Real-Time Well-Integrity Monitoring Using Fiber-Optic Distributed Acoustic Sensing

Summary Proper cemented casing strings are a key requirement for maintaining well integrity, guaranteeing optimal operation and safe provision of hydrocarbon and geothermal resources from the pay zone to surface facilities. Throughout the life cycle of a well, high–temperature/high–pressure changes in addition to shut–in cyclic periods can lead to strong variations in thermal and mechanical load on the well architecture. The current procedures to evaluate cement quality and to measure downhole temperature are mainly dependent on wireline–logging campaigns. In this paper, we investigate the application of the fiber–optic distributed–acoustic–sensing (DAS) technology to acquire dynamic axial–strain changes caused by propagating elastic waves along the wellbore structure. The signals are recorded by a permanently installed fiber–optic cable and are studied for the possibility of real–time well–integrity monitoring. The fiber–optic cable was installed along the 18⅝–in. anchor casing and the 21–in.–hole section of a geothermal well in Iceland. During cementing operations, temperature was continuously measured using distributed–temperature–sensing (DTS) technology to monitor the cement placement. DAS data were acquired continuously for 9 days during drilling and injection testing of the reservoir interval in the 12¼–in. openhole section. The DAS data were used to calculate average–axial–strain–rate profiles during different operations on the drillsite. Signals recorded along the optical fiber result from elastic deformation caused by mechanical energy applied from inside (e.g., pressure fluctuations, drilling activities) or outside (e.g., seismic signals) of the well. The results indicate that the average–axial–strain rate of a fiber–optic cable installed behind a casing string generates trends similar to those of a conventional cement–bond log (CBL). The obtained trends along well depth therefore indicate that DAS data acquired during different drilling and testing operations can be used to monitor the mechanical coupling between cemented casing strings and the surrounding formations, hence the cement integrity. The potential use of DTS and DAS technology in downhole evaluations would extend the portfolio to monitor and evaluate qualitatively in real time cement–integrity changes without the necessity of executing costly well–intervention programs throughout the well's life cycle.

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Detecting and Correcting Pipeline Leaks Before They Become a Big Problem

Marine Technology Society Journal ◽

10.4031/mtsj.49.1.1 ◽

2015 ◽

Vol 49 (1) ◽

pp. 31-46 ◽

Cited By ~ 5

Author(s):

Ron Cramer ◽

David Shaw ◽

Robert Tulalian ◽

Pabs Angelo ◽

Maarten van Stuijvenberg

Keyword(s):

Acoustic Wave ◽

Real Time ◽

Fiber Optic ◽

Cost Effective ◽

Leak Detection ◽

Rate Of Change ◽

Fiber Optic Cable ◽

History Of ◽

Distributed Acoustic Sensing ◽

Critical Lines

AbstractTimely pipeline leak detection is a significant business issue in view of a long history of catastrophic incidents and growing intolerance for such events. It is vital to flag containment loss and location quickly, credibly, and reliably for all green or brown field critical lines in order to shut down the line safely and isolate the leak. Pipelines are designed to transport hydrocarbons safely; however, leaks have severe safety, economic, environmental, and reputational effects. This paper will highlight robust, reliable, and cost-effective methods, most of which leverage real-time instrumentation, telecommunications, SCADA, DCS, and associated online leak detection applications. The purpose of this paper will be to review the underlying leak detection business issues, catalogue the functional challenges, and describe experiences with available technologies. Internal and external techniques will be described, including basic rate of change of flow and pressure, compensated mass balance, statistical, real-time transient modeling, acoustic wave sensing, fiber optic cable (distributed temperature, distributed acoustic sensing), and subsea hydrophones. The paper will also describe related credibility, deployment, organizational, and maintenance issues with an emphasis on upstream applications. The scope will include leak detection for pipelines conveying various flowing fluids—gas, liquid, and multiphase flow. Pipeline environments will include subsea and onshore. Advantages, disadvantages, and experiences with these techniques will be described and analyzed.

