shadow

Well Control

Basically, all formations penetrated during drilling are porous and permeable to some degree. Fluids contained in pore spaces are under pressure that is overbalanced by the drilling fluid pressure in the well bore. The borehole pressure is equal to the hydrostatic pressure plus the friction pressure loss in the annulus. If for some reason the borehole pressure falls below the formation fluid pressure, the formation fluids can enter the well. Such an event is known as a kick. This name is associated with a rather sudden

flowrate increase observed at the surface.

A formation fluid influx (a kick) may result from one of the following reasons:

  • abnormally high formation pressure is encountered
  • lost circulation
  • mud weight too low
  • swabbing in during tripping operations
  • not filling up the hole while pulling out the drillstring
  • recirculating gas or oil cut mud.

If a kick is not controlled properly, a blowout will occur.A blowout may develop for one or more of the following causes:

  • lack of analysis of data obtained from offset wells
  • lack or misunderstanding of data during drilling
  • malfunction or even lack of adequate well control equipment

 SURFACE EQUIPMENT

A formation gas or fluid kick can be efficiently and safely controlled if the proper equipment is installed at the surface. One of several possible arrangement of pressure control equipment is shown in Figure. The blowout preventer (BOP) stack consists of a spherical preventer (i.e.,Hydril) and ram type BOPs with blind rams in one and pipe rams in another with a drilling spool placed in the stack.

A spherical preventer contains a packing element that seals the space around the outside of the drill pipe. This preventer is not designed to shut off the well when the drill pipe is out of the hole. The spherical preventer allows stripping operations and some limited pipe rotation.

wellhead

Hydril Corporation, Shaffer, and other manufactures provide several models with differing packing element designs for specific types of service. The ram type preventer uses two concentric halves to close and seal around the pipe, called pipe rams or blind rams, which seal against the opposing half when there is no pipe in the hole. Some pipe rams will only seal on a single size pipe; 5 in. pipe rams only seal around 5 in. drill pipe. There are also variable bore rams, which cover a specific size range such as 3½ in. to 5 in. that seal on any size pipe in their range.

Care must be taken before closing the blind rams. If pipe is in the hole and the blind rams are closed, the pipe may be damaged or cut. A special type of blind rams that will sever the pipe are called shear blind rams.

These rams will seal against themselves when there is no pipe in the hole, or, in the case of pipe in the hole, the rams will first shear the pipe and then continue to close until they seal the well.

A drilling spool is the element of the BOP stack to which choke and kill lines are attached. The pressure rating of the drilling spool and its side outlets should be consistent with BOP stack. The kill line allows pumping mud into the annulus of the well in the case that is required. The choke line side is connected to a manifold to enable circulation of drilling and formation fluids out of the hole in a controlled manner.

Driller A degasser is installed on the mud return line to remove any small amounts of entrained gas in the returning drilling fluids. Samples of gas are analyzed using the gas chromatograph.

If for some reason the well cannot be shut in, and thus prevents implementation of regular kick killing procedure, a diverter type stack is used rather, the BOP stack described above. The diverter stack is furnished with a blow-down line to allow the well to vent wellbore gas or fluids a safe distance away from the rig. Figure bellow shows a diverter stack arrangement.

Read also about Drilling Bits

WHEN AND HOW TO CLOSE THE WELL

While drilling, there are certain warning signals that, if properly analyzed, can lead to early detection of gas or formation fluid entry into the wellbore.

  1. Drilling break. A relatively sudden increase in the drilling rate is called a drilling break. The drilling break may occur due to a decrease in the difference between borehole pressure and formation pressure. When a drilling break is observed, the pumps should be stopped and the well watched for flow at the mud line. If the well does not flow, it probably means that the overbalance is not lost or simply that a softer formation has be encountered.
  2. Decrease in pump pressure. When less dense formation fluid enters the

borehole, the hydrostatic head in the annulus is decreased. Although reduction in pump pressure may be caused by several other factors, drilling personnel should consider a formation fluid influx into the wellbore as one possible cause. The pumps should be stopped and the return flow mud line watched carefully.

  1. Increase in pit level. This is a definite signal of formation fluid invasion into the wellbore. The well must be shut in as soon as possible.
  2. Gas-cut mud.Whendrilling through gas-bearing formations, small quantities

of gas occur in the cuttings. As these cuttings are circulated up, the annulus, the gas expands. The resulting reduction in mud weight is observed at surface. Stopping the pumps and observing the mud return line help determine whether the overbalance is lost.

