Oil 101 - A Free Introduction to Oil and Gas
Introduction to Drilling
Today we’re going to talk about the Drilling function of Upstream. If you missed our previous podcasts on Upstream Fundamentals and Exploration, be sure to go check them out. We’ll put the relevant links in the program notes.
In this drilling overview we touch on the wildcat well and current drilling capabilities, offer more insight into the role of oilfield services, and give some historical perspective on this segment of upstream oil and gas.
Drilling Details
As we discussed in the Exploration podcast, the first step in adding value is to locating the oil and gas reservoirs that are often far below the surface, and in deeper offshore prospects.
Even with the latest seismic technology and computer modeling, many characteristics of a prospect remain unknown until an exploratory or “wildcat” well is drilled. Repeating from that podcast, “you can’t find oil if you don’t drill wells.”
Oil 101 - A Free Introduction to Oil and Gas
Introduction to Drilling
Today we’re going to talk about the Drilling function of Upstream. If you missed our previous podcasts on Upstream Fundamentals and Exploration, be sure to go check them out. We’ll put the relevant links in the program notes.
In this drilling overview we touch on the wildcat well and current drilling capabilities, offer more insight into the role of oilfield services, and give some historical perspective on this segment of upstream oil and gas.
Drilling Details
As we discussed in the Exploration podcast, the first step in adding value is to locating the oil and gas reservoirs that are often far below the surface, and in deeper offshore prospects.
Even with the latest seismic technology and computer modeling, many characteristics of a prospect remain unknown until an exploratory or “wildcat” well is drilled. Repeating from that podcast, “you can’t find oil if you don’t drill wells.”
Petroleum classification physical propertiesAshik R S
Petroleum classification physical properties.
Petroleum or crude oil
Naturally occurring & flammable liquid
Complex mixture of hydrocarbons & other organic compounds
Found in geologic formations beneath the Earth’s surface
The term ‘petroleum’ first used in the treatise De Natura Fossilium published in 1546- Georg Bauer (German mineralogist).
Derived from the Latin word petra oleum, meaning “stone oil”
Oil and gas provide about 60% of all the energy used by the society today
COAL BED METHANE (CBM); Coal Seam Gas (CSG), or Coal-mine Methane (CMM); What and why CBM?; How do we estimate the amount of methane gas which will come from a region underlain by coal? ; Benefits of CBM ; Coal seams as aquifers; CBM product water ; What is saline water and why is it considered saline?; What is sodic water and why is it considered sodic? ; Irrigation of crops with CBM water; Current management practices for disposal of CBM product water
What’s shale gas ?
Finding the sweet spot?
How is shale gas formed?
How to produce the shale gas ?
Why We Fracture Shale Gas Wells…!
Shale Gas; Shale Gas Revolution; Main Shale Gas Reservoir Characterization; produce the shale gas; Shale Gas Play; Roadmap to Shale Gas; EVALUATION SHALE GAS; Shale Gas Production Cost Curve
DRILLING: It is defined as art & science of making a hole in an object.
OIL & GAS WELL DRILLING: It is an art & science of drilling a hole in the earth crust down to a desired depth in search / extraction of natural gas or oil(petroleum)
Oil 101 - A Free Introduction to Oil and Gas
Introduction to Oil and Gas Exploration
This brief overview of exploration includes segments on exploration processes, some historical perspective including an explanation of hydrocarbons, and finally we’ll discuss the ‘basin-play concept’.
There are 4 key steps to summarize the oil and gas exploration process:
First is understanding and evaluating the geologic setting, called a play,
Next is obtaining access to the potential reserves usually in the form of a lease.
The third step is determining where to drill and completing a successful discovery or “wildcat” well.
Finally, additional hydrocarbon reserves can be added to the portfolio of an oil company using guidelines set by the Society of Petroleum Engineers (SPE) and the US Securities and Exchange Commission (SEC).
Oil and gas is composed of compressed hydrocarbons. It was formed millions of years ago in a process that began when plant and animal remains were covered by very deep layers of sediment – minute particles of rock and minerals. With time, extreme pressure and high temperatures, these particles became a mix of both solid (coal) and liquid hydrocarbons. Even diamonds are a form of hydrocarbons.
