This article gives general guidance for non-telecommunications-specialists about the overall telecommunication requirements and gives details of the various systems available.

Most of the systems proposed are radio based which in some instances implies limitations which should be understood before any commitment to purchase a particular system is made. One of the factors involved is the characteristics of the various radio frequency bands.

Whatever systems are chosen it is important to include communications in the exercises which are carried out in connection with the contingency plans. In fact, it would be prudent to have exercises to check the communications alone, prior to any simulated emergencies.

1 System requirements

All drilling operations require reliable 24 hours per day communications between the various units and locations involved. These include:

• - Head Office;
• - drilling unit;
• - residences of all senior staff and key junior staff;
• - vehicles of key senior staff and key junior staff;

plus whichever of the following field locations are applicable:

• Construction camp;
• Materials base;
• Helipad/airstrip;
• Supply vessels;
• Vehicles.

Various types of telecommunication facilities may be needed depending upon the type of information to be transmitted, for example:

• voice;
• written text (telex);
• other pictorial information (fax);
• digital data transmission.

Communication facilities used may be provided by the local telecommunications authority (PTT equivalent), private ventures, or be a mixture of the two.

2 Provision of telecommunications services

When planning the telecommunications system, the first question which should be asked is if the local PTT are able to provide the various services, or failing this, is there an alternative, reliable supplier who can do the same. In many countries, cellular phones provide a reliable means of communications even in remote rural areas.

In the  PTT is not able to provide the desired services. In that case the company will have to provide its own services. Invariably such systems will be radio based. However, it is essential that the right radio systems are selected for the application. The various types of available equipment types are described in Appendix x.

3 Choice of equipment

The selection should be based on the following criteria:

• The availability of radio frequencies which may be provided by the local authorities.
• Whether the authorities will permit the equipment to be used in their country.
• The availability of local technical support for installation and servicing.
• The duration of the operation.
• The cost of the systems.

Whatever solution is adopted, the type of equipment and its operation should be kept as simple as possible, consistent with requirements.

Only proven equipment be (preferably) leased, or as a last resort purchased, and any potential suppliers should be required to submit a list of those systems already supplied and in operation. This should be verified if possible.

The proposed system(s) is (are) discussed with the potential supplier before finalising the purchase, and that all equipment be installed and commissioned by the manufacturer or his trained representative, who should also be able to arrange operator training.

Consideration is given to awarding a contract to provide specified communication links, as an alternative to purchasing/leasing equipment (with a bonus for trouble free operation). In this way the supplier becomes responsible not only for the maintenance of the individual pieces of equipment but also for the functioning of the networks as a whole.

Encryption (scrambling) for communications, in order to maintain confidentiality, is not normally required. If required ITS can provide devices for secure telephone conversation and facsimile transmission.

4 Legislative aspects

Importation of telecommunications equipment needs a variety of permits. It is usually a state monopoly which has security implications. However, the permission to run a private system will usually be granted if the PTT cannot supply the services themselves. In any case, it will be necessary for the selected equipment to be compliant or even be certified as suitable for use within that country by the PTT. This requirement will often influence the ultimate selection of equipment.

The time required to obtain all the required licenses. should not be underestimated. Also a failure to follow the required import procedure may result in confiscation of the equipment, which may not be replaced in time for the drilling operation.

The handling of Inmarsat accounts is through an authorised billing agent. Most PTTs are billing agents and add on varying percentages to the charge levied by each particular earth station and the cost for the terrestrial landline. If the PTT is not a billing agent it may be reluctant to license satellite systems due to the perceived loss of revenue. If some reluctance is noted when approaching the PTT for licenses for an Inmarsat system, a successful point for negotiation may be an offer to re-imburse the PTT with the value of their lost calls.

In some parts of the world, the local PTT may insist that the licensing of contractor supplied communications systems, i.e. walkie-talkie radios associated with the rig site, be made via the company. If this is the case the contract must take it into account as a "Provision by Company", however it must also be stipulated that the Contractor will provide all the required information in good time, and that the Company will only be committed to obtaining licences on a "best endeavours" basis.

