PEEN3006: Drilling

Engineering and Fluids Lab

A. Prof. Moacyr Bartholomeu Laruccia

Introduction

When a drilling project is commenced, two goals govern its aspects.

The first is to build the well according to its purpose and in a safe manner (i.e, avoiding personal injuries and avoiding technical problems).

The second is to complete it with minimum cost. Thereto the overall costs of the well during its lifetime in conjunction with the field development aspects shall be minimized.

The overall cost minimization, or optimization, may influence the location from where the well is drilled (e.g., an extended reach onshore or above reservoir offshore), the drilling technology applied (e.g., conventional or slim–hole drilling, overbalanced or underbalanced, vertical or horizontal, etc),

and which evaluation procedures are run to gather subsurface information to optimize future wells.

On the other hand, the optimization is influenced by logistics, environmental regulations, etc.

Different drilling technologies

have been invented:

Percussion drilling

Cable drilling - “Pennsylvanian drilling”

Rotating drilling

Full cross-section drilling

Surface driven

Rotary bit

Rotary nozzle

Subsurface driven

Turbine drilling

Positive displacement motor drilling

Electro motor drilling

– Annular drilling

Diamond coring

Shot drilling

Different drilling technologies

have been invented:

Special techniques

– Abrasive jet drilling

– Cavitating jet drilling

– Electric arc and plasma

drilling

– Electric beam drilling

– Electric disintegration drilling

– Explosive drilling

– Flame jet drilling

– Implosion drilling

– Laser drilling

Special techniques

– REAM drilling

– Replaceable cutterhead

drilling

– Rocket exhaust drilling

– Spark drilling

– Subterrene drilling

– Terra drilling

– Thermal-mechanical drilling

– Thermocorer drilling

Drilling Rig Currently, rotary drilling is the standard oilwell drilling

method for the drilling industry, with almost all operations being performed by rotary-drilling rigs.

Rigs will vary widely in size, drilling capability, level of automation, and environment in which they can operate.

Nevertheless, the basic rotary-drilling process is the same for all types of rigs as shown in Fig. 1.9:

The well is drilled using a bit that, under a downward force and rotation, breaks the rock into small pieces.

The force is provided by the weight of pipes placed above the drilling bit, while rotation generally is provided at surface by equipment that rotates the drillstring, which in turn transmits rotation to the bit.

As the bit drives into the ground, deepening the well, new pipes are added to the drillstring.

The small pieces of rock ( cuttings ), resulting from the bit action, are transported to surface by a fluid ( drilling fluid or mud ) that is constantly pumped into the hollow drillstring all the way to the bottom of the hole, where it passes through small orifices placed at the bit, and returns to surface carrying the cuttings through the annular space formed between the well and the drillstring.

Once reaching the surface, the cuttings are separated from the fluid, which is treated for reuse.

Generally, rotary rigs are classified as either land rigs or

marine rigs. Fig. 1.10 shows rig classification under those

categories.

Land Rigs Land rigs, in a broad sense, can be categorized as conventional and

mobile.

Mobile rigs tend to be more easily transported, while the conventional

rigs will take longer to be moved from one location to another.

Conventional rigs normally use a standard derrick that needs to be built

on location before drilling the well and is usually dismantled before

moving to the next location.

In the past, quite often the derrick was left standing above the well

after it began production in case workovers became necessary; however,

today’s modern rigs are usually built so that the derrick can be easily

disassembled and moved to the next wellsite.

There also are special rigs that are built in a way that rig pieces, when

disassembled, will never exceed a certain weight, allowing

transportation by helicopter. Those rigs, also called helitransportable

rigs, are used in remote areas with no road infrastructure and also on

jungle operations.

Mobile rigs have a cantilever derrick or a portable mast that is raised

and lowered as a whole rather than being constructed piecemeal. The

rig-up and rig-down operation is less time-consuming than on

conventional rigs.

Generally, all important rig components are skid-mounted and can be

transported and reconnected easily.

Land Rigs

Fig. 1.11—Rig with cantilever

derrick (Derrick Engineering

Company 2010).

Fig. 1.12—Mobile rig with portable mast

(GEFCO 2007). Courtesy of GEFCO.

The cantilever derrick has its

components assembled

horizontally on the ground and then

is raised using the rig hoisting

equipment

Rigs with portable masts usually

are mounted on a truck together

with its hoisting system. Upon

arrival on location, the

telescoped portable mast is

easily raised to vertical and

extended to its fully operational

position.

