What are the best practices for minimizing lost circulation and wellbore breathing during offshore drilling?

Reduce ECD by using best GPM and drill string. Use correct size and type of LCM to plug the pores. Use MPD and close monitoring the well reactions. Consolidate the lose and permeable formations by correct methods.

Conduct a thorough analysis of the geological formation, pore pressure, and fracture gradient to optimize wellbore design. Implement wellbore stability analysis using advanced software to predict potential lost circulation zones. Opt for casing and cementing programs that provide suitable barriers to prevent lost circulation.

Even with detailed studies there is always the importance to evaluate drilling conditions all the time, there are possibilities that the most advanced studies could not avoid getting into a ballooning/breathing scenario. Practical methods and monitoring play a huge rol in maintaining well integrity, then those results can serve to optimize reservoir modeling, drilling/tripping practices and improve safety and drilling efficiency.

From personal experience what it helped is to add more casing to pass the fractured formation into more solid layers. Check the density and experiment with the drilling fluid to find which works best for that formation, as each formation reacts different so as the fluid should. Also the flow itself could be very crucial so the drillers should also try different approach. The drilling is very unpredictable, in theory and what actually works in practice could be completely different story.

Understanding geology and pore pressure will help in designing suitable drilling fluids and optimizing its properties. The size and dosages of the bridging material, based on the pore throat size , will hep in minimizing the loss problems.

Utilize appropriate drilling fluid systems, such as low-density fluids, to minimize the risk of lost circulation. Incorporate lost circulation materials (LCM) into the drilling fluid to seal fractures and control fluid loss. Maintain a well-engineered mud program that considers fluid rheology, filtration control, and fluid loss control additives.

Loses not only happen during drilling, it may happen during cementing: Two stage cementing, ECP, light cement additives will be useful. Loses may also happen during completion: Use of smart reservoir drilling fluids (Flothru MI or similar) will be useful. This fluids will not allow water based fluids to pass through and prevent loses but it will allow hydrocarbons (oil and/or gas) to pass so during well flow it will be cleaned easily (no need acid or and surfactants).

Methodical use of sweep pills with high concentration of LCM/bridging agents and elastic properties has proven effective for preventing the problem.

Knowing the cause of losses , will help in selecting correct bridging material. Optimize Rheological properties to minimize ECD and monitor annulus pressure to prevent annulus loading. Keeping lowest possible MW for drilling and use of appropriate wellbore sealant, will provide additional layer of protection.

I will list some practices that can minimize circulation losses during offshore drilling, without describing them: -Use of Suitable Drilling Fluids; -Circulation Control System; -Continuous assessment of the well's geology; -Adequate casing system; -Use of additives and cementing systems;

Use of continuous circulation technology does drastically reduce the swab and surge pressure fluctuations during pipe connections. That is an innovative technique that, by means of special subs allows you to never stop the mud pumps during the pipe connections.

Employ advanced monitoring technologies to continuously assess drilling parameters, mud properties, and wellbore stability. Implement a real-time data acquisition system to detect and respond promptly to wellbore breathing or lost circulation events.

Una operación manejada bajo parámetros de perforación controlados sería lo ideal, manteniendo claro está, un seguimiento estricto de los resultados obtenidos con la perforación: presión, retorno volumétrico de cortes en las zarandas, control de torque y presión antes de las conexiones.

There are some sensors in drilling equipment that measure bottom hole pressure while drilling, Schlumberger introduced a service to the client to improve drilling efficiency by measuring bottom hole pressure. An increase in ROP will lead to higher hydrostatic pressure in case there isn’t enough mud circulation to take cutting out of the well. In porous formations, adding lost circulation materials to drilling fluid prevents mud loss.

Preventing annulus loading by minimizing cutting in annulus and optimizing pressure losses , will minimize chances of losses due to higher ECD.

Don’t try to out drill what Mother Nature will let you have. It’s a lot more expensive for redrill. Very easy on and off the slips during connections, flow checks, etc. Utilize MPD equipment on your rig and believe what it tells you.

Remember that each drilling operation is unique, and the best practices should be tailored to specific well conditions and operational requirements. Engaging experienced drilling professionals and considering the advice of industry experts is crucial for successful drilling operations while minimizing lost circulation and wellbore breathing.

Use offset well data to understand the geology and anticipate challenges. Choose the appropriate drilling fluid based on well conditions and formations to help prevent fluid loss. Ensure the mud weight is optimized for wellbore stability. Include LCM in the drilling fluid to bridge and seal fractures or porous zones. Tailor LCM types and particle sizes to the specific loss zones Consider using lightweight cement or other additives for specific well conditions. Utilize wellbore strengthening additives to enhance the mechanical properties of formations and reduce the risk of lost circulation. For example Starshield Employ real-time monitoring systems to detect signs of lost circulation early