Bentley Case Studies ZADCO's Use of SACS for Restoration of Ship-Impacted Wellhead Platform

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	ZADCO's Use of SACS for Restoration of Ship-Impacted Wellhead Platform Bentley

ZADCO's Use of SACS for Restoration of Ship-Impacted Wellhead Platform

Bentley

Technology Category	Drones - Drone Payloads & Accessories Platform as a Service (PaaS) - Application Development Platforms
Applicable Industries	Marine & Shipping Transportation
Applicable Functions	Maintenance Quality Assurance
Use Cases	Infrastructure Inspection Structural Health Monitoring
Services	Testing & Certification
Challenge	Zakum Development Company (ZADCO) faced a significant challenge when a 1,600-ton marine vessel collided with an operating wellhead platform in the Upper Zakum oil field, located offshore of Abu Dhabi, United Arab Emirates. The impact threatened the structural integrity of the platform, causing a 6.6 percent loss in platform strength. The platform was capable of surviving seasonal storms post-impact, but could only support the landing of helicopters and docking of light vessels. With oil production halted until repairs could be carried out, ZADCO was tasked with quickly assessing and repairing the platform to minimize losses, ensure safe startup, and avoid environmental pollution. The company also needed to substantiate the accident and resulting damage for an insurance claim. The structural analysis of the platform was complicated by several factors, including the absence of a current SACS model for the required analyses, unreliable vessel speed data for modeling the impact, and the difficulty of modeling the nonlinear soil-pile interaction in combination with a nonlinear inelastic structure. Read More
About Customer	Zakum Development Company (ZADCO) is a leading oil company developing the Upper Zakum field, the fourth largest oil field in the world, on behalf of Abu Dhabi National Oil Company (ADNOC) and shareholders in the joint venture between ADNOC, ExxonMobil, and Japan Oil Development Company Ltd. ZADCO is committed to managing the Upper Zakum field in a way that is safe, efficient, and environmentally responsible. The company faced a significant challenge when a marine vessel collided with an operating wellhead platform in the field, causing a halt in oil production and threatening the structural integrity of the platform. ZADCO's primary objective was to quickly assess and repair the platform to minimize losses and ensure safe startup, while also substantiating the accident and resulting damage for an insurance claim. Read More
Solution	ZADCO decided to conduct a rapid, iterative boat-impact analysis in-house using various SACS modules. These included SACS Precede for platform modeling and load application, SACS PSI for pile and soil property modeling, and SACS Collapse for non-linear boat impact analysis and parameter coding, and for result verification. The non-linear boat impact analysis performed in the SACS Collapse module helped to accurately simulate the post-impact behavior of the platform and the spread of damages. ZADCO performed a linear static in-place analysis to assess the damage caused by the impact and verify whether the damaged platform’s primary members and piles were safe for a one-year storm event. The team also carried out detailed dent mapping, and subsea and topside inspections. By conducting impact analyses with SACS, ZADCO was able to optimize the scope of the inspections and focus attention on critical subsea nodes that required a more detailed review. The optimized inspection scope and schedule allowed work to be performed within the narrow window dictated by weather conditions. Read More Log in to view content
Contents

Technology Category

Drones - Drone Payloads & Accessories

Platform as a Service (PaaS) - Application Development Platforms

Applicable Industries

Marine & Shipping

Transportation

Applicable Functions

Maintenance

Quality Assurance

Use Cases

Infrastructure Inspection

Structural Health Monitoring

Services

Testing & Certification

Challenge

Zakum Development Company (ZADCO) faced a significant challenge when a 1,600-ton marine vessel collided with an operating wellhead platform in the Upper Zakum oil field, located offshore of Abu Dhabi, United Arab Emirates. The impact threatened the structural integrity of the platform, causing a 6.6 percent loss in platform strength. The platform was capable of surviving seasonal storms post-impact, but could only support the landing of helicopters and docking of light vessels. With oil production halted until repairs could be carried out, ZADCO was tasked with quickly assessing and repairing the platform to minimize losses, ensure safe startup, and avoid environmental pollution. The company also needed to substantiate the accident and resulting damage for an insurance claim. The structural analysis of the platform was complicated by several factors, including the absence of a current SACS model for the required analyses, unreliable vessel speed data for modeling the impact, and the difficulty of modeling the nonlinear soil-pile interaction in combination with a nonlinear inelastic structure.

