petroleum drilling engineering-i

Introduction of Drilling Engineering

Petroleum Drilling Engineering-I


What is Drilling Engineering?

Drilling engineering is a branch of knowledge where the design, analysis, and implement procedure are completed to drill a well as sustainably as possible.

Drilling engineering, in a word, it is the technology used to utilize crude oil and natural gas reserves.


Why Drilling Engineering is important?

The present modern civilization is based on energy and hydrocarbon resources. Inother words, the petroleum industry drives the energy sector, which in turn drives themodern civilization.

To keep serving the whole civilization, drilling engineering has a significant role in thisissue. Moreover, the world’s energy sector is dependent on the drilling engineering.

To the best of our knowledge, right now, there is no alternative technology availableto extract hydrocarbon without drilling a hole.

Therefore, for the survival of our existence, we need to know and keep updating ourknow ledge, especially on the technology, of drilling engineering.

Imp

ort

ance


Role of drilling and drilling engineer during field development

Managing rig side people (i.e., management job)


Drilling rig organizational chart

Drilling methods


Drilling methods

Cable Tool Drilling

Rotary Drilling


Cable Drilling method




The cable tool (also called churn or percussion)drilling method was used for drilling the first oilwell in USA to depth of 65 ft in 1859.

This was the historic Drake well located nearTitusville, Pennsylvania. It is credited with havingstarted the American Petroleum Industry.

However, it is believed that this drilling method hasbeen employed first by the early Chinese in thedrilling of brine wells.



Chinese drilling (Matthias Reich lectures „orignally from Arnold Werner“ [Flachbohrtechnik])



„Colonal“ Drake, oil field in Titusville (Matthias Reich lectures)


Cable Drilling method In this method, drilling is accomplished by the pounding action of a steel bit which is

alternately raised by a steel cable and allowed to fall, delivering sharp, successive blowsto the bottom of the hole. This principle is the same as that employed in drillingthrough concrete (air hammer), or (driving a nail through a board).

A conventional cable tool rig

Cable Drilling method: Some equipments and basic techniques

The drill string

Rig lines

Surface equipment

Portable cable tool rigs



The drill string


Typical cable tool bits. Courtesy Span and Company (A) Straight regular pattern, (B) Twisted Mother Hubbard pattern.

The drill stem:A cylindrical steel bar generally 10 to 20 feetlong is screwed directly above the bit. Itsdiameter depends on the hole size and theamount of weight desired. The purpose of thismember is to furnish additional weight for thedownward drilling blow.

The drill bit:A heavy steel bar, generally four to eight feetlong, having the lower or drilling end dressed tovarying degrees of sharpness depending on theformation to be drilled.


The drill string


Typical cable tool bits. Courtesy Span and Company (A) Straight regular pattern, (B) Twisted Mother Hubbard pattern.

Tool joints:Connectors for the bit, drill stem, etc. Theseconsist of tapered, coarse threaded connectorsmachined on the ends of the tools. The threaddesign allows easy makeup, and the necessarytightness is obtained from the metal to metal fitat the flat shoulders of the joint.

Jars:Heavy steel links which telescope within eachother much like two links in a chain. Theirfunction is to produce a sharp upward blow onthe tools, causing them to be jerked loose fromsoft, sticky formations, and allowing a clean,sharp drilling blow.



Sand lines:

Drilling lines:

Calf lines:

Illustration of right and left, regular and lang lay. Courtesy API.

Rig lines: 3 lines or cables for various purposes




Drilling lines:The cable tool drilling line is spooled on the bullwheel, passed over a sheave at the top of thederrick, and suspended from the walking beamby the screw where the driller pays it out asdrilling progresses.

This line is subjected to extremely severeservice. It must not only support the tools plusits own weight, but is also subjected to thejarring, fluctuating loads of drilling as well assevere abrasion against the casing and hole wall.





Sand lines:The spooled on the sand reel, passed over asheave at the top of the derrick, and is normallyattached to a bailer which stands vertically toone side of the derrick floor while drilling isunderway.

Periodically, the drill string must be removedfrom the hole and the bailer run to removeaccumulated fluid and cuttings.

The loads and service requirements on the sandline are very light compared to the drilling line.





Calf lines:The calf line is spooled on the calf wheel and isused to run a casing into the well.

It may be subjected to the greatest loads of anyrig line.

However, this loading is not as severe as thedrilling service and may be more accuratelypredicted. Illustration of right and left, regular and

lang lay. Courtesy API.

Cable Drilling method: Relative merits of cable tool drilling


The lower initial equipment cost, hencelower depreciation

The lower daily operating expense (lowerfuel and maintenance costs, fewerpersonnel, lower water requirement).

