IWCF Driller's Study Guide

Introduction

This study guide is designed to help candidates preparing for the IWCF Drilling Well Control Level 3 (Driller) assessment. It provides a structured review of the key knowledge areas covered during training and assessment.

Target Audience:

• Drillers
• Assistant Drillers
• Derrickmen progressing to Driller positions
• Drilling Supervisors seeking refresher training

 

How to Use This Guide

Before attending the course:

✓ Read each section thoroughly

✓ Review key formulas

✓ Complete practice questions

✓ Familiarize yourself with well control terminology

✓ Practice calculations regularly

 

Module 1: Well Control Fundamentals

Understand the principles of primary and secondary well control.

What is Well Control?

Well control is the process of maintaining pressure in the wellbore to prevent the uncontrolled flow of formation fluids.

Primary Well Control

Primary well control is achieved using drilling fluid (mud) to maintain hydrostatic pressure greater than formation pressure.

Secondary Well Control

Secondary well control involves:

• Blowout Preventers (BOPs)
• Choke Manifolds
• Kill Procedures

Used when primary control fails.

 

Key Definitions- 

 

Formation Pressure

Pressure exerted by fluids within a formation.

 

Hydrostatic Pressure

Pressure exerted by the column of drilling fluid.

 

Bottom Hole Pressure (BHP)

Total pressure acting at the bottom of the well.

 

Kick

An undesired influx of formation fluid into the wellbore.

 

Blowout

Uncontrolled flow of formation fluids to surface.

 

Module 2: Pressure Concepts

 

Hydrostatic Pressure Formula

P=0.052×MW×TVDP

Where:

• P = Hydrostatic Pressure (psi)
• MW = Mud Weight (ppg)
• TVD = True Vertical Depth (ft)

Example

Mud Weight = 10 ppg

TVD = 10,000 ft

Hydrostatic Pressure:

= 0.052 × 10 × 10,000

= 5,200 psi

 

Pressure Relationships - 

 

Bottom Hole Pressure

BHP = Hydrostatic Pressure + Surface Pressure

 

Formation Pressure

If Formation Pressure exceeds BHP:

Kick enters well.

 

Module 3: Causes of Kicks

 

1. Insufficient Mud Weight

• Most common cause.
• Hydrostatic pressure becomes less than formation pressure.

 

2. Swabbing

• Occurs when pulling pipe too quickly.
• Creates pressure reduction below bit.

 

3. Lost Circulation

• Loss of mud to formation reduces hydrostatic pressure.

 

4. Failure to Fill Hole

• While tripping out:
• Failure to replace steel volume removed from well causes reduction in hydrostatic pressure.

 

5. Gas-Cut Mud

• Gas entering mud decreases density and hydrostatic pressure.

 

Module 4: Kick Detection

 

Flow Indicators:-

1. Increased Flow Rate - Flow out exceeds flow in.
2. Pit Gain
3. Increase in active pit volume.

 

Drilling Break:-

Sudden increase in rate of penetration.

Increase in Background Gas

Gas readings increase unexpectedly.

Reduction in Pump Pressure

Possible influx indication.

 

Tripping Indicators

 

Trip Tank Gain

Unexpected fluid gain.

Hole Not Taking Fill

May indicate influx.

 

Module 5: Shut-In Procedures

 

Driller's Method of Shut-In

Steps

1. Stop drilling.
2. Space out.
3. Stop pumps.
4. Observe Flow.
5. Close BOP.
6. Record pressures.

 

Important Pressures

 

SIDPP

• Shut-In Drill Pipe Pressure
• Indicates underbalance in the well.

 

SICP

• Shut-In Casing Pressure
• Pressure measured at casing side.

 

Pit Gain

• Total influx volume.

 

Module 6: Blowout Preventer Equipment

 

Annular Preventer

Functions:

• Seal around drill pipe
• Seal around casing
• Seal open hole (limited)

Advantages:

• Versatile sealing capability

 

Ram Preventers

 

Pipe Rams

Seal around specific pipe size.

