How do you prevent and mitigate wellbore cleaning related incidents and non-productive time (NPT)?

1 Identify wellbore cleaning challenges

The first step to prevent and mitigate wellbore cleaning related incidents and NPT is to identify the potential challenges and risks that may affect the wellbore cleaning performance. These include the well geometry, the drilling fluid properties, the drill string configuration, the hole cleaning tools and practices, the cuttings transport and disposal, and the environmental conditions. By conducting a thorough wellbore cleaning analysis, you can anticipate the possible problems and design a suitable wellbore cleaning program.

2 Optimize drilling fluid properties

The second step to prevent and mitigate wellbore cleaning related incidents and NPT is to optimize the drilling fluid properties, such as density, viscosity, rheology, solids content, and chemical additives. The drilling fluid plays a vital role in wellbore cleaning, as it carries the cuttings from the bottom hole to the surface, lubricates and cools the drill bit and string, and stabilizes the wellbore. By adjusting the drilling fluid properties, you can enhance the cuttings transport efficiency, reduce the risk of differential sticking, avoid excessive pressure losses, and prevent formation damage.

3 Select appropriate drill string configuration

The third step to prevent and mitigate wellbore cleaning related incidents and NPT is to select an appropriate drill string configuration, such as the bit type, the drill collar size and weight, the stabilizer placement, and the nozzle design. The drill string configuration affects the wellbore cleaning performance, as it influences the annular velocity, the turbulence, the hole cleaning efficiency, and the bit performance. By choosing a suitable drill string configuration, you can optimize the hydraulic energy, avoid excessive torque and drag, improve the bit penetration rate, and reduce the vibration and wear.

4 Use effective hole cleaning tools and practices

The fourth step to prevent and mitigate wellbore cleaning related incidents and NPT is to use effective hole cleaning tools and practices, such as reamers, scrapers, brushes, wipers, centralizers, and backreaming. These tools and practices help to remove the cuttings and debris that may accumulate in the wellbore, especially in deviated or horizontal sections, and cause problems such as stuck pipe, hole collapse, or poor cementing. By using effective hole cleaning tools and practices, you can maintain a clean and smooth wellbore, improve the hole stability, and ensure a good cement bond.

5 Manage cuttings transport and disposal

The fifth step to prevent and mitigate wellbore cleaning related incidents and NPT is to manage the cuttings transport and disposal, such as the shaker performance, the solids control equipment, the cuttings injection, and the waste management. These aspects affect the wellbore cleaning performance, as they determine the quality and quantity of the drilling fluid that returns to the surface, the environmental impact of the drilling operation, and the cost of the wellbore cleaning program. By managing the cuttings transport and disposal, you can reduce the drilling fluid contamination, comply with the environmental regulations, and save money and resources.

6 Monitor wellbore cleaning performance

The sixth step to prevent and mitigate wellbore cleaning related incidents and NPT is to monitor the wellbore cleaning performance, such as the drilling parameters, the mud logging data, the real-time measurements, and the post-drilling analysis. These indicators help to evaluate the effectiveness of the wellbore cleaning program, identify any deviations or anomalies that may indicate a problem, and implement corrective actions or improvements if needed. By monitoring the wellbore cleaning performance, you can ensure that the wellbore cleaning objectives are met, avoid any surprises or delays, and learn from the experience.

7 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?