21 research outputs found
Prediction of diagenesis and reservoir quality using wireline logs: evidence from the Upper Triassic (Raethian) fluvial reservoir tags - Toual field, Gassi Touil Area, SE Algeria
Reservoir quality is mainly controlled by environment deposit type and diagenesis processes. To investigate such subject we usually proceed to microscopic techniques. Absence of outcrops and missing of core samples let us use conventional wireline logs and core lab measurements as primary data. Direct lecture of well logs calibrated by core photos and wellsite description, well logs correlation and cross plots were our main methodology axis. Target of this study is the fluvial Shaly Sandstones of Upper Triassic (Rhaetian) reservoir (abreviated in French; TAGS) located in Toual field – SE of Algeria. The present investigation confirms the absence of clean sandstone levels in the studied reservoir. It detects also the presence of halite and clays (Illite) as cements in sandstone. The influence of illite on permeability was confirmed whereas porosity is less affected.Keywords: Diagenesis; Reservoir Quality; Well logs; Fluvial System; Triassic; Toua
PERFORMANCES EPURATOIRES ET INTERET DU PROCEDE DE PHYTOTRAITEMENT DES EAUX USEES PAR DES VEGETAUX MACROPHYTES
Le but de ce travail estl’étude des performances épuratoires des eaux usées au profit des petites collectivités par le biais d’un système utilisant des lits plantés en végétaux. Les expériences à travers le monde, montrent l’intér êt grandissant de cette technique et de sa fiabilité, tant sur le plan économique que sur le plan et écologique. Dans une perspective d’application de cette nouvelle technique à échelle réelle, il a été procédé à la mise en œuvre d’un pilote expérimen tal, reproduisant le procédé dans toutes ses phases, suivie des analyses d’échantillons à l’entrée et la sortie des eaux traitées. Quatre (4) filières de traitement ont été expérimentées, tenant compte de la variabilité des écoulements (vertical, horizontal, mixte). Chaque filière consiste à faire passer l’effluent à travers des bassins, remplis de graviers et plantés en phragmites. Les résultats des principaux indicateurs de la pollution hydriques par rapport à ceux obtenus par une station de référence (lagunage aéré de Ghriss), semblent être très prometteurs pour l’avenir de ce procédé d’épuration en Algérie, particulièrement au profit en milieu rural. The aim of this work is the study of wastewater purification efficiency for small communities through a system using beds planted with macrophytes. Many experiences around the world show a growing interest in this technique and its reliability, both economically and environmentally. In view of application of this new technique at actual scale, we proceeded to implement a pilot experiment, replicating the process in all its phases, followed by analyzes of sam ples at the input and output of treated water. Four treatment processes were tested, taking intoaccount the flow variability (vertical, horizontal, mixed). Each process consists of passing the effluent through a basin filled with gravel and planted with Phragmites. The results of the main indicators of water pollution compared to those obtained froma reference station (aerated lagoon Ghriss) seem to be very promising for the future of this treatment process in Algeria, particularly in rural region
ANTILEISHMANIAL ACTIVITY OF SOME PLANTS GROWING IN ALGERIA: JUGLANS REGIA, LAWSONIA INERMIS AND SALVIA OFFICINALIS.
The current study was undertaken to evaluate in vitro the antileishmanial activity of three plants growing wild in Algeria : Juglans regia, Lawsonia inermis and Salvia officinalis. The hydroalcoholic extracts of these plants were tested on the growth of the promastigotes of Leishmania major. The plant extract effects were compared with three controls : CRL1 composed of 1 ml RPMI inoculated with 106 of promastigotes, CRL2 composed of 1 ml RPMI inoculated with 106 of promastigotes and 100 ÎĽl of hydroalcoholic solvent, CRL3 composed of 1 ml RPMI inoculated with 106 of promastigotes and 100 ÎĽl of Glucantim as a reference drug in the management of leishmaniasis. The results showed that both J. regia and L. inermis extracts reduced the promastigotes number significantly (
Évaluation par analyse multicriteres de la vulnérabilité des sols a l'érosion : cas du bassin versant de l'Isser – Tlemcen – Algérie |Full article|
The drainage basin of Isser, space weakened by the
periods of drought and characterized
by exposures of marls and very fragile clays, prese
nts a high sensitivity to erosion. In addition to
the deterioration of the quality of water, the eros
ion phenomenon in this zone presents risks of
depletion of topsoil, loss of fertility, loosening
of plants and pollution by pesticides dissolved in
surface water runoff.