Lower transportation costs.

Lower rig-up time and expense.

Drilling rates comparable to those ofrotary in hard, shallow areas.

Some advantages

The limitations on drilling rate and depth.

Other disadvantages stemming largelyfrom the absence of a drilling fluid are:

- Lack of automatic control over highpressures which may beencountered, consequently blowout, hazards to personnel andequipment.

- Lack of control over unconsolidatedand caving formations.

Some disadvantages

Cable Drilling method: Relative merits of cable tool drilling


The lower initial equipment cost, hencelower depreciation

The lower daily operating expense (lowerfuel and maintenance costs, fewerpersonnel, lower water requirement).

Lower transportation costs.

Lower rig-up time and expense.

Drilling rates comparable to those ofrotary in hard, shallow areas.

Some advantages

The limitations on drilling rate and depth.

Other disadvantages stemming largelyfrom the absence of a drilling fluid are:

- Lack of automatic control over highpressures which may beencountered, consequently blowout, hazards to personnel andequipment.

- Lack of control over unconsolidatedand caving formations.

Some disadvantages

It should be pointed out that many of the advantagesand disadvantages of this method are due to eitherthe absence or presence of a drilling fluid.

Rotary drilling



First practiced by a French civil engineer, in 1863.

U.S. patents on rotary equipment were issued as early as 1866.

The early application was for water well drilling.

A discovery well was drilled using rotary tools in Texas, 1901. This spectaculardiscovery is credited with initiating the widespread use of the rotary method.R

ota

ry d

rilli

ng

Rotary drilling

Petroleum Drilling Engineering-IR

ota

ry d

rilli

ng

Rotary drilling

A conventional rotary drilling rig (left) an onshore rotary rig, (right) an offshore rotary rig.

Th

eb

asi

cco

mp

on

en

tso

fa

rota

ryd

rill

ing

rig


Rotary drilling

Th

eb

asi

cco

mp

on

en

tso

fa

rota

ryd

rill

ing

rig


Rotary drilling: Class activity

Mud pumps

The drill string

Drawworks

Derricks, masts,

and substructures

Drilling line

Bits

Auxiliary equipment

Prime movers


Rotary drilling: The basic components1

-De

rric

ks,

ma

sts,

an

dsu

bst

ruct

ure

s

The function of a derrick is to provide thevertical clearance necessary to raising andlowering of the drill string into and out ofthe hole during the drilling operations. Itmust be of sufficient height and strengthto perform these duties in a safe andexpedient manner.


Rotary drilling: The basic componentsC

ho

ice

of

De

rric

k:Ty

pe

an

dsi

zeThe size of derrick for a specific application will normally depend on:

1- Maximum compressive load anticipated (normally thecasing load).

2- Maximum wind velocities expected in area of use.

3- Derrick height will normally be governed by tripfrequency and the relative saving from pulling fourblesversus triples versus doubles, etc.



-Dra

ww

ork

s (H

ois

ts)

The functions of the drawworks are:

1- Control center for operating the rig.

2- Houses the drum which spools the drilling line duringhoisting operations and allows feed-off during drilling.



-Mu

d p

um

ps

(re

cip

roca

tin

g p

isto

n)

The functions of the mud or slush pumps are:

1- Circulate the drilling fluid at the desired pressure andvolume.

The term „double-acting“ denotes that each side of thepiston does work.

Duplex pump (2 pistons)

Triplex pump (3 pistons)

3-M

ud

pu

mp

s(r

eci

pro

cati

ng

pis

ton

)Proper pump selection and utilization is extremely important tothe over-all efficiency of a drilling operation. The circulationrequirements in the area of use should be carefully analyzedbefore the final selection is made.


Rotary drilling: The basic components

4-

Pri

me

Mo

vers

Drilling services that must be performed, the bulk of rig power isconsumed mainly by two operations:



Circulation of drilling fluid + rotary table

Hoisting

Power consumption is essentially constant over

reasonable time

It is not the case with hoisting

5-

Th

e d

rill

str

ing



The drill string is:

An expensive rig component

Must be replaced periodically; consequently

Schematic diagram of drill string components and bit.