If the kick is gained while tripping, the only warning signal we have is an increase in fluid volume at the surface (pit gain). Once it is determined that the pressure overbalance is lost, the well must be closed as quickly as possible. The sequence of operations in closing a well is as follows:

  1. Shut off the mud pumps.
  2. Raise the Kelly above the BOP stack.
  3. Open the choke line
  4. Close the spherical preventer.
  5. Close the choke slowly.
  6. Record the pit level increase.
  7. Record the stabilized pressure on the drill pipe (Stand Pipe) and annulus pressure gauges.
  1. Notify the company personnel.
  2. Prepare the kill procedure.

If the well kicks while tripping, the sequence of necessary steps can be given below:

  1. Close the safety valve (Kelly cock) on the drill pipe.
  2. Pick up and install the Kelly or top drive.
  3. Open the safety valve (Kelly cock).
  4. Open the choke line.
  5. Close the annular (spherical) preventer.
  6. Record the pit gain along with the shut in drill pipe pressure (SIDPP) and shut in casing pressure (SICP).
  1. Notify the company personnel.
  2. Prepare the kill procedure.

Depending on the type of drilling rig and company policy, this sequence of operations may be changed.

Read also Drilling Rotating Equipment

 KICK CONTROL PROCEDURES

There are several techniques available for kick control (kick-killing procedures).

In this section only three methods will be addressed.

  1. Driller’s method. First the kick fluid is circulated out of the hole and hen the drilling fluid density is raised up to the proper density (kill mud density) to replace the original mud. An alternate name for this procedure is the two circulation method.
  2. Engineer’s method. The drilling fluid is weighted up to kill density while the formation fluid is being circulated out of the hole. Sometimes this technique is known as the one circulation method.
  3. Volumetric method. This method is applied if the drillstring is off the bottom.

The guiding principle of all these techniques is that bottomhole pressure is held constant and slightly above the formation pressure at any stage of the process. To choose the most suitable technique one ought to consider

(a) complexity of the method,

(b) drilling crew experience and training,

(c) maximum expected surface and borehole pressure.

(d) Time needed to reestablish pressure overbalance and resume normal drilling operations.

Arabic Drilling Videos

فيديوهات حفر الابار النفطية Arabic Drilling Videos

Drillingيقدم لكم موقع النفط والغاز الطبيعي العربي مجموعة كبيرة من الأفلام التعليمية الخاصة بحفر الآبار النفطية باللغة العربية تم تحميلها وتجميعها من مواقع مختلفة ورفعها الى السيرفرات الخاصة بموقعنا لكي يتسنى لكم تحميلها بشكل مباشر ، كل ما عليك فعله هو النفر على كلمة Download أو Download Link الموجودة أسفل الفيديو المطلوب وسيتم تعزيز مكتبة افلام الحفر هذه بكل ما يتوفر من الأفلام الجديدة إن شاء الله. نتمنى لكم المنفعة والفائدة مع هذه السلسلة:

 

 

مضخات طين الحفر
Download           Download Link 2


عمل أدوات الحفر في برج الحفر
Download               Download Link 2


تنظيف سائل الحفر
Download            Download Link 2


حفر آبار النفط
Download               Download Link 2


ما هي رفسة البئر Oil Well Kick
Download            Download Link 2


حفر آبار النفط – الحفر المائل Directional Drilling
Download           Download Link 2


سمنتة الآبار النفطية Oil Well Cementing
Download               Download Link 2


تغليف البئر أثناء الحفر Oil Well Casing
Download              Download Link 2


يمكنكم زيارة قسم أفلام حفر الآبار النفطية – أكثر من 140 فلم تعليمي عن حفر الآبار النفطية


مجموعة أفلام شركة شلمبرجير :

الجزء الأول – الحلقة الأولى:
أبراج الحفر Drilling Rigs
Download           Download Link 2


الجزء الأول – الحلقة الثانية  
Kelly and Top Drive
Download                 Download Link 2


الجزء الأول – الحلقة الثالثة
Drill string Components – part.1
Download                     Download Link 2


الجزء الأول – الحلقة الرابعة
Drill string Components – part.2
Download               Download Link 2


الجزء الأول – الحلقة الخامسة
مثقاب الحفر Drilling Bits
Download                   Download Link 2


الجزء الأول – الحلقة السادسة 
Special drill String Equipment
Download               Download Link 2


الجزء الثاني – الحلقة الأولى
السيطرة على ضغط البئر Pressure Control
Download                 Download Link 2