Land rig specification

Besides portability, another important feature for a rig is its maximum operating depth, which is closely related to its derrick loading capacity. A variety of rig types are available in the market with maximum depth capacity ranging from less than 3,000 ft (~900 m) up to 30,000 ft (~9000 m) and beyond.

These specifications must be used to evaluate and compare rigs of various contractors before selecting the right one for an upcoming well. Information contained in the rig specifications generally addresses the following items:

Derrick type

Drawworks type

Maximum operating depth

Hookload capacity

Mud pumps (number, manufacturer, horsepower)

Engines (type, horsepower)

Topdrive or rotary table

Well-control equipment

Fishing tools

Main rig equipment information

Drillstring and accessories

Circulating system and mud-processing equipment

Miscellaneous equipment

The rig specification usually contains a schematic of the rig’s layout so that the rigsite can be properly prepared. This information is of extreme importance in certain areas where logistic or environmental conditions may drastically limit the drillsite area.

Marine Rigs Modern offshore drilling started in the mid-1940s, when offshore wells started to be

drilled in shallow waters from fixed platforms. Today, marine drilling activity is an

important segment of the industry, with offshore rigs carrying amazing technological

developments.

Fixed platforms require a large up-front investment, for they first must be constructed

and transported to a specified location. Obviously, such investment should be made only

after there is reasonable assurance about the presence of commercial oil and/or gas

accumulations.

This reality pushed the industry to develop mobile drilling vessels—rigs that could be used

for exploration drilling and, afterward, drill the subsequent production wells or be moved

to another location.

Less than a decade after offshore wells started to be drilled from fixed platforms,

movable, submersible offshore drilling barges were introduced. The portability of these

drilling vessels created a major increase in the attractiveness of offshore drilling.

Besides portability, another important characteristic of an offshore drilling unit is its

maximum water depth of operation. There are rigs that can drill only in very shallow

waters, while some modern drilling vessels can drill in very deep oceans.

Offshore drilling rigs can be bottom-supported or floating vessels.

The various types of offshore rigs

The various types of fixed and floating

Production Platforms commonly used for Oil

and Gas exploitation in deep water Gulf of

Mexico:

Bottom-Supported Offshore Drilling Rigs

A submersible drilling barge is a bottom-supported vessel typically used in 8 to 20 ft of water (3 to 6 m).

In order to operate, the barge is towed to the location and sunk to the bottom by flooding various vessel compartments. After conclusion of the drilling operation, the water is pumped out of the compartments, allowing the rig to float so that it can be moved to the next location.

The barge usually is designed as a fully self-contained vessel. In addition to a complete drilling rig, it has sleeping quarters for the crew and ancillary personnel and galley facilities.

Crew boats are used for transportation between the rig and the nearest docking facility and for emergency evacuation of personnel.

Water depth and weather limit the areas for submersible barge operation. A minimum water depth of 6 to 8 ft (2 to 3 m) is required for vessel draft during transport to the location. The upper range on the water depth can be extended to 40 ft (12 m) if a shell mat or pad is built as a support base for the barge. Quite often, the shell pad is required due to poor seafloor supporting capabilities.

The submersible drilling platform is supported on

large pontoon-like structures. These pontoons

provide buoyancy allowing the unit to be towed

from location to location.

Once on the location, the pontoon structure is

slowly flooded until it rests securely on its anchors,

of which there are usually two per corner.

The operating deck is elevated 100 feet above the

pontoons on large steel columns to provide

clearance above the waves.

After the well is drilled, the water is pumped out of

the buoyancy tanks and the vessel is re-floated and

towed to the next location.

Submersibles, as they are known informally, operate

in relatively shallow water, since they must rest on

the sea floor.

A Cantilever rig on a barge

• Drilling barges are widely used in areas such as the Gulf of Mexico and the Niger

basin marsh areas, and in coastal waters immediately adjacent to land areas.

• Specially dredged channels may be required in marshes where no other access is

available. These channels, or canals, may add significantly to the well costs.

• Barges are not used when wave height exceeds 5 ft. (1.5 m).

• The discovery of significant petroleum reserves in an offshore area usually requires the

installation of a production platform to extract the reserves economically.

• A number of wells are drilled directionally from the platform to exploit the reservoir. This

approach is more cost-effective, in most cases, than using many single-well platforms

with vertical wells.

