Clastic Sand Research Articles

Evaluating GGBS and Clastic Sand as Eco-Friendly Substitutes for Sustainable Concrete

Evaluating GGBS and Clastic Sand as Eco-Friendly Substitutes for Sustainable Concrete

Evaluating the durability performance of concrete containing clastic sand and GGBS

The manufacturing process of materials utilized in concrete production has environmental implications. The production of cement releases significant amounts of greenhouse gases, while the extraction of aggregates and sand poses challenges to the natural environment. To minimize the aforementioned challenges researchers are suggested to utilize industrial by-products as a partial alternative for these materials Fly ash, stone dust, GGBS, silica fume, and metakaolin are widely utilized alternatives to construction materials. The specific use of clastic sand as a partial substitute for fine aggregate has recently gained popularity . However, studies on the characteristics of concrete prepared using cementitious materials and clastic sand are very few. In this work, the effect of clastic sand with ground granulated blast furnace slag concrete is being investigated. The GGBS is added in place of cement from 0% to 45%. Further, clastic sand is added in different proportions in GGBS concrete. The electrical resistivity, water absorption, acid attack, and micro-structural studies are carried out on all mixes to know the durability properties. The results confirm that the addition of GGBS as a cementitious material enhances durability. The inclusion of 35% of GGBS as a substitute for cement is optimum for enhancing durability. Further, the inclusion of 35% GGBS as a cement substitute and 20% clastic sand shows a dense matrix and optimum results in enhancing durability. This is due to the pozzolanic activity of GGBS and clastic sand works as filler materials. This investigation suggests utilizing clastic sand along with GGBS as a cementitious material.

Characterising sand channel from seismic data using linear programming (l1-norm) sparse spike inversion technique: a case study from offshore, Canada

In this study, a linear programming (l1-norm) sparse spike inversion (LPSSI) technique is used to estimate acoustic impedance distribution in the subsurface of the Blackfoot Field, Alberta, Canada. The aim of study is to determine high-resolution subsurface rock properties from the low-resolution seismic data and characterise the clastic Glauconitic channel. There are many traditional post-stack seismic inversion techniques available to estimate rock properties from seismic data, but LPSSI is a relatively simple and quick to compute subsurface model that can be used for qualitative as well as quantitative interpretation. The technique is applied in two steps; first, composite traces near to well locations are extracted and inverted for acoustic impedance, and comparison with well log impedance is used to optimise the LPSSI parameters. Analysis of the composite traces indicates that the algorithm has good performance with high correlation (0.97). In the second step, LPSSI is applied to the Blackfoot seismic data to estimate the distribution of acoustic impedance in the subsurface. Analysis of inverted acoustic impedance shows a low impedance anomaly ranging from 6500 to 8500 m/s*g/cc at the 1060–1075 ms time interval, which is characterised as a clastic Glauconitic sand channel. Thereafter, to confirm the sand channel, another important rock property, porosity, is estimated in the inter-well region using multi-attribute analysis. Analysis of the porosity shows the presence of a high porosity (15–22%) zone in the 1060–1075 ms time interval which coincides with the low impedance zone and confirms the presence of the sand channel.

Lithofacies and sedimentary structures of Tanjero Formation at Heeran area North Iraq

The lithofacies and sedimentary structures of Tanjero Formation (campanian- maastrichtian) have been studied in the field at Heeran area east of Shaqlawa north of Iraq. It is found that the thickness of the formation is (120) m., the lower contact is conformable with Shiranish formation while the upper contact is unconformable with Kolosh Formation and recognized by the presents of basal conglomerate about (1.5)m. in thickness. According to the lithofacies, the formation is divided in to three parts; the lower and the upper parts composed of clastic sand stone interbedded with thin beds of marl and carbonate. While the middle part is friable and composed of marl and shale. The studied sedimentary structures in the formation confirmed that the sediment deposited by turbidite currents with unstable tectonic conditions.

