L&TD

III. ANTI-COLLISION TO PRE-EXISTING WELLBORE WHILE DRILLING - ADVANCED SECURITY SYSTEM (ASS-2002):  

1. Introduction: 

   In drilling from offshore platforms there have been several cases where drilling a new well went directly into another neighboring production well and destroyed the casing of that well. This is due to very narrow well-to-well spacing (distance between the wells is 2.5-3.0m). So there is a demand to employ an Advanced Security System to detect this at an early stage before collision.

    The advanced security system detects the approach of the drill bit to casing of neibouring production wells. Data is sampled at high frequency from vibration sensors (Installed on well heads) and drilling sensors (WOH, RPM, TORQUE, SPP). The system uses the spectrum analyses of vibration signals by Fast Fourier Transform Algorithm. While drilling, if the drill bit   approaches a well then the is increasing and frequency of signal is concentrated in range of 300Hz - 700Hz. This phenomenon occurs more serverly with drilling parameter changes (eg: increasing of torque and/or decreasing of rate of penetration,..).

•  The system provides automated monitoring and detection of clash between the drill bit and casing of other neighboring production wells.

•  Internal Alarm Management (Set High /Low alarm, activates a buzzer when an alarm is detected).

• Printer management (Print out Real-time and Playback logs)
• Data management: Backup and store of Real-time database
• Calibration of the drilling sensors