Training Report on Drilling of Petroleum Oil Hydrocarbons

Performed at ONGC, Rajahmundry (Andhra Pradesh)

(In partial fulfillment of academic requirements

for the course of Industrial Training)

Prepared by
Akshay Chauhan
Narottam Tomar
Piyush Pathak
Dhirendra Singh

June 2018

GRAPHIC ERA UNIVERSITY

Dehradun, Uttarakhand - 248001
Abstract

The dissertation highlights the fundamentals of the drilling operations involved

in extraction of petroleum hydrocarbons as carried out by the Drilling
department of ONGC, RAJAHMUNDRY. It is loosely an overview of rotary drilling
operations and the associated tasks. The different elements of the drill-string
and other important drilling tools, which are actively maintained within the
department premises, have been introduced as observed during the
programme. The Rig-Building section of the Drilling department maintain the
different types of rigs which, as per work order,are used to make the
accomplishments of creating oil wells and work-over any interruption in the
production of crude-oil, natural gas and other by-products. The different
components of drilling rig, being extremely bulky, are transported in parts and
assembled at the site, while a work-over rig is smaller and may be truck-
mounted consisting of all the systems except the circulating system and auxiliary
system which must be separately arranged. Drilling operations possess
tremendous risk. Hence, safety of the working crew must be sincerely taken care
of at all costs.
Acknowledgements

We extend our sincere thanks to TKM. LAKSHMI , CM(HR) -STI, for considering
the interest of ONGC RAJHAMUNDRY (Andhra pradesh). Our thanks also goes to
the Administration of Drilling Department especially Mr. TUSHAR KUMAR
Executive Engineer for his due consideration in all regards. We are indebted to
Mr.Mohan E(D) and Mr. Sushil kumar EE(D) for their immense encouragement
and guidance throughout the programme.
A special thanks to Mr. SHRIHARI for helping us with his time and knowledge in
acknowledging all queries regarding drilling and production.
We would also like to express our gratitude to a few other people who took their
time in making us familiar to the different aspects of drilling and drilling
equipments.
We are indebted to the Course Coordinator Mr. Anand sahu and Dr. Virendra
bahdur singh (HOD) Petroleum department graphic era university for their
valuable consent and support throughout the programme.
1.0 Oil And Natural Gas Corporation

1.1 Company profile

ONGC is the largest crude oil and natural gas Company in India, contributing around 70 per cent to
Indian domestic production. Crude oil is the raw material used by downstream companies like IOC,
BPCL, and HPCL to produce petroleum products like Petrol, Diesel, Kerosene, Naphtha, and Cooking
Gas-LPG.

This largest natural gas company ranks 11th among global energy majors (Platts). It is the only public
sector Indian company to feature in Fortune’s ‘Most Admired Energy Companies’ list. ONGC ranks 18th
in ‘Oil and Gas operations’ and 183rd overall in Forbes Global 2000. Acclaimed for its Corporate
Governance practices, Transparency International has ranked ONGC 26th among the biggest publicly
traded global giants. It is most valued and largest E&P Company in the world, and one of the highest
profit-making and dividend-paying enterprise.

ONGC has a unique distinction of being a company with in-house service capabilities in all areas of
Exploration and Production of oil & gas and related oil-field services. Winner of the Best Employer
award, this public sector enterprise has a dedicated team of over 33,500 professionals who toil round
the clock in challenging locations.

1.2 Current Status

ONGC supplies crude oil, natural gas, and value-added products to

major Indian oil and gas refining and marketing companies. Its primary
products crude oil and natural gas are for the Indian market.
Product-wise revenue breakup for FY 2016–17 (₹ billion)

Product Revenue

Crude oil 562.38

Gas 168.88

LPG 31.48

Naptha 76.80

C2-C3 13.44

SKO 3.69

Others 1.59

Adjustments – 32.74

Total 825.52
 1.3 Awards And Recognisation

 ONGC is the top Employer in the Energy sector in India, in

the Randstad Awards 2013.

 ONGC was one of 12 winners of the 'Golden Peacock Award 2014' for
its corporate social responsibility practices and one of 24 winners of the
'Golden Peacock Award 2013' in the occupational safety and health category

 In April 2013, it was ranked at 155th place in the Forbes Global 2000 for 2012.

 In 2011, ONGC was ranked 39th among the world's 105 largest listed
companies in 'transparency in corporate reporting' by Transparency
International making it the most transparent company in India.
 It was conferred with 'Maharatna' status by the Government of India in
November 2010. The Maharatna status to select PSUs allows more freedom in
decision making.

