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SUPPLEMENT Well Control for Drilling Operations –

Well Completion and Workover for Supervisors

Core Curriculum and Related Learning Objectives

Form WCT-02-DO-SU-WOC-S© Revision 0

13 February 2015

Core Curriculum and Related Learning Objectives for Drilling Operations

SUPPLEMENT: Well Completion & Workover for Supervisors of Drilling Operations

SUPPLEMENT: Well Completions and Workover for Supervisors of Drilling Operations of 13 Revision 0 Last updated: 13 February 2015

Contents Contents ....................................................................................................................................................................................................................... 2

1.0 Course Overview .......................................................................................................................................................................... 3

2.0 Curriculum ............................................................................................................................................................................................................ 4

2.1 Introduction to Well Completions and Workover for Drilling Operations............................................................................................. 4

2.2 Completion and Workover Fluids .............................................................................................................................................................. 5

2.3 Well Completion and Workover Equipment ............................................................................................................................................ 6

2.4 Workover Well Control Practices and Kill Methods................................................................................................................................ 9

2.5 Complications ............................................................................................................................................................................................ 11




1.0 Course Overview

The purpose of this course core curriculum is to identify the well control body of knowledge and set of job skills needed by supervisory personnel who may be engaged in completion and workover operations. The curriculum is designed to supplement the Drilling Operations’ Supervisory-level course.

Acceptable Delivery Methods: Instructor-led training for the initial and repeat delivery of this Supplement is required, along with a knowledge assessment. Simulator or live well exercises are also required ; however, a simulator assessment is not required for this supplement.

Minimum Course Length: Eight (8) hours are required for teaching the core curriculum. Course length includes simulator exercises, but excludes the knowledge assessment time. Maximum knowledge assessment time is forty-five (45) minutes.

Course Curriculum Notes: The curriculum that follows includes five components: Sub-modules, AIM, Learning Topics, Learning Objectives and Assessment Guidelines.

AIM: The AIM letters indicate the level of knowledge and skills required at the job level. The codes used in the AIM column are as follows:

A = Awareness of Learning Topic

I = Implementation of the Learning Topic at this job level; needs an increased level of knowledge because they may have to take action on some task related to the topic.

M = Mastery of Learning Topic at this job level; needs a full knowledge because they have to take action, perhaps unsupervised, on some task related to the topic.

Learning Topics: This section provides guidance for instructors on what the trainee should learn.

Learning Objectives and Assessment Guidelines: This section defines what trainees should be able to do at the conclusion of the training, and defines the assessment process, whether theoretical or practical, by providing examples of assessment content and expectations.




2.0 Curriculum

2.1 Introduction to Well Completions and Workover for Drilling Operations

Module Name: 2.1 Introduction to Well Completions and Workovers for Drilling Operations

Sub-Modules AIM Learning Topics Learning Objectives and Assessment Guidelines

The instructor will impart knowledge on: The trainee will be able to:

Introduction to Workover and Completions

A Objectives of workover and completion operations.

Describe the purpose of conducting workover or completion (for example, initiates, improves, or restores production).

A Different workover activities and types.

Describe the different types of activities that may occur during a workover in order to accomplish the objective (for example, wellbore activities: acidizing, fracking, sand clean out and removal, recompleting in new reservoir, scale or paraffin removal, control water, sidetrack or deepen, plug and abandon; equipment activities: removal or addition of tools, mechanical repair of worn or damaged equipment, pump change, clean perforation, or skin damage).

A Completion activities and types.

Describe the different types of activities that may occur during a completion in order to accomplish the objective (for example, perforating, fracking, acidizing, flowing, reservoir test, openhole vs. cased-hole completion techniques).

Differences Between Drilling Operations and Workover / Completion Operations

M Differences in workover and drilling activities that could result in a loss of containment.

Describe the primary differences between workovers/completions and drilling (for example, fluid differences, downhole equipment (plugs, packers, flow-through valves), shut-in considerations, formation pressures, depleted reservoirs, damage to tubing/casing, open hydrocarbon reservoir, fluid column characteristics).