Early oil discoveries were traced from natural hydrocarbon seeps at the surface. Many major fields of California, Oklahoma, Mexico, Iran, Iraq and Indonesia were related to surface hydrocarbon seeps.
There are three primary techniques of EOR: gas injection, thermal injection, and chemical injection. Gas injection, which uses gases such as natural gas, nitrogen, or carbon dioxide (CO2), accounts for nearly 60 percent of EOR production in the United States. Thermal injection, which involves the introduction of heat, accounts for 40 percent of EOR production in the United States, with most of it occurring in California. Chemical injection, which can involve the use of long-chained molecules called polymers to increase the effectiveness of waterfloods, accounts for about one percent of EOR production in the United States. In 2013, a technique called Plasma-Pulse technology was introduced into the United States from Russia. This technique can result in another 50 percent of improvement in existing well production.
Petroleum classification physical propertiesAshik R S
Petroleum classification physical properties.
Petroleum or crude oil
Naturally occurring & flammable liquid
Complex mixture of hydrocarbons & other organic compounds
Found in geologic formations beneath the Earth’s surface
The term ‘petroleum’ first used in the treatise De Natura Fossilium published in 1546- Georg Bauer (German mineralogist).
Derived from the Latin word petra oleum, meaning “stone oil”
Oil and gas provide about 60% of all the energy used by the society today
COAL BED METHANE (CBM); Coal Seam Gas (CSG), or Coal-mine Methane (CMM); What and why CBM?; How do we estimate the amount of methane gas which will come from a region underlain by coal? ; Benefits of CBM ; Coal seams as aquifers; CBM product water ; What is saline water and why is it considered saline?; What is sodic water and why is it considered sodic? ; Irrigation of crops with CBM water; Current management practices for disposal of CBM product water
What’s shale gas ?
Finding the sweet spot?
How is shale gas formed?
How to produce the shale gas ?
Why We Fracture Shale Gas Wells…!
Shale Gas; Shale Gas Revolution; Main Shale Gas Reservoir Characterization; produce the shale gas; Shale Gas Play; Roadmap to Shale Gas; EVALUATION SHALE GAS; Shale Gas Production Cost Curve
DRILLING: It is defined as art & science of making a hole in an object.
OIL & GAS WELL DRILLING: It is an art & science of drilling a hole in the earth crust down to a desired depth in search / extraction of natural gas or oil(petroleum)
Oil 101 - A Free Introduction to Oil and Gas
Introduction to Oil and Gas Exploration
This brief overview of exploration includes segments on exploration processes, some historical perspective including an explanation of hydrocarbons, and finally we’ll discuss the ‘basin-play concept’.
There are 4 key steps to summarize the oil and gas exploration process:
First is understanding and evaluating the geologic setting, called a play,
Next is obtaining access to the potential reserves usually in the form of a lease.
The third step is determining where to drill and completing a successful discovery or “wildcat” well.
Finally, additional hydrocarbon reserves can be added to the portfolio of an oil company using guidelines set by the Society of Petroleum Engineers (SPE) and the US Securities and Exchange Commission (SEC).
Oil and gas is composed of compressed hydrocarbons. It was formed millions of years ago in a process that began when plant and animal remains were covered by very deep layers of sediment – minute particles of rock and minerals. With time, extreme pressure and high temperatures, these particles became a mix of both solid (coal) and liquid hydrocarbons. Even diamonds are a form of hydrocarbons.
Early oil discoveries were traced from natural hydrocarbon seeps at the surface. Many major fields of California, Oklahoma, Mexico, Iran, Iraq and Indonesia were related to surface hydrocarbon seeps.
There are three primary techniques of EOR: gas injection, thermal injection, and chemical injection. Gas injection, which uses gases such as natural gas, nitrogen, or carbon dioxide (CO2), accounts for nearly 60 percent of EOR production in the United States. Thermal injection, which involves the introduction of heat, accounts for 40 percent of EOR production in the United States, with most of it occurring in California. Chemical injection, which can involve the use of long-chained molecules called polymers to increase the effectiveness of waterfloods, accounts for about one percent of EOR production in the United States. In 2013, a technique called Plasma-Pulse technology was introduced into the United States from Russia. This technique can result in another 50 percent of improvement in existing well production.
