BUR (drilling)

Test Your Knowledge

BUR Quiz: Build-Up Rate in Drilling

Instructions: Choose the best answer for each question.

1. What does BUR stand for in drilling?

a) Bit Uplift Rate b) Build-Up Rate c) Bottom Up Rate d) Borehole Uplift Rate

2. Which of the following factors does NOT directly influence Build-Up Rate?

a) Mud weight b) Formation properties c) Ambient temperature d) Rotary speed

3. What is a potential consequence of uncontrolled Build-Up Rate?

a) Increased wellbore stability b) Reduced drilling costs c) Wellbore collapse d) Improved trajectory accuracy

4. Which technology allows for real-time monitoring of Build-Up Rate?

a) Mud logging b) Wireline logging c) MWD (Measurement While Drilling) d) Seismic surveys

5. Adjusting which drilling parameter can help control Build-Up Rate?

a) Mud density b) Drilling depth c) Rig horsepower d) Drilling fluid viscosity

BUR Exercise:

Scenario:

A wellbore is being drilled with the following parameters:

• Weight on Bit (WOB): 40,000 lbs
• Rotary Speed: 100 RPM
• Mud Weight: 12.5 ppg

The wellbore is currently at an inclination of 30 degrees. The drilling engineer observes that the Build-Up Rate is 1 degree per 100 feet drilled.

Task:

1. Calculate the expected inclination of the wellbore after drilling 500 feet.
2. Analyze the potential consequences of this BUR for the wellbore stability and trajectory.
3. Suggest two possible actions the drilling engineer can take to control the BUR and achieve the desired trajectory.

Techniques

Chapter 1: Techniques for Managing Build-Up Rate (BUR)

This chapter explores the various techniques employed to manage and control the Build-Up Rate (BUR) during drilling operations.

1.1. Real-Time Monitoring:

• MWD (Measurement While Drilling): This technology transmits data from sensors located in the drill bit to the surface in real-time, providing continuous monitoring of BUR, wellbore inclination, and other crucial parameters.
• LWD (Logging While Drilling): Similar to MWD, LWD utilizes sensors in the drill bit to gather data about the formation being drilled, including formation properties that can influence BUR.
• Geosteering: This technique integrates real-time data from MWD and LWD with geological models to guide the wellbore trajectory and control BUR effectively.

1.2. Adjusting Drilling Parameters:

• Weight on Bit (WOB): Reducing WOB can significantly decrease BUR, especially in formations with low rock strength.
• Rotary Speed: Lowering rotary speed can also minimize BUR, reducing the rate of bit penetration and minimizing the tendency for the wellbore to deviate.
• Mud Weight: Increasing mud weight provides better borehole stability and can help reduce BUR in formations with high pore pressure.
• Bit Selection: Choosing the appropriate bit type and size for the formation being drilled can optimize the drilling process and minimize BUR.

1.3. Directional Drilling Techniques:

• Whipping: This technique involves rapidly alternating the direction of the bit, creating a "whipped" trajectory that helps control BUR and maintain the desired wellbore inclination.
• Walking: This technique uses controlled lateral movements of the bit to steer the wellbore along a specific path, effectively managing BUR and achieving the desired trajectory.
• Sidetracking: In cases where the wellbore deviates significantly from the planned trajectory, sidetracking may be required to re-enter the desired path.

1.4. Wellbore Design:

• Wellbore Trajectory Planning: Designing the wellbore trajectory with an optimized inclination and azimuth is crucial for minimizing BUR and achieving the desired target zone.
• Anticipated Formation Properties: Incorporating knowledge of the expected formation properties during wellbore design can help anticipate BUR and plan appropriate drilling strategies.

Conclusion:

By effectively implementing these techniques, drilling teams can minimize the impact of BUR on wellbore stability, trajectory control, and overall drilling efficiency.