الجزء الثاني – الحلقة الثانية
مانعات الأنفجار Blow Out Preventers BOPS

Download Link 2                    Download


الجزء الثاني – الحلقة الثالث
معدات مانع الانفجار Basic “Blow Out Preventers” BOP Equipment
Download                     Download Link 2


الجزء الثاني – الحلقة الرابعة  مانعات الأنفجار في المنصات البحرية Subsea BOP Equipment
Download Link 1          Download Link 2


الجزء الثاني – الحلقة الخامسة  
Drill String Valves and IBOPs
Download Link 1          Download Link 2


سلسلة شلومبرجر لحفر الآبار النفطية – 10 أقراص CD – تحميل مجاني


كورس Well Control باللغة العربية للمهندس عبدالله محمود :
(1) – Well Control Key Definitions
Download Link 1          Download Link 2


(2) – رفسة البئر Well Kick- الجزء الأول  
Download Link 1          Download Link 2


(3) – رفسة البئر Well Kick- الجزء الثاني
Download Link 1          Download Link 2


(4) – رفسة البئر Well Kick- الجزء الثالث 
Download Link 1      Download Link 2


(5) – رفسة البئر Well Kick- الجزء الرابع 
Download Link 1        Download Link 2


 

(6) – رفسة البئر Well Kick- الجزء الخامس
Download Link 1          Download Link 2


(7) – رفسة البئر Well Kick- الجزء السادس
Download Link 1          Download Link 2


(8) Pump Pressure and APL

Download Link 1         Download Link 2


(9)  Kick Warning Signs – part.1  
Download Link 1       Download Link 2


(10) Kick Warning Signs – part.2  
Download Link 1       Download Link 2


(11) Top Hole Drilling – Part.1
Download


(12) Top Hole Drilling – Part.2
Download

يرجى تبليغنا عن أي رابط لا يعمل من خلال وضع تعليق أو من خلال الأتصال بفريق عمل الموقع على البريد الألكتروني التالي:
files(at)arab-oil-naturalgas.com

OilWell Drilling Books page.2

Blow Out Preventers “BOP” Books

Blowout and Well Control Handbook
Download


Advanced Blowout and Well Control
Download


Blowout Prevention
Download 


BOP Basic Safety Functions
Download


  BOP Control Unit
Download


    BOPs   Download



Petroleum Well Construction
Download


 Drilling Engineering Laboratory Manual
Download


 Drilling, Fishing & Completion
Download


 Drilling Assembly Handbook
Download


  Choosing Perforation Strategy
Download


  Horizontal Well Technology
Download


  Deviated Drilling
Download


   Drilling Source Book
Download


  Extended Reach Drilling Guidelines
Download


Prevention, Fishing and Casing Repair – Jim Short – Part 1    55 MB
Download

Prevention, Fishing and Casing Repair – Jim Short – Part 2   42 MB
Download


  Introduction to Workover Operation
Download


 Casing Design _University of Petroleum/China
Download


   Well Stimulation
Download


 Drilling Sequences
Download


  Introduction to Well Integrity
Download


   Brief Introduction to Wireline
Download


    Drilling Problems
Download


  Oil Well Drilling Machines
Download


  Formulas & Calculations for Drilling, Production & WO
Download


  Open Hole Log Analysis and Formation Evaluation
Download


  Introduction to Well testing from Schlumberger
Download


  Well Test Design and Analysis    27 MB
Download


  Introduction to Mud Logging
Download


  Underbalanced Drilling
Download Link 1     Download Link 2


  Wellhead Christmas Tree
Download Link 1     Download Link 2


  Drilling Rig Components Hayder Lazim English+Arabic
  Download Link


  Wellhead Basics
Download Link 2


  Drilling Tools
Download Link


  IWCF 34 MB
Download Link 1     Download Link 2


 Well Engineering and Construction – Hussain Rabie
Download Link 1     Download Link 2


  IADC 139 MB
Download Link 1     Download Link 2


  Oil Well Drilling Machines
Download 


  Advanced Drilling Systems
Download 


  Introduction to Oil and Gas Well Drilling and Well Operations
Download Link 1     Download Link 2


  Casing and liners for drilling and completion design and application
Download Link 1     Download Link 2


  Introduction to Drilling
Download Link


  Subsurface Safety Valve Basics
Download Link


  the brief in Oil Well Drilling
Download Link 1     Download Link 2


  Well Heads, Chokes and SSSV
Download Link 


Casing Reference Tables
Download Link 1     Download Link 2


Simulating Underbalanced Drilling
Download Link


Managing Drilling Operations

Download


 

 

 

Oilwell Drilling Course2

Drillingthe biggest collection of FREE movies about Oil Well Drilling , it contains movies about:
well casing – cementing & cement additives – Drilling mud systems & additives – Blow Out Preventers BOP – Drilling bits – well logging – directional drilling – drilling rig – Permeability  & Porosity.