أكثر من 663 مليون شخص حول العالم يعيشون بدون مياه نظيفة هذا يعني أن من بين كل 10 أشخاص هناك شخص واحد يفتقر إلى المياه الصالحة للشرب. والأغلبية يعيشون في المناطق الريفية البعيدة حيث يقضون ساعات طويلة كل يوم مشيًّا على الأقدام من أجل جلب المياه؛ الأمر الذي يجعل الكثير من الأطفال يتركون مدارسهم.. حتى الآباء والأمهات لا يملكون الوقت الكافي من أجل كسب الرزق، وبعد كل هذا المجهود يعودون للبيت بماء غير صحي يسبب الأمراض، وفي بعض الأحيان الموت. إن توفير المياه النظيفة يعني في الوقت نفسه: توفير التعليم، والدَّخل، والصحة، وخاصة للنساء والأطفال.
أعمال الانشاءات النفطية - Oil Structure WorksHussain Sbetan
أعمال الانشاءات النفطية وتشمل :-
أعمال أرضية
أعمال الخوازيق
أعمال بحرية
أعمال الخرسانة وحديد التسليح والشدات الخشبية
أعمال الهياكل المعدنية
أعمال اللحام والتصنيع
أعمال الرافعات
أعمال البناء
أعمال الأنابيب والقنوات والكوابل
أعمال حفر الأنفاق
أعمال متنوعة
أعمال المساحة
اعمال السلامة والبيئة
أعمال الادارة
أعمال ضمان الجودة
أعمال البرمجة ومراقبة العمليات
أعمال مرافق الموقع
أعمال المباشرة بالعمليات
Marco Sully Perez said Oil and gas workers face unique health and safety challenges and are recognized by the National Institute for Occupational Safety and Health (NIOSH) as a priority industry sector under the National Workplace Research Initiative (NORA) to identify and develop intervention strategies in the labor sector Protect. health and safety issues. In 2011, the oil and gas and ancillary industries employed more than 450,000 people (Quarterly Census of Employment and Wages). Therefore, oil well drilling and field maintenance are two different types of business activities in the oil and gas industry.
A brief summary of Oil and Gas Upstream. PPT includes basic Chemistry, Basic Geology, Oil formation, Migration of Petroleum, Reservoir, porosity, permeability, Geological structures for petroleum entrapment, Exploration methods, Geological methods, Geophysical methods, geophysical methods, seismic methods, seismic methods, gravity methods, magnetic methods, well drilling, preparation to drill, setting the rig, drilling, enhanced oil recovery, EOR, primary oil recovery, secondary oil recovery, thermal recovery, gas injection and chemical injection
Techshore Inspection Services, (An ISO 9001-2008 certified Organisation) since its inception in the year 2006, has been a leading engineering service provider, offers a wide range of innovative services, engineering solutions, and professional training in the field of Oil and Gas, Power and other major industries in the disciplines of Mechanical, Civil, Instrumentation and NDT(Concrete NDT/Mechanical).
Francesca Gottschalk - How can education support child empowerment.pptxEduSkills OECD
Francesca Gottschalk from the OECD’s Centre for Educational Research and Innovation presents at the Ask an Expert Webinar: How can education support child empowerment?
Macroeconomics- Movie Location
This will be used as part of your Personal Professional Portfolio once graded.
Objective:
Prepare a presentation or a paper using research, basic comparative analysis, data organization and application of economic information. You will make an informed assessment of an economic climate outside of the United States to accomplish an entertainment industry objective.
Palestine last event orientationfvgnh .pptxRaedMohamed3
An EFL lesson about the current events in Palestine. It is intended to be for intermediate students who wish to increase their listening skills through a short lesson in power point.
Read| The latest issue of The Challenger is here! We are thrilled to announce that our school paper has qualified for the NATIONAL SCHOOLS PRESS CONFERENCE (NSPC) 2024. Thank you for your unwavering support and trust. Dive into the stories that made us stand out!
