This document provides the outline of COMPANY minimum standard and general practices for carrying out sampling, running logs, and mud logging. It also defines the RTC (Real Time Centre) standards.
1. GENERALITIES
1. The Well Programme shall include details of planned geological operations including mud logging, sampling, geological circulation criteria, coring, open-hole, cased-hole, LWD logging and contingency logging.
2. The sampling and logging requirements will be developed specifically for each well and will be contained in the Well Operations Programmes.
3. The well and drilling data will be transmitted in real time to the ADEC Aberdeen RTC, where they will be analysed and stored by RTC Engineers based in the ADEC office. Their primary role is safety monitoring and surveillance.
2. MUDLOGGING EQUIPMENT LIST
1. All offshore rigs must be equipped with a real time data transmission system to shore, and where possible, to the COMPANY RTC (Real Time Centre).
2. The mudlogging equipment list below has to be considered as a minimum and must be extended for difficult wells such as HP/HT:
a. Drilling parameters:
o Depth/ROP
o Weight on it/ Hookload
o Rotary Speed
o Torque
b. Pumping/mud parameters:
o Pump Stroke Counters (all pumps)
o Mud Flow Out
o Mud Weight Out (In/Out compulsory for HP/HT)
o Standpipe Pressure
o Mud Temperature out (IN and Out are compulsory for HP/HT wells)
o Gas Trap Degasser + Back-Up + Spares
o Total Gas + Chromatograph
o H2S Sensors
o Trip Tank Volume Sensor
o Pits Volume Sensor (on all pits for HP/HT wells)
o Casing Pressure and annulus casing pressure when relevant
o Choke Pressure and Temperature
o CMT Unit Strokes
o CMT Unit Pressures
o MGS Pressure
o Spares inventory (rig pit sensors, H 2 S sensors + spare cables)
c. Other equipments:
o Calcimeter
o Workstations inc. hydraulics package and all relevant software
o Drill Floor Screen
o Additional screens for Drilling Supervisor (DSV) / Well Site Geologist (WSG) or as required
o Facility to wash and dry cuttingso Control of Substances Hazardous to Health (COSHH) data sheets
3. REAL TIME CENTRE (RTC)
3.1 RTC SAFETY MONITORING
The ADEC RTC is manned by experienced monitoring specialists, with the primary role of a “second set of eyes” for safety monitoring and surveillance.
Audible alarms are used to help alert the RTC monitors to a potential safety issue.
To be efficient, the RTC Engineers need to have all programme and information concerning the well:
a. Detailled BHA and drill string characteristics
b. Mud rheology
c. Pore Pressure (PP), Fracture Gradient (FG) and temperature profile
The RTC team has signed a confidentiality agreement with COMPANY.
All data recorded, or monitored on the rig shall be transmitted to ADEC Real Time Centre in real time.
The following data shall be transmitted to the RTC:
a. Drilling data
b. MWD data
c. LWD data
3.2 COMMUNICATIONS
When deviations from expected trends are noted, an intervention protocol is triggered, which is based on a colour coded risk based system. These interventions to be used between Aberdeen RTC and
affiliates, are logged and recorded for future reference.
Green interventions are essentially clarifications of a situation and will be progressed by telephone contact with the rig mudloggers, if available, or by email to the rig well operations engineer where there are no mudloggers.
Yellow interventions indicate a developing problem or opportunity for improvement. Ther are typically communicated directly to the rig drilling supervisor and copied to the mudloggers/well operations engineer. In the event that the intervention has not received a response within 30 minutes, the intervention will be copied to the onshore rig team and ADEC team.
Red interventions signify an immediate and serious problem and will be sent immediately to the offshore and onshore rig teams and ADEC team at the same time, with telephone communication (if required) to the onshore Engie Focal Point.
3.3 PERFORMANCE ANALYSIS
Performance analysis is conducted on the data received and is used for rig activity determination, to aid in the analysis of Non Productive Time (NPT) and to help improve the economic performance of the wells whilst maintaining safety.
3.4 WELL DATA CAPTURE AND STORAGE
Data is stored in an Insite database which is backed up daily, and additionally stored on a Network Attached Storage (NAS) device .The NAS is also used to stored copies of all daily reports.
A DVD of all stored data including a depth based ASCII file is provided to ADEC at the end of each well, and is filed in the Petrotechnical Data Management System (PDMS) at HO.
LOGGING
1. A detailed logging programme shall be prepared by the onshore operations geologist and approved by the Well Operations Manager.This programme will specify the roles and responsibilities of the Wellsite Geologist and Well Operations Supervisor.
2. Open-hole wireline logging shall only be carried out where:
- a. The hole is contained, monitored and controlled.
- b. The COMPANY Well Operations Supervisor is satisfied that the hole conditions are stable, clean and suitable for the logging tools to be run.
c. The first logging suite must not contain radioactive sources unless the well is in very good condition, i.e.no wellbore stability issues, or hole problems, have been seen during the trip out of hole on elevators prior to logging. The Affiliate Well Operations Manager shall then assess if it is appropriate to include a radioactive source in the first run. - d. Primary depth control will be performed using magnetic marks and stretch on the logging cable
- e. First run will be the depth reference for subsequent runs
- f. The length of the logging string shall be shorter than the distance between the logging sheave and the BOP shear rams. The Affiliate Well Operations Manager can make the decision to deviate from this rule to the condition that a specific well control procedure approved by the Drilling Contractor, the logging company representative and the Well Operations Superintendent is in place. A copy of this procedure shall be sent to ADEC.
3. Prior to commencing any logging operation a safety meeting shall be held.
4. Specific procedures will be in place when using hazardous materials and tools (explosives and radioactive sources). These procedures shall include safe surface handling, storage, restriction of
personnel and radio silence (if required).
5. Specific procedures will be in place for safe cutting of the cable; should the well start flowing and cannot be contained by closing the annular preventer. A demonstration will be made to drilling crews prior to logging ie. once with everyone present to minimise blade wear) If Tough Logging Condition (TLC) system (side entry sub) is used, the logging cable must be cut prior to attempting to close in the well.
6. Tension modelling will be at the planning stage to assess the need for additional measures, ie. Flywheels, hole finders, or a Capstan unit. 7. An electric disconnect and/or mechanical weak point and jars included in every tool stringIt is recommended to have fishing equipment, logging while fishing, and pipe conveyed logging equipment on location.
8. It is recommended to use the Safe system for rig up i.e. system that does not require radio silence (or equivalent if the logging company is not Schlumberger).
9. Should logging tools become stuck, dispensation will be required to pull up to maximum weak point strength. The permitted limit (as a % of maximum strength) will be agreed prior to logging.
10. During well operations, significant change to the geological operations must be approved through the proper Management of Change procedure.
11. The winch driver should have either direct line of site or a video link to the rotary table. Where possible, the unit will have phone and network/internet connection. 12. There should be minimum personnel in the logging unit to reduce the possibility of distracting the logging crews.
13. Radio contact between Driller and Loggers will be maintained at all times
14. The drill floor will not be left unattended during logging operations
15. Barriers to be used when the cable passes above/across the deck under tension
16. The string should be kept moving whenever possible with static times kept to a minimum
17. Max pump through volume will be 500 litres
18. DSV to receive a tool diagram prior to each run
19. Mudloggers to monitor trip tank when RIH & POOH
20. Max BHT will be recorded on each run
21. When recovering formation samples to surface; H 2 S monitoring to be carried out.
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