 In February 2014, FICCI conferred it with Best Company Promoting Sports

Award.

 ONGC wins the "Greentech Excellence Award" for the year 2013 in Platinum
Category
 ONGC was ranked 82nd among India's most trusted brands according to the
Brand Trust Report 2012, a study conducted by Trust Research Advisory. In the
Brand Trust Report 2013, ONGC was ranked 191st among India's most trusted
brands and subsequently, according to the Brand Trust Report 2014, ONGC
was ranked 370th among India's most trusted brands.

 The country's favourite newspaper Amar Ujala and oil and natural gas
company ONGC have rewarded the country's giant companies. ONGC is the
title sponsor for the first edition of the Corporate social responsibility(CSR)
Award organised by Amar Ujala.
2.0Drilling

2.1 Drilling history

In India there used to be a method of boring wells withordinary crow bars. A log
2.4 to 3 metre in length and 15 to 20 cm in diameter is taken, and a hole 10 to
12.5 cm in diameter is drilled in the centre of entire length of the log. This hollow
log of wood is used as a guide pipe for the bore. The remaining depth of bore is
kept unlined. If the bore hole tends to cave in, another similar drilled log of wood
is lowered in continuation of the first one which serves to line the bore further
down. The crow bar called ‘sang’ is lowered with an ordinary rope and is worked
up and down the bore. It is found that this old ‘sang’ method 10 cm diameter
bore holes can very rapidly be drilled to about 30 metre below ground level. As
more and more deeper wells began to be drilled, efforts were made to improve
the drilling equipment. Steam engines began to be used, walking beams
replaced the spring pole, steel cables replace the manila ropes and other
improvements followed.

2.2 Drilling characteristics

The study of geological structure is of great importance in prospecting. Folded

structures in the shape of domes, anticlines favour the formation of oil, gases,
rock salt and sulphur. In rock drilling, tectonic features also assume special
significance. Each of the many types of igneous, sedimentary and metamorphic
rocks has its own particular drilling characteristics produced by its mineral
composition and grain size. A coarse grained structure is easier to drill and
causes less wear than a fine grained structure. Well depth measurements are of
necessity made along the course of the well which is not always in a vertical
direction. Such measurements are commonly used in geologic studies as
representing the vertical depth of various given points below the surface. In
either a crooked hole or a deflected hole, failure to consider deviation from the
vertical may result in misinterpretation regarding the geologic structure and
improper correlation between adjacent wells.
2.3 Drilling operations

Drilling operations as they are performed today can be divided into three broad
types. Exploration drilling in the traditional sense is primarily concerned with the
quest for quality and quantity data of a geological deposit. A second type of
drilling operation deals with geotechnical data of a deposit or a construction
site. The driller assists here by delivering core samples that identify the
performance and behavior aspects of geological body, rather than its genetic
aspects. A third type of drilling for geotechnical data has been termed here
‘special purpose’ drilling. It is suggested that far too little drilling is done for the
safe emplacement of foundationsfor industrial buildings, as well as for private
dwellings.

2.4 Drilling targets

The geological setting of an area to be explored usually determines the type of

drilling targets. The selection and definition of such targets are now often aided
by various geophysical investigations. It is an integral part of exploration
programmes. Geophysical investigations will bring almost a more exact
definition of drilling targets and could also reduce the number of “special
purpose” holes. Drilling targets should also encompass the structural and
lithological setting of area drilled. The discovery of igneous bodies, faults,
washouts, palaeo-channels and shear zones for example in the underground
operation lead too often to expensive geological ‘surprises’ which can be
avoided by defining the target better and weighed in its geological context.

2.5 Rotary Drilling system

The conventional rotary drilling method is becoming most effective and widely
practiced procedure from all available drilling systems, having been introduce
by the mining industries and later adopted by the petroleum industry as the
standard drilling system. The distinguishing characteristic of drilling by the
conventional rotary method may be generally described as the process of
forcing drilling fluid, by means of a suitable pump, down through the inside of
the drill pipe and out through the bit openings. The drilling fluid being under
pressure from above, flows back to the surface by way of the annulus formed
between the outside of the drill pipe and hole wall or casing. With the bit at the
bottom, the drill stem is rotated.

Drilling fluid: The drilling fluid is important to the success of the drilling, logging,
testing and completion of a well. Mud properties affect the drilling rate in
clearance of cuttings and applying pressure to the rock. Mud must be specially
treated to prevent hole enlargements from washouts and caving, or from
dissolving soluble salts. Mud cools the bit and lubricates the drill string. Drilling
is faster and bit life longer with gaseous as compared to liquid drilling fluids. But
the use of gas is limited by the problem of controlling the influx of formation
fluids. Various types of organic or inorganic materials can be added to a high
yield bentonite that cause changes to occur within the mud system. The term
mud is applied to a suspension of solids in liquids and water. Oil-based drilling
fluids may contain oil-soluble substances, emulsified water, and oil insoluble
materials in suspension.