Tender Assist Drilling (TADs) units were the rig of

choice in the 1950s and early 1960s in the Gulf of

Mexico for development drilling off fixed

platforms. They are used less commonly now, but

are appropriate for certain situations, and

sometimes for new drilling from an aging platform

near shore.

Situations favorable to TAD use

They may be particularly attractive for

standard platforms in water depths over

jackup-rig rating and where space and/or

load limits are a major factor, for deepwater

spars and TLPs with the right number of

wells, and for any platform where weight

and space for long ERW are limited.

Generally, a TAD costs more than a platform

rig, especially the modular type, but they

are a very attractive option for certain

situations.

Tender Assisted Platforms

Rigs that drill from platforms can be fully self-contained or tender-supported. If the production platform is

sufficiently large, all drilling equipment and personnel can stay on the rig. Alternatively, a floating tender is used if

the platform working area or load capacity is restricted.

• Fixed platforms are usually of jacket-type construction and are supported by piling.

• There are also areas, with firmer bottom sediments, where massive concrete structures are built

and simply placed on the bottom.

• In both cases there will be a large structure running from the seafloor all the way to surface.

Obviously, installation of such large structures will be possible only up to a certain water depth

because construction and transportation of platforms for very deep areas would be either

extremely expensive or technically unfeasible.

• Normally, fixed platforms are used for development of fields in water depths up to 1,500 ft (460

m).

• Slender and lighter platforms, the so-called compliant towers, may be installed in deeper areas.

Those platforms have a flexible tower as opposed to the relatively rigid structures of the regular

fixed platforms.

• Normally, the main purpose of fixed platforms is to remain in place permanently after drilling has

been concluded, producing and processing the oil and gas from the wells.

• Actually, there are fields where the wells are drilled previously by another drilling vessel and it is

only afterward that a fixed structure is installed and the wells are tied back to the platform to

initiate production.

• When fixed platforms are used for drilling operations, the drilling equipment may either remain in

place for future use in some necessary well intervention or it may be removed for use elsewhere.

In the latter case, if well intervention or new drilling jobs are necessary, the required equipment

has to be reinstalled.

Offshore Fixed Platforms

jacket-type Platforms

• Steel Jackets (Up to 250-300 m. Water

Depth)

• This can be fairly simple structures,

like the minimized Well Head Platforms

used by Chevron in the Gulf of Thailand

• Or very large "Integrated Platforms" used in the

North Sea and other places.

• Where drilling, wellheads, production and injection

equipment and living quarters are all on the same

platform, supported by a single large steel jacket.

jacket-type Platforms

Here is a schematics of a typical small 4-

pile Platform for shallow water: (<100 m.)

A more common way of developing large Oil and Gas Fields is with multiple Platforms for the various functions:

The Well Head Platforms (WHP) can be quite a distance from the Production Platform (PP) and the Living Quarters (LQ).

The last two are usually connected with bridges.

A normal such Platform consists of a Steel Jacket and Topsides, which may contain "anything".

This is a typical such shallow water

Platform:

Drilling of the wells will be performed by

Drill Tender, or by a Jack-up Rig, which

move in close.

Jack-up rig

• The premise of a jackup rig is that it is self-elevating;

here, the legs are stationed on ocean floor and the

drilling equipment is jacked up above the water's

surface.

• Providing a very stable drilling environment, in

comparison to other types of offshore drillingrigs,

jackups can drill in waters up to 350 feet deep.

Facts about the jack-up rig Maersk Intrepid (and

the other three jack-up rigs):

World’s largest jack-up rigs

Leg length = 206.8 m (678 ft)

Designed to work in the North Sea at water depths

up to 150 m (492 ft)

Dual pipe handling (more uptime and drilling

efficiency)

Multi Machine Control - a fully remote operated

pipe handling system giving the possibility all

operations such as stand building and tripping to be

conducted without personnel

Jack-up rig• The principal components are a barge-type unit and three to five legs capable of supporting the

vessel when positioned over the seafloor.

• When moving between locations, the legs are up in the air, allowing the barge to float. Upon arrival

at the new location, the legs are jacked down to contact the seafloor, and the barge is raised into

the air.

• When drilling is completed, the rig is lowered to the water level, the legs are raised, and the rig is

towed to the next location.

• It is not uncommon to have some difficulty removing the legs from loosely consolidated, sticky

subseafloor soils; therefore, most rig legs are equipped with water-jetting systems to help release

the legs.

Fixed Offshore Platforms

• The Troll A platform is

a condeep offshore natural gas platform in

the Troll gas field off the west coast of Norway.

