How can you evaluate cement job integrity and detect leaks or channels?

1 Pressure tests

One of the simplest and most common ways to check cement job integrity is to perform pressure tests on the casing and the annulus. Pressure tests involve applying a certain pressure level to the casing or the annulus and monitoring the pressure response over time. If the pressure drops or fluctuates significantly, it indicates a leak or a channel in the cement. Pressure tests can be done before and after the cement has set, and can also be repeated periodically to monitor the cement condition over time.

3 Temperature logs

A third method to evaluate cement job integrity is to run temperature logs in the casing or the annulus. Temperature logs measure the temperature distribution along the wellbore, which reflects the heat transfer between the fluids and the formation. By comparing the temperature logs with the baseline or expected temperature profiles, you can identify leaks or channels in the cement by observing deviations or anomalies in the temperature readings. Temperature logs can also indicate gas migration or fluid circulation in the cement.

4 Tracer surveys

A fourth method to evaluate cement job integrity is to conduct tracer surveys in the casing or the annulus. Tracer surveys involve injecting a tracer substance, such as radioactive material, dye, or chemical marker, into the cement slurry or the annular fluid, and then measuring its concentration or distribution along the wellbore. By tracking the movement and dispersion of the tracer, you can detect leaks or channels in the cement by finding zones of high or low tracer concentration or unexpected tracer locations.

5 Simulation models

A fifth method to evaluate cement job integrity is to use simulation models that can predict the behavior and performance of the cement under various conditions. Simulation models can incorporate various parameters, such as fluid properties, rheology, density, temperature, pressure, well geometry, and formation characteristics, to simulate the cement placement, setting, bonding, and stress. Simulation models can help you design and optimize your cement job, as well as identify potential risks or failures that can cause leaks or channels in the cement.

6 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?