Análise do Funcionamento do B.O.P

Esta é uma pré-visualização de arquivo. Entre para ver o arquivo original

POLYTECHNIC HIGHER INSTITUTE OF TECHNOLOGIES 
AND SCIENCES 
 DEPARTMENT OF GEOSCIENCES 
 PETROLEUM ENGINEERING COURSE 
 
 
 
Eliane de Sousa 
Jaime João 
Jonivaldo Simone 
José Mandele 
Patrício Jaime 
Shanidzy Cardoso 
 
 
 
 
 
ANALYSIS OF THE OPERATION OF THE B.O.P IN BLOWOUT 
PREVENTION 
 
 
 
 
 
 
 
 
 
LUANDA,2026 
 
 
 
 
DEPARTMENT OF GEOSCIENCES 
 PETROLEUM ENGINEERING COURSE 
 
 
Eliane de Sousa 20240777 
Jaime João 20241620 
Jonivaldo Simone 20240611 
José Mandele 20230285 
Patrício Jaime 20242047 
Shanidzy Cardoso 20240899 
 
 
 
 
 
 
 
 
 
 
 
TEACHER 
Anito Pereira 
 
Class 
 EPT2-M3 
 
 
 
 
 
 
 
 
LUANDA,2026 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 We dedicate this work to our parents, 
guardians, family members, teachers, 
 mentors, colleagues, friends, 
 and above all, to God. 
 
 
 
 
ACKNOWLEDGMENTS 
We express our sincere gratitude to everyone who contributed to the completion of this 
work. 
We especially thank our team, whose commitment, dedication, and collaboration were 
essential for the development of this project. Every idea shared, every effort invested, and every 
challenge overcome reinforced the importance of teamwork and mutual cooperation. It was an 
enriching experience that provided us with valuable learning and strengthened our ability to 
work together toward a common goal. Our gratitude also extends to the teachers, advisors, and 
others involved who, with their guidance and support, helped make this work possible. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
SUMMARY 
Safety in oil well drilling operations is an essential factor in preventing major accidents 
such as blowouts. In this context, the Blowout Preventer (B.O.P) stands out as the main well 
safety equipment, responsible for controlling abnormal pressures and stopping uncontrolled 
hydrocarbon flow. This study aims to analyze the operation of the B.O.P in blowout prevention, 
addressing the concepts of kick, well control methods, and safety systems involved in drilling 
operations. The methodology is based on bibliographic research, technical analysis, and the 
presentation of the main components and types of preventers, as well as their operating 
principles. The results show that the proper functioning of the B.O.P, combined with adequate 
primary, secondary, and tertiary well control procedures, is fundamental to ensuring well 
integrity, personnel safety, and environmental protection. It is concluded that technical 
knowledge of the B.O.P and its correct application are indispensable for accident prevention in 
the oil industry. 
Keywords: Oil well; Blowout Preventer; Kick; Well control; Operational safety. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 LIST OF ILLUSTRATIONS 
FIGURA 1 B.O.P (BLOWOUT PREVENTER) ANNULAR .................................................................. 14 
FIGURA 2 TUBE DRAWER ................................................................................................................ 14 
FIGURA 3 SHEARING DRAWER .................................................................................................... 15 
FIGURA 4 ACCUMULATOR OR ACTUATOR UNIT ......................................................................... 15 
FIGURA 5 CHOKE MANIFOLD ...................................................................................................... 17 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
INDEX 
 
1 INTRODUCTION ........................................................................................................ 9 
1.2 OBJECTIVES.......................................................................................................... 10 
1.2.1 General Objective ........................................................................................ 10 
1.2.2 Specific Objectives ...................................................................................... 10 
2 THEORETICAL FOUNDATION .................................................................................. 11 
2.1 OIL WELL DRILLING .............................................................................................. 11 
2.2 KICK ..................................................................................................................... 11 
2.2.1 SIGNS OF KICK .................................................................................................. 12 
2.2.2 WELL CONTROL DURING A KICK ...................................................................... 12 
2.3 BLOWOUT ........................................................................................................... 12 
2.4 WELL SAFETY SYSTEM ......................................................................................... 13 
2.5 B.O.P (BLOWOUT PREVENTER) ........................................................................... 13 
2.5.1 B.O.P (BLOWOUT PREVENTER) ANNULAR ....................................................... 13 
2.5.2 DIVERTER SYSTEM ............................................................................................ 14 
2.5.3 DRAWER B.O.P ................................................................................................. 14 
2.5.3.1 Tube Drawer .................................................................................................. 14 
2.5.3.2 Blind Drawer ................................................................................................. 15 
2.5.3.3 SHEARING DRAWER ...................................................................................... 15 
2.6 ACCUMULATOR OR ACTUATOR UNIT ................................................................. 15 
2.6.1 PRINCIPLES OF ACCUMULATOR DESIGN .......................................................... 16 
2.6.2 REMOTE CONTROL PANELS.............................................................................. 16 
2.7 KILL LINE .............................................................................................................. 16 
2.8 CHOKE LINE ......................................................................................................... 16 
2.9 CHOKE MANIFOLD ............................................................................................... 17 
3 COST AND DANGER OF BLOWOUT ........................................................................ 17 
 