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Caprock and Well Integrity Monitoring Using Fiber Optic Cable - Distributed Strain Measurement at a Shallow Well during Water Extraction Tests

EAGE/SEG Research Workshop 2017 ◽

10.3997/2214-4609.201701929 ◽

2017 ◽

Author(s):

Z. Xue

Keyword(s):

Strain Measurement ◽

Fiber Optic ◽

Water Extraction ◽

Fiber Optic Cable ◽

Integrity Monitoring ◽

Well Integrity ◽

Distributed Strain

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Expanding the Envelope of Fiber-Optic Sensing for Reservoir Description and Dynamics

10.2118/200888-ms ◽

2021 ◽

Author(s):

Abdulaziz Al-Qasim ◽

Sharidah Alabduh ◽

Muhannad Alabdullateef ◽

Mutaz Alsubhi

Keyword(s):

Performance Optimization ◽

Fiber Optic ◽

Thermal Recovery ◽

Production Performance ◽

Flow Profile ◽

Distributed Temperature Sensing ◽

Integrity Monitoring ◽

Well Integrity ◽

Fiber Optic Sensing ◽

Reservoir Description

Abstract Fiber-optic sensing (FOS) technology is gradually becoming a pervasive tool in the monitoring and surveillance toolkit for reservoir engineers. Traditionally, sensing with fiber optic technology in the form of distributed temperature sensing (DTS) or distributed acoustic sensing (DAS), and most recently distributed strain sensing (DSS), distributed flow sensing (DFS) and distributed pressure sensing (DPS) were done with the fiber being permanently clamped either behind the casing or production tubing. Distributed chemical sensing (DCS) is still in the development phase. The emergence of the composite carbon-rod (CCR) system that can be easily deployed in and out of a well, similar to wireline logging, has opened up a vista of possibilities to obtain many FOS measurements in any well without prior fiber-optic installation. Currently, combinations of distributed FOS data are being used for injection management, well integrity monitoring, well stimulation and production performance optimization, thermal recovery management, etc. Is it possible to integrate many of the distributed FOS measurements in the CCR or a hybrid combination with wireline to obtain multiple measurements with one FOS cable? Each one of FOS has its own use to get certain data, or combination of FOS can be used to make a further interpretation. This paper reviews the state of the art of the FOS technology and the gamut of current different applications of FOS data in the oil and gas (upstream) industry. We present some results of traditional FOS measurements for well integrity monitoring, assessing production and injection flow profile, cross flow behind casing, etc. We propose some nontraditional applications of the technology and suggest a few ways through. Which the technology can be deployed for obtaining some key reservoir description and dynamics data for reservoir performance optimization.

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Real Time Measurement of Airplane Flutter via Distributed Acoustic Sensing

Aerospace ◽

10.3390/aerospace7090125 ◽

2020 ◽

Vol 7 (9) ◽

pp. 125

Author(s):

Ezzat G. Bakhoum ◽

Cheng Zhang ◽

Marvin H. Cheng

Keyword(s):

Optical System ◽

Fiber Optic ◽

New Technology ◽

Time Measurement ◽

Fiber Optic Cable ◽

Acoustic Sensing ◽

Real Time Measurement ◽

Distributed Acoustic Sensing ◽

Mechanical Disturbances ◽

New System

This research group has recently used the new technology Distributed Acoustic Sensing (DAS) for the monitoring and the measurement of airplane flutter. To the authors’ knowledge, this is the first such use for this new technology. Traditionally, the measurement of airplane flutter requires the mounting of a very large number of sensors on the wing being monitored, and extensive wiring must be connected to all these sensors. The new system and technology introduced in this paper dramatically reduces the hardware requirements in such an application: all the traditional sensors and wiring are replaced with one fiber optic cable with a diameter of 2 mm. An electro-optical system with the size of a desktop PC monitors simultaneously one or more of such fiber optic cables and detects/characterizes any mechanical disturbances on the cables. Theoretical and experimental results are given.

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High precision and high resolution monitoring of subsurface changes with DAS and airgun

10.5194/egusphere-egu2020-10096 ◽

2020 ◽

Author(s):

Baoshan Wang ◽

Xiangfang Zeng ◽

Jun Yang ◽

Yuansheng Zhang ◽

Zhenghong Song ◽

...