Permeability
Download Link 1     Download Link 2


Trapping Mechanism
Download Link 1       Download Link 2


Porosity
Download Link 1        Download Link 2


 Water Flooding
Download Link 1         Download Link 2


 Water Flooding
Download Link 1         Download Link 2


 Enhanced Oil Recovery with Permanent CO2 Storage
Download Link 1         


 UnderGround Injection Wells
Download Link 1         Download Link 2


 Well Cementing
Download Link 1          Download Link 2


 Oil Drilling Machine
Download Link 1        Download Link 2


  Petroleum Engineers
Download Link 1         Download Link 2


 Oil Rig Coiled Tubing Animation
Download Link 1        Download Link 2


Cementing
Download Link 1     Download Link 2


 Drilling Bits
Download Link 1     Download Link 2


  Fishing Operations
Download Link 1     Download Link 2


 Typical Downhole Drilling
Download Link 1        Download Link 2


  3D Oil Drilling
Download


  Directional Drilling Rig
Download Link 1      Download Link 2


  Basics of Well Completion
Download Link 1      Download Link 2


   Oil & Gas Wells from Start to End
Download Link 1        Download Link 2


  BOPs in Subsea platforms
Download


  Directional Drilling Rig
Download


  Jackup Drilling Rig – How Does it Work?
Download


  Connection on a Drilling Rig
Download


  Drilling Fluids Monitoring – Well Control Events
Download


  Drilling Techniques
Download


  Drilling Fluids Monitoring – Operational Efficiency
Download


  Drilling Fluid Overview elementary
Download Link 1      Download Link 2


  Introduction to Drilling Fluids Monitoring
Download


   Casing
Download Link 1     Download Link 2


  Rig Types and Basic Drill String Components
Download


  What are Drill Bits?
Download


  Well Logging in Offshore Drilling
Download


  How Drilling Mud Works in Offshore Rig?
Download


  Well Completion – Cased and Perforated
Download


  Well Completion – Perforation
Download


 Well Logging – SP and GR Logs
Download


 Well Test – DST Direct Information
Download


 Well Test – DST Operation P vs T
Download


 Well test – Qualitative DST Chart-1
Download


 How to care & maintain of Mud Pump
Download Link 1     Download Link 2


 How does water base mud works in Offshore Rig
Download Link 1     Download Link 2


 CCS (Continuous Circulation Drilling System)
Download Link 1     Download Link 2


 How does Mud Engineer work on Offshore Rig
Download Link 1     Download Link 2


 Drilling Fluid Circulation System ( Mud )
Download Link 1     Download Link 2


 Introduction to UnderBalanced and OverBalanced Drilling
Download Link 1     Download Link 2


 Managed Pressure Drilling MPD
Download Link 1     Download Link 2


 Drilling Fluids Overview
Download


  Openhole Fishing
Download Link 1        Download Link 2


Openhole Fracture Completion System

Download Link 


Gas Well Blowout
Download Link 1        Download Link 2


3D Animation of Drilling Rig
Download Link 1               Download Link 2 

Well Pressure Control

Basically all formations penetrated during drilling are porous and permeable to some degree.
Fluids contained in pore spaces are under pressure that is overbalanced by the drilling fluid pressure in the well bore.
The borehole pressure is equal to the hydrostatic pressure plus the friction pressure loss in the annulus. If for some reason the borehole pressure falls below the formation fluid pressure, the formation fluids can enter the well. Such an event is known as a kick. This name is associated with a rather sudden flowrate increase observed at the surface.

SURFACE EQUIPMENT
A formation gas or fluid kick can be efficiently and safely controlled if the proper equipment is installed at the surface. One of several possible arrangement of pressure control equipment . The blowout preventer (BOP) stack consists of a spherical preventer (i.e.,Hydril) and ram type BOPs with blind rams in one and pipe rams in another with
a drilling spool placed in the stack.
A spherical preventer contains a packing element that seals the space around the outside of the drill pipe. This preventer is not designed to shut off the well when the drill pipe is out of the hole. The spherical preventer allows stripping operations and some limited pipe rotation.