Most drill string failures are due to material fatigue which has been aggravated by corrosion and improper care and handling

Every care should be exercised to insure its long life

5-

Th

e d

rill

str

ing

(ke

lly

Join

t)



kelly Joint:

The topmost joint in the drill string

Commonly square, may be hexagonal

Primary function: Transmitting rotary table‘s rotation tothe entire drill string

5-

Th

e d

rill

str

ing

(Dri

ll

pip

e a

nd

to

ol j

oin

ts)



Drill pipe and tool joints:

Are hollow, seamless tubes manufactured from high gradesteel

Function: furnishes the necessary length for the drillstring

Function: serves as a conduit for the drilling fluid

5-

Th

e d

rill

str

ing

(D

rill

co

lla

rs)



Drill collars:

Are heavy walled, large O.D. steel tubes

Function: furnishes the compressive load on the bit

Function: allowing the lighter drill pipe to remain intension

6-

Ro

tary

bit

sPetroleum Drilling Engineering-I

Rotary drilling: The basic componentsDrill bits: Numerous individual rotary bit designs areavailable. All are designed to give optimum performance invarious formation types. However, there is no universalagreement on this subject. The bits are classified here into 3types:

1- Drag type

2- Rolling cutter (roller bits)

3- Diamond

6-

Ro

tary

bit

s

(D

rag

bit

s)



Drag bits: have no moving parts and drill by the shovellingaction of their blades on the encountered formation.

Rotary drilling bits. Courtesy Christensen Diamond Products, Hughes tool company, and reed roller bit company (A) Drag bit (Reed)

But, later they have been replaced largely by rolling cutterbits.

They were once widely used for drilling soft, stickyformation.

The water courses are placed such that the drilling fluid isdirected on blades, keeping them clean.

6-

Ro

tary

bit

s

(R

oll

ing

cutt

er

(bit

s))



Rolling cutter (roller bits): This bit allowed the rotary method tocompete with cable tools in hard formations which are undrillablewith drag bits.

For harder formation, bits have shorter, and more closelyspaced teeth.

For instance, for soft formation, three cone bits haverelatively long, and widely spaced teeth.

Tooth length, spacing, and pattern are balanced to obtainthe fastest penetration rate with a minimum of ballingbetween teeth.

Typical jet bit. Courtesy security Engineering divission, dresser industries.

6-

Ro

tary

bit

s

(R

oll

ing

cutt

er

(bit

s))



Rolling cutter (roller bits): Jet bits are rolling cutter bits whichhave been equipped with fluid nozzles.

However, the pressure losses through these nozzles areconsiderable and require extra pump capacity.

So, this allows each bit tooth to strike new formationrather than expend some of its energy in regrindingpreviously loosened chips.

Each nozzle directs a high velocity fluid jet directly on thehole bottom which rapidly removes the cuttings.

Diamond bit (Christensen)

6-

Ro

tary

bit

s

(D

iam

on

d b

its)



Diamond bits: drill by a scraping, drag-bit action of the stoneswhich protrude from a steel matrix.

They are normally used in hard formations.

Their use is justified in many areas where their long lifeand the consequent reduction in trip time affordssufficient advantage to offset the higher bit cost.

Typical strand constructions for oil field wire ropes. Courtesy API

7-

Dri

llin

g li

ne



Drilling line: The rotary drilling line affords a means of handlingthe loads suspended from the hook during all drilling operations.

Although, fishing operations frequently require line pullsin excess of the drill string weight.

The maximum load occurs when running casing.

8-

Mis

cell

an

eo

us

rig

eq

uip

me

nt



Rotary tables:

Function: Suspends the pipe weight during connectionsand trips.

Function: Transmits the rotation to the drill string byturning the Kelly joint.

8-

Mis

cell

an

eo

us

rig

eq

uip

me

nt



Travelling Block, Hook, and Swivel:

The swivel must suspend the drill string and allow rotationat the same time. Further, it affords drilling fluid passagefrom the mud hose into the drill string.

The travelling block is merely the travelling pulley (sheave)assembly which connects the drilling line to the hook andswivel.


- In the rotary method, the hole is drilled by a rotating bit to which adownward force is applied. The bit is fastened to, and rotated by, adrill string, composed of high quality drill pipe and drill collars, withnew sections or joints being added as drilling progresses.

Rotary drilling

- The cutting are lifted from the hole by the drilling fluid which iscontinuously circulated down inside the drill string through watercourses or nozzles in the bit, and upward in the annular spacebetween the drill pipe and the bore hole.

- At the surface, the returning fluid (mud) is diverted through a seriesof tanks or pits which afford a sufficient period to allow cuttingseparation and any necessary treating. In the last of these pits themud is picked up by the pump suction and repeats the cycle.


Rotary drillingThe process of adding a new joint of pipe to the drillstring(Making a connection)


Rotary drillingPeriodically the pipe must be removed from the hole in orderto replace the bit. The pipe is pulled in stands of four, three,two joints each for example depending on the derricks ormasts.

petroleum drilling engineering-i

Documents