About Customer

Zakum Development Company (ZADCO) is a leading oil company developing the Upper Zakum field, the fourth largest oil field in the world, on behalf of Abu Dhabi National Oil Company (ADNOC) and shareholders in the joint venture between ADNOC, ExxonMobil, and Japan Oil Development Company Ltd. ZADCO is committed to managing the Upper Zakum field in a way that is safe, efficient, and environmentally responsible. The company faced a significant challenge when a marine vessel collided with an operating wellhead platform in the field, causing a halt in oil production and threatening the structural integrity of the platform. ZADCO's primary objective was to quickly assess and repair the platform to minimize losses and ensure safe startup, while also substantiating the accident and resulting damage for an insurance claim.

Solution

ZADCO decided to conduct a rapid, iterative boat-impact analysis in-house using various SACS modules. These included SACS Precede for platform modeling and load application, SACS PSI for pile and soil property modeling, and SACS Collapse for non-linear boat impact analysis and parameter coding, and for result verification. The non-linear boat impact analysis performed in the SACS Collapse module helped to accurately simulate the post-impact behavior of the platform and the spread of damages. ZADCO performed a linear static in-place analysis to assess the damage caused by the impact and verify whether the damaged platform’s primary members and piles were safe for a one-year storm event. The team also carried out detailed dent mapping, and subsea and topside inspections. By conducting impact analyses with SACS, ZADCO was able to optimize the scope of the inspections and focus attention on critical subsea nodes that required a more detailed review. The optimized inspection scope and schedule allowed work to be performed within the narrow window dictated by weather conditions.

Impact #1	The use of SACS for the rapid, iterative boat-impact analysis allowed ZADCO to accurately simulate the post-impact behavior of the platform and the spread of damages. This understanding of post-impact behavior helped to execute the stage-wise release of the platform so that it could become operational earlier than anticipated. Production resumed with the platform reinstated to nearly full pre-impact capacity. By performing the preliminary analyses in-house, optimizing the scope of inspections, and outsourcing the detailed engineering for short-term and final repair packages, ZADCO significantly reduced the project delivery time and costs. The platform life and usability were ultimately enhanced as a result of the fully updated SACS model, which can be easily referenced for future operations and maintenance. The technical documentation generated from SACS simulations allowed the company to substantiate the insurance claim resulting from the accident, saving the operator considerable costs.

Impact #1

The use of SACS for the rapid, iterative boat-impact analysis allowed ZADCO to accurately simulate the post-impact behavior of the platform and the spread of damages. This understanding of post-impact behavior helped to execute the stage-wise release of the platform so that it could become operational earlier than anticipated. Production resumed with the platform reinstated to nearly full pre-impact capacity. By performing the preliminary analyses in-house, optimizing the scope of inspections, and outsourcing the detailed engineering for short-term and final repair packages, ZADCO significantly reduced the project delivery time and costs. The platform life and usability were ultimately enhanced as a result of the fully updated SACS model, which can be easily referenced for future operations and maintenance. The technical documentation generated from SACS simulations allowed the company to substantiate the insurance claim resulting from the accident, saving the operator considerable costs.

Benefit #1	Subsea inspections by divers were reduced from 134 days to 34 days, a 75 percent savings of inspection time.
Benefit #2	Saved USD 850,000 in project costs due to reduced inspection time.
Benefit #3	Reduced inspection and repair costs from USD 3.75 million to USD 1.15 million.

Benefit #1

Subsea inspections by divers were reduced from 134 days to 34 days, a 75 percent savings of inspection time.

Benefit #2

Saved USD 850,000 in project costs due to reduced inspection time.

Benefit #3

Reduced inspection and repair costs from USD 3.75 million to USD 1.15 million.

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Overview

ZADCO's Use of SACS for Restoration of Ship-Impacted Wellhead Platform

Operational Impact

Quantitative Benefit