• It is the tallest structure that has ever been

moved to another position, relative to the

surface of the Earth, and

• It is among the largest and most complex

engineering projects in history.

• towed into the North Sea in 1996, it is now

operated by Statoil.

Troll A Concrete Platform in the North Sea

Tension Leg Platforms has been used successfully both in the GOM

and the North Sea, but is not being constructed any more with the

influx of FPSOs, which is less expensive and more flexible.

Here is a typical Tension Leg Platform:

On the surface it looks

just like any FPU.

A type of floating production system,

tension leg platforms (TLPs) are buoyant

production facilities vertically moored to

the seafloor by tendons.

Offshore Drilling Rigs: Officially called "Mobile

Offshore Drilling Units" (MODU), of which there are

many types.

• The first one is the "Modularized Platform Drilling Rig", which is placed on a fixed platform by means of Floating Crane. Each module can be as heavy as 2-300 m.t

• Once the Production Wells are drilled, the Drilling Rig is removed and Production equipment takes it's place. (Not much used outside the GOM)

• The next type is; "Self-erecting

Tender assisted Drilling Rigs".

• This type consist of the Drill packet,

which is lifted up and assembled on

a Fixed Platform by a crane on the

Tender Barge.

• The rest of the Drilling equipment is

built into the Tender and does not

need to be dismantled/assemble for

every move.

• Most are barges with a 100 m.t.

SWL crane and living quarters etc.

Here is a modern semi-submersible Tender

Rig in operation:

Tenders can work in any water depth in which

fixed platform can be installed.

Floating rigs Floating rigs such as drillships and semisubmersible platforms do not rest on

the seafloor.

As such, these rigs are not restricted by the length of the rig’s legs for

maximum operating water depth.

Normally these rigs are more expensive than jackups and are used in areas

where, due to the water depth, jackups cannot operate.

For station keeping while drilling, these rigs use either an anchoring system

or a dynamic positioning (DP) system.

The semisubmersible drilling unit usually has two lower hulls that provide

flotation.

When drilling, the ballasted lower hulls, filled with water, grant stability to the rig.

After conclusion of the drilling operation, the water is pumped out of the

compartments and the rig can be moved to the next location.

Anchored semisubmersible rigs are held in place by huge anchors that,

combined with the submerged portion of the rig, provide great stability,

allowing the rig to be used in turbulent offshore waters.

There are semisubmersible rigs that use a dynamic positioning system.

This system uses electric motors installed in the hulls that allow propelling of the

rig in any direction.

A computer system, using satellite positioning technology and sensors located near

the wellhead, commands the motors, ensuring that the ship will be kept directly

above the subsea wellhead at all times.

• Ocean Rover Drilling Production Wells in the Kikeh

Field, offshore Sabah, East Malaysia

It is about 3,950 ft. / 1,200 m. water depth, which is

relatively shallow in today's context. (The record is

over 10,000 ft. WD in GOM and Brazil)

OWNER GAZFLOT

CLIENT VYBORG SHIPYARD JSC

LICENSOR MOSS MARITIME

SCOPE

Detailed Engineering of

Lower Hull & Living

Quarter including

Helideck.

Pontoon length 118 m

Pontoon breadth 17 m

Pontoon depth 10 m

Hull

weight17,000 MT

Drilling Depth 7,500 m

Classification RMRS

LQ

Habitation128 persons

Outside des.

Temp.(-30) Deg C

Approx

weight1200 MT

Helideck Aluminium

HULL SPECIFICATIONS:

Semi-submersible Drilling Rigs

The latest GOM deep water developments has

used the Spar technology. Here is a overview of the

Spars of Technip design: (Not all for the GOM)

Most of these are built in Finland and

transported to GOM

- Kikeh Spar: Production unit in the Kikeh Field

in Sabah

- The Spar is afloat and permanently anchored

Drillships

Drillships use a ship-type vessel as the primary structure

to support the rig.

It may be a converted seagoing vessel or, most

commonly, a specially designed drilling vessel.

Most drillships are self- propelled, not requiring

oceangoing tugs for transportation between locations.

Obs.: Semisubmersible rigs generally are not self-propelled.

New-generation drillships usually are dynamically

positioned, but there are also anchored vessels.

Anchored drillships normally are built with a central

turret where the anchoring system is installed. This

allows vessel rotation around the central turret in order

to always keep the ship facing the waves, reducing

wave action.

