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The seismic sensors will be dropped by six autonomous aerial drones and later be retrieved by an unmanned ground vehicle instead of conventional manual deployment and recovery by ground-based teams. A US-government-sponsored program is putting new methane leak detection systems to the test with a goal of achieving functionality costs of $3,000/year/wellsite while hitting stringent performance criteria. Southwest Research Institute has developed a leak detection system to autonomously monitor pipelines for hazardous chemical spills. R&D Magazine recently recognized the system as one of the 100 most significant innovations of 2017.
Providing quick response time and accurate detection of small leaks in multiphase pipelines is of great importance for risk mitigation in the oil and gas industry. The emphasis of implementing state-of-the-art technologies to mitigate both safety and environmental risks in the field becomes of particular importance as aging pipelines transport sour hydrocarbon products crossing populated areas. Fiber Optics Leak Detection Systems (FOLDS) have the capability to detect small pinhole leaks even in multiphase flow, due to its distributed sensing and advanced signal processing features. With this motivation in mind, it is important to evaluate the ability of FOLDS to detect leaks under different scenarios of varying fiber cable location, product phase distribution, propagation media, pressure, temperature, leak sizes and leak locations.
Due to the high amount of varying parameters, safety hazards and environmental constraints associated with field testing FOLDS, an industrial third-party multiphase flow facility enables FOLDS performance evaluation across the range of applications of interest. In this particular case, different Distributed Acoustic Sensing (DAS) and Distributed Temperature Sensing (DTS) FOLDS were simultaneously tested for detecting the pipeline leaks. The overall performance test scope and procedure presented in this paper was custom developed to simulate as close as field parameters for validation across multiphase and wet gas flow conditions.
The customized performance evaluation test program led to results that show the sensitivity of technology performance to different operational conditions, ranging from physical flow parameters to fiber optic location with respect and leak propagation media. FOLDS solutions performance validation is presented in terms of leak detection, stability and consistency. This leads to a conclusive benchmarking of each solution performance based on the test results for multiphase pipelines.
This paper guides the audience through the methodology of customized performance evaluation testing of pinhole leak detection for oil multiphase and wet gas pipelines. It also provides value by highlighting the impact of testing procedures, different flow parameters and installation setups on the actual system performance.
A US-government-sponsored program is putting new methane leak detection systems to the test with a goal of achieving functionality costs of $3,000/year/wellsite while hitting stringent performance criteria. Southwest Research Institute has developed a leak detection system to autonomously monitor pipelines for hazardous chemical spills. R&D Magazine recently recognized the system as one of the 100 most significant innovations of 2017.
The performance of pipeline leak detection systems has been a hot subject for discussions in the past few years . In response to the public pressure and regulatory requirements, API published its recommended practice (RP) for continuous improvement of leak detection program . While the main objective of API 1175 is to provide guidance to pipeline operators for developing and maintaining management of pipeline leak detection programs, it encourages them to “go beyond” in order to achieve advancement in culture and strategy, overall performance, control center procedures, alarm management, roles and responsibilities, training and equipment maintenance. One important part of the leak detection program is the ongoing improvement.
Leak detection systems range from non-continuous to continuous, physical inspection to sensor-based monitoring, manual observation to computational pipeline monitoring (CPM) . The more widely applied systems are CPM ones based on volume balance, pressure monitoring, real-time transient model and statistical analysis . One common feature of the CPM methods is the use of pressure and/or flow measurements and SCADA (Supervisory Control And Data Acquisition) system. It is also the common limitation of such systems. To improve the leak detection performance of CPM systems, non-intrusive sensors have been developed.
Refining NZ is New Zealand’s only oil refinery and the leading supplier of refined petroleum products to the New Zealand market, including gasoline, diesel, jet fuel and other products. It supplies most of the fuel needs for Auckland through a 169 kilometre (105 mile) long, 273 millimetre (10.75 inch) diameter pipeline terminating at the Wiri Terminal in South Auckland.
