“DRILLING”

MIDDLE EAST TECHNICAL UNIVERSITYMIDDLE EAST TECHNICAL UNIVERSITY

Spring 2008Spring 2008

DepartmentDepartment of Petroleum and Natural Gas Engineeringof Petroleum and Natural Gas Engineering

Dr. Mahmut ParlaktunaRes. Assist. Sevtaç Bülbül

PETROLEUM

Petroleum

Petra

ROCK

oleum

OIL

PETROLEUM

In Pennsylvania,

a mixture of naturally occurring hydrocarbons

may exist in the solid, liquid or gaseous states, depending upon the conditions of pressure and temperature

When the chemical mixture is composed of molecules of small size; gas at normal T &P NATURAL GAS

When larger molecules; liquid at normal T&P CRUDE OIL

(Approximately 11-13wt % hydrogen and 84-87 wt % of carbon. Traces of oxygen, sulphur, nitrogen and helium maybe found as impurities in crude oil.)

Oil is formed in a source rock, Oil is formed in a source rock, along with water and gas.along with water and gas.

Over millions of years, the oil and Over millions of years, the oil and gas float upwards along a gas float upwards along a migration path. migration path.

If oil and gas does not rise to the surface, it collects in a If oil and gas does not rise to the surface, it collects in a reservoir; a rock that has spaces where oil can collect. (e.g. reservoir; a rock that has spaces where oil can collect. (e.g. Sandstone) Sandstone)

There must also be a trap - a rock structure that forms an There must also be a trap - a rock structure that forms an impermeable seal above and around the reservoir rock impermeable seal above and around the reservoir rock (e.g. clay and shale)(e.g. clay and shale)

PETROLEUM

AfterAfter an oil company’s exploration geologists and an oil company’s exploration geologists and geophysicists have obtained and analyzed the geophysicists have obtained and analyzed the data from a prospective petroleum site,data from a prospective petroleum site,

the landman has secured a lease,the landman has secured a lease,

drilling permits and other preliminary papers are drilling permits and other preliminary papers are in orderin order

DRILLING

DRILLING

Repeatedly dropping a heavy Repeatedly dropping a heavy metal bit into the ground, metal bit into the ground, eventually breaking through rock eventually breaking through rock and punching a hole through to and punching a hole through to the desired depth.the desired depth.

The cuttings removed with a The cuttings removed with a “bailer”, an open tube with a “bailer”, an open tube with a valve at the bottom.valve at the bottom.

With today’s technology, cable-With today’s technology, cable-tool drilling is almost not in use. tool drilling is almost not in use.

CABLE-TOOL DRILLING

First oil well built in 1859 by Edwin L. Drake in Pennsylvania

Rotary drilling uses a sharp, rotating Rotary drilling uses a sharp, rotating drill bit to drill the ground. As the drill bit to drill the ground. As the hole gets deeper, pipes are added hole gets deeper, pipes are added to the drill bit to allow it to go further. to the drill bit to allow it to go further.

Most land rotary rigs are portable Most land rotary rigs are portable and and movemovedd toto different different drilling sitedrilling sitess..

Some Some offshore rotary rigs offshore rotary rigs are are mobile; a boat tows the rig onto the mobile; a boat tows the rig onto the drill site.drill site. Some offshore rigs are immobile; Some offshore rigs are immobile; they staythey stay in the site in the site throughout the throughout the life of the field.life of the field.

ROTARY DRILLING

PowerPower System System

HoistingHoisting System System

RotatingRotating System System

CirculatingCirculating System System

RIG COMPONENTS

Provides the power to the Provides the power to the entire rig.entire rig.

Diesel engines compose Diesel engines compose the majority of power the majority of power sources on rotary rigs.sources on rotary rigs.

Diesel engines drive large Diesel engines drive large electric generators. The electric generators. The generators, in turn, produce generators, in turn, produce electricity that is sent electricity that is sent through cables to electric through cables to electric switch and control gear.switch and control gear.

POWER SYSTEM

The hoisting system is used to The hoisting system is used to raise and lower pipe in and out raise and lower pipe in and out of the hole and to support the of the hole and to support the drill string to control the weight drill string to control the weight on the drill bit during drilling. on the drill bit during drilling.

The hoisting system consists The hoisting system consists of of

– derrick, derrick,

– traveling and crown blocks, traveling and crown blocks,

– the drilling linethe drilling line

– the drawworks the drawworks

HOISTING SYSTEM

The derrickThe derrick is a steel tower that is a steel tower that is used to support the traveling is used to support the traveling and crown blocks and the drill and crown blocks and the drill string. string.

HOISTING SYSTEM

The drawworksThe drawworks is a big, heavy piece of machinery is a big, heavy piece of machinery. . It It consists of a revolving drum around which the wire rope consists of a revolving drum around which the wire rope called drilling linecalled drilling line is spooled or wrapped. is spooled or wrapped.

The crown and traveling blocksThe crown and traveling blocks are a set of pulleys are a set of pulleys that raise and lower the drill string. that raise and lower the drill string.

The rotary system includes all the equipment The rotary system includes all the equipment used to achieve bit rotation. used to achieve bit rotation.

The main parts of the rotary system are:The main parts of the rotary system are:

– SwivelSwivel– KellyKelly– Rotary driveRotary drive– Rotary tableRotary table– Drill pipeDrill pipe– Drill collarsDrill collars

ROTATING SYSTEM

The swivelThe swivel supports the weight supports the weight of the drill string and permits of the drill string and permits rotation. rotation. The swivel is attached The swivel is attached to the bottom of the traveling to the bottom of the traveling block and permits the drill block and permits the drill string to rotate.string to rotate.