Drillships Drillship: Energy

Searcher

Rig Type: Drillship

Drillship

Type:

Conventionally

Moored

Rig Design: Norwegian Rig

Consultants

Rated Water

Depth:

2,500 ft

Drilling

Depth:

25,000 ft.

Rig Name: Pacific Santa Ana

Rig Manager: Pacific Drilling Limited

Rig Owner: Pacific Drilling Limited

Rig Type: Drillship

Drillship Type: Dynamic Positioning

Rig Design: Samsung Heavy

Industries S12000

Rated Water

Depth:

12,000 ft

Drilling Depth: 40,000 ft

The Drilling Team Modern well drilling is an activity that involves many specialists and usually various companies. The expertise and number

of engineers and technicians involved in the planning and execution of a drilling operation will depend on the type of well

being drilled, its purpose, the well location, its depth, and the complexity of the operation.

A well drilled with the purpose of discovering a new petroleum reservoir is called an exploration (or wildcat ) well.

Wildcat wells are the very first ones drilled in a certain unexplored area.

After a wildcat well has shown the potential of a reservoir to be productive, appraisal wells may be drilled to obtain more

information about the reservoir and its extension.

Once a newly discovered reservoir is considered economically viable, a development plan is established and development

wells are drilled to produce the oil and gas present in the reservoir.

Besides the most common exploration and development wells, special wells may be drilled for a variety of purposes

including stratigraphic tests and blowout relief.

Fig. 1.6 presents an overall classification of wells according to their purpose. The rights for a company to explore a certain

area must be secured before any activity is carried out.

Due to the high risk involved in the business, it is not uncommon to have two or more companies forming a consortium for

the venture.

Normally in that case, one company—the operating partner—will lead the operation while the other partners, who will have

proportional participation in all expenses and profits, may or may not have a say on the operational procedures depending

on the clauses accorded in the joint operating agreement (often referred to as the JOA).

The Drilling Team Prior to any drilling activity, seismic and geologic studies are carried out in order to determine the best location for

the first exploration well. Those studies are performed by a company’s geological team, which usually is responsible for recommending locations for wildcat wells, while the reservoir team will be responsible, on a later phase, for locating development wells.

In either situation, the drilling team will be responsible for the planning and execution of the operation including its budget (cost estimation) and contingency plans. Leading a drilling operation is not an easy task.

Normally, the oil company that owns the exploration rights for the area, or the operating partner in case of a consortium, assembles a drilling team that in turn will prepare the detailed well design and the drilling program and establish operational procedures according to local regulations and the company’s own health, safety, and environment (HSE) policy. This is done in order to conduct drilling operations in the most safe, clean, and economical way.

The drilling operation itself generally will be carried out by a drilling contractor that may be hired specifically for a certain well or on a long-term contract. The contractor will be responsible for performing the operations according to the well program using the equipment and procedures specified in the contract. Prior to the initiation of the drilling operations, the wellsite must be prepared to receive the drilling rig and all other related equipment.

The specific type of work for wellsite preparation will depend on the location and the infrastructure present. Offshore operations in unexplored areas may require a seafloor survey to determine the feasibility of installation of subsea equipment.

Some onshore areas may require extensive preparation, and remote areas, without any infrastructure, may require costly and time-consuming preparation including road construction.

Fig. 1.7 shows an offshore location in the North Sea, an operation in western Canada, and another in Brazil’s Amazon jungle.

The Drilling Team

The Drilling Team During drilling operations, the operator will have at least one representative, usually

a drilling engineer or technician, responsible for ensuring that operational standards

are being followed by the drilling contractor and other service contractors involved

in the process.

Depending on the importance of the well, the operator may be represented by a

team of specialists including engineers, geologists, drilling-fluid specialists, and

others.

The operator’s representatives, besides ensuring that the well program is properly

executed, will also be responsible for on-site decisions regarding minor adjustments

or major changes to the drilling program that may be necessary due to unpredicted

conditions.

During well drilling, various services will be needed depending on the type of well

and its complexity. Common services required for oilwell drilling are related to

drilling fluids, directional drilling, casing and cementing, drilling bits, and well

logging.

Fig. 1.8 presents a typical drilling structural organization. The drilling engineer

recommends the drilling procedures that will allow the well to be drilled as safely

and economically as possible.

In many cases, the original well plan must be modified as drilling progresses because

of unforeseen circumstances. These modifications also are the responsibility of the

drilling engineer.

