Asset Integrity Management. Enhance Process Safety

Transcription

1 Asset Integrity Management To Enhance Process Safety S.K.Bagchi Addl. Director (Asset Integrity) Oil Industry Safety Directorate

2 SIZE OF THE HYDROCARBON INDUSTRY IN INDIA Total installed refining capacity Oil production capacity Gas production capacity Gas Pipeline Volume of POL handling Crude & Product pipeline : ~ 194 MMTPA : ~ 38 MMTPA : ~ 130 MMSCMD : ~ 14,000 km : ~ 145 MMTPA : ~ 26,000 km

3 ASSETS OF PROCESS PLANTS ARE INHERENTLY HAZARD PRONE Assets of process plants are inherently hazard prone due to the following reasons: Large inventory of petroleum products are highly inflammable; Processing at high pressure, temperature; Using hazardous chemicals; High complexity & process integration; Loss of containment results in Fire/Explosion; and, History of major incidents in India & abroad

4 TESRO ANACORTES REFINERY Date of accident April 2, 2010 Catastrophic Rupture of Heat Exchanger Seven Fatalities

5 TESRO ANACORTES REFINERY Post-Incident View of D/E/F NHT Heat Exchanger Bank The naphtha and hydrogen likely auto ignited upon release into the atmosphere, creating a large fireball.

6 The Incident TESRO ANACORTES REFINERY Catastrophic Rupture of Heat Exchanger in Catalytic Reformer / Naphtha Hydrotreater Unit. Workers were in the final stage of start up activities of A/B/C bank of HE after cleaning. The D/E/F HE remained in service during this operation. E exchanger in the middle of D/E/F bank catastrophically ruptured. Seven fatalities (1- shift supervisor, 6- operators) Highly flammable hydrogen and naphtha at more than 500 deg. F released from the ruptured HE The naphtha and hydrogen auto ignited upon release into atmosphere.

7 TESRO ANACORTES REFINERY Key Findings The CS HE shell failed due to High Temperature Hydrogen Attack (HTHA). API 941- Nelson curve: Cr-Mo steel & SS better & safe material than CS The welds of exchanger shell were not post weld heat treated. Rupture took place in the unclad portion of pressure containing shell. Tesoro did not monitor actual operating conditions of the B and E exchangers Inspection for HTHA is very difficult. It may be microscopic and may be present in small localised area. Specific technique and skill of the inspector is required. This is a difficult inspection challenge.

8 TESRO ANACORTES REFINERY Process Flow of NHT Unit

9 TESRO ANACORTES REFINERY Example of Fouling Deposits on the Inside of Heat Exchanger Tubes. Fouling greatly reduces heat transfer between the shellside and tube-side process fluids.

10 TESRO ANACORTES REFINERY Figure- Fabrication layout of the B and E heat Exchangers

11 TESRO ANACORTES REFINERY Figure -Circumferential Weld Damage in the B Heat Exchanger.

12 TESRO ANACORTES REFINERY Lesson Learnt: Inherently safe material (Cr-Mo steel & SS) could have prevented the Heat Exchanger shell rupture. (Design) Monitoring of actual operating conditions of the B and E exchangers should have been done. (Production) HTHA was not identified by Inspection. (Inspection) Repair / replacement of damaged shell of heat exchanger due to HTHA was not carried out. (Maintenance) Difficult inspection challenge to identify HTHA (Inspection)

13 ASSET INTEGRITY

14 ASSET INTEGRITY MANAGEMENT SYSTEM Key components: Design, fabricate and install all facilities and equipment in accordance with applicable industry codes and recognised best practices. Operate facilities and equipment within design tolerances and within the safe operating envelope. Routinely inspect and maintain equipment in accordance with industry codes and recognised practices, including manufacturer recommendations where appropriate. Analyse equipment failures to determine their cause.

