QUOTES

“The Heavelock is needed for almost any offshore MPD operation, except maybe the Caspian”
– Industry expert with strong MPD knowledge.


“Any floater offshore will benefit from this product if it requires MPD for safely drilling the formations.”
– Industry expert with strong MPD market and technology knowledge.

HEAVING DOWNWARDS

DURING CONNECTIONS, THE DRILLSTRING MOVES TOGETHER WITH THE RIG, CAUSING FLUCTUATING DOWNHOLE PRESSURES.

When the string moves downwards, there is a sudden increase in downhole pressure, which can surpass fracture pressure and severely damage well.

HEAVING UPWARDS

DURING CONNECTIONS, THE DRILLSTRING MOVES TOGETHER WITH THE RIG, CAUSING FLUCTUATING DOWNHOLE PRESSURES.

When the string moves upwards, there is a sudden decrease in downhole pressure. If downhole pressure falls below the pore pressure it causes well to start producing, which may lead to kicks and in the absolute worst case scenario: blow out.

HEAVING DOWNWARDS

DURING CONNECTIONS, THE DRILLSTRING MOVES TOGETHER WITH THE RIG, CAUSING FLUCTUATING DOWNHOLE PRESSURES.

When the string moves downwards, there is a sudden increase in downhole pressure, which can surpass fracture pressure and severely damage well.

HEAVING UPWARDS

DURING CONNECTIONS, THE DRILLSTRING MOVES TOGETHER WITH THE RIG, CAUSING FLUCTUATING DOWNHOLE PRESSURES.

When the string moves upwards, there is a sudden decrease in downhole pressure. If downhole pressure falls below the pore pressure it causes well to start producing, which may lead to kicks and in the absolute worst case scenario: blow out.

HEAVING DOWNWARDS

When using Heavelock these harmful pressure fluctuations are cancelled out.

When the string is moving downwards, there is in effect “too much” mud concentrated downhole, causing the sudden pressure increase. The Heavelock valve autonomously detects this and constricts drill string flow, balancing out the downhole pressure.

HEAVING UPWARDS

When using Heavelock these harmful pressure fluctuations are cancelled out.

When the string moves upwards, there is in effect a lack of mud downhole, causing the pressure to drop. The Heavelock valve autonomously detects this and opens up for increased flow from drill string to the hole, balancing out the downhole pressure.

HEAVING DOWNWARDS

When using Heavelock these harmful pressure fluctuations are cancelled out.

When the string is moving downwards, there is in effect “too much” mud concentrated downhole, causing the sudden pressure increase. The Heavelock valve autonomously detects this and constricts drill string flow, balancing out the downhole pressure.

HEAVING UPWARDS

When using Heavelock these harmful pressure fluctuations are cancelled out.

When the string moves upwards, there is in effect a lack of mud downhole, causing the pressure to drop. The Heavelock valve autonomously detects this and opens up for increased flow from drill string to the hole, balancing out the downhole pressure.

THE TECHNOLOGY

Sensing the movement of the drillstring

The Heavelock™ is a result of many years collaboration between the leading Norwegian technical university, NTNU, and Statoil. Together with the Research Council of Norway this strong constellation of partners is developing Heavelock, an autonomous sub for use where pressure windows are tight. This is typically while drilling through the reservoir section. Experiencing even small fluctuations in pressure, around 2-3 bars, can lead to both dangerous and costly consequences such as kicks and formation damage.

The Heavelock works by autonomously sensing the movement of the drillstring, and dynamically allowing or restricting flow through it is able to efficiently counteract the detrimental pressure changes that arise downhole due to heave of the rig.

ENABLING MPD FROM FLOATERS

Heavelock solves one of the very few remaining obstacles

MPD from floaters has been proposed as the solution to this problem, but it will only work as long as there is very little heave of the rig. Once rig heave is a factor and a connection is to be performed, the drillstring starts moving up and down into the hole acting like a piston. The pressure changes from this are shown to be very large – as high as in the range of 10-20 bars in given cases. In other words: Almost 10 times more than what is needed for MPD in general.

Therefore we are able to say that the Heavelock solves one of the very few remaining obstacles for offshore MPD to become a reality.