METHODS OF DEFLECTING A WELLBORE con't 3
Downhole Motor
- Turbodrills have been around for many years but are seldom used for directional drilling
- Turbodrills have very high rotary speeds (500 to 1200 rpm)
- Because of the high rpm, bit life is limited
- Diamond and PDC bits are more applicable to turbodrills
- Turbodrills have low starting torque
- If the motor is in a bind, it is hard to get the motor started
- Turbodrills are used in directional drilling where the temperature exceeds the limit of a positive displacement motor
Positive displacement motors were introduced in the 1960’s
Rotor/stator configuration
Speed (RPM) / Torque (Ft-Lbs.)
- For best performance, the power section should be matched to the bit and formation being drilled. The speed and torque of a power section is directly linked to the number of lobes on the rotor and stator. The higher the number of lobes, the higher the torque and the lower the RPM.
Dump sub
- Not often used
- Allows string to fill or drain when tripping
- Allows low volume circulation in stuck bit situations
Power pack section
Rotor is hard
Stator is flexible
Stator housing is thin
PDM is not a drill collar
- Reverse application of the Moineau pump principle
- Elastomer lined - steel tube stator
- Chrome coated steel rotor
- Converts Hydraulic HP (flow & pressure) to Mechanical HP (rpm & torque) There are three main producers of motor power sections in the world:
Typical PDM power curve
- Rotor is coupled to transmission
- Transmission shaft is coupled to the bearing pack
- The adjustable bent housing enables the bend to be changed at the wellsite
- The housing can be adjusted 0.26 to 3.0 degrees depending upon motor size
Bearing function
- On bottom thrust bearings carry force from the bit (WOB)
- Off bottom thrust bearings carry the hydraulic load of the mud and weight of the rotor
- Radial bearings carry side loads
- Flow restrictor diverts a portion of the mud for lubrication
Advanced Reservoir Engineering
Advanced
Reservoir
Engineering
Reservoir
Engineering
Tarek Ahmed
Senior Staff Advisor
Anadarko Petroleum Corporation
Paul D. McKinney
V.P. Reservoir Engineering
Anadarko Canada Corporation
Senior Staff Advisor
Anadarko Petroleum Corporation
Paul D. McKinney
V.P. Reservoir Engineering
Anadarko Canada Corporation
Dedication
This book is dedicated to our wonderful and understanding wives, Shanna Ahmed and Teresa McKinney, (without whom this
book would have been finished a year ago), and to our beautiful children (NINE of them, wow), Jennifer (the 16 year old
nightmare), Justin, Brittany and Carsen Ahmed, and Allison, Sophie, Garretson, Noah and Isabelle McKinney.
book would have been finished a year ago), and to our beautiful children (NINE of them, wow), Jennifer (the 16 year old
nightmare), Justin, Brittany and Carsen Ahmed, and Allison, Sophie, Garretson, Noah and Isabelle McKinney.
The primary focus of this book is to present the basic
physics of reservoir engineering using the simplest and
most straightforward of mathematical techniques. It is only
through having a complete understanding of physics of
reservoir engineering that the engineer can hope to solve
complex reservoir problems in a practical manner. The book
is arranged so that it can be used as a textbook for senior
and graduate students or as a reference book for practicing
engineers.
Chapter 1 describes the theory and practice of well testing
and pressure analysis techniques, which is probably one
of the most important subjects in reservoir engineering.
Chapter 2 discusses various water-influx models along with
detailed descriptions of the computational steps involved in
applying these models. Chapter 3 presents the mathematical
treatment of unconventional gas reservoirs that include
abnormally-pressured reservoirs, coalbed methane, tight
gas, gas hydrates, and shallow gas reservoirs. Chapter 4
covers the basic principle oil recovery mechanisms and the
various forms of the material balance equation. Chapter 5
focuses on illustrating the practical application of the MBE
in predicting the oil reservoir performance under different
scenarios of driving mechanisms. Fundamentals of oil field
economics are discussed in Chapter 6.
physics of reservoir engineering using the simplest and
most straightforward of mathematical techniques. It is only
through having a complete understanding of physics of
reservoir engineering that the engineer can hope to solve
complex reservoir problems in a practical manner. The book
is arranged so that it can be used as a textbook for senior
and graduate students or as a reference book for practicing
engineers.
Chapter 1 describes the theory and practice of well testing
and pressure analysis techniques, which is probably one
of the most important subjects in reservoir engineering.
Chapter 2 discusses various water-influx models along with
detailed descriptions of the computational steps involved in
applying these models. Chapter 3 presents the mathematical
treatment of unconventional gas reservoirs that include
abnormally-pressured reservoirs, coalbed methane, tight
gas, gas hydrates, and shallow gas reservoirs. Chapter 4
covers the basic principle oil recovery mechanisms and the
various forms of the material balance equation. Chapter 5
focuses on illustrating the practical application of the MBE
in predicting the oil reservoir performance under different
scenarios of driving mechanisms. Fundamentals of oil field
economics are discussed in Chapter 6.
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