Hydril Corporation, Shaffer, and other manufactures provide several models with differing packing element designs for specific types of service. The ram type preventer uses two concentric halves to close and seal around the pipe, called pipe rams or blind rams, which seal against the opposing half when there is no pipe in the hole. Some pipe rams will only seal on a single size pipe; 5 in. pipe rams only seal around 5 in. drill pipe. There are also variable bore rams, which cover a specific size range such as 312 in. to 5 in. that seal on any size pipe in their range.
Care must be taken before closing the blind rams. If pipe is in the hole and the blind rams are closed, the pipe may be damaged or cut. A special type of blind rams that will sever the pipe are called shear blind rams.
These rams will seal against themselves when there is no pipe in the hole, or, in the case of pipe in the hole, the rams will first shear the pipe and then
continue to close until they seal the well. A drilling spool is the element of the BOP stack to which choke and kill lines are attached. The pressure rating of the drilling spool and its side outlets should be consistent with BOP stack. The kill line allows pumping mud into the annulus of the well in the case that is required. The choke
line side is connected to a manifold to enable circulation of drilling and formation fluids out of the hole in a controlled manner.
A degasser is installed on the mud return line to remove any small amounts of entrained gas in the returning drilling fluids. Samples of gas
are analyzed using the gas chromatograph.
If for some reason the well cannot be shut in, and thus prevents implementation of regular kick killing procedure, a diverter type stack is used rather, the BOP stack described above. The diverter stack is furnished with a blow-down line to allow the well to vent wellbore gas or fluids a safe distance away from the rig.

WHEN AND HOW TO CLOSE THE WELL
While drilling, there are certain warning signals that, if properly analyzed, can lead to early detection of gas or formation fluid entry into the wellbore.
1. Drilling break. A relatively sudden increase in the drilling rate is called a drilling break. The drilling break may occur due to a decrease in the difference between borehole pressure and formation pressure. When a drilling break is observed, the pumps should be stopped and the well watched for flow at the mud line. If the well does not flow, it probably means that the overbalance is not lost or simply that a softer formation has be encountered.
2. Decrease in pump pressure. When less dense formation fluid enters the borehole, the hydrostatic head in the annulus is decreased. Although reduction in pump pressure may be caused by several other factors, drilling personnel should consider a formation fluid influx into the wellbore as one possible cause. The pumps should be stopped and the return flow mud line watched carefully.
3. Increase in pit level. This is a definite signal of formation fluid invasion into the wellbore. The well must be shut in as soon as possible.
4. Gas-cut mud. When drilling through gas-bearing formations, small quantities of gas occur in the cuttings. As these cuttings are circulated up, the annulus, the gas expands. The resulting reduction in mud weight is observed at surface.
Stopping the pumps and observing the mud return line help determine whether the overbalance is lost.
If the kick is gained while tripping, the only warning signal we have is an increase in fluid volume at the surface (pit gain). Once it is determined that the pressure overbalance is lost, the well must be closed as quickly as possible. The sequence of operations in closing a well is as follows:
1. Shut off the mud pumps.
2. Raise the Kelly above the BOP stack.
3. Open the choke line
4. Close the spherical preventer.
5. Close the choke slowly.
6. Record the pit level increase.
7. Record the stabilized pressure on the drill pipe (Stand Pipe) and annulus pressure gauges.
8. Notify the company personnel.
9. Prepare the kill procedure.
If the well kicks while tripping, the sequence of necessary steps can be given below:

  1. Close the safety valve (Kelly cock) on the drill pipe.
    2. Pick up and install the Kelly or top drive.
    3. Open the safety valve (Kelly cock).
    4. Open the choke line.
    5. Close the annular (spherical) preventer.
    6. Record the pit gain along with the shut in drill pipe pressure (SIDPP) and shut in casing pressure (SICP).
    7. Notify the company personnel.
    8. Prepare the kill procedure.
    Depending on the type of drilling rig and company policy, this sequence of operations may be changed.

A formation fluid influx (a kick) may result from one of the following
reasons:
• abnormally high formation pressure is encountered
• lost circulation mud weight too low
• swabbing in during tripping operations
• not filling up the hole while pulling out the drill string
• recirculating gas or oil cut mud.
If a kick is not controlled properly, a blowout will occur.
A blowout may develop for one or more of the following causes:
• lack of analysis of data obtained from offset wells
• lack or misunderstanding of data during drilling
• malfunction or even lack of adequate well control equipment

References:
1. Drilling Equipment and Operation.
2. drilling Operation.