5 Requirements

It should be noted that a back-up power supply should be provided for every piece of equipment which is a critical link in a communications chain.

Non-telecommunications facilities such as Aviation Navigation Beacons (Non-Directional Beacons - NDBs) have also been included in this section, primarily as a reminder that such facilities may be needed and that an application to operate these systems should be made to the PTT at the same time that the applications for the other licenses are submitted.

Head office

The requirements are:

• Internal communications within the building.
• Voice links to the drill site/camp, materials base, residences, personnel in and around town, and internationally.
• Telex/fax links to the drill site, materials base, and internationally.
• Data links to the drill site, and internationally.

The internal communications are provided by a PABX for telephones in the office building (with optional extensions to residences).

If the local telephone network is reliable it can be used for communications with residences and other locations within the limits of the local exchange and with fixed bases connected to other exchanges within the country. If the line quality is also good, nothing more is required for voice, fax and data links internationally and to all fixed bases.

If the telephone line quality is poor (or the system not reliable) an Inmarsat satellite set should be installed for international voice, fax and data links, which can then also be used between the office and remote fixed bases when communication by SSB-HF becomes impractical due to poor reception. This means that a decision has to be made about how many external lines are required for simultaneous use and the same number of satellite sets installed. If discipline is enforced only one is required though two are preferred to give some redundancy. The use of a satellite set should be severely limited for routine communications as it is a very expensive option.

In areas with a high security risk it is recommended to have a satellite set at the residence of the Country Manager. This set could be considered as the back-up office set, depending on the utilisation of the principal office set.

For routine communications between the office and fixed bases without a telephone line it is recommended to use SSB-HF radio see the following section.

A VHF or UHF Radio System is normally used for contacting vehicles and personnel in and around town. If the telephone network is not reliable this system should be extended to staff residences. If the telephone network is reliable a possible means of contacting staff is to use cordless telephones. Modern sets can have a range of several kilometers. These have the advantage of privacy over a VHF or UHF radio system.

A cheap solution for contacting personnel is the use of pagers, but the disadvantage is that it gives very limited communication. Given the far greater flexibility of walkie-talkies it is recommended that pagers are not used.

If Inmarsat sets are the principle means of receiving calls, a method of alerting personnel to emergency calls outside office hours is required.

Three possibilities exist:

• to have an automatic interface with the VHF radio network. This is the preferred solution;
• to have a telephone operator in attendence 24 hours/day, who can relay messages via the VHF radio network;
• to install HF radios in the residences of staff who then have to remain at home when on duty. Regardless of the inconvenience of this, it is not recommended as night-time HF voice communication is unreliable.

E-mail and fax facilities will be the main means of communication between an company and shareholders, partners, contractors, service companies, etc.

Drilling location

The requirements are:

• Voice links to the Head Office, materials base, residences of key staff, supply vessels, plus stand-by vessels and helicopters (offshore) or vehicles (onshore).
• Voice links between staff on foot.
• Fax links to the Head Office.
• Data links to the Head Office, and internationally.

A satellite link should be installed on a remote drilling unit in order to guarantee the ability to communicate with the outside world. However the primary communications should be a PTT-installed system if available.

In some onshore cases the national telephone company will have a Rural telephone system with a Microwave network covering the country. If so all that is required for "long distance" links is to install a Microwave link into that system and install the appropriate transceivers. It is recommended to use equipment supplied (or at least specified) by the local company and to have the installation done by them.

The more usual situation will be that an independent radio system must be installed. The quality of SSB-HF radio links has improved in recent years, due to enhancement by means of a computer driven telex-over-radio system such as the one provided by "Paktel", and in most cases these will provide an adequate solution. Even when reception is too poor for verbal communication routine reports can be passed by telex and brief conversations/discussions can be held by typing the messages on the keyboard and reading the reply on the screen. If reception is consistently poor E-mail through Inmarsat C also offers a possible, but expensive, alternative to HF/Paktel for routine office-rig-materials base communications.