To meet the growing demand for jet fuel, Refining NZ started a pipeline capacity increase project in 2017. The first 2 of 3 phases of this project have been completed with the 3rd phase due to kick-off in 2019.
Refining NZ rely on an Online Real-Time Transient Modelling (RTTM) system to provide decision support applications for the pipeline controllers such as batch tracking, scraper tracking and leak detection. The RTTM was updated in 2017 to include the changes made in the pipeline operation.
On September 14th, 2017, Refining NZ experienced a significant incident on the pipeline which threatened their business.
This paper details how Refining NZ use their RTTM as a decision support tool, some key learnings from the incident, including analysis of the incident using the RTTM, and what Refining NZ has done to improve its operations as a result of the incident and the subsequent analysis.
The Negative Pressure Wave (NPW) leak detection method has been increasing in popularity recently due to the promise of highly accurate leak location calculations compounded with response times on the order of seconds. Additionally, when compared to other leak detection methods such as Real Time Transient Models (RTTM), NPW can be implemented on many different pipelines in a relatively short period of time with only the need for pressure transmitters. However, as with all engineering applications, there are tradeoffs to consider. In this analysis, a NPW solution was evaluated on two different liquid pipelines running offline simulators: one pipeline transports crude oil and one pipeline transports diesel. It was observed that, under very specific operating and test conditions, NPW could perform adequately. The conditions which allow for accurate NPW performance are limited when considering real world operations. With this consideration, NPW can be a complimentary method to other leak detection methodologies. This analysis is intended to provide pipeline operating companies with a greater understanding of when and where an NPW solution may be appropriate, as well as the limitations and challenges associated with the NPW methodology.
The Alvin deep-sea submersible awaits another collection run in the Guaymas Basin in November 2018. In a paper published in Nature Communications, researchers documented extensive diversity in the microbial communities living in the extremely hot, deep-sea sediments located in the Guaymas Basin in the Gulf of California. The team uncovered new microbial species that are so genetically different from those that have been previously studied that they represent new branches in the tree of life. Many of these same species possess keen pollutant-eating powers, like other, previously identified microbes in the ocean and soil. "This shows the deep oceans contain expansive unexplored biodiversity, and microscopic organisms there are capable of degrading oil and other harmful chemicals," said assistant professor of marine science Brett Baker, the paper's primary investigator.
We follow up on our previous paper describing an API RP 1130 compliant test method that imposes simulation-based leak perturbation signatures on archived SCADA data. The perturbation-based simulated leak testing (PSLT) approach combines a faithful representation of the leak with the real-world impacts of noise, calculation uncertainties, and measurement errors. The current paper expands on the previous work by providing an analysis and testing of hydraulic limitations as well as benchmarking against other commonly employed leak testing methods. The work continues to demonstrate that previous conclusions regarding its relatively low cost, high hydraulic fidelity, coverage, and flexibility are maintained, while producing extensive output metrics that include detailed leak detection sensitivity maps, false alarm rates, and supporting statistical analysis.
INTRODUCTION AND BACKGROUND
Testing of Pipeline Leak Detection Systems
A leak detection system (LDS) is a safety and integrity-critical component of an operating pipeline that is designed to help mitigate negative consequences following an unplanned commodity release. Its intended purpose is to reduce the potential negative impacts from a breach in pipeline hydraulic integrity (e.g., a leak with its resulting spill). Rapidly detecting the leak and determining its most probable location enables the pipeline operator to respond rapidly, effectively, and with precision to the spill, thus reducing its size and negative impacts. Note that the most commonly applied method for leak detection is via Computational Pipeline Monitoring (CPM) systems, which are the explicit focus of this document.
As part of the operator’s overall spill response plan the organization should be able to quantify the leak detection system’s predicted performance. This allows the operator to identify areas where further leak detection improvements are desirable and refine location specific response plans. It also provides a mechanism by which the LDS performance can be monitored and tracked over time.