2.2 Completion and Workover Fluids

Module Name: 2.2 Completion and Workover Fluids Sub-Modules AIM Learning Topics Learning Objectives and Assessment Guidelines


Friction

I Friction loss in the different well sections.

Describe frictional losses in different well sections (slimhole, tight tubing/casing clearances). Explain how downhole tools/equipment affect friction and fluid flow.

I Reverse Circulation method. Describe the friction losses in the circulating system and the resulting well pressures when reverse circulating.

I Effect of friction on bottomhole pressure (BHP).

Determine the effect on BHP when circulating with tools, equipment.

Completion and Workover Fluids

I Types of fluid. Describe the different types of brine and completion fluids (water-based, oil-based mud/synthetic-based mud).

I Purpose of fluid. Describe the purpose and characteristics of fluids that make them suitable for workover and completions (for example, compatibility with the zone; pressure control).

I Purpose of packer fluid. Describe the purpose of packer fluid in a completion.

Brine Characteristics

I Solids carrying capacity.

Explain solids carrying capacity of brines with viscosifiers and without viscosifiers (for example, brines without viscosifiers have poor solids transport capacity, lower than that of drilling fluids).

M Gas migration in brines. Explain gas migration in brines (for example, gas migrates at a much higher rate in brine than in viscous drilling fluid).

A Density and composition. Explain how various salt compositions affect the density range (for example, sodium chloride brine solutions can be weighted up to 10.0 ppg before saturation is reached.

I Temperature and pressure.

Describe the effect of temperature and pressure on brine density. Calculate the correct brine weight needed to balance BHP in a wellbore at a given temperature.




Module Name: 2.2 Completion and Workover Fluids Sub-Modules AIM Learning Topics Learning Objectives and Assessment Guidelines


A Crystallization.

Recognize brine density loss due to crystallization and hygroscopic properties. Identify cause of crystallization and effect on brine density.

A Eutectic point/freezing point. Define the eutectic point / freezing point of brine and describe how it is related to crystallization.

A Saturation. Describe brine saturation and how it relates to crystallization, maximum fluid weight, and the eutectic point.

2.3 Well Completion and Workover Equipment

Module Name: 2.3 Well Completion and Workover Equipment Sub-Modules AIM Learning Topics Learning Objectives and Assessment Guidelines

The instructor will impart knowledge on: The trainee will be able to: M Barrier Define and explain “barrier” and provide examples.

Barrier Management M

Surface equipment. Demonstrate how the wellhead, tubing hanger, and Christmas tree act as a barrier to flow.

Blowout preventer (BOP) or Christmas tree removal.

Identify and evaluate the steps and barriers used to isolate the well prior to removing a BOP or Christmas tree.

Christmas Tree (Valves, Tees, Gauge Panels, Tree Caps, Chokes, Surface Safety Valves)

I Christmas tree components.

Identify primary components of a Christmas tree and their purpose (for example, tree-cap; why use of a secondary master valve is important). Identify the appropriate locations of the equipment.

I Pressure testing.

Identify pressure-sealing components and explain when these components should be tested as a barrier (for example, explain why a wing valve may need to hold pressure during a Bullhead).






I Pressure limitations.

Identify the pressure rating, mechanical limits, and conditional limits of equipment. Summarize how equipment may be degraded after service exposure.

A Metallurgical composition. Identify different trim types and their different service limits (for example, AA is a trim type).

I Ring seals and O-ring seals.

Describe the type of seal created by: 1. a ring gasket between connections, and 2. O-ring seals between other components (for example, ring gasket seals provide a metal-to-metal seal and require compression; O-ring seals do not require compression and typically have shorter service life).

Tubing Hangers and Wellhead Bowls

I

Tubing hangers and wellhead bowls.

Explain the purpose of a tubing hanger and wellhead bowl (for example, access to the annulus for pressure monitoring, chemical injection, barrier to flow for the annulus, and possible barrier to the tubing).

Testing tubing hanger seals. Identify test ports and voids that are tested to verify a tubing hanger seal.

Types of tubing hanger and wellhead bowl annulus seals.