Offshore the company may need to install its own Inmarsat terminal on the drilling unit for long distance communication and data transmission. The drilling unit may already have one installed, but because of the single line limitation a set for the exclusive use of the Company should be considered.

In order to ensure continuous communications in case of a drilling rig emergency there should be reliable long distance communications available away from the immediate vicinity of the rig, or there should be a reliable VHF link to another location which has such communications available (such as the materials base), and who can relay messages to the Head Office. Offshore the Stand-by Vessel can provide the back-up by relaying a message via the materials base. For onshore operations the emergency link should be in the camp. Unless there is confidence that HF communications will always be effective this means in practice either that calls can be routed by VHF through the materials base or that a second Inmarsat set should be installed in the camp.

If there is an Inmarsat set on an onshore drilling location it only has one line, and it should be reserved for the use of the company, except in case of real emergency. The drilling contractor will thus need his own communications. If he installs a second Inmarsat set this could be the one in the camp. For facilitating data transmission of wireline- and mud-logs the company set should be on the drilling location.

For an onshore operation a VHF or UHF Radio system should be available for voice communication with vehicles and groups working in the area. One fixed base station should be installed, preferably at the camp, with a mobile station in each of the Company vehicles and say three walkie-talkies available. The contractor should be encouraged to provide VHF radios in his own vehicles, to enable proper journey management.

On an offshore drilling unit, communication with supply vessels will be by means of the marine and aeronautical radios which are part of the rig equipment. For onshore communication with aircraft refer to the "Airstrip/Helipad" section below. Even if a land rig has neither airstrip nor helipad associated with it, it is always possible to land a helicopter on a rigsite in an emergency. If there is any possibility of an evacuation having to be carried out by helicopter, it should be considered to install an NDB in the vicinity.

Unless the hardware is being provided under the terms of a communications package contract with a specialist company, or was already procured for the seismic campaign, it should be endeavoured to include these facilities among those to be supplied as part of an offshore drilling contract. Onshore, so much equipment will be required before the drilling rig arrives and after it leaves that this approach is not practical.

Materials base

Requirements are voice links to the Head Office, drilling rig and residences of key staff, plus supply and stand-by vessels, helicopters, fixed wing aircraft and vehicles as appropriate.

The recommendations are as for an onshore drilling unit, except that it is not necessary to have a back-up long distance communications link "off-site".

Marine radios will be required for communicating with supply/stand-by vessels if used, or with tugs and barges etc. if a beach landing is being undertaken.

Onshore airstrip/helipad

(either isolated or in combination with a drilling rig or materials base)

The requirements are:

• Voice link to drilling rig or materials base.
• An NDB.
• Aircraft communications.

Any airstrip/helipad should be within VHF range of either a land drilling location, a materials base or a construction camp, and the voice communication can be provided by participation in the VHF network.

An NDB needs to be installed at ca. 20 m from a helipad or airstrip - in the latter case it should be about half-way along it. The choice of power supply for the NDB will depend on the frequency of use and its remoteness from other operations. If it is close to other facilities it can be connected into the same power network. The simplest alternative is solar panels if the climate is suitable. For frequent use at a remote location a generator could be considered (with watchman !). For infrequent use the recommended solution would be to carry batteries there prior to each arrival. Note that the power requirements are of the order of 80-100 watts.

On the aeronautical side the aircraft will already be fitted with radios. At one extreme, for crew change flights between an commercial airport and a field airstrip/helipad, the equipment to be provided by the company will simply be a walkie-talkie (plus back-up) for communication with the aircraft in the few minutes before it arrives. At the other extreme, with one or more helicopters based at one field location shuttling underslung loads to and from a second field location, it will be necessary to provide two base stations for flight monitoring plus at least four walkie-talkies for the loadmasters. Depending on the distance involved HF sets may also be required for flight monitoring.

There should also be fax facilities for receiving weather charts wherever the aircraft are based.