The company representative, using the well plan, makes the on-site decisions

concerning drilling operations and other services needed.

Rig operation and rig personnel supervision are the responsibility of the tool pusher

or drilling supervisor.

Drilling Engineer

It is the responsibility of the drilling engineer to design and plan the well and guide the drilling tools to the zone of interest.

A drilling engineer is a planner of operations, a technologist/engineer, and a scientist.

He or she must understand and be able to synthesise the principles of geology, physics, mathematics, chemistry, and engineering science.

Drilling technology is changing daily as well get deeper and rigs operate in deeper offshore waters.

Drilling Engineer

It is the job of the drilling engineer is to design and implement a procedure to drill the well as economically as possible.

It is also important that the well be drilled so that the formations of interest can be evaluated as to their commercial value to the oil-company.

He/she does however, have limitations. The safety of the drilling crews and rig must be a prime concern. Governments of countries have rules and regulations that must be followed.

Multilateral. Horizontal Directional.

Drilling Superintendent.

Drilling Superintendent : He works hand in hand with the drilling engineer as the plan develops. He will source out equipment and companies that will be needed for the success of the operation.

Tools and equipment will vary considerably depending on the reason for the hole to be drilled.

Drilling Superintendent.

He will be the direct link to and organise all the contractors. This includes the drilling contractor and all the service companies that will be used for the operation.

In fact from experience, this position requires the more experienced person as this individual will carry much of the responsibility throughout the operation.

Once the location is selected and the well plan developed, a rig must be selected.

The selection of a rig will depend on many variables but the depth of the intended hole will be the main concern.

Drilling Superintendent Rig Superintendent

Drilling Supervisor

TourpusherDrillerMechanicElectricianAssistant-DrillerDerrickmanCrane OperatorFloormenRoustaboutsMedicRadio OperatorWelderDriversTruck DriversCatering

Mud EngineerDirectional CrewMud LoggersCement CompanyLogging CompanyWireline CompanyFishing CompanyCompletion CompanyTesting Company

Toolpusher

Drilling ContractorOperator

Management

Base Team

Service Companies

Field Team

Before continuing it is extremely important that the people going out to the rig understand the infrastructure and the chain of responsibility within the working boundaries of the rig.

It is often this misunderstanding that brings about many of the problems faced on the rig.

It must be understood the company rep and the toolpusher work for separate companies.

It must also be understood that the final cost, be it direct or indirect will be born by the operator

Company Rep in the Field.

In the field the drilling operation and service personnel are supervised by the company rep.

He is the witness for the operator and will remain with the operation from start to finish

His duties are to see that instructions sent from the base in the form of the contract or well program are carried out to the companies satisfaction

It is not his duty to run the rig. Many operators over the years have attempted to run their own drilling operation. Most have failed or found it to be somewhat more expensive.

Logistics plays a major part in this mans work. Having equipment on site and ready is possibly the most cost effective part of a operation.

Accurate and honest reporting is also very important. It is his report that affects the daily running of the operation

Rig Toolpusher.

Of all the position within the industry the most underrated is the job of the rig toolpusher

It is a position that shoulders most of the responsibility without the authority.

It is often his knowledge and skills that carry the operation

Toolpusher

He and he alone, is responsible for the rig and keeping it running.

The safety of the well and the people on site are also his responsibility.

Once orders are passed to him from the drilling supervisor, it is his responsibility to see they are carried out as efficiently and safely as possible.

He will check all equipment coming to the rig and report any defects to the drilling supervisor.

He will ensure all the rig equipment is maintained and in good working order.

He will relieve or supervise the driller should there be problems with the wellbore.

He will plan and suggest a rig budget for the coming year

He is supported by a team of: Drillers, Mechanics, Electricians and a Tourpusher

The Crews

Under normal conditions a drilling crew will consist of: Assistant Driller, Derrick man and 3 Floormen. They are backed up by a crane operator and the roustabout crew.

Backing up the rig floor are the maintenance people . The mechanic and his department, Electrician, Medic, Radio operator, Welder.

The conditions under which they work will vary and depend on the part of the world the rig is operating in. Work schedules will vary with the type of rig.

As a rule, once an operation starts it is a 24 hour a day operation.

Offshore the crews will work 12 hours on and 12 hours off for periods ranging from 7 days on and 7 days off, to 28 days on and 28 days off. The living conditions would be close to that of a local hotel.

However on land operations, conditions can very drastically and the standard of living can range from living in a hotel or camp, to looking after yourselves.