QUIZ – ECD management in high-angle and complex wells

While drilling a 12 ¼” hole section the stand pipe pressure limit (maximum pressure that the rig can deliver) is approached. A decision is made to pull out of hole due to an MWD tool failure, but there is still 3,300 ft to drill. For the next run to TD which of the options below would be feasible options for reducing the stand pipe pressure, without adding significant risk for the rest of the section?

What effects ECD:

You have just finished drilling an 8 ½” high-angle reservoir section, which is known to have intervals that are susceptible to weak bedding-plane failure. A full clean-up cycle has been performed, but residual cuttings/caving’s beds are known to exist, with several over-gauge zones.

The next operation will be to run a 7” liner to TD. Based on the data shown on the fixed-depth (TD) swab/surge model, which of the following tripping options would be safest overall. Assume a pulling speed of 3 minutes per stand (range 2 drill pipe), except where otherwise stated.

Which of the following are indicators of borehole instability?

An 8 ½” hole section is drilled in an ERD well (33,000 ft MD; 82° inclination) with 5 ½” drill pipe and a short, light BHA (~200ft) and oil based mud. What would you expect to contribute the most to surge and swab pressures?

What technique for addressing lost returns is shown in the diagram?

While drilling a 16” hole in a potentially pre-fractured formation at over 60 degrees inclination, a high amount of the returns (>50%) contained caving’s as shown in picture #1.
The MW was increased by 1.0ppg but the amount of caving’s increased and now look like those shown in picture #2.

What should be the next course of action?

In a high angle 8 ½” hole section what open hole drilling activity is shown on the chart?

The leak off test shown on the chart was taken below the 13 ⅜” casing shoe. The DSV is ready to make some hole, the geologist has his concerns because the minimum stress is lower than expected. The minimum required leak off is an absolute minimum for well control. Who is correct?

While drilling a high angle 6” section with 4” drill pipe at 20,000 ft, using optimal parameters for hole cleaning,  a crew change takes place and the AD takes over at stand down for the drillers to handover. The keen AD begins reaming the stand up and down before making the connection. When beginning reaming down, partial losses occur, even though there is no change in formation over the stand just drilled. The same parameters are used and average pipe movement speeds remain as per the previous stands. What could have caused the losses?