The erosion results from the conjunction of many pe
rmanent factors (as those related to
the soil or to the topography), that are evolving o
r presenting a random character (such as
precipitations) and intervene at different levels i
n erosion processes. The purpose of the work is to
produce a map of soil vulnerability to the erosion
by integrating field data, different thematic maps
and
satellite images through GIS solution. This map sho
uld be a basis for the development of the anti-eros
ive
land use plan adapted to the specific context of th
e drainage basin of Isser. We do integrate four
factors which determine the erosion: precipitations
, topography, lithology, and vegetation cover.
For combining these different factors, we use a cut
ting space in regular meshes. The resulting map of
the vulnerability to the erosion should reveal homo
geneous areas for priority interventions
Analyse et suivi du phénomène de la désertification en Algérie du nord
The present study aims to work out a methodology based on the use of the sensors such TERRA MODIS (MODerate resolution Imaging Spectroradiometer) in the desertification following and the detection of desertification risk zones in the  northern area of Algeria.  To this end, some geophysical parameters (albedo "R0", vegetation index "NDVI'' and surface temperature "TS") are produced regularly and cover the period of 2000 to 2005. The combination of these parameters two per two especially R0 -TS, NDVI-TS and R0 - NDVI has allowed respectively the characterization of the hydric and vegetation state. The synthesis of the totality of results under a geographical information system GIS as well as their confrontation with others types of data have allowed to map the desertification risk following five degrees (very high, high, moderated, weak and stable). Our results show that 75 % of the risk zones are already desertify or near of desertification
Analyse et suivi du phénomène de la désertification en Algérie du nord
The present study aims to work out a methodology based on the use of the sensors such TERRA MODIS (MODerate resolution Imaging Spectroradiometer) in the desertification following and the detection of desertification risk zones in the  northern area of Algeria.  To this end, some geophysical parameters (albedo "R0", vegetation index "NDVI'' and surface temperature "TS") are produced regularly and cover the period of 2000 to 2005. The combination of these parameters two per two especially R0 -TS, NDVI-TS and R0 - NDVI has allowed respectively the characterization of the hydric and vegetation state. The synthesis of the totality of results under a geographical information system GIS as well as their confrontation with others types of data have allowed to map the desertification risk following five degrees (very high, high, moderated, weak and stable). Our results show that 75 % of the risk zones are already desertify or near of desertification
EVALUATION OF THE EFFECTS OF LAND COVER CHANGES AND URBANIZATION ON LAND SURFACE TEMPERATURE: A REMOTE SENSING STUDY OF SUB-WATERSHED OF OUED FEKAN, NORTHWEST ALGERIA
International audienceUrban growth is a worldwide phenomenon. The rate of urbanisation in developing countries such as Algeria is speedy. Sub-watershed of Oued Fekan is included in the large watershed of Macta which is located in northwestern Algeria and is one of the most important sites of this country characterized by an abundant amount of biodiversity as well as a highly productive ecosystem. The valuable landscape undergoes a radical change in the form of a sub-watershed recently due to anthropogenic change on land use and land cover. The exponential increase in population and human activities are increasing the demand for land and soil resources for agriculture, urban and industrial uses. Anthropogenic factors, especially urban sprawl, have a significant role in controlling the temperature change. In this paper, four Landsat-8 OLI/TIRS images of 2018 have been used from different seasons to estimate land surface temperature (LST), Normalized Difference Built-up Index (NDBI) and Normalized Difference Vegetation Index (NDVI) in order to study the phenomenon of difference distribution temperature in urban with the surrounding rural areas. Analysis based on linear regression was used to generate relationships between LST with NDVI and NDBI. Our analysis indicates that for the four seasons, a strong linear relationship between NDBI and LST was marked compared with the relationship between NDVI and LST, which was less intense and varied by seasons. We suggest that NDBI is a visible indicator for studying surface Urban Heat Island phenomenon (UHI). Useful information that occurs as a consequence of land-use changes and urbanization are then provided for understanding the local climate and environmental changes of our study area
Analyse et suivi du phénomène de la désertification en Algérie du nord
The present study aims to work out a methodology based on the use of the sensors such TERRA MODIS (MODerate resolution Imaging Spectroradiometer) in the desertification following and the detection of desertification risk zones in the  northern area of Algeria.  To this end, some geophysical parameters (albedo "R0", vegetation index "NDVI'' and surface temperature "TS") are produced regularly and cover the period of 2000 to 2005. The combination of these parameters two per two especially R0 -TS, NDVI-TS and R0 - NDVI has allowed respectively the characterization of the hydric and vegetation state. The synthesis of the totality of results under a geographical information system GIS as well as their confrontation with others types of data have allowed to map the desertification risk following five degrees (very high, high, moderated, weak and stable). Our results show that 75 % of the risk zones are already desertify or near of desertification