 
4 CONCLUSION .......................................................................................................... 18 
5 REFERENCES ........................................................................................................... 19 
 
 
 
 
 
 
 
9 
 
 
1 INTRODUCTION 
The oil industry is characterized by highly complex operations and significant risks 
associated with pressure control in oil wells. During drilling activities, imbalances between the 
hydrostatic pressure of the drilling fluid and the formation pressure may result in undesired 
fluid influxes, known as kicks, which, if not properly controlled, can develop into a blowout. 
Such events pose serious threats to worker safety, facility integrity, and the environment. 
 
In this context, the development and use of efficient safety systems are essential for 
accident prevention. Among these systems, the Blowout Preventer (B.O.P) stands out as a 
fundamental piece of equipment installed at the wellhead, whose primary function is to stop 
uncontrolled fluid flow from the formation, ensuring well control under critical conditions. The 
B.O.P acts as the main component of secondary well control and is activated when primary 
control, provided by the hydrostatic pressure of the drilling fluid, fails. 
 
The
proper operation of the B.O.P depends not only on its mechanical and hydraulic 
design but also on the technical knowledge of the personnel involved, adequate maintenance of 
its components, and correct application of operational procedures. Therefore, understanding the 
operating principles of this equipment, as well as its types, configurations, and activation 
methods, is essential to ensure safety in drilling operations, both onshore and offshore. 
 
In this context, this study aims to analyze the operation of the Blowout Preventer in 
blowout prevention, addressing the fundamental concepts related to kicks, well control 
methods, and the main safety systems used in the oil industry. Thus, it seeks to highlight the 
importance of the B.O.P as an indispensable element for risk mitigation, preservation of human 
life, and environmental protection in petroleum operations. 
 
 
 
 
 
 
 
10 
 
 
1.2 OBJECTIVES 
1.2.1 General Objective 
To analyze the operation of the Blowout Preventer (B.O.P) as a safety system in the 
prevention of blowouts in oil wells, highlighting its importance in pressure control and drilling 
operation safety. 
1.2.2 Specific Objectives 
 To understand the fundamental concepts of kick and blowout and their relationship with 
oil well control; 
 To describe primary, secondary, and tertiary well control methods used in the oil 
industry; 
 To identify the main components and types of Blowout Preventers, as well as their 
operational characteristics; 
 To analyze the operation of annular and ram-type preventers in controlling fluid 
influxes; 
 To evaluate the importance of auxiliary B.O.P systems, such as the accumulator unit, 
choke and kill lines, and control panels; 
 
 
 
 
 
 
 
 
 
 
 
 
 
