TDH Software Quiz | Merlin ERD

2. When taking the rotating off bottom weight close to TD in the S-shape well shown, which point shown above is experiencing the highest side force?

3. On the drillers torque view below, the torque at 0.40 friction factor is below the torque limit of the drill pipe. Is it safe to assume that drilling with that torque close to TD is within the drill string limit?

4. On the tension profile chart above it is seen that the slack-off ability will be lost for a friction factor higher than 0.2 and the pickup force will exceed the tensile limit for the friction factor above 0.3. How this should be addressed during a well design phase? Tick the correct answer(s).
- Increase the weight below the buckling point to increase tension throughout the buckled interval and therefore eliminate buckling.
- Ensure the friction factor does not exceed 0.2 for slack-off and 0.30 for pickup through good hole-cleaning practices and use of lubricants. If necessary, run in hole with rotation to prevent buckling. Document actions in an operating procedure.
- Reduce the weight of the lower part of the drill string to reduce drag, possibly eliminating compression in the drill string that leads to buckling and reducing tension while picking up. This will increase the operating envelope of the drill string.

5. Driller is picking up the string from 4,000m MD, after rotating the string at 60 RPM for 30 seconds. What should be the stroke-up length at the surface to collect true pick-up force? Also, what should be the stroke down length to collect a true slack-off force?

6. The chart above shows a slack-off weight for a floated casing run. At what depth has the floatation collar been installed?

7. You are in charge of designing a 4.5 in liner running string and creating an operating procedure for the liner run. You know that the liner hanger system supplier requires a 45k lb setting weight. You run the T&D model and the results are shown below. What could you try changing in the string to be able to transfer the required weight to the liner top packer? Tick the correct answer(s).
- Increase the length, size and weight of HWDP.
- Move the HWDP higher up and place the drill pipe in the curve.
- Use a swivel tool above the liner hanger.

9. You are about to trip out from a 6” hole section. What is the best way to manage swab in this case?

10. You are required to lower standpipe pressure in a 6” hole section as the pop-off valve limit (4,000PSI) is exceeded for the required flow rate of 250 GPM. Reduction in flow rate is not possible. Rheology has been optimised for effective hole cleaning and will likely not change. The BHA configuration is fixed and defined by the LWD requirements, and the mud weight cannot be lowered because of wellbore stability requirements. What actions should you take based on the chart above? Tick the correct answer(s).
- Optimise the tool joint OD and ID – select the custom 4” string.
- Optimise ID of the 4” drill pipe.
- Optimise the bit pressure drop.

11. A 6” hole is planned to be drilled with a 250 GPM flow rate in a well that reaches horizontal at 5,000 ft MD. The rule of thumb for effective and efficient hole cleaning says that an annular velocity of 150 ft/min is required. This requirement is satisfied for the 6” hole section. Is it safe to assume that hole cleaning is not an issue considering that sufficient string RPM and good rheology and good wellbore stability are observed throughout this section?

12. A 6” hole is planned to be drilled with a 250 GPM flow rate in a well that reaches horizontal at 5,000 ft MD. The rule of thumb for effective and efficient hole cleaning says that an annular velocity of 150 ft/min is required. This 12. You are running a tool in the string approx. 5,000ft from the bit. The tool is rated to 10,000 PSI differential pressure. Can you run that tool based on the pressure profile on the chart? The red line is pressure in the string, blue represents pressure in the annulus.

13. While tripping out of the 8 ½” open hole you plan to lubricate out of the hole to the previous casing shoe, mitigating formation collapse risk. The swab/surge driller’s view without pumps on is presented on the image above. Inside the casing shoe, you decided to pull the string on elevators. Has the risk of collapsing 8 ½” open hole been mitigated?

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