15 ASSET INTEGRITY MANAGEMENT SYSTEM Conduct all related tasks using trained and qualified individuals who use approved procedure and complete the tasks as scheduled. Use high quality parts and materials, including a system for positive material identification (PMI). Maintain an equipment archive with up to date equipment history. Safely dismantle and dispose of the facility at the end of its life cycle. A systematic implementation of the above will help in preventing accidents.

16 COMMON CAUSES OF INCIDENTS Maintenance, Inspection Related- Not adhering to PMS schedule Delay in handing equipment for Inspection Overstretching equipment run Postponement of Tank M&I & Annual Turnaround schedule Mechanical seal failures Improper maintenance practices Impaired safety critical items for long time Integrity of flame proof fittings not maintained Not undertaking proper inspection upon repair

17 RISK BASED INSPECTION What is RBI- RBI is a method for using Risk as a basis for prioritising and managing the efforts of an inspection program. In an operating plant, a relatively large percentage of the risk is associated with a small percentage of equipment items. These potential high-risk components can require greater attention through a revised inspection plan RBI permits the shift of Inspection & Maintenance resources to provide a higher level of coverage on the high risk items and an appropriate effort on lower risk equipment.

18 RISK ANALYSIS PROBABILITY INTERNAL CORROSION EXTERNAL CORROSION CRACKING & OTHERS RISK CONSEQUENCE Release of flammable/ Toxic material Release of excessive pressure Environment damage Production loss

19 . RISK MATRIX

20 . MANAGING ACCEPTABLE RISK

21 MANAGING ACCEPTABLE RISK Risk Based Inspection R I S K Risk with Typical Inspection Program Risk Using RBI Uninspectable Risk INSPECTION COSTS (level of inspection activities)

22 . THE TRANSITION

23 . RBI PLANNING PROCESS

24 MULTIDISCIPLINARY TEAM inspector maintenance corrosion engineer operator process engineer

25 Benefits from RBI Implementation Optimise Inspection expenditure by focussing on high risk items and employ most appropriate inspection technique to reduce operating risk. Extension of turn around interval Reduction of turn around period as some inspection can be done on stream. Increase inspection efficiency and effectiveness Reduce risk exposure and increase safety and reliability of the plant

26 Reliability Centered Maintenance (RCM) (Best suited for Rotary, Instrument & light Electrical items)

27 Role of RCM RCM is a technique for developing a most cost effective PM program. The elimination of counter productive tasks leads to more effective maintenance. RCM creates awareness in Maintenance professionals regarding six patterns of failures. Maintenance professionals, as such, comes to terms with the reality of randomness after decades in bathtub. An awareness of these facts has led some organisations to abandon the idea of PM altogether for failures with minor consequences.

28 F A Failure is not dependent on age B C D E F

29 RCM Process Overview STEP-1 RCM process determines the functions and associated performance standards of the assets in its present operating context. Output, Thru put, Quality Safety & Environmental Integrity, Quality STEP-2 RCM process identifies the ways in which the asset can fail to live up to these expectations (failed states)..

30 RCM Process Overview STEP-3 Then follows FMECA (failure modes and effects criticality analysis), to identify all the events which are reasonably likely to cause each failed state. STEP-4 RCM process seeks to identify a suitable failure management policy for dealing with each failure mode in the light of its consequences and technical characteristics..

31 RCM Process Overview STEP-5 The RCM process provides powerful rules based on RCM decision logic diagram and decides whether any failure management policy is technically appropriate and worth doing. Failure management policy options include: predictive maintenance preventive maintenance detective maintenance change the design or configuration of the system change the way the system is operated run-to-failure.

32 RCM Process Overview Failure Management Basics The consequences of failures are far more important than their technical characteristics. Proactive maintenance is not to avoid failure per se, but to avoid or at least to reduce the consequence of failure. It also encourages us to think more broadly about different ways to manage failure, rather than to concentrate only on failure prevention.

33 BENEFITS OF RCM Greater safety and environmental integrity Improved operating performance(output, product quality and customer service) Greater maintenance cost effectiveness Longer useful life of expensive items A comprehensive data base Better team work.

34 . THANKS