Lithology identification using an optimized KNN clustering method based on entropy-weighed cosine distance in Mesozoic strata of Gaoqing field, Jiyang depression

KNN (K-Nearest Neighbors) clustering in machine learning is a very efficient clustering method applied in lithology identification, reservoir type recognition, flow unit classification and so on, but it is not working consistently because of its inherent limitation, like its initial center selection and clustering center shift caused by outliers. Moreover, KNN clustering is based on a mathematical algorithm, and does not necessarily cluster the space due to the geological and petrophysical aspects. To address this issue, an optimized KNN clustering method based on weighed cosine distance is proposed to better fit the lithology model. To deal with the problem of the initial center selection and outliers, a set of statistic methods is conducted. A set of data, sampled by different logging series, is made use to feature information about lithology as much as possible. New distance algorithm selection based on geology model and well logging data similarity attribute is obtained when utilizing. Taking the Mesozoic strata in Gaoqing field as example, a procedure fitter for utilization of machine learning technique in lithology identification is carried on, and the overall accurate rate of the optimized K-means clustering in lithology identification raised nearly 10% compared with the traditional K-means clustering especially in the differentiation between fine-sand and coarse-grained clastic sand. The predicted lithology match the core plugs better than the traditional KNN clustering.

Internal structure of event layers preserved on the Andaman Sea continental shelf, Thailand: tsunami vs. storm and flash-flood deposits

Abstract. Tsunami, storm and flash-flood event layers, which have been deposited over the last century on the shelf offshore Khao Lak (Thailand, Andaman Sea), are identified in sediment cores based on sedimentary structures, grain size compositions, Ti / Ca ratios and 210Pb activity. Individual offshore tsunami deposits are 12 to 30 cm in thickness and originate from the 2004 Indian Ocean Tsunami. They are characterized by (1) the appearance of sand layers enriched in shells and shell debris and (2) the appearance of mud and sand clasts. Storm deposits found in core depths between 5 and 82 cm could be attributed to recent storm events by using 210Pb profiles in conjunction with historical data of typhoons and tropical storms. Massive sand layers enriched in shells and shell debris characterize storm deposits. The last classified type of event layer represents reworked flash-flood deposits, which are characterized by a fining-upward sequence of muddy sediment. The most distinct difference between storm and tsunami deposits is the lack of mud and sand clasts, mud content and terrigenous material within storm deposits. Terrigenous material transported offshore during the tsunami backwash is therefore an important indicator to distinguish between storm and tsunami deposits in offshore environments.

Large-Scale Fluidization Features from Late Holocene Coseismic Paleoliquefaction in the Willamette River Forearc Valley, Central Cascadia Subduction Zone, Oregon, USA

A search of Willamette River cutbanks was conducted for the presence of late Holocene paleoli-quefaction records in the Willamette forearc valley, located 175 ± 25 km landward from the buried trench in the central Cascadia subduction zone. Eight cutbank sites are reported that show evidence of large-scale fluidization features (≥10 cm width) including clastic sand dikes and intruded sand sills in Holocene overbank mud deposits. The targeted alluvial sequences, and hosted paleoliquefaction records, are of late Holocene age, as based on radiocarbon dating, flood silt thickness (≤4 m thickness), and minimal consolidation of dike sand (~1.5 ± 0.5 kg·cm-2 unconfined compressive strength). Two of the paleoliquefaction sites, which are separated by 150 km distance, overlap in age (175 - 500 yr BP) with the last great megathrust rupture (Mw 8.5 - 9.0) in the Cascadia margin, dated at AD 1700. The scarcity of exposed late Holocene paleoliquefaction sites in the Willamette River cutbanks motivated subsurface searches for thick basal sand deposits and overlying fluidization features, using floodplain geomorphological analyses, ground penetrating radar, and remote pole-camera scans of deep trench walls (3 - 4 m depth). The onset of large-scale fluidization features occurred in overbank mud deposits (2 - 3 m thickness) above unconsolidated sand bodies (≥2 m thickness) with unconfined compressive strengths of ~1.5 ± 0.5 kg·cm-2. We recommend geomorphically-targeted subsurface explorations rather than traditional cutbank searches for evidence of coseismic paleoliquefaction in high-gradient river valley systems.

