The compact passive acoustic monitor; a tool for marine mammal risk mitigation

Abstract Proactive well diagnostic surveillance helps with safe delivery of production by effective well management and risk mitigation. The objective of the paper is to demonstrate the data analytics approach utilizing passive acoustic technology in combination with conventional methods of detecting low magnitude dynamic events behind single or multiple casing strings. The results of integrated interpretation of passive acoustic wireline technology with the data from different sources helped to make optimal decision. Traditional well integrity diagnostic includes temperature and passive acoustic data analysis that are associated with high uncertainty. A newer generation of array passive acoustic technology with enhanced sensitivity capabilities was deployed offshore Azerbaijan. A combination of array passive acoustics data, single point temperature and distributed fiber optic data have been acquired during a multi-well campaign. Extensive review of well integrity history, downhole and surface gauge data incorporated with passive acoustic data from arrays of spectral sensors in time and depth domain helped to refine the process and evolve into a unique interpretation methodology. The comprehensive interpretation accounted for integration of all available static and dynamic data such as: fluids and formation pressure distribution along the borehole, cement bond logs evaluation, annuli pressure and temperature, production and downhole gauge measurements, fibre optic data, temperature and passive acoustic logs. This helped to understand the low scale dynamic events behind the casing and make an informed decision on safe and reliable well operations. The sensitivity of array passive acoustic technology proved successful in detecting subtle acoustic events where conventional methods failed or had limited success. Successful results have been achieved by customizing the logging program using a multiple well evolutionary approach that improved data quality and saved rig time. Interpretation and decisions derived from each well involved multi-disciplinary well review panel sessions with specialists from subsurface & geohazards, drilling & completions, production & operations departments. Case studies presented in this paper describe the interpretation approach of highly sensitive array passive acoustic sensors in combination with available static and dynamic point and distributed data. The logging program and interpretation approach used in this article could be considered as a basis for future applications in wells with similar design.

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Glider-Based Passive Acoustic Monitoring in the Arctic

Marine Technology Society Journal ◽

10.4031/mtsj.48.5.2 ◽

2014 ◽

Vol 48 (5) ◽

pp. 40-51 ◽

Cited By ~ 12

Author(s):

Mark F. Baumgartner ◽

Kathleen M. Stafford ◽

Peter Winsor ◽

Hank Statscewich ◽

David M. Fratantoni

Keyword(s):

Real Time ◽

Marine Mammal ◽

Low Frequency ◽

Acoustic Monitoring ◽

Bowhead Whale ◽

The Arctic ◽

Mammal Species ◽

Frequency Detection ◽

Passive Acoustic ◽

The Impact

AbstractPersistently poor weather in the Arctic makes traditional marine mammal research from aircraft and ships difficult, yet collecting information on marine mammal distribution and habitat utilization is vital for understanding the impact of climate change on Arctic ecosystems. Moreover, as industrial use of the Arctic increases with the expansion of the open-water summer season, there is an urgent need to monitor the effects of noise from oil and gas exploration and commercial shipping on marine mammals. During September 2013, we deployed a single Slocum glider equipped with a digital acoustic monitoring (DMON) instrument to record and process in situ low-frequency (<5 kHz) audio to characterize marine mammal occurrence and habitat as well as ambient noise in the Chukchi Sea off the northwest coast of Alaska, USA. The DMON was programmed with the low-frequency detection and classification system (LFDCS) to autonomously detect and classify sounds of a variety of Arctic and sub-Arctic marine mammal species. The DMON/LFDCS reported regularly in near real time via Iridium satellite detailed detection data, summary classification information, and spectra of background noise. The spatial distributions of bowhead whale, bearded seal, and walrus call rates were correlated with surface salinity measured by the glider. Bowhead whale and walrus call rates were strongly associated with a warm and salty water mass of Bering Sea origin. With a passive acoustic capability that allows both archival recording and near real-time reporting, we envision ocean gliders will become a standard tool for marine mammal and ocean noise research and monitoring in the Arctic.

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