Blind Rams

Seal when no pipe present.

Shear Rams

Cut pipe and seal well.

 

BOP Control System

Components:

• Accumulators
• Control Panels
• Hydraulic Lines
• Regulators

 

Module 7: Choke Manifold

 

Purpose

Controls pressure while circulating influx from well.

Functions:

• Maintain Bottom Hole Pressure
• Direct flow safely
• Control well during kill operation

 

Components

• Adjustable Choke
• Fixed Choke
• Kill Line
• Choke Line
• Pressure Gauges

 

Module 8: Well Kill Methods

 

Driller's Method

 

First Circulation

Remove influx using original mud weight.

 

Second Circulation

Pump kill mud.

Advantages:

• Simple
• Quick to initiate

Disadvantages:

• Requires two circulations

 

Wait and Weight Method

 

Procedure

1. Calculate Kill Mud Weight.
2. Mix kill mud.
3. Circulate influx while introducing kill mud.

Advantages:

• One circulation

Disadvantages:

• Requires accurate calculations

 

Module 9: Kill Sheet Calculations

 

Kill Mud Weight Formula

KMW=OMW+SIDPP/(0.052×TVD)

Where:

• KMW = Kill Mud Weight
• OMW = Original Mud Weight

 

Example

OMW = 10 ppg

SIDPP = 520 psi

TVD = 10,000 ft

KMW:

= 10 + (520 ÷ 520)

= 11 ppg

 

Module 10: Gas Behavior

 

Boyle's Law

Gas volume increases as pressure decreases.

Important during:

• Tripping
• Gas migration
• Circulating kicks

 

Gas Expansion

As gas rises:

• Pressure decreases
• Volume increases
• Surface pressures increase

 

Module 11: Well Control During Tripping

 

Tripping Out

Risks:

• Swabbing
• Failure to fill hole

Controls:

• Monitor trip tank
• Maintain fill-up schedule
• Control pulling speed

 

Tripping In

Risks:

• Surge pressures

Controls:

• Maintain controlled running speed
• Monitor pressures

 

Module 12: Barrier Philosophy

 

Primary Barrier

Drilling fluid hydrostatic pressure.

 

Secondary Barrier

BOP system.

 

Tertiary Barrier

Contingency systems and intervention methods.

 

Frequently Tested IWCF Questions

 

Q1 - What is the first indication of a kick while drilling?

Answer: Increase in flow rate and pit gain.

Q2 - What does SIDPP represent?

Answer: Difference between hydrostatic pressure and formation pressure acting through drill pipe.

Q3 - What is the purpose of the choke?

Answer: Maintain Bottom Hole Pressure while circulating influx.

Q4 - What causes swabbing?

Answer: Pulling pipe too quickly causing pressure reduction below bit.

Q5 - Why is gas dangerous during circulation?

Answer: It expands as it rises, increasing surface pressure.

 

IWCF Driller Exam Preparation Checklist

 

One Week Before Assessment

✓ Review all course notes

✓ Practice kill sheet calculations

✓ Understand BOP components

✓ Review kick indicators

✓ Review shut-in procedures

✓ Study well kill methods

 

One Day Before Assessment

✓ Review formulas

✓ Complete mock test

✓ Verify calculator operation

✓ Get adequate rest

 

Key Formulas Summary

Hydrostatic Pressure- 

P=0.052×MW×TVDP 

 

Kill Mud Weight- 

KMW=OMW+SIDPP/(0.052×TVD)​

 

Final Advice

The IWCF Driller assessment is designed to test your understanding of:

• Kick detection
• Well shut-in procedures
• Pressure concepts
• BOP equipment
• Choke operations
• Well kill methods
• Barrier management

 

Focus on understanding why actions are taken during a well control event, not just memorizing procedures. Candidates who understand pressure relationships, kick behavior, and kill operations generally perform much better during both the written and practical assessments.