Name types of tubing hanger and wellhead bowl annulus seals, and identify the correct uses of each (for example, elastomer seals; metal-to-metal seals).

Control lines, electric submersible pump cables, and other components penetrating tubing hangers.

Indicate where tubing hangers must hold pressure (including around this external equipment).

Subsurface Equipment

I Downhole equipment recognition. Match downhole equipment to the correct name.

I Pressure isolation.

Identify various downhole components that provide pressure isolation (packers, subsurface safety valve (SSSV), plugs, completion equipment, retrievable bridge plug (RBP), surface controlled subsurface safety valve (SCSSSV), wireline plugs, tubing, etc.).





The instructor will impart knowledge on: The trainee will be able to: Explain how subsurface equipment can be used to provide pressure isolation (for example, SCSSSV retains tubing flow when the wellhead is damaged by shutting a flapper).

I Testing of downhole equipment. Give examples of how to test downhole equipment to confirm it is a competent barrier. Identify limitations of downhole tests.

A Working pressure. Identify factors that affect working pressure ratings and limitations of subsurface equipment (for example, corrosion, wear, degradation, and burst rating).

A Subsurface complications.

Describe hazards that may relate to downhole equipment (for example, trapped pressure under retrievable plugs; variation of thread types and correct matching of threads; correct rental equipment selection to match rig and completion equipment; testing limitations). Identify how to mitigate hazards.

Removable Wellhead Equipment

I

Removable wellhead equipment.

Define removable wellhead equipment. Explain what valve removal plugs, two-way checks, and backpressure valves are and where they are located on a tree or wellhead.

Applications. State reasons for using removable wellhead equipment; state when it could be used versus should not be used.

Lubricator tools. Describe the key components of a lubricator and how a lubricator may be used to pull or retrieve removable wellhead equipment.

Safe removal of wellhead equipment. Identify when trapped pressure may be present prior to removal of wellhead equipment, and demonstrate the ability to check for trapped pressure.




2.4 Workover Well Control Practices and Kill Methods

Module Name: 2.4 Workover Well Control Practices and Kill Methods Sub-Modules AIM Learning Topics Learning Objectives and Assessment Guidelines


Practices I

Maintaining a fluid column. Identify reasons why keeping the hole full in workover or completion may not always be an option.

Hole fill and fluid loss.

Choose the correct action to take if filling the hole does not maintain enough hydrostatic (for example, losses of 10 bbl/hr are acceptable but any losses above 60 bbl/hr on a certain job may require a lost circulation material pill).

Tracking fluid loss. Explain the importance of tracking losses when unable to maintain fluid level.

Shut-in procedures for tree components. Demonstrate the ability to shut in the tree at the proper location (for example, using the crown valve to isolate wireline lubricator).

Shut-in procedures. Choose correct procedures for shutting in on downhole equipment and completions (for example, kill stand, Blind Shear Ram, drop the string).

Determining Kill Mud Weight (KMW).

Explain why using shut in tubing pressure may not give an accurate measure of bottomhole pressure and resulting kill mud weight (for example, unknown fluids in tubing). State other ways to measure bottomhole pressure (for example, pressure bomb, quartz gauge, Amerada gauge on wireline).

Bullheading I

Reasons for using Bullheading.

Identify conditions when Bullheading may be preferred to circulation (for example, toxic gas present; unable to handle influx at surface; potential to exceed equipment limitations if circulated to surface).

Basic principles. Describe the basic principles of Bullheading (for example, push the formation fluid back into the formation).

Effect of gas migration. Explain how the rate of gas migration affects the chosen Bullhead rate (for example, circulating rates must overcome the rate of migration).






A Formation limitations.

Describe how a Bullheading operation can fracture the formation (for example, hydrostatic pressure plus surface pressure can exceed formation strength and fracture the formation).

I Mechanical limitations.

Determine the weakest mechanical link in a Bullheading operation

Summarize how to mitigate a mechanical issue (for example, place pressure on the annulus to assist in burst).

