Subscribe to be notified for updates: RSS Feed

Amna Nawfal Abdulla

Control Engineer, TC-E&P, ADCO

Amna graduated with B.Sc in Electrical Engineering from the American University of Sharjah (AUS). She started working in Abu Dhabi Company for Onshore Petroleum Operations Ltd. (ADCO) in June 2008. Currently she is working in the Technical Center – Engineering and Projects (TC-E&P) department. She is responsible for developing company standards and investigating technical problems.

New Design of HIPSS for Onshore wells

Functional Safety & SIS

Abstract: HIPPS (High Integrity Pressure Protection System) is an SIS (Safety Instrumented System) that is approved in API 521 to provide safe economical overpressure protection of a well flow line by detecting unacceptable high operating pressure and initiate closure of SSVs (surface safety valves) on the wellhead piping. As an SIS, HIPPS consists of redundant sensor, logic solver, redundant solenoid and single or redundant shutdown valve. Normally the logic solver is a safety PLC (Programmable Logic Controller) that requires field operators with special skills to maintain and can become obsolete more than once over the well life. The greatest challenge to HIPPS implementation is the long term inspection, preventive maintenance and proof testing required for maintaining its high SIL (Safety Integrity Level). When an onshore oil field has many wells scattered across large desert area, this becomes quite a cumbersome task. The risk of overpressure especially in sour wells results in the need of high SIL of the HIPPS loop (usually SIL 3 and minimum SIL 2). This paper presents a design of well flow line HIPPS that uses simple hardwired logic installed in the WHCP (Well Head Control Panel) as logic solver rather than a safety PLC in a separate panel. It utilizes the HIPPS valve(s) for other well surface safety functions as well as for remote well closing which should meet the target SIL with extended proof TI (Test Interval). The design doesn’t need personnel with special skills to operate and maintain and it ensures the system is frequently tested and remains healthy all the time.

Copyright 2013 DMS Global - Design by DMS Cybernation