Keyword(s):

Large Scale ◽

Fiber Optic ◽

Epicentral Distance ◽

Low Cost ◽

Fiber Optic Cable ◽

The Road ◽

Air Gun ◽

Distributed Acoustic Sensing ◽

On The Road ◽

Road Crossing

Recently large-volume airgun arrays have been used to explore and monitor the subsurface structure. The airgun array can generate highly repeatable seismic signals, which can be traced to more than 200 km. And the airgun source can be ignited every 10 minutes. The airgun source makes it possible to precisely monitor subsurface changes at large scale. The spatial resolution of airgun monitoring is poor subjecting to the receiver distribution. The distributed acoustic sensing (DAS) technique provides a strategy for low-cost and high-density seismic observations. Two experiments combing DAS technique and airgun source were conducted at two sites with different settings. At the first site, a telecommunication fiber-optic cable in urban area was used. After moderate stacking, the airgun signal emerges on the 30-km DAS array at about 9 km epicentral distance. In the second experiment, a 5-km cable was deployed from the airgun source to about 2 km away. About 800-m cable was frozen into the ice above the air-gun, the rest cable was cemented on the road crossing through a fault. And the airgun has been fired continuously for more than 48 hours with one-hour interval. On the stacking multiple shots&#8217; records, the wavefield in fault zone emerges too. These two experiments demonstrate the feasibility of using various fiber-optic cables as dense array to acquire air-gun signal in different environments and to monitor the subsurface changes.

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On the use of Distributed Acoustic Sensing for seismic divergence and curl estimations

10.5194/egusphere-egu21-12443 ◽

2021 ◽

Author(s):

Pascal Edme ◽

Patrick Paitz ◽

David Sollberger ◽

Tjeerd Kiers ◽

Vincent Perron ◽

...

Keyword(s):

Strain Rate ◽

Rayleigh Scattering ◽

Axial Strain ◽

Vertical Component ◽

Real Data ◽

Gauge Length ◽

Acoustic Sensing ◽

Rotational Components ◽

Distributed Acoustic Sensing ◽

The Impact

Distributed Acoustic Sensing (DAS) is becoming an established tool for seismological and geophysical applications. DAS is based on Rayleigh scattering of light pulses conveyed in fibre optic cables, enabling unprecedented strain rate measurements over kilometers with spatial resolution of less than a meter. The low cost, logistically easy deployment, and the broadband sensitivity make it a very attractive technology to investigate an increasing number of man-made or natural phenomena.One key restriction however is that DAS collects axial strain rate instead of the vector of ground motion, resulting in a poor sensitivity to broadside events like (at the surface) vertically incident waves or surface waves impinging perpendicular to the cable. Helically wound cables partially mitigate the issue but still do not provide omni-directional response as the typical vertical component of seismometers or geophones.The present study is about the potential of using unconventional DAS cable layouts to replace and/or complement traditional sensors. We investigate the possibility of estimating the divergence and the vertical rotational components of the wavefield from cables deployed in a square or circular shape. The impact of the size of the arrangement as well as that of the interrogation gauge length is discussed. &#160;Real data are shown and the results suggest that DAS has the potential to offer additional seismic component(s) useful for wave type identification and separation for example.

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Backward piping erosion detection in levees by fiber optic acoustic sensing

10.5194/egusphere-egu2020-7465 ◽

2020 ◽

Author(s):

Juan Pablo Aguilar-López ◽

Andres Garcia-Ruiz ◽

Thom Bogaard ◽

Miguel Gonzalez-Herraez

Keyword(s):

Ambient Noise ◽

Fiber Optic ◽

Geophysical Methods ◽

Innovative Technology ◽

Fiber Optic Cable ◽

Acoustic Sensing ◽

Characteristic Frequencies ◽

Distributed Acoustic Sensing ◽

Piping Erosion ◽

Set Up

Backward piping erosion (BEP) is considered the most dangerous failure mode for levees due to its unpredictable nature. This erosive process happens most of the time underneath the impermeable layers on which levees are commonly founded. This makes it very difficult to detect as conventional geophysical methods are either too expensive or too imprecise for real time monitoring of longitudinal soil made structures such as Dams or levees. Fiber optic based distributed acoustic sensing (DAS) is an innovative technology which allows to retrieve information from an acoustic propagating medium in a spatially dense manner by using a fiber optic cable. The present study aimed to explore the potential of DAS for early detection of BEP&#160; under levees based on the frictional emissions of the sand grains during the erosive process. The tests were performed in the lab under controlled ambient noise conditions. The technology was tested by embedding fiber optic based microphones underneath and outside a laboratory scaled aquifer set up capable of recreating BEP. The results show that indeed the process emits certain characteristic frequencies which may be located between 1200 to 1600 Hz and and that they can easily be captured by the fiber optic cables.

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