Reverse Circulation Rotary Drilling: Reverse circulation rotary drilling is done

with a flow of drilling fluid reversed as compared with the system used in the
conventional rotary method. The suction end of the rig pump – rather than the
discharge end – is connected through the swivel to the Kelly and the drill pipe.
The drilling fluid and its load of cuttings move upward inside the drillpipe and
are discharged by the pump in to the settling pit. The fluid returns to the bore
hole by gravity flow. It moves down the annular space around the drill pipe to
the bottom of the hole, picks up cuttings and re-enters the drill pipe through
ports in the drill bit.
2.6 Drilling mechanism

An oil well is a general term for any boring through the earth’s surface that is
designed to find and acquire petroleum oil hydrocarbons. The creation and life
of a well can be divided into five segments :
a. Planning
b. Drilling
c. Completion
d. Production
e. Abandonment
The drilling operation may be carried out in stages of three, four or five. Based
on target depth (determined by seismic survey), the type of drilling is carried
out. Average depth of oil well is 3700 m achieved usually by 3-stage drilling. 4-
stage or 5-stage drilling is applied for greater target depths (higher than 5000
m). The oil drilling is based on the difference of hydrostatic pressure between
the pressure of the drilling fluid (mud) and the formation pressure. The applied
fluid pressure is calculated to be higher than the formation pressure during
drilling. After each stage of drilling a casing (each smaller in diameter than the
previous stage) is inserted into the hole and the annular is cemented. Cementing
serves the following two purposes:
i. To fill the annular and block communication between the external bore hole
and the inside of the casing.
ii. To hold the casing in place
The generated rock “cuttings” are swept up by the drilling fluid as it circulates
back to surface outside the drill pipe. The fluid then goes through ‘shale shaker’,
‘de-sander’ and ‘de-silter’ which strain the cuttings from the good fluid before it
returning to the pit. Watching for abnormalities in the returning cuttings and
monitoring pit volume or rate of returning fluid are imperative to catch ‘kicks’
early. A ‘kick’ is when the formation pressure at the depth of the bit is more than
the hydrostatic head of the mud above, which if not controlled temporarily by
closing the ‘blowout preventer’ and ultimately increasing the density of the
drilling fluid would allow formation fluids and mud to come up through the drill
pipe uncontrollably. The pipe or ‘drill string’ to which the bit is attached is
gradually lengthened as the well gets deeper by screwing more sections (only
drill-pipes after a certain depth is reached) under the ‘kelly’ or top-drive at the
surface. The process is called making a connection.
This process is all facilitated by a drilling rig which contains all necessary
equipment to circulate the drilling fluid, hoist and turn the pipe. Control
downhole, remove cuttings from the drilling fluid, and generate on-site power
for these operations. After drilling and casing the well, it must be ‘complete’.
Completion is the process in which the well is enabled to produce oil or gas. The
production stage is the most important stage of a well’s life, when the oil and
gas are produced. By this time , the oil rigs and workover rigs used to drill and
complete the well have moved off the wellbore, and the top is usually outfitted
with a collection of valves called a ‘X-mas tree’. These valves regulate pressures,
control flows, and allow access to the wellbore in case further completion work
is needed. Workovers are often necessary in older wells, which may need
smaller diameter tubing, scale or paraffin removal, acid matrix jobs, or
completing new zones of interest in a shallower reservoir.

2.7 Drilling equipments (courtesy Equipment Section)

A. Handling tools
1. Elevators
a. Drill pipe (5”)
b. Drill collar (6.5”, 8”, 9.5”)
c. Tubing elevator (2 7/8 “)
2. Hand sleeve
a. Drill pipe
b. Drill collar
c. Tubing
d. Casing
3. Pipe wrench
4. Chain tongs
5. Drill collar safety clamp
6. 5 lbs hammer

B. Spudding materials
1. Kelly bushing & Wrench (1.5”)
2. Bushing lifter
3. Change shaft
4. Hook bari
5. Bit breaker
C. Casing gears
1. Heavy duty spider slip and elevator
2. Side door elevator
3. Single joint elevator
4. Casing hand sleeve
5. Base plate
6. Bell guide
7. Circulating head
8. Casing bushing with split bowl
D. Materials for casing line reeving
1. Dead end wrench
2. Dead end studs
3. Wire line grip
4. Brass plate
5. Cover plate
6. Dead-end safety clamp
E. Well head equipment
1. Casing head housing
2. Adapter spool
3. Drilling spool
2.0 Oil And Gas Processing

