Fiber Optic Leak Detection Systems for Subsea Pipelines

2012 ◽  
Author(s):  
Benjamin Eisler ◽  
Glenn A. Lanan
Keyword(s):  
Fiber Optic ◽  
Leak Detection ◽  
Detection Systems ◽  
Subsea Pipelines

Industrial Validation and Verification Approach for External Fiber Optic Based Leak Detection

2020 ◽  
Author(s):  
Chris Minto ◽  
Alastair Godfrey ◽  
Paul Clarkson ◽  
Alasdair Murray
Keyword(s):  
Negative Pressure ◽  
Large Scale ◽  
Pressure Pulse ◽  
Fiber Optic ◽  
Leak Detection ◽  
Probability Of Detection ◽  
Test Facility ◽  
Detection Systems ◽  
Mode Behavior ◽  
Valve Opening

Abstract External Leak Detection systems based on distributed fiber optic sensors (DFOS) offer the exciting potential to significantly reduce the overall amount of spilled product before a leak is detected and localized. Such systems are not well represented by industrial standards or recommended procedures and as a result most industrial attempts to validate the technology have been research-oriented and whilst these have contributed greatly to the knowledge base they have never been aimed at a full validation of the technology. Additionally, the lack of test facilities that can support the significant scale needed for validation (> 500 m straight line run) have led to a paucity of attempts to provide a baseline validation of such sensing technology leading to a lack of certainty over performance claims within the industrial user base and no robust method of testing such claims. With a significant customer base of deployed systems, OptaSense have developed a reproducible technology validation approach using full scale, full flow, representative leaks at the CTDUT test facility in Brazil. We have used these tests to validate 15 lpm leaks, detected and classified via their negative pressure pulse in ∼10 seconds and larger 150 lpm leaks, detected by our four modes of leak detection in ∼1 minute. Valid automated detection of a negative pressure pulse (NPP) was observed down to 1 mm holes in the pipe — representing a leak rate of only 1.5 lpm. The use of the NPP is shown to be a compelling rapid detection method. However, care is needed in testing since the use of a valve opening to stimulate a pulse is shown to be significantly inferior to burst disks due to the increased valve-opening time giving rise to a reduced amplitude pressure pulse. The conventional external leak detection signals of Orifice Noise, Ground Strain and Temperature Change can all be shown to be replicated at the large-scale test facility by these means leading to the potential to establish a valid Probability of Detection for all approaches. With validation now possible, client verification on site has also been addressed with a two-step approach being developed that replicates the validation approach detailed above. Negative Pressure Pulses are used for stand-alone leak detection and can be safely stimulated via accessible valve sites and product release via a burst disc / valve and orifice combination. To stimulate the Multiple Mode behavior (excluding Negative Pressure Pulse) a controlled fluid release injection mechanism has been developed, which can be introduced at an appropriate offset from the pipeline (mirrored from fiber offset) at any desired location with the minimum of preparation. Ground probe deployment techniques have been designed to simulate a leak event at the appropriate location resulting in the similar external signals arising on the fiber. This paper presents the benefits of large-scale validation approaches to performance bound acoustic-based leak detection systems and presents established options for in-field verification on customer owned systems.

Probabilistic Performance Assessment of Fiber Optic Leak Detection Systems

2016 ◽  
Vol 138 (2) ◽  
Author(s):  
Alireda Aljaroudi ◽  
Faisal Khan ◽  
Ayhan Akinturk ◽  
Mahmoud Haddara
Keyword(s):  
Performance Assessment ◽  
Financial Risk ◽  
Oil And Gas ◽  
Fiber Optic ◽  
Oil Spills ◽  
Limit State ◽  
Leak Detection ◽  
False Detection ◽  
Detection Systems ◽  
Detection Failure

Leak detection systems (LDSs) play a major role in enhancing reliability and operability of oil and gas pipelines. They have the functional capabilities to detect, locate, and quantify leaks before they can cause devastating effects to the environment and operation. The performance of LDSs is typically influenced by three different types of failures that may have severe consequences: delayed detection, missed detection, and false detection of a leak. The consequences of these failures lead to extensive financial losses. For example, missed detection leads to oil spills and exposes operating companies to financial risk and destroyed image while false detection results in unnecessary deployment of personnel and equipment. To maintain safety of personnel and the environment and ensure operation continuity, LDSs should be assessed regularly. To fulfill this need, a probabilistic performance assessment scheme based on limit state approach for fiber optic LDS has been developed. The inherent uncertainties associated with leak detection and reporting capabilities are modeled to determine the LDS detection failure probability that combines two failure events: missed detection and delayed detection. Moreover, the probability of false detection is derived in terms of the lowest detectable change, the threshold. These three parameters establish the basis for an overall assessment scheme that can be used to predict the performance of the LDS. The proposed assessment scheme has been applied to a case study to demonstrate its usefulness and feasibility.

Probabilistic Performance Assessment of Fiber Optic Leak Detection Systems

2014 ◽  
Author(s):  
Alireda Aljaroudi ◽  
Faisal Khan ◽  
Ayhan Akinturk ◽  
Mahmoud Haddara
Keyword(s):  
Performance Assessment ◽  
Oil And Gas ◽  
Fiber Optic ◽  
Detection System ◽  
Financial Burden ◽  
Limit State ◽  
Leak Detection ◽  
False Detection ◽  
Detection Systems ◽  
Detection Failure

Leak Detection Systems play a major role in enhancing reliability and operability of oil and gas pipelines. They have the functional capabilities to detect, locate and quantify leaks before they can cause drastic effects to environment and operation. The performance of Leak Detection Systems is typically affected by three different failures that have severe consequences, namely, delayed detection, missed detection and false detection of a leak. These failures pose a financial burden on operating companies. Missed detection leads to oil spill and exposes operating companies to financial risk and destroyed image while false detection results in unnecessary deployment of personnel and equipment. To insure operation continuity and maintain safe environment, Leak Detection Systems should be assessed at regular basis. To fulfill this need, a probabilistic performance assessment scheme based on limit state approach for Fiber Optic Leak Detection System (LDS) has been developed. The inherent uncertainties associated with leak detection and reporting capabilities are modeled to determine the LDS detection failure probability that combines two failure events, missed detection and delayed detection. Moreover, the probability of false detection is derived in terms of the lowest detectable change, the threshold. These three parameters establish the basis for an overall assessment scheme that can be used at any time to provide an up to date assessment about the Leak Detection System. The results will serve as the basis for deciding the actions that need to be taken to upgrade, repair or replace the system components or the system as a whole. The proposed assessment scheme has been applied to a case study to demonstrate its usefulness and feasibility.

COMPARATIVE ANALYSIS OF WATER LEAK DETECTION SYSTEMS AND METHODOLOGIES

2016 ◽  
Vol 15 (9) ◽  
pp. 2063-2074
Author(s):  
Pedro Rosas Quiterio ◽  
Florencio Sanchez Silva ◽  
Ignacio Carvajal Mariscal ◽  
Jesus Alberto Meda Campana
Keyword(s):  
Comparative Analysis ◽  
Leak Detection ◽  
Detection Systems ◽  
Water Leak
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