Slide 1

Leak Detection & Well Integrity

To be able to

Identify the need for leak detection log.

Identify different leak detection techniques.

Identify the need for Time-Lapse technique.

Objectives

2

Casing and Tubing Corrosion costs the oil industry Billions of dollars annually. This does not include the cost of Lost Oil underground through leaks and cross-flows caused by corrosion. Many of our wells producing today were completed decades ago when corrosion control and corrosion monitoring were not a primary concern.

As a result of this, most wells are either closed down or producing below their potential. Hence, Corrosion monitoring, prevention and control feature as the prominent steps in efforts to extend the life of wells and increase Hydrocarbon recovery.

Technological advances can now help in predicting corrosion hot-spots and can offer options for quick preventive measures to arrest the corrosion rate and provide rectification.

Impact on Corrosion Losses to our Business

Leak Detection Techniques

Spinner

Temperature

Noise

Mechanical

Electromagnetic

Spinner

Application

Physical measurement (direct contact) of flow

Casing leak

Single tubing and/or accessories leak

How

Spinner measure fluid movement.. Hence they are used to detect flow phenomena..

Example

Temperature

Application

Casing leak (may detect across tubing as well/)

Tubing and/or accessories leak

Behind casing channelling but be extra cautious on this type of evaluation

How

Temperature react to fluid entry.. Be it warming or cooling effect..

Example

Example: Water Channelling

Example: Gas Channelling

Noise

Application

Casing leak

Single tubing and/or accessories leak

Reservoir flow and channel behind casing (new application)

How

Noise generated based on various differential pressure and flowrate.. The leak need to be active in order for it to be detected..

Example

Example: Ultrasonic (Leak Point Tool)

Courtesy: TGT

Courtesy: TGT

Mechanical Caliper

Application

Monitor casing and tubing thickness

Monitor any deposits build-up

How

Use multi-caliper radii measurements to reconstruct internal geometry of pipe..

Principle: Finger Map

Perf Map

Example

Example: MIT Image

Electro/Magnetic

Application

Monitor casing and tubing (preferably single tubing cases) thickness

How

Magnetic wave is emitted.. At areas where there is corrosion or missing metal, the magnetic field "leaks" from the steel..

24

Principle

Courtesy: Baker

Example: Vertilog Baker Inner Defect

Courtesy: Baker

Example: Vertilog Baker Outer Defect

Courtesy: Baker

Example: MTT GE Sondex

Courtesy: GE Sondex

Courtesy: GE Sondex