Jason A Whyte, National Oilwell

SAFETY REMAINS A paramountconcern for drilling operations where amultitude of operations and equipmentmovements are taking place simultane-ously at a rapid pace. The drill floor is alocation of many activities that presentsafety hazards to those working withinits confines.

Familiar to most are the obvious safetyconcerns around traditional manual

methods for pipe handling, making andbreaking tubular connections, handlingof pipe slips, and the manipulation oftubulars and other ancillary equipmentto and from the well center.

Continued improvements in drill floordesign and mechanization have provento reduce the amount of manual laborrequired for many of these operationswhile at the same time reducing the inci-dents of related injuries.

However, the addition of more machinesand automated systems around thedrilling operation have created an even

more congested work environment forrig personnel who are still required tocarry out manual interventions.

A benefit of modern automation beingemployed at the drill floor is the abilityto control machines in a fully or semiautomated mode to perform a variety oftasks.

Often these operations consist of repeti-tive cycles with the same task and move-ment being performed over and over, as

is the case with tripping pipe, for exam-ple. The machines and their related con-trol computers can work in harmony tocomplete the pre-programmed taskswithout being hampered by fatigue andinaccuracies that can occur withhumans performing the same job.

Since these machines are located andoperating within a relatively small area,there exists the potential for machinesto collide or otherwise interfere with oneanother.

The addition of an Anti-Collision System(ACS), tied together between the

automation systems controlling eachmachine, is a common solutionemployed for ensuring automated equip-ment can work harmoniously in thesame area.

A completely automated drilling opera-tion free from human manual activitieshas yet to be completely realized.

Although the industry continues tomake great strides in further automat-ing drilling activity at the surface therestill exists the need for human interven-tion on the drill floor, even if only peri-odically.

Regular tasks such as equipmentinspection, maintenance, and servicestill make it necessary for personnel toenter the drill floor area, often whiledrilling continues around them.

Commonly, rigs that operate with a vari-ety of automated systems will continueto have some processes completed man-ually, creating a drill floor that is a mixof automatic or mechanized and manualor human activities. Herein lies thepotential hazard for accidents andinjuries.

The next logical step is to employ tech-nologies that allow the human entity tobe incorporated into the rig’s anti-colli-sion system. By being able to identifythe presence and movement of person-nel on the drill floor, there is an oppor-tunity to take a proactive approach toavoiding injuries caused by accidentalman-machine collisions, therebyincreasing safety and rig efficiency.

This protection for personnel can beadditionally applied to other areas ofthe drilling installation such as at thepipe deck, within crane operating areas,and other various work platforms andlocales.

B A S I S O F T H E S Y S T E M

The theory of this safety enhancementsystem is to add active location monitor-ing of humans working in the same areaas automated equipment.

Although human movement cannot bepredicted and anticipated in advance, itis possible to limit machine movementand activity when that equipment reach-es an area occupied by a human worker,

40 D R I L L I N G C O N T R A C T O R September/October 2003

Adding Human Factor to Rig Anti-Collision Systems

The basic elements of the system and their respective locations on atypical drill floor installationinclude (1) Passive Ring Transponders, each with their own unique ID embedded in safety floor matmaterial (each floor mat segment is 3.28 ft. (1.0 m) square); (2) less exposed zone occupied bydrilling crew (Doper); (3) Tracking of workers; (4) passive transponders on the floor (shown as agrid of green circles above). The entire yellow area is covered by customer built transponder matsfixed to the floor; (5) wireless communication (radio link) to and from workers; (6) Radio Antenna;(7) Radio Base Station with interface to ACS in safe area; and (8) potential danger zone for work-ers outside monitored mat area.

thus preventing potential collisioninjuries.

S Y S T E M D E S C R I P T I O N

A Human Entity Protection System(HEPS) utilizes proven wireless technol-ogy in order to integrate the human ele-ment into the drilling machinery ACS fora safer, more efficient drilling operation.

Candidate drilling installations forHEPS are those that employ automatedmachines that are controlled by centralcomputers.

