This article only describes specific safety and environmental aspects during production testing. A separate document must be available with detailed procedures for the safety precautions during all other rig operations.
Safety Meetings
A "Pre-Testing Safety Meeting", attended by the Company Drilling Supervisor and Platform Production Supervisor, shall be held with each crew and all sub-contractor personnel prior to the start of testing activities.
The following operations (where applicable) shall be discussed in detail with all concerned personnel. The emphasis should be on safety awareness while conducting these operations:
- pressure testing,
- wireline operations,
- chemical handling,
- house keeping,
- communications, organisation, and reporting,
- perforating,
- acidising,
- emergency shut down systems,
- fire prevention measures,
- equipment handling,
- any other relevant matters, i.e.: the precautions and possible dangers relating to:
- explosives,
- mercury,
- hydrocarbons,
- hydrogen sulphide (H2S).
Note: The Company Drilling Supervisor shall ensure that the minutes (being a compulsory requirement) are forwarded to Base by being processed through the normal system for reporting Safety Meetings. Also, a fax/telex of the minutes shall be sent to Base.
Fire Contingency
Before perforating or opening up the well at any time during the course of the test, a full fire fighting crew must be on standby with fire hoses trained on the following areas:
- surge tanks,
- separators,
- choke manifolds.
The crew shall remain on station for thirty minutes following each operation. The fire-hoses shall be left laid out.
Safety Precautions During Acid Jobs(when appropriate) the annulus return pits.
c) Pressure test all pipework and connections before use.
d) Eye baths to be available at strategic positions, e.g.: rig floor, pumping unit, wellhead area, etc.
e) Gloves and eye protection to be worn when handling/mixing acid, and when monitoring/analysing returns. Protective gear to be cleaned after use.
f) Verbal communication equipment to be available at all times between the rig floor and pumping unit.
g) All equipment to be washed down thoroughly with fresh water on completion of acidising operations.
Safety Requirements Before Production Testing
a) Sufficient natural or artificial light to clearly observe all process and flow line connections. The initial opening up of a well to unload the tubing contents shall only be performed during daylight hours, providing there are two hours or more of daylight left.
b) Unloading the well to commence testing shall only be carried out when:
- the weather is suitable for rescue operations,
- the wind force and direction will carry gasses away from the platform,
- shipping and aircraft have been warned to stand clear during flaring.
c) Notify all personnel on board the platform of imminent production testing before the operations commence. The standby boat to be advised of the extent and nature of the perforation and flowing operation.
d) Due consideration shall be given to the protection of the environment by minimising the potential for discharge of hydrocarbons to the sea.
e) The integrity of the well test process installation has been fully verified including pressure testing, and function testing of trips and alarms to the satisfaction of the OIM and the regulatory authorities.
f) The surface pumping pressure during any killing or stimulating operations must not exceed the test pressure for the Xmas tree. Check that the Coflexip hose is compatible with the pressures and fluids to be used. Specifications to be provided by well test contractor.
On offshore locations, the ultimate decision that all conditions have been satisfied, shall lie with the designated OIM.
g) The following shall be performed:
- carry out Evacuation and Fire Drill,
- carry out equipment pressure tests,
- check fire pumps, water spray cooling systems and pilot flare burners,
- check all appropriate vent lines on production system are open,
- prepare adequate volume of killing fluid,
- check all breathing apparatus is ready for use.
h) Fire hoses shall be laid out ready for use to areas affected by the heat generated by the burners. The cooling and fire fighting systems shall be tested, and the fire fighting system shall be under pressure before commencing perforating operations.
The heat radiation will be absorbed by the use of several water spray cooling systems:
a. Water shield at the burner heads
b. Water shield at the burner boom
c. Water curtain on the platform NE corner
d. Deluge on the horizontal separator
e. Deluge on the vertical surge tank
a,b and c are permanently installed while d and e will be intermittently installed.
The seawater to these cooling systems is delivered by the platform seawater utility system, except at the burner heads where 1 mud pump and 1 mud tank will have to be used to provide seawater.
k) On the burner side of the platform, all vent lines on P-tanks and doors to legs shall be kept closed prior to flowing the well. Helicopter fuel tanks and all pressurised bottles are to be located in a safe place and cooled with water if necessary.
Safety Requirements During Production Testing
a) Restrict crane operations, i.e.; they shall not be used over or near electric/slick wirelines, flow lines, separator, heater, choke manifold, or any part of the system that is under pressure.
b) The surface pressure shall not exceed the lowest pressure that the system (or part thereof) has been tested to on site.
c) If an increase in pressure occurs on the casing/tubing annulus, the pressure shall be bled off, and the annulus pressure checked for rate of build up. If the annulus pressure cannot be bled off, the well shall be killed.
d) The rig floor and area around the production testing equipment shall be kept clear at all times.
In the event that H2S is anticipate the following should be carried out:
e) During opening of the well and flowing periods, a lookout is positioned at a point higher than the test site and with a good clear view of the operators. The lookout shall have with him, a self contained breathing apparatus, a portable H2S detector and a portable radio for contact with the control room.
f) Sufficient self contained breathing apparatus available at the test site for the well test crew. The apparatus to be standing by or carried ready for immediate use depending on the level of H2S expected.
g) Gas explosion meters, a hydrogen sulphide detector, and sets of portable breathing apparatus must be available. As soon as possible, gas must be checked for the presence of hydrogen sulphide by the Production Supervisor.
Environment
Discharge of oil in connection with testing/ clean-up is not permitted. Fallout of hydrocarbons into the sea must be kept to the minimum level achievable.
A programme for sampling any fallout of hydrocarbons from the crude burner or the gas flare must be prepared and followed to report accurately the discharge.