activity in question, and to what extent previous or existing environmental risk analyses can be used. Surface flow tree should be consulted early, if uncertainties exist. 4.14 Safety Drills Safety drills shall be planned and regularly executed to accomplish for the highest possible awareness. Drills involving use of blow-out preventers or other well control equipment to handle and unintentional influx of fluid or gas into the well shall be carried out prior to start of operation and further at regular intervals. Special wells or operations or analyses may result in specific input to type and scope of training and drills. (E.g. for deep water drilling and HPHT wells). 4.15 Reporting to the NPD In the event of significant alterations of the activity programme, operational interruptions, dangerous incidents and accidents, the operator shall immediately notify the NPD. The Operator shall outline and communicate criteria for such reporting to personnel with dedicated responsibilities for such operation. During the time that drilling and well activities are in progress, the operator shall on a daily basis keep the NPD informed with regard to the progress of the operations. The NPD and CDRS define the extent of the reporting and reporting routines. 4.16 Experience Transfer Performance shall be evaluated against the goals set up before commencement of the operations. Besides the Operators own assessment of performance, and for the purpose of the continuous improvement and transfer of experience, the Contractor is encouraged to advise the Operator of such matters as: Challenges in performance versus set goals for the activity. Contractor's suggestions for improvements or simplifications in work processes and methods that might contribute to more efficient or cost effective performance by the Operator and his other contractors for future work. Information and feedback from circumstances arising during operations, that have reinforced or changed contractors perception of specific subjects, or could lead to a change in contractors relevant documentation, methods or work process. Contractor's assessment of deviations from this standard and mandatory requirements, including future recommendations. 4.17 Documentation 4.17.1 Communication or Documentation In order to ensure proper communication and documentation of planned work performed or to be performed, a structured system for ensuring continuity shall be in place. The system shall include: Hand-over reports or meetings at all work levels at crew change and between shifts NORSOK standard Page 25 of 55