In order for HEPS to be effective, it isessential that the rig’s automatedmachines, equipment, and controllingcomputers are capable of supporting ananti-collision system (if an ACS is notalready in place) to which HEPS can beadded.

The HEPS system utilizes relatively sim-ple and reliable radio frequency technol-ogy to identify and track the location ofpersonnel within a defined area.

The basic elements of the system andtheir respective locations on a typicaldrill floor installation are:

• Passive Ring Transponders, each withits own unique ID embedded in safetyfloor mat material (each floor mat seg-ment is 3.28 ft. (1.0 m) square);

• Less exposed zone occupied bydrilling crew (Doper);

• Tracking of workers;

• Passive transponders on the floor;

• Wireless communication (radio link)to/from workers;

• Radio Antenna;

• Radio Base Station with interface toACS in safe area; and

• Potential danger zone for workers out-side monitored mat area.

Passive transponders are placed withina series of protective floor segments.The floor segments are placed together

in the work area to be monitored, creat-ing a safety mat with complete coverage.

These transponders are passive (coiland chip with a unique ID) and thereforecontain no batteries nor require anyconnecting cables.

Personnel on the drill floor wear arechargeable battery operatedtransponder reader that is encapsulatedinside specially provided safetyfootwear (only one shoe or boot has thereader installed) or alternatively thereader may be worn as a strap-on deviceat the ankle.

Using radio communication, the readertransmits any transponder positions inreal-time to a radio base station.

One base station monitors up to 14 per-sons simultaneously.

The host system accommodates up to 64users onboard a rig or vessel. Multiplebase stations may be used to protectadditional personnel in other areas, or

September/October 2003 D R I L L I N G C O N T R A C T O R 41

in the event system redundancy isdesired.

Using Radio Frequency Identification(RFID) technology, installing and config-uring the HEPS system is accomplishedby installing the required mat segmentson the drill floor and identifying the areaand its coordinates from a layout draw-ing.

This process maps the mat segmentswith their corresponding location intothe host system software.

Since the embedded transponders eachpossess a unique identification, the sys-tem is able to determine the exact posi-tion of each transponder.

The system monitors and comparesmovement of personnel and machineson the X and Y-axis.

Future development includes adding themovement of machines and objects onthe Z-axis, with special attention tooverhead equipment and potential forfalling objects in areas where personnelmay be located below.

When someone with a reader in his orher footwear steps onto the mat, theHEPS along with the ACS knows exactlywhere that person is positioned.

The system then compares the worker’sposition to that of machinery operatingin the same area and can limit themachine’s movement to prevent comingwithin a predetermined safety radiusaround the worker.

With HEPS employed, the system wouldsend a halt command to the equipment,maintaining the safety radius aroundthe worker.

D E S I G N C R I T E R I A

Where possible, proven “off-the-shelf”industrial components are utilized. Theindustrialized version of HEPS is builtaccording to relevant IEC standards(e.g. IEC61508) and regulations for EEx& EMC requirements as well as con-formity to communication standards.

As a safety enhancement system, HEPSis additionally designed with a fail-safeelement that causes the rig’s ACS tosend a halt command to all machines inthe event of an error in HEPS communi-cation or similar condition where per-sonnel tracking may be lost.

This fail-safe situation must be manual-ly reset once the error in the system hasbeen resolved.

P E R F O R M A N C E I N F O R M A T I O N

The RFID technology used in HEPSallows for crew tracking accuracy with-in 6.89-in. (175 mm) nominal from thelocated transponder. Each moldedtransponder has a predefined “physi-cal” location inside its mat segment.

The system operates in real-time, updat-ing personnel position every 100 mil-liseconds (nominal). Machinery haltresponse is less than 100 milliseconds(to send halt command to the machine’scontrol system).

HEPS has been developed to meet Zone1 (EExim) area classification require-ments.

A P P L Y I N G T H E S Y S T E M

The HEPS system is designed as a pro-active rather than reactive tool that con-stitutes a supplement to the localmachinery shut down systems andexisting HSE procedures for a givendrilling installation.

