Advanced MPD Applications: Beyond CBHP

MPD is established as a familiar tool within the drilling industry. The most common application for MPD is holding a Constant Bottom Hole Pressure (CBHP) to enable drilling in narrow windows. Beyond this core function, there is a side benefit from using MPD in its Early Kick and Loss Detection (EKLD) capabilities.

However, MPD’s utility extends into a variety of other applications where CBHP is not the main focus, Including for example Mud Cap Drilling (MCD) and Influx Management. In this article, we’ll explore these methods and other usage areas of MPD going beyond the CBHP approach. 

 

Influx Management

This is possibly the most common application after the CBHP approach. Especially in deepwater operations, where traditional well control becomes problematic due to friction in long choke lines. With MPD, a riser closure device such as an RCD, ACD or Dual Annular is used together with a surface choke or a subsea pump to control and circulate out the influx.

Learn more about how EC-Drill® Dual MPD helps you with Influx Management here.

Mud Cap Drilling

MCD is a method for drilling in loss zones without returns to surface. MPD offers two methods for Mud Cap Drilling – Pressurized Mud Cap Drilling (PMCD) and Controlled Mud Cap Drilling (CMCD).

There are several advantages for using MPD in these conditions. MPD provides continuous monitoring of the annular pressure and pressure management, whereas conventional MCD leaves you “blind” with regards to what is happening in the well. With conventional MCD there is an increased risk for gas migrating up the well, in addition to the mud consumption being higher compared to when using MPD.

Well Design

Improving and simplifying the well design applies especially for deepwater operations. The hydrostatic pressure profile from RKB down to the well misaligns with the operating window which is also commonly narrow in deepwater environments. This leads to multiple sections and a complex well architecture which sometimes requires unusual hole sizes and casing/liner sizes.

By lowering the riser level, the hydrostatic profile aligns better with the operating window. This approach, known as the Dual Gradient Effect, enables the elimination of casings or liners in about 80% of deepwater wells drilled with the Controlled Mud Level (CML).

Read more: 11 Things All Drilling and Completion Engineers Need to Know About MPD

Depletion

Mature fields face depletion which can prevent reaching new areas of the reservoir. This challenge can be addressed with CML, by lowering the level according to actual degree of depletion. In several fields, CML has enabled continuation of drilling and even increasing the length of the wells to unlock reserves otherwise inaccessible. In some of these fields this has been achieved by drilling “conventionally” in the sense that there is no CBHP approach and no pressure management while drilling. The fluid level is kept constant during drilling and connections and is only adjusted for when encountering losses. This approach applies particularly for fields where low density/unweighted fluids still generate too high hydrostatic pressure.

Completion

A more recent development is utilizing MPD in Completion. Particularly Open Hole Gravel Pack with CML has given a significant increase in production. With CML the wells have achieved a full screen out with the Beta-wave compared to former results when the gravel packing ended when losses incurred. CML is now used consistently for Completion to improve production rates.

Insurance

In scenarios involving high-risk formations – either due to potential losses or anticipated pressure ramps – MPD serves as a critical tool. In these cases, MPD is utilized for its ability to increase or reduce the pressure according to actual well conditions. When adjusting the Bottom Hole Pressure (BHP) it is often combined with the CBHP approach, and it is the setpoint value which is moved.

EKLD provides better insurance through improved detection, and reaction, of gains or losses. Additionally, Riser Gas Handling (RGH) can provide an essential safety feature, as it can be used to divert gas from returning to the drill floor.

Check out: What Are Undrillable Wells in 2025 and How to Make Them Drillable 

Conclusion

The evolution of MPD is not limited to equipment and automation improvements. The additional applications have taken MPD to a new level. From being used solely for a CBHP approach for wells otherwise undrillable, the driver for MPD is now more frequently for other purposes such as removing a casing/liner, drilling in mature fields and for Completion. For some wells a combination of these applications is used.

In addition to the drivers for MPD, other side benefits are also discovered and benefited from on a regular basis. The main one is likely tripping in and out with CML, avoiding displacements, saving rig time and leave the formations exposed for a shorter period.

Snorre Lutnes

Snorre works as a Technical Sales Manager for Enhanced Drilling. He has worked within drilling for 20 years primarily with Drilling fluids and MPD. He started his career offshore as a mud engineer before assuming project management roles onshore. After working internationally for a decade, he has returned to Norway moving from an operational role to focusing more on technical sales.