11 
 
2 THEORETICAL FOUNDATION 
2.1 OIL WELL DRILLING 
The drilling of an oil well is carried out using a rig. The rocks are drilled by the rotary 
action of a bit located at the end of a drill string. Rock fragments are removed by the action of 
a drilling fluid or mud pumped through this string. Upon reaching a certain depth, the drill string 
is withdrawn and a steel casing of a smaller diameter than the bit is installed, and cementing is 
performed between the annular spaces (connections) of the casing pipes to ensure safety. 
Afterward, the drill string is lowered into the well again with a new bit of smaller diameter, and 
the process is repeated until the drilling is completed. (Thomas, 2004). 
2.2 KICK 
One of the main functions of drilling fluids is to exert hydrostatic pressure on the 
formations drilled by a bit. When this pressure is lower than the pressure of the fluids confined 
in the pores of rock formations and these have permeability, there will be an influx of these 
fluids into the well. If this influx can be controlled, then the well is experiencing a Kick. 
According to Oliveira et al. (1988), the probable causes of a Kick are: 
 Loss of circulation 
It is the loss of drilling fluid from the well into the formation. In the case of total loss of 
circulation, the fluid level in the annulus drops, causing the hydrostatic pressure at all points 
along the well to also decrease. As a result, the well may be at risk of experiencing a kick. 
 Abnormally high formation pressure 
The problem in these situations is that the weight of the drilling fluid is insufficient to 
maintain hydrostatic balance with the formation pressure. During drilling, the failure to detect 
zones of abnormally high pressure in a timely manner and the use of an inadequate fluid weight 
can result in a kick when a permeable formation is encountered. 
 Poor cementing 
A self-supporting structure is formed during cement setting, causing the hydrostatic 
pressure of the cement paste to be the hydrostatic pressure of the mixing water. As a result, 
there is a loss of hydrostatic pressure, and there is a possibility of relative gas permeability and 
inducing a kick; 
A kick can also cause well instability, such as collapse, enlargement, wellbore 
obstruction, and contamination of the drilling fluid. 
12 
 
 
2.2.1 SIGNS OF KICK 
There are numerous signs that help identify a potential kick situation. When recognized 
and interpreted quickly, appropriate measures can be taken to avoid a large volume of fluid. 
The main signs of a kick are: Increased fluid volume in the tanks, increased return flow rate, 
well flow with the pumps turned off, decreased circulation pressure, and increased pump speed. 
The well receiving less fluid than the volume of steel removed. The well delivering more fluid 
than the volume of steel lowered into it. Increased penetration rate due to an imbalance between 
pore pressures and formation pressures, causing a force in the direction from formation to well 
that aids the drill bit. Fluid cutting by gas, oil, or water. This occurs when the fluid contained 
in the pores of a formation is released and mixes with the drilling fluid (mud). 
2.2.2 WELL CONTROL DURING A KICK 
The main information that can be obtained from the Kick includes the pressures read on 
the gauges when the well is shut in and the volume gained in the tanks. With the well shut in, 
the person responsible for the ongoing project or an engineer must prepare to regain control of 
the well, which consists of circulating the invading fluid out of the well and, if necessary, 
increasing the weight of the mud to contain the formation pressure and prevent another kick. 
There are some procedures used to prevent the flow of hydrocarbons from the formations into 
the wells during drilling, as well as methods used to combat this possible influx. According to 
Aird (2009), these procedures are divided into three levels: 
1. Primary control, which is performed through the action of the hydrostatic pressure of 
the drilling fluid on the rock, keeping it higher than the pressure existing in the pores of the 
rock to be drilled; 
2. Secondary control, which is carried out through a set of safety equipment that comes 
into action when primary control fails. At this stage, the goal is to prevent a blowout, as the 
kick has already occurred; 
3. Tertiary control, which comes into action if well control at the secondary level cannot 
be maintained. A blowout will occur, and formation control can only be achieved through 
special measures. 
2.3 BLOWOUT 
A Blowout is an uncontrolled flow of hydrocarbons that come out of an oil well and 
reach the surface. Generally, a blowout can occur as a result of human or equipment failures in 
some operation carried out incorrectly, in which the well control was lost. A blowout can occur 
13 
 