Numerous machine activities aroundthe drilling operation pose the potentialfor accidents and serious injury to per-

sonnel working around the drill floor.Types of injuries that can be preventedby HEPS include:

• Crew being pinched or crushed by amachine;

• Crew becoming caught between sever-al machines;

• Crew being hit by a moving machine;

• Injuries caused by crew trespassinginto an machine activity area;

• Fatal injuries caused by lifting opera-tions;

• Injuries caused by unsuitable opera-tional modes; and

• Consequential damage and injuriesfrom machine collisions.

A number of drilling activities have beenstudied for the ability of HEPS toincrease safety and efficiency factors.

The following are specific types/areas ofoperations with inherent man-machinecollision risks that also have a signifi-cant impact on drilling efficiencies:

• Dual operations/double derricks;

•Iron Roughneck travel between parkedand well center positions;

42 D R I L L I N G C O N T R A C T O R September/October 2003

The safety radius around workers and the monitored envelope around machines and equipment areindicated by green lines in the illustration above.

• Casing Roughneck travel betweenparked and well center positions;

• Casing Tongs makeup / breakout oper-ations (manual operation);

• Pipe Handling Systems pick-up andlay-down movements to and from thepipe deck/catwalk to well center;

• Horizontal-to-Vertical machines mov-ing pipe into the well center;

• Pipe Conveyor sequences movingtubulars from pipe deck into the wellcenter;

• Pipe Handler movements at the drillfloor;

• Top Drive/elevator link movements;

• Top Drive raising/lowering in Derrick;

• Special operations (well control oper-ations, BHA deployment, service opera-tions, etc.);

• Manual doping operations;

• Manual handling of pipe slips;

• Manipulator arm movements;

• Raised backup systems;

• Extra mouse hole operations;

• Riser handling from storage towell center location;

• Derrick utility baskets; and

•Monkey/casing stabbing boardareas.

T E S T I N G T H E P R O T O T Y P E

Factory testing of the HEPS pro-totype was carried out by set-ting up a test “drill floor” com-plete with a series of safety matsegments installed around animaginary well center.

Actual automated machinerywas employed to test theresponse times and actual per-formance of the system whenintegrated into a machine’sACS.

Tests were performed using aprototype transponder readermounted in a boot.

As the wearer moved across thesafety mats, the system auto-matically detected the proximityof the reader and relayed the

information to the ACS.

An indication of the person’s positionand movement was tracked on a screenin a similar fashion to a computer’smouse causing a pointer to move on thescreen.

An iron roughneck was then started inan automated sequence where it wouldmove towards the well center.

As designed, once the iron roughneckreached the safety radius of the testworker the ACS delivered a halt com-mand to the iron roughneck. Furthertests with various other scenarios haveproven to be highly successful.

Efficiencies can be taken into considera-tion when installing and customizing theHEPS systems for a particular drillingoperation.

The halt command received by amachine can be followed by a pro-grammed “pause” for a period of timebefore the machine can resume its auto-mated sequence only after the personhas left the operating vicinity.

It is also possible to completely cancelthe sequence, requiring a manualrestart command from the driller.

These variables must be carefully con-sidered when integrating the HEPS withthe rig’s ACS to ensure the highest lev-els of safety while taking advantage ofthe HEPS ability to augment automationefficiency.

F U T U R E A P P L I C A T I O N S

Monitoring machine and human interac-tion at the drill floor level is initiallyconcentrated on the horizontal X and Y-axis but many overhead operations takeplace above the floor.

It is possible to add the Z-axis to HEPSin order to provide monitoring of over-head systems such as pipe rackingmachines, top drives, traveling equip-ment, and various hoisting components.

By adding the third dimension to HEPSit is clear we can achieve even greaterimprovements in safety and operationefficiency can be achieved. �

September/October 2003 D R I L L I N G C O N T R A C T O R 43

Personnel on the drill floor wear a rechargeable batteryoperated transponder reader that is enclosed inside spe-cially provided safety footwear. The transponder can also beworn as a strap-on device at the ankle.