I Limiting factor for Bullheading operation. Identify whether it is mechanical or formation limitations that determine the maximum surface pressure that can be applied.

I Determining if Bullheading was a success. Explain the difference between trapped pressure post Bullhead and a well in which hydrostatic is not sufficient to kill the well.

I Flow paths and barriers. Identify the flow paths of kill fluid during a Bullhead operation and the barriers restricting flow elsewhere.

I Detecting initial injection (break-over) and Kill Mud Weight (KMW) hitting the perforations.

Explain difference between rising surface pressure and injection.

I Bullheading procedure and calculations.

Indicate the procedure needed to Bullhead a well from start to finish. Use a kill sheet to prepare for a Bullheading operation. List reasons record keeping during Bullhead operation is important.

I Calculating Bullhead volume. Calculate the volume needed to Bullhead and kill the well.

I Calculating Kill Mud Weight. Calculate Kill Mud Weight (KMW) needed to Bullhead and kill the well.

Volumetric Techniques and Lubricate (Lube) and Bleed

I Applying the Volumetric technique to a workover kill.

Explain the main differences between the Volumetric technique during drilling phase and during workover (for example, fluids in the well, gas migration rates, well configuration, potential leak paths).






Applying the Lube and Bleed technique to a workover kill.

Explain the main differences between a Lube and Bleed technique during drilling phase and during workover (for example, fluids in the well, well configuration, reducing pressure to a level for Bullheading).

Constant Bottomhole Pressure Methods (Forward and Reverse Circulation)

I

Applying Normal Circulation method to a workover kill.

Explain the main differences between a normal circulation kill technique during drilling phase and during workover (for example, potential for greater friction, uncertainty of a clear flow path, integrity of circulating path, different wellbore fluids).

Applying Reverse Circulation method to a workover kill.

Explain the main differences between a normal circulation kill technique during drilling phase and a reverse circulating technique during workover (for example, position of choke in the circulating path, start-up procedure, tubing string friction, different fluids in the well, integrity of circulating path).

2.5 Complications

Module Name: 2.5 Complications Sub-Modules AIM Learning Topics Learning Objectives and Assessment Guidelines


Workover Complications I

Trapped pressure. Explain the occurrence of trapped pressure in a workover operation and give examples of where this may occur.

Workover issues due to mechanically degraded equipment.

Explain and give examples of common failed barriers and mechanical parts occurring during workover. Explain and give examples of how to mitigate failed barriers and mechanical parts (for example, a hole in the tubing that leads to formation communication between the tubing/casing annulus; seals or packer leak; poor cement condition or placement).






Accuracy of well records.

Explain the importance of accurate well records to the workover operation (plan and execution of the plan). List potential data issues with well records and how these inaccuracies can impact the workover plan and execution (for example, lost sinker bars; wireline or other tools left in the hole and never reported; incorrect depth correlation; perforations out of zone or in the wrong place; bridge plugs or cement dumped in the wrong place debris; inaccurate old surveys).

Importance of proven barriers.

Explain the importance of proving a barrier has pressure-retaining capability (for example, never assume a well barrier has integrity until tested; well conditions or data accuracy can mislead rig crews into believing they have barrier integrity; having contingency plans if the barriers installed are not holding pressure or fail during a workover; understanding of maximum pressure that could be trapped below a shallow plug if a lower plug fails).

A

Hydrates – their formation and hazards.

Indicate where hydrates may form, how pressure and temperature influence hydrate formation, and the hazards they present (for example, trapped pressure, equipment blockage).

Hydrate removal and prevention. Explain how hydrates can be removed if they are blocking ram functions or creating a plug (for example, temperature, chemical injection, flow rate).

Paraffin / Asphaltenes.

Describe where paraffin / asphaltenes are found and the problems they can cause (for example, commonly found in older oil producing wells; prevent wireline tools from being run in the hole; plug up valves and surface equipment).

Scale. Explain the problems scale can cause and the potential for contamination and other associated risk.






Bacteria. Explain the causes of bacteria growth (with emphasis on sulfide reducing bacteria) and the problems and associated risk (for example, create H2S; effect on equipment).

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