The Roman Empire A Historical Colossus.pdfkaushalkr1407
The Roman Empire, a vast and enduring power, stands as one of history's most remarkable civilizations, leaving an indelible imprint on the world. It emerged from the Roman Republic, transitioning into an imperial powerhouse under the leadership of Augustus Caesar in 27 BCE. This transformation marked the beginning of an era defined by unprecedented territorial expansion, architectural marvels, and profound cultural influence.
The empire's roots lie in the city of Rome, founded, according to legend, by Romulus in 753 BCE. Over centuries, Rome evolved from a small settlement to a formidable republic, characterized by a complex political system with elected officials and checks on power. However, internal strife, class conflicts, and military ambitions paved the way for the end of the Republic. Julius Caesar’s dictatorship and subsequent assassination in 44 BCE created a power vacuum, leading to a civil war. Octavian, later Augustus, emerged victorious, heralding the Roman Empire’s birth.
Under Augustus, the empire experienced the Pax Romana, a 200-year period of relative peace and stability. Augustus reformed the military, established efficient administrative systems, and initiated grand construction projects. The empire's borders expanded, encompassing territories from Britain to Egypt and from Spain to the Euphrates. Roman legions, renowned for their discipline and engineering prowess, secured and maintained these vast territories, building roads, fortifications, and cities that facilitated control and integration.
The Roman Empire’s society was hierarchical, with a rigid class system. At the top were the patricians, wealthy elites who held significant political power. Below them were the plebeians, free citizens with limited political influence, and the vast numbers of slaves who formed the backbone of the economy. The family unit was central, governed by the paterfamilias, the male head who held absolute authority.
Culturally, the Romans were eclectic, absorbing and adapting elements from the civilizations they encountered, particularly the Greeks. Roman art, literature, and philosophy reflected this synthesis, creating a rich cultural tapestry. Latin, the Roman language, became the lingua franca of the Western world, influencing numerous modern languages.
Roman architecture and engineering achievements were monumental. They perfected the arch, vault, and dome, constructing enduring structures like the Colosseum, Pantheon, and aqueducts. These engineering marvels not only showcased Roman ingenuity but also served practical purposes, from public entertainment to water supply.
The French Revolution, which began in 1789, was a period of radical social and political upheaval in France. It marked the decline of absolute monarchies, the rise of secular and democratic republics, and the eventual rise of Napoleon Bonaparte. This revolutionary period is crucial in understanding the transition from feudalism to modernity in Europe.
For more information, visit-www.vavaclasses.com
Embracing GenAI - A Strategic ImperativePeter Windle
Artificial Intelligence (AI) technologies such as Generative AI, Image Generators and Large Language Models have had a dramatic impact on teaching, learning and assessment over the past 18 months. The most immediate threat AI posed was to Academic Integrity with Higher Education Institutes (HEIs) focusing their efforts on combating the use of GenAI in assessment. Guidelines were developed for staff and students, policies put in place too. Innovative educators have forged paths in the use of Generative AI for teaching, learning and assessments leading to pockets of transformation springing up across HEIs, often with little or no top-down guidance, support or direction.
This Gasta posits a strategic approach to integrating AI into HEIs to prepare staff, students and the curriculum for an evolving world and workplace. We will highlight the advantages of working with these technologies beyond the realm of teaching, learning and assessment by considering prompt engineering skills, industry impact, curriculum changes, and the need for staff upskilling. In contrast, not engaging strategically with Generative AI poses risks, including falling behind peers, missed opportunities and failing to ensure our graduates remain employable. The rapid evolution of AI technologies necessitates a proactive and strategic approach if we are to remain relevant.
Operation “Blue Star” is the only event in the history of Independent India where the state went into war with its own people. Even after about 40 years it is not clear if it was culmination of states anger over people of the region, a political game of power or start of dictatorial chapter in the democratic setup.
The people of Punjab felt alienated from main stream due to denial of their just demands during a long democratic struggle since independence. As it happen all over the word, it led to militant struggle with great loss of lives of military, police and civilian personnel. Killing of Indira Gandhi and massacre of innocent Sikhs in Delhi and other India cities was also associated with this movement.