during any operation performed on the well during its production time. A blowout does not 
happen unexpectedly; it is a series of events combined. The first signs are related to the mud 
density: as oil and gas enter, the fluid tends to decrease in density because it mixes with 
hydrocarbons that are naturally lighter than water. 
2.4 WELL SAFETY SYSTEM 
In order to prevent an uncontrolled influx of formation fluids into the well, well safety 
equipment was created. The essential equipment of the Well Safety System are: a set of well 
shut-off valves, known as BOP (Blowout Preventer) or ESCP (Wellhead Safety Equipment); 
accumulator unit, remote control panels, kill and choke lines, and choke manifold. 
All oil wells can experience a kick at any moment, either due to a decrease in fluid 
density or because of pressure higher than the hydrostatic pressure. As a result of this 
possibility, all wells are equipped with equipment specially designed for kick situations. 
Blowout preventers are valves that can be operated hydraulically or manually to shut in the well 
at any time if a kick occurs. With the well shut in, the responsible engineer must present a plan 
for it, through circulating the influx and replacing the initial (lighter) drilling fluid
with a heavier 
fluid. 
2.5 B.O.P (BLOWOUT PREVENTER) 
The BOP is the equipment that allows an oil well to have its production stopped, 
ensuring the safety of the drilling operation while also preventing environmental disasters and 
loss of life among the work team. The Blowout Preventer is equipment that consists of a set of 
valves, and can be further classified as annular or ram-type, with specifications for drilling in 
both onshore and offshore operations. The preventers are activated whenever a kick occurs, an 
unwanted flow of fluid from a formation into the well. If this flow is not efficiently controlled, 
it can result in a blowout, that is, the well flowing completely uncontrolled, causing personal 
accidents, partial or total loss of the reservoir, pollution, and environmental damage, etc. 
(THOMAS et al, 2001, p.67). 
2.5.1 B.O.P (BLOWOUT PREVENTER) ANNULAR 
A B.O.P like the one shown in Figure 1 allows the well to be closed or production to be 
stopped whether it has a production string or not. For this to happen, the pressurized fluid is 
directed into a closing chamber, from where a piston is pushed, causing the sealing element to 
exert pressure against the production string. This can be used on any pipe diameter. 
 
 
14 
 
 
Figura 1 B.O.P (BLOWOUT PREVENTER) ANNULAR 
 
2.5.2 DIVERTER SYSTEM 
A system whose function is to ensure that the return of drilling fluid or well effluents 
through the riser is directed to points of interest, according to the operation. In emergency cases, 
it can be closed, ensuring the safety of people where well access work is taking place. The 
Diverter has a packer, which allows the well to be closed around the drill pipe or without its 
presence. 
2.5.3 DRAWER B.O.P 
The gate-type Blowout Preventer operates similarly to a conventional gate valve, except 
for the presence of a pair of opposing gates. When activated, both are pressed toward the center 
of the valve, causing the well to close or seal. There are four (4) types of gate-type preventers: 
Pipe, Blind, Shear, and Blind-shear. 
2.5.3.1 Tube Drawer 
As shown in Figure 2, it is designed to close the annular space of the well around the 
drill string, accommodating either a fixed or variable diameter. 
Figura 2 Tube Drawer 
 
15 
 
2.5.3.2 Blind Drawer 
The blowout preventer is designed to close the wellbore when it is without a drill string 
or when the string is not in front of the preventer. 
 
2.5.3.3 SHEARING DRAWER 
The shearing gate is designed to make cuts in tubes with larger diameters and coatings, 
differing from the blind-shearing gate, which does not provide sealing, but has a greater 
capacity for making the cut (Figure 3). 
Figura 3 SHEARING DRAWER 
 
2.6 ACCUMULATOR OR ACTUATOR UNIT 
The Blowout Preventer must have an immediate response after it is activated. Therefore, 
it is necessary to have a volume of hydraulic fluid maintained under pressure sufficient to close 
or open all the preventer rams. This fluid is stored in the system's accumulator or actuator unit, 
which has valves and pumps that can be electric or pneumatic, along with a pressure gauge and 
high- and low-pressure piping. In the accumulator, separated by a rubber membrane, there is 
nitrogen gas and hydraulic fluid. This fluid is pumped into the accumulators, increasing the gas 
pressure. When any element of the Blowout Preventer is activated, the energy is released and 
the fluid is driven into the preventer's opening or closing chamber (Figure 4). 
Figura 4 ACCUMULATOR OR ACTUATOR UNIT 
 
 
 
 
16 
 
2.6.1 PRINCIPLES OF ACCUMULATOR DESIGN 
Accumulators or actuators have certain notable characteristics as listed below: 
• They store the hydraulic fluid under pressure so that the Blowout Preventer can 
operate. 
• In most cases, the principle of using a pre-charge pressure of 1,000 Psi can reach a 
working pressure of 3,000 Psi. 
• The pre-charge provides supply and operating energy when the vessel is fully depleted. 
 
2.6.2 REMOTE CONTROL PANELS 
In addition to the activation of the B.O.P. equipment by the accumulator or actuator unit, 
there is also the possibility of activation through remote panels operated pneumatically. There 
are usually two panels: one next to the driller on the drilling platform, and another located away 
from the area that could pose a greater risk. 
2.7 KILL LINE 
For fluid injection through the annular space, the kill line is used, which is employed 
for well kill operations, where a fluid is pumped into the well during a well control process. 
 
