In order to assess the possible environmental impact of oily cuttings discharged during oil exploration activities, we studied the benthic foraminiferal faunas in a five-station, 4-km-long sampling transect around a cuttings disposal site at about 670 m depth offshore Angola (W Africa), where drilling activities started 1.5 years before sampling. Living (Rose Bengal stained) and dead foraminiferal faunas were sampled in March 2006. The faunal patterns mirror the spatial distribution of hydrocarbons, which are dispersed into a southeastern direction. Four different areas can be distinguished on the basis of the investigated faunal parameters (density, diversity and species composition of the living fauna, and comparison with subrecent dead faunas). The fauna at station S31, 300 m SE of the oil cuttings disposal site, appears to be clearly impacted: the faunal density and diversity are maximal, but evenness is minimal. Taxa sensitive to organic enrichment, such as Uvigerina peregrina, Cancris auriculus and Cribrostomoides subglobosus, have largely disappeared, whereas the low-oxygen-resistant taxon Chilostomella oolina and opportunistic buliminids and bolivinids attain relatively high densities. At station S32, 500 m SE of the disposal site, environmental impact is still perceptible. The faunal density is slightly increased, and U. peregrina, apparently the most sensitive species, is still almost absent. The faunas found at 1 and 1.8 km SE of the disposal site are apparently no longer impacted by the drill mud disposal. Faunal density and diversity are low, and the faunal composition is typical for a mesotrophic to eutrophic upper slope environment. Finally, Station S35, 2 km NW of the disposal site, contains an intermediate fauna, where both the lowoxygen-resistant C. oolina and the more sensitive taxa (U. peregrina, C. auriculus and C. subglobosus) are present. All taxa live close to the sediment-water interface here, indicating a reduced oxygen penetration into the sediment. Since the hydrocarbon concentration is low at this station, it appears that the faunal characteristics are the consequence of a slightly different environmental setting, and not due to a contamination with drill cuttings. Our data underline the large potential of benthic foraminifera as bio-indicators of anthropogenic enrichment in open marine settings, such as caused by the disposal of oily drill cuttings. The foraminiferal faunas react essentially by a density increase of a number of tolerant and/or opportunistic taxa, and a progressive disappearance of more sensitive taxa in the most impacted area. Rather surprisingly, large-sized taxa appear to be more sensitive than small-sized foraminiferal taxa.

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Remote sensing technologies can be applied for a wide range of gas leak flowrates and in three main cases: (1) major leaks in crisis management; (2) medium size leaks in safety monitoring; (3) small leaks in environmental monitoring. A gas test campaign, conducted by Total, the ONERA – the French Aerospace Lab – and ADCIS in September 2015 using three hyperspectral infrared cameras from Telops, confirmed our capacity to visualize in 3D and quantify in real time plumes of methane in the range of 1 g/s to 50g/s. The R&D project on gas remote quantification continued with a second gas test campaign in 2017. The second gas test campaign was organized on Total's Lacq Pilot Platform in France and involved several gas spectral imaging systems: (1) mobile hyperspectral cameras in the Long-Wavelength InfraRed (LWIR) band (7.7-12μm); (2) a multispectral camera in the LWIR band (7-9μm); (3) a multigas lidar (LIght Detection And Ranging) system coupled with a wind lidar system; (4) five other international teams (US, Spain, Norway and France) were also invited to assess the capacity of their remote-sensing systems to quantify methane and carbon dioxide releases. The two-week test demonstrated that methane leak emissions ranging from 0.7 g/s to 140 g/s could be visualized and quantified in real time using a mobile Telops Hyper-Cam. This campaign also served to validate the performance of several remote sensing technologies. Total's Lacq Pilot Platform is a test area for qualifying cost-effective systems designed to complement the gas detection system of a plant and provide valuable information should a gas leak incident occur. New methodologies for the early detection of anomalies using remote observation systems including drones, robots and artificial intelligence data processing systems are currently being investigated there.

Texas 75083-3836 U.S.A., fax +1.972.952.9435. AbstractDuring E&P offshore activities, and in particular during drilling operations, the living conditions of the flora and fauna on the seabed may be disturbed.The paper describes the study made for assessing the actual impact of the discharged cuttings, the regenerating capacity of the ecosystem and the medium and long-term recolonization processes, based on in situ measurements. A previous study undertaken on cuttings recently discharged offshore Congo measured kinetics of space and time restoration of the drilling site. To validate the results we carried out a similar study dedicated on aged cuttings offshore Gabon.