In oil and gas processing we separate oil from water and gas. Oil and gas wells
produce a mixture of hydrocarbon gas, condensate or oil; water with dissolved
minerals, usually including a large amount of salt; other gases, including
nitrogen, carbon dioxide (CO2), and possibly hydrogen sulfide (H2S); and solids,
including sand from the reservoir, dirt, scale, and corrosion products from the
tubing. The purpose of oil and gas processing is to separate, remove, or
transform these various components to make the hydrocarbons ready for sale.

For the hydrocarbons(gas or liquid) to be sold, they must be:

 separated from the water and solids

 measured
 sold
 transported by pipeline, truck, rail, or ocean tanker to the user

3.1Types of Oil And Gas Separator

(i) Based upon shape and orientation

(A) Horizontal separator

(B) Vertical separator

(ii) Based upon phase separation

(A) 2 phase separator

(B) 3 phase separator
Horizontal separator

Vertical separator
3.2 Types of valve used in Gas Processing

1 Gate valve
A gate valve, also known as a sluice valve, is a valve which opens by lifting a
round or rectangular out of the path of the fluid.

2 Plug valve
Plug valves are valves with cylindrical or conically tapered "plugs" which can be
rotated inside the valve body to control flow through the valve.

3 Ball valve
A one-way valve that is opened and closed by pressure on a ball which fits into
a cup-shaped opening.

4 Globe valve
Globe valves are named for their spherical body shape with the two halves of
the body being separated by an internal baffle.

5 Needle valve
An instrument needle valve uses a tapered pin to gradually open a space for fine
control of flow.

6 Butterfly valve
A valve consisting of a rotating circular plate or a pair of hinged semi-circular
plates, attached to a transverse spindle and mounted inside a pipe in order to
regulate or prevent flow.

3.3 Types of Storage Tanks Used In Oi and gas Processing

(i) Based on roof

(A) Fixed roof tanks
(B) Floating roof tanks

(ii) Based on shape

(A) Cylindrical horizontal tank
(B) Cylindrical vertical tank
(C) Spherical tank
3.0 Artificial lift
Artificial lift is a method used to lower the producing bottomhole pressure (BHP)
on the formation to obtain a higher production rate from the well. This can be
done with a positive-displacement downhole pump, such as a beam pump or
a progressive cavity pump (PCP), to lower the flowing pressure at the pump
intake. It also can be done with a downhole centrifugal pump, which could be a
part of an electrical submersible pump (ESP) system. A lower bottom hole
flowing pressure and higher flow rate can be achieved with gas lift in which the
density of the fluid in the tubing is lowered and expanding gas helps to lift the
fluids. Artificial lift can be used to generate flow from a well in which no flow is
occurring or used to increase the flow from a well to produce at a higher rate.
Most oil wells require artificial lift at some point in the life of the field, and many
gas wells benefit from artificial lift to take liquids off the formation so gas can
flow at a higher rate.

4.1Types Of Artificial lift

1 SRP(SUCKER ROD PUMP)

Beam pumping, or the sucker-rod lift method, is the oldest and most widely used
type of artificial lift for most wells. A sucker-rod pumping system is made up of
several components, some of which operate aboveground and other parts of
which operate underground, down in the well. The surface-pumping unit, which
drives the underground pump, consists of a prime mover (usually an electric
motor) and, normally, a beam fixed to a pivotal post. The post is called a
Sampson post, and the beam is normally called a walking beam.
2 PROGRESSIVE CAVITY PUMP
Progressing cavity pumping (PCP) systems derive their name from the unique,
positive displacement pump that evolved from the helical gear pump concept
first developed by Rene Moineau in the late 1920s. Although these pumps are
now most commonly referred to as progressing cavity (PC) pumps, they also are
called screw pumps or Moineau pumps. They are increasingly used for artificial
lift, and have been adapted to a range of challenging lift situations (e.g., heavy
oil, high sand production, gassy wells, directional or horizontal wells).