1. OIL DRILLING
Central Polytechnic College, Trivandrum PAGE NO: 1
INTRODUCTION
In January 2001 alone, the United States produced an estimated 181
million barrels of crude oil and imported 273 million barrels from other
countries. This oil gets refined into gasoline, kerosene, heating oil and other
products. To keep up with our consumption, oil companies must constantly
look for new sources of petroleum, as well as improve the production of
existing wells.
How does a company go about finding oil and pumping it from the
ground? You may have seen images of black crude oil gushing out of the
ground, or seen an oil well in movies and television shows like "Giant,"
"Oklahoma Crude," "Armageddon" and "Beverly Hillbillies." But modern oil
production is quite different from the way it's portrayed in the movies. In this
article, we will examine how modern oil exploration and drilling works. We
will discuss how oil is formed, found and extracted from the ground.
OIL EXPLORATION
Oil is a fossil fuel that can be found in many countries around the world.
In this section, we will discuss how oil is formed and how geologists find it.
FORMING OIL
Oil is formed from the remains of tiny plants and animals (plankton) that
died in ancient seas between 10 million and 600 million years ago. After the
organisms died, they sank into the sand and mud at the bottom of the sea.
2. OIL DRILLING
Central Polytechnic College, Trivandrum PAGE NO: 2
Over the years, the organisms decayed in the sedimentary layers. In
these layers, there was little or no oxygen present. So microorganisms broke
the remains into carbon-rich compounds that formed organic layers. The
organic material mixed with the sediments, forming fine-grained shale, or
source rock. As new sedimentary layers were deposited, they exerted intense
pressure and heat on the source rock. The heat and pressure distilled the
organic material into crude oil and natural gas. The oil flowed from the source
rock and accumulated in thicker, more porous limestone or sandstone, called
reservoir rock. Movements in the Earth trapped the oil and natural gas in the
reservoir rocks between layers of impermeable rock, or cap rock, such as
granite or marble.
FINDING OIL
The task of finding oil is assigned to geologists, whether employed
directly by an oil company or under contract from a private firm. Their task is
to find the right conditions for an oil trap -- the right source rock, reservoir rock
and entrapment. Many years ago, geologists interpreted surface features,
surface rock and soil types, and perhaps some small core samples obtained by
shallow drilling. Modern oil geologists also examine surface rocks and terrain,
3. OIL DRILLING
Central Polytechnic College, Trivandrum PAGE NO: 3
with the additional help of satellite images. However, they also use a variety of
other methods to find oil. They can use sensitive gravity meters to measure tiny
changes in the Earth's gravitational field that could indicate flowing oil, as well
as sensitive magnetometers to measure tiny changes in the Earth's magnetic
field caused by flowing oil. They can detect the smell of hydrocarbons using
sensitive electronic noses called sniffers. Finally, and most commonly, they use
seismology, creating shock waves that pass through hidden rock layers and
interpreting the waves that are reflected back to the surface.
(1) (2) (3)
1) Can be trapped by folding.
2) Faulting.
3) Oinching out.
4. OIL DRILLING
Central Polytechnic College, Trivandrum PAGE NO: 4
Searching for oil mover water using seismology
The shock waves travel beneath the surface of the Earth and are reflected
back by the various rock layers. The reflections travel at different speeds
depending upon the type or density of rock layers through which they must
pass. The reflections of the shock waves are detected by sensitive microphones
or vibration detectors -- hydrophones over water, seismometers over land. The
readings are interpreted by seismologists for signs of oil and gas traps.
Although modern oil-exploration methods are better than previous ones,
they still may have only a 10-percent success rate for finding new oil fields.
Once a prospective oil strike is found, the location is marked by GPS
coordinates on land or by marker buoys on water.
5. OIL DRILLING
Central Polytechnic College, Trivandrum PAGE NO: 5
PREPARING TO DRILL
Once the site has been selected, it must be surveyed to determine its
boundaries, and environmental impact studies may be done. Lease agreements,
titles and right-of way accesses for the land must be obtained and evaluated
legally. For off-shore sites, legal jurisdiction must be determined.