Supply/stand-by vessels, work boats, etc

(in addition to standard ships equipment)

The requirement is a voice link to drilling rig and materials base.

All vessels, including the drilling unit, will be fitted with appropriate VHF/UHF radios. In addition the following should be considered:

• Small marine radar sets (*)
• Inmarsat or HF radio if considerable distance offshore (*)
• Solas EPIRB (Emergency Position-Indicating Radio Beacon) distress radio system (**)
• Navigation aids, Satnav, Decca or Loran as appropriate (**)
• Lifeboat radios (**)

(*): Highly desirable and essential if operating offshore.

(**): Essential for safety reasons.

It is recommended that if contracts for workboats or other supply vessels are being written that the above list be included as a contractual requirement. It may also be appropriate to place the onus on the contractor to obtain the necessary PTT licences for the equipment.

To increase flexibility it may also be useful to consider fitting a mobile radio set to each of the vessels.

Although marine VHF radio can be used for telecoms traffic, the channels are public and other marine users can listen in. The use of a mobile radio system does offer a degree of privacy.

Field vehicles

Requirements are a voice link to drilling rig, materials base and each other.

Either HF SSB radio or VHF/UHF Radio (or both) should be installed in all Company vehicles, depending on the range of operations.

6 System implementation

Given below is a brief summary of the actions involved in implementing the telecommunication system needed for a drilling venture:

• Assessment of communications needs, taking into account any experience during the seismic campaign and any hardware available from that phase.
• Discussions with PTT to discuss what facilities they can provide, and if they are unable to assist, what facilities they are likely to license, what equipment is approved, and what frequencies (or bands) they will permit.
• Site surveys to determine:

• If line of sight paths exist between the desired locations
• Type of system for the task
• Provision and suitability of local power supplies and equipment housing
• Locations for antenna mounting and type of antenna.
• The availability of equipment, local support for maintenance, installation etc.
• The availability of spares.

Once the above have been determined, an approach to the PTT should be made for licences. Some countries also require import licences which may be issued by a different authority. In some coutries it is advisable to utilise the services of a local agent to obtain licences. This must be done with caution and only after ascertaining whether the agent has the necessary influence that he claims to have.

Before granting licences for transmitters, the relevant authorities may require full technical documentation of the proposed equipment.

7 Administration of the telecommunications system

Radio operations

In some countries, it may be necessary to employ licensed radio operators, and to record all radio calls in a log book. This should be determined at the time licence applications are made.

Switchboard and telex operations

Instruction on how to operate the switchboard should be given to operators as part of the installation process.

The operator should be capable after training of invoking all the facilities and efficiently handling both incoming and outgoing calls.

The operator should also produce printouts of the call logger for audit by accounts, and circulate all users with telephone directories from time to time.

Depending upon the size and nature of the operation, the preparation and transmission of telex messages may be handled either by a dedicated operator or by the person who prepares the telex on a word-processor. A log of sequence numbers will need to be maintained along with a method of filing record copies.

Equipment maintenance

All equipment requires to be checked occasionally to ensure optimum performance. Depending upon the nature of the operation and the prevailing local conditions, this may be entrusted to the local agent who may also offer a first line repair facility; alternatively regular visits from the vendor or manufacturer should be arranged. As mentioned above the best solution is to have a contract to operate the telecommunications systems rather than a purchase or lease agreement, in which case maintenance will be included.

8 Erection of antennae

The use of "home-made" masts should be avoided where possible. If such a mast is used for a simple HF antenna, it should never be climbed. All fittings should be in place before the mast is erected and the tensioning system arranged so that any tensioning can be done from the mast foot. Account must be taken of exceptional weather conditions which may be experienced in the region (cyclones, hurricanes, etc). For antennae which need adjustment after installation, eg microwave dishes, a mast designed for the purpose must be used, and it must be erected by an experienced rigger.

If possible the erection of an HF antenna close to telephone lines should be avoided. Signals transmitted from an HF antenna may be picked up by the telephone lines and cause interference to the telephone system, making the latter unusable while the HF radio is in use.