3 ELECTRIC SUBMERSIBLE PUMP

The electrical submersible pump, typically called an ESP, is an efficient and
reliable artificial-lift method for lifting moderate to high volumes of fluids from
wellbores. These volumes range from a low of 150 B/D to as much as 150,000
B/D (24 to 24,600 m3/d). Variable-speed controllers can extend this range
significantly, both on the high and low side.
4 GAS LIFT
Gas lift is a method of artificial lift that uses an external source of high-pressure
gas for supplementing formation gas to lift the well fluids. The principle of gas
lift is that gas injected into the tubing reduces the density of the fluids in the
tubing, and the bubbles have a “scrubbing” action on the liquids. Both factors
act to lower the flowing bottom hole pressure (BHP) at the bottom of the tubing.
There are two basic types of gas lift in use today—continuous and intermittent
flow.
4.0 SICK WELL

A well is known to be sick well when it has low oil and gas production or min oil
production.

5.1Factors Leading Sick well

 Depletion of reservoir
 Water loading
 Sanding
 Thieve zone
 High GOR
 Tubing choke

5.0 WELL CONTROL

Well control is the technique used in oil and gas operations such
as drilling, well work over, and well completions for maintaining the fluid
column hydrostatic pressure and formation pressure to prevent influx of
formation fluids into the wellbore. This technique involves the estimation
of formation fluid pressures, the strength of the subsurface formations and
the use of casing and mud density to offset those pressures in a
predictable fashion.[1]Understanding of pressure and pressure
relationships are very important in well control.

5.1Fluid Pressure
Fluid is any substance that flows; e.g. oil, water, gas, and ice are all examples of
fluids. Under extreme pressure and temperature almost anything will
become fluid. Fluid exerts pressure and this pressure is as a result of the density
and the height of the fluid column. Most oil companies usually represent density
measurement in pounds per gallon (ppg) or kilograms per cubic meter (kg/m3)
and pressure measurement in pounds per square inch (psi) or bar or pascal (Pa).
Pressure increases as the density of the fluid increases. To find out the amount
of pressure a fluid of a known density exerts for each unit of length, the pressure
gradient is used. A pressure gradient is defined as the pressure increase per unit
of the depth due to its density and it is usually measured in pounds per square
inch per foot or bars per meter.It is expressed mathematically as;
pressure gradient = fluid density × conversion factor.
 5.2 Hydrostatic Pressure
Hydro means water, or fluid, that exerts pressure and static means not moving
or at rest. Therefore, hydrostatic pressure is the total fluid pressure created by
the weight of a column of fluid, acting on any given point in a well. In oil and gas
operations, it is represented mathematically as; Hydrostatic pressure = pressure
gradient × true vertical depth or Hydrostatic pressure = fluid density × conversion
factor × true vertical depth .

5.3 Formation Pressure

Formation pressure is the pressure of the fluid within the pore spaces of the
formation rock. This pressure can be affected by the weight of the overburden
(rock layers) above the formation, which exerts pressure on both the grains and
pore fluids. Grains are solid or rock material, and pores are spaces between
grains.

5.4 Bottom Hole Pressure

Bottom hole pressure is used to represent the sum of all the pressures being
exerted at the bottom of the hole. Pressure is imposed on the walls of the hole.

5.5 KICK
Kick is defined as an undesirable influx of formation fluid into the wellbore . If
left unchecked, a kick can develop into blowout (an uncontrolled influx of
formation fluid in to the wellbore).The result of failing to control a kick leads to
loss operation time, loss of well and quite possibly, the loss of the rig and lives
of personnel.

Causes of kick
Once the hydrostatic pressure is less than the formation pore pressure,
formation fluid can flow into the well. This can happen when one or a
combination of the following occurs;
 Improper hole fill up
 Insufficient Mud density
 Swabbing/Surging
 Lost circulation
 Abnormal formation pressure
 Gas cut mud
6.0 VISITING SITES
1 RIG (E-760M)
 This rig is located in mandapeta near rajhamundry.
 This rig has a dc motor of 1000 hp.
 Target depth - 3120m.
 Drilling operation is carrying out there.
 At present the well is drilled up to approx 960m.
2 RIG (E2000-1)
 This rig is also located in mandapeta near rajhamundry.
 This rig has a dc motor of 2000 hp.
 Pulling operation is carrying out there.
 Drilled depth of the well is 3576m.
3Production site
It is joint venture between ONGC and B. G. SHRIKE Oil India Ltd.
In this production zone three phase vertical separator is used.
This separator is designed by Mr. Gajula ShriHari DGM(production) – Head
RCMT.
Well is drilled for production in 2013.
Target depth - 3200m
Separator capacity -3 LCMP
Temprature-125degree celcius.
Porosity – 12 to 50
Condensate casing - 4089m
Intermediate casing- 2398m
Linear casing- 2796m to 3197m

REFRENCES
1. www.google.com
2. www.petrowiki.org