Once the legal issues have been settled, the crew goes about preparing the land:
1. The land is cleared and leveled, and access roads may be built.
2. Because water is used in drilling, there must be a source of water
nearby. If there is no natural source, they drill a water well.
3. They dig a reserve pit, which is used to dispose of rock cuttings and
drilling mud during the drilling process, and line it with plastic to
protect the environment. If the site is an ecologically sensitive area, such
as a marsh or wilderness, then the cuttings and mud must be disposed
offsite -- trucked away instead of placed in a pit.
Once the land has been prepared, several holes must be dug to make way
for the rig and the main hole. A rectangular pit, called a cellar, is dug around
the location of the actual drilling hole. The cellar provides a workspace around
the hole, for the workers and drilling accessories. The crew then begins drilling
the main hole, often with a small drill truck rather than the main rig. The first
part of the hole is larger and shallower than the main portion, and is lined with
a large-diameter conductor pipe. Additional holes are dug off to the side to
6. OIL DRILLING
Central Polytechnic College, Trivandrum PAGE NO: 6
temporarily store equipment -- when these holes are finished, the rig equipment
can be brought in and set up.
SETTING UP THE RIG
Depending upon the remoteness of the drill site and its access,
equipment may be transported to the site by truck, helicopter or barge. Some
rigs are built on ships or barges for work on inland water where there is no
foundation to support a rig (as in marshes or lakes). Once the equipment is at
the site, the rig is set up. Here are the major systems of a land oil rig:
Anatomy of an oil rig
7. OIL DRILLING
Central Polytechnic College, Trivandrum PAGE NO: 7
Power system
Large diesel engines - burn diesel-fuel oil to provide the main
source of power
Electrical generators - powered by the diesel engines to provide
electrical power
Mechanical system - driven by electric motors
Hoisting system - used for lifting heavy loads; consists of a
mechanical winch (drawworks) with a large steel cable spool, a
block-and-tackle pulley and a receiving storage reel for the cable
Turntable - part of the drilling apparatus
Rotating equipment - used for rotary drilling
Swivel - large handle that holds the weight of the drill string;
allows the string to rotate and makes a pressure-tight seal on the
hole
Kelly - four- or six-sided pipe that transfers rotary motion to the
turntable and drill string
Turntable or rotary table - drives the rotating motion using power
from electric motors
Drill string - consists of drill pipe (connected sections of about 30
ft / 10 m) and drill collars (larger diameter, heavier pipe that fits
around the drill pipe and places weight on the drill bit)
8. OIL DRILLING
Central Polytechnic College, Trivandrum PAGE NO: 8
Drill bit(s) - end of the drill that actually cuts up the rock; comes
in many shapes and materials (tungsten carbide steel, diamond)
that are specialized for various drilling tasks and rock formations
Casing - large-diameter concrete pipe that lines the drill hole, prevents
the hole from collapsing, and allows drilling mud to circulate
Circulation system - pumps drilling mud (mixture of water, clay,
weighting material and chemicals, used to lift rock cuttings from the
drill bit to the surface) under pressure through the kelly, rotary table,
drill pipes and drill collars
Pump - sucks mud from the mud pits and pumps it to the drilling
apparatus
Pipes and hoses - connects pump to drilling apparatus
Mud-return line - returns mud from hole
Shale shaker - shaker/sieve that separates rock cuttings from the
mud
Shale slide - conveys cuttings to the reserve pit
Reserve pit - collects rock cuttings separated from the mud
mud pits - where drilling mud is mixed and recycled
mud-mixing hopper - where new mud is mixed and then sent to
the mud pits
9. OIL DRILLING
Central Polytechnic College, Trivandrum PAGE NO: 9
Mud circulation in the hole
Derrick - Support structure that holds the drilling apparatus; tall enough
to allow new sections of drill pipe to be added to the drilling apparatus
as drilling progresses.