ROTATING SYSTEM

ROTATING SYSTEM

TheThe kelly kelly is the first section of pipe below the swivel. is the first section of pipe below the swivel. The outside cross section of the kelly is square orThe outside cross section of the kelly is square or hexagonal to permit it to be gripped easily for turning. hexagonal to permit it to be gripped easily for turning.

Torque is transmitted to Torque is transmitted to the kelly through the kelly through kelly kelly bushingsbushings, which fit inside , which fit inside the the master bushingmaster bushing of the of the rotary table. rotary table.

A kelly saver subA kelly saver sub is used is used between the kelly and the between the kelly and the first joint of drill pipe.first joint of drill pipe.

As the rotary table turns the kelly is also turned. As the rotary table turns the kelly is also turned. The movement of the kelly rotates the drill string The movement of the kelly rotates the drill string and the drill bit.and the drill bit.

The major portion of the drill string is composed of The major portion of the drill string is composed of drilldrill pipepipe.. Drill pipe is round steel tubes about 30 Drill pipe is round steel tubes about 30 feet long with a diameter of from 4 to 5 inches.feet long with a diameter of from 4 to 5 inches.

The lower section of the rotary drill string is The lower section of the rotary drill string is composed of composed of drill collarsdrill collars. The drill collars are . The drill collars are thick-walled heavy steel tubulars used to apply thick-walled heavy steel tubulars used to apply weight to the bit and prevent buckling of the weight to the bit and prevent buckling of the drillpipes. drillpipes.

ROTATING SYSTEM

The process of drilling a hole in the ground The process of drilling a hole in the ground requires the use of requires the use of drilling bitsdrilling bits. .

Rotary drilling bits usually are classified according Rotary drilling bits usually are classified according to their design asto their design as::– DDrag bitsrag bits:: F Fixed cutter bladesixed cutter blades, , rotate as a unit rotate as a unit

with the drill stringwith the drill string. . – RRolling cutter bitsolling cutter bits:: Usually three cones that are Usually three cones that are

free to turn as bitfree to turn as bit rotates.rotates.

ROTATING SYSTEM

Circulating system Circulating system circulates drilling fluid.circulates drilling fluid.

The drilling fluid is most commonly a suspension of The drilling fluid is most commonly a suspension of clay and other materials in water and is called clay and other materials in water and is called drilling muddrilling mud. Drilling mud removes cuttings from . Drilling mud removes cuttings from the hole and cools and lubricatethe hole and cools and lubricatess the drilling bit. the drilling bit.

The principal components of the circulating system The principal components of the circulating system includeinclude::– Mud pumpsMud pumps and and mud pitsmud pits– Mud-mixing equipmentMud-mixing equipment– Contaminant-removal equipmentContaminant-removal equipment

CIRCULATING SYSTEM

The drilling mud travels:The drilling mud travels:

SSteel tanksteel tanks

MMud pumpud pump

DDrillrill stringstring

BBitit

AAnnular space btw drillnnular space btw drill string string & & hole to thehole to the surface surface

CContaminant-removalontaminant-removal e equiquip.p.

BBack to the suction tank.ack to the suction tank.

CIRCULATING SYSTEM

The mud pumpThe mud pump takes in mud from the mud pits and takes in mud from the mud pits and sends it out a discharge line to a standpipe. sends it out a discharge line to a standpipe.

TheThe standpipestandpipe is a steel pipe mounted vertically on one is a steel pipe mounted vertically on one leg of the mast or derrick.leg of the mast or derrick.

The mud is pumped up the standpipe and into a The mud is pumped up the standpipe and into a

flexible, very strong, reinforced rubber hose called flexible, very strong, reinforced rubber hose called thethe rotary hoserotary hose or or kelly hosekelly hose. The rotary hose is connected . The rotary hose is connected to the swivel. to the swivel.

The mud enters the The mud enters the swivelswivel, goes down , goes down the kellythe kelly, , drill pipedrill pipe and and drill collarsdrill collars and and the bitthe bit. It then . It then does a sharp U-turn and heads back up the hole does a sharp U-turn and heads back up the hole in the annulus. in the annulus.

CIRCULATING SYSTEM

Finally the mud leaves the hole through a steel pipe Finally the mud leaves the hole through a steel pipe called called the mud return linethe mud return line and falls over a vibrating, and falls over a vibrating, screen like device called screen like device called the shale shakerthe shale shaker. .

Agitators Agitators installed on the mud pits help maintain a installed on the mud pits help maintain a uniform mixture of liquids and solids in the mud. uniform mixture of liquids and solids in the mud.

If any fine silt or sand is being drilled, then devices If any fine silt or sand is being drilled, then devices called called desiltersdesilters or or desandersdesanders may be added. may be added.

If there areIf there are small amounts of gas small amounts of gas in the in the formation, formation, a device called a device called degasserdegasser is also is also addedadded. .

CIRCULATING SYSTEM

DRILLINGDRILLING IS A COMPLEX IS A COMPLEX OPERATIONOPERATION THAT INCLUDES THAT INCLUDES

MANY DIFFERENT MANY DIFFERENT PROCESSES, PROCESSES, TECHNOLOGIES AND DISCIPLINES. TECHNOLOGIES AND DISCIPLINES.

THANKS FOR LISTENING.