An experimental system for coiled tubing partial underbalanced drilling (CT-PUBD) technique

Area of Science:

• Petroleum Engineering
• Drilling Technology

Background:

• Improving drilling efficiency in hard rock formations is crucial for oil and gas exploration.
• Conventional drilling methods often face limitations in Rate of Penetration (ROP).

Purpose of the Study:

• To introduce and evaluate a new high-speed drilling technique: Coiled Tubing Partial Underbalanced Drilling (CT-PUBD).
• To investigate the hydraulic characteristics and drilling performance of CT-PUBD.
• To validate the feasibility of CT-PUBD for enhancing ROP and ensuring drilling safety.

Main Methods:

• Development and setup of a full-scale laboratory experimental system for CT-PUBD.
• The system incorporates a rotary packer to create differential pressure conditions near the drill bit.
• Key components include a cuttings discharge device, rotary packer, and backflow device.

Main Results:

• Experimental results demonstrate a linear relationship between pressure loss and drilling fluid flow rate.
• CT-PUBD exhibited a significantly higher drilling speed compared to conventional drilling methods.
• The developed experimental system provides a foundational basis for CT-PUBD research.

Conclusions:

• CT-PUBD is a feasible and effective method for enhancing ROP in hard formations.
• The technique contributes to improved drilling efficiency and safety.
• The experimental setup serves as a valuable tool for future CT-PUBD studies.