Drill-mud circulation system
10. OIL DRILLING
Central Polytechnic College, Trivandrum PAGE NO: 10
Blowout preventer - High-pressure valves (located under the land rig or
on the sea floor) that seal the high-pressure drill lines and relieve
pressure when necessary to prevent a blowout (uncontrolled gush of gas
or oil to the surface, often associated with fire)
DRILLING
The crew sets up the rig and starts the drilling operations. First, from the
starter hole, they drill a surface hole down to a pre-set depth, which is
somewhere above where they think the oil trap is located. There are five basic
steps to drilling the surface hole:
1. Place the drill bit, collar and drill pipe in the hole.
2. Attach the kelly and turntable and begin drilling.
3. As drilling progresses, circulate mud through the pipe and out of the bit
to float the rock cuttings out of the hole.
4. Add new sections (joints) of drill pipes as the hole gets deeper.
5. Remove (trip out) the drill pipe, collar and bit when the pre-set depth
(anywhere from a few hundred to a couple-thousand feet) is reached.
Once they reach the pre-set depth, they must run and cement the casing --
place casing-pipe sections into the hole to prevent it from collapsing in on
itself. The casing pipe has spacers around the outside to keep it centered in the
hole.
11. OIL DRILLING
Central Polytechnic College, Trivandrum PAGE NO: 11
The casing crew puts the casing pipe in the hole. The cement crew pumps
cement down the casing pipe using a bottom plug, a cement slurry, a top plug
and drill mud. The pressure from the drill mud causes the cement slurry to
move through the casing and fill the space between the outside of the casing
and the hole. Finally, the cement is allowed to harden and then tested for such
properties as hardness, alignment and a proper seal.
Drilling continues in stages: They drill, then run and cement new casings,
then drill again. When the rock cuttings from the mud reveal the oil sand from
the reservoir rock, they may have reached the final depth. At this point, they
remove the drilling apparatus from the hole and perform several tests to
confirm this finding:
Well logging - Lowering electrical and gas sensors into the hole to take
measurements of the rock formations there
Drill-stem testing - Lowering a device into the hole to measure the
pressures, which will reveal whether reservoir rock has been reached
Core samples - Taking samples of rock to look for characteristics of
reservoir rock
Once they have reached the final depth, the crew completes the well to
allow oil to flow into the casing in a controlled manner. First, they lower a
perforating gun into the well to the production depth. The gun has explosive
charges to create holes in the casing through which oil can flow. After the
casing has been perforated, they run a small-diameter pipe (tubing) into the
12. OIL DRILLING
Central Polytechnic College, Trivandrum PAGE NO: 12
hole as a conduit for oil and gas to flow up the well. A device called a packer is
run down the outside of the tubing. When the packer is set at the production
level, it is expanded to form a seal around the outside of the tubing. Finally,
they connect a multi-valved structure called a Christmas tree to the top of the
tubing and cement it to the top of the casing. The Christmas tree allows them to
control the flow of oil from the well.
Once the well is completed, they must start the flow of oil into the well. For
limestone reservoir rock, acid is pumped down the well and out the
perforations. The acid dissolves channels in the limestone that lead oil into the
well. For sandstone reservoir rock, a specially blended fluid containing
proppants (sand, walnut shells, aluminum pellets) is pumped down the well and
out the perforations. The pressure from this fluid makes small fractures in the
sandstone that allow oil to flow into the well, while the proppants hold these
fractures open. Once the oil is flowing, the oil rig is removed from the site and
production equipment is set up to extract the oil from the well.
EXTRACTING THE OIL
After the rig is removed, a pump is placed on the well head. In the pump
system, an electric motor drives a gear box that moves a lever. The lever
pushes and pulls a polishing rod up and down. The polishing rod is attached to
a sucker rod, which is attached to a pump. This system forces the pump up and
down, creating a suction that draws oil up through the well.
13. OIL DRILLING
Central Polytechnic College, Trivandrum PAGE NO: 13
Pump on an oil well
In some cases, the oil may be too heavy to flow. A second hole is
then drilled into the reservoir and steam is injected under pressure. The
heat from the steam thins the oil in the reservoir, and the pressure helps
push it up the well. This process is called enhanced oil recovery.
15. OIL DRILLING
Central Polytechnic College, Trivandrum PAGE NO: 15
CONCLUSION
With all of this oil-drilling technology in use, and new methods in
development, the question remains: Will we have enough oil to meet our
needs? Current estimates suggest that we have enough oil for about 63 to 95
years to come, based on current and future finds and present demands.