2.8 CHOKE LINE 
This line allows the connection between the drilled wellhead and the Choke Manifold, 
requiring a working pressure that is compatible with the working pressure of the B.O.P., and 
must have a diameter with a sufficient opening, greater than 3 nominal inches, to reduce 
pressure losses, erosive processes, or even clogging. The Blowout Preventer is activated, the 
fluid passage is sealed for the removal of mud and screens. The flow is diverted through a line 
that exits below the Blowout Preventer, which is called the choke line. The choke line is 
connected to the well through a piping system using a set of valves, including choke valves and 
other elements that direct the fluids to the area where the mud is located or to the Flare line (gas 
kick). This piping has at least two chokes: one manual and one hydraulic. 
 
 
 
 
 
17 
 
2.9 CHOKE MANIFOLD 
This equipment is used for flow restriction. This same restriction generates a counter 
pressure that will be transmitted through the circulating fluid to the formation. 
 
Figura 5 CHOKE MANIFOLD 
 
 
3 COST AND DANGER OF BLOWOUT 
The final cost of a blowout can easily reach several thousand or even millions of dollars, 
but the money spent is not as important or as considered when compared to other damages 
caused. The waste of precious non-renewable resources can cause or lead to irreparable damage 
to the environment, ruin equipment, and most importantly, can endanger the safety and lives of 
the professionals involved in drilling, whether onshore or offshore. In any dangerous situation, 
as occurs in a blowout, the safety of the drilling rig personnel becomes a major concern and 
priority, followed by the rig itself, and lastly, the well. The value of a lost life cannot be counted 
or measured. 
 
 
 
 
 
 
 
 
 
 
18 
 
4 CONCLUSION 
Around 50% of all blowout occurrences happen during tripping operations. The drill 
string displaces a volume of fluid in the well. When it is removed, the fluid level in the well 
decreases, and the pressure at the bottom of the well follows accordingly. If the drilling fluid 
level in the well is not maintained, the overbalance will be lost and a kick can occur. This is a 
process of shooting with a pressure higher than the formation to create a pressure differential 
towards the well-formation. A tank called a Trip Tank is used to keep the well filled with fluid 
during tripping. If the drill string is pulled too abruptly or quickly, it can suck gas out of the 
formation and initiate a kick. B.O.P. tests are regularly carried out on rigs to check the condition 
of the equipment and to analyze the response of the control crew. We analyze in this way how 
the operation of a Blowout Preventer takes place, as well as how the influxes from a Kick are 
controlled and prevented to save lives, equipment, and the drilled well. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
19 
 
5 REFERENCES 
[1]https://www.monitor-systemsengineering.com/bop_control_engineering_solutions.html 
Accessed on: March 28, 2020 
[2] http://petroleoinfonet.blogspot.com/2012/03/o-que-e-bop.html?m=1 Accessed on: October 
5, 2020 
[3]http://enahpe2019.ipt.br/Arquivos%20Anais%20do%20evento/141.pdf?Mobile=1 
Accessed on: October 5, 2020 
[4] http://www.petroquimica.com.br/edicoes/ed_324/324.html Accessed on:
October 5, 2020 
[5] http://inspecaoequipto.blogspot.com/2013/05/blow-out.html?m=1 Accessed on: March 23, 
2020 
[6] AIRD, P. Drilling & Well Engineering: Introduction to Well Control, 2009 
[7] CASTILHO, F.V.: Study of the Pipe Cutting Process in BOP CORRÊA, Oton Luiz Silva. 
Petroleum: Concepts on Exploration, Drilling, Production, and Microbiology. Rio de Janeiro: 
Interciência, 2003. 102p. ISBN: 8571930937. 
[8] FUNDAMENTALS of Petroleum Engineering. 2nd ed. Rio de Janeiro: Interciência, 2004. 
ISBN: 8571930996. 
[9] FUNDAMENTALS of Petroleum Refining: Technology and Economics. 3rd ed., updated 
and expanded. Rio de Janeiro: Interciência, 2012. ISBN: 9788571933026. 
 
 
 
 
 
http://enahpe2019.ipt.br/Arquivos%20Anais%20do%20evento/141.pdf?Mobile=1