Evidence for Storegga tsunami run‐up at the head of Nordfjord, western Norway

ABSTRACTNumerical simulations show that the Storegga tsunami (∼8 150 cal a BP) penetrated into fjords and sounds along the Norwegian coast because of its large wavelengths of about 600–800 km. Despite this, deposits from the tsunami have not previously been reported from the innermost fjord district, probably because suitable sedimentary archives are lacking in the steep fjord landscape. Here we describe a persistent and well‐defined depositional unit, up to 3 m thick, found in a lake sequence at the head of the 106‐km‐long Nordfjord, which we interpret as a deposit from the Storegga tsunami. The unit is identified and mapped in seismic profiles as a continuous semi‐transparent unit which in places cut deeply into the underlying strata. In sediment cores the unit consists of grey silt with sub‐units containing shell or plant fragments, gravel and sand clasts, and redeposited lake mud. Radiocarbon ages date the deposit to the time of the Storegga tsunami (∼8 150 cal a BP). We estimate a minimum run‐up of 1–7.5 m for the tsunami based on the inferred elevation of the lake outlet relative to sea level at that time. Copyright © 2013 John Wiley & Sons, Ltd.

Lithology Dependence of Porosity In Slope and Deep Marine Sediments

Abstract Compilation of porosity data from 11 Ocean Drilling Program legs and 53 sites show that compaction in deep marine to upper-slope sediments is, at least in part, a function of both burial depth and lithology. Overall porosities range from 4 to 94%. Despite the broad range of porosities, there is an exponential trend toward decreasing porosity with depth. Comparison among samples dominated (90 to 100%) by each of six lithologies, based on grain size and composition, reveals the lithology dependence of compaction, except for biogenic silt-size sediments and clastic sands. In the former case, this may, in part, be due to mixing of calcareous and siliceous nannofossils. Clay-size clastic sediments show a clear change from rapid porosity reduction in the top 172 meters (porosity = 82.7 e−depth/430) to less pronounced loss of porosity below (porosity = 61.4 e−depth/1671). The remainder of the lithologies, silt (porosity = 75.5 e−depth/1091), biogenic sand (porosity = 88.5 e−depth/1338) and micrite (porosity = 69.5 e−depth/1235) show a good to strong exponential reduction of porosity with depth. These relations compare well with literature studies, taking into account the less pure nature of the lithologies used in this work. The silt compaction curve is unique; no previous studies of porosity separated silt from other grain sizes. Most sediment samples are of mixed grain sizes and types. The lithology-based porosity-depth relations were used to test four approaches to decompaction in mixed-lithology sediment used in backstripping. All methods generated porosity estimates that correlated strongly to the observed values, with correlation coefficients ranging from 0.629 to 0.686. These methods that have been used for years are, for the first time, shown to be valid.

Classification of Modern and Old Río Tinto Sedimentary Deposits Through the Biomolecular Record Using a Life Marker Biochip: Implications for Detecting Life on Mars

The particular mineralogy formed in the acidic conditions of the Río Tinto has proven to be a first-order analogue for the acid-sulfate aqueous environments of Mars. Therefore, studies about the formation and preservation of biosignatures in the Río Tinto will provide insights into equivalent processes on Mars. We characterized the biomolecular patterns recorded in samples of modern and old fluvial sediments along a segment of the river by means of an antibody microarray containing more than 200 antibodies (LDCHIP200, for Life Detector Chip) against whole microorganisms, universal biomolecules, or environmental extracts. Samples containing 0.3-0.5 g of solid material were automatically analyzed in situ by the Signs Of LIfe Detector instrument (SOLID2), and the results were corroborated by extensive analysis in the laboratory. Positive antigen-antibody reactions indicated the presence of microbial strains or high-molecular-weight biopolymers that originated from them. The LDCHIP200 results were quantified and subjected to a multivariate analysis for immunoprofiling. We associated similar immunopatterns, and biomolecular markers, to samples with similar sedimentary age. Phyllosilicate-rich samples from modern fluvial sediments gave strong positive reactions with antibodies against bacteria of the genus Acidithiobacillus and against biochemical extracts from Río Tinto sediments and biofilms. These samples contained high amounts of sugars (mostly polysaccharides) with monosaccharides like glucose, rhamnose, fucose, and so on. By contrast, the older deposits, which are a mix of clastic sands and evaporites, showed only a few positives with LDCHIP200, consistent with lower protein and sugar content. We conclude that LDCHIP200 results can establish a correlation between microenvironments, diagenetic stages, and age with the biomarker profile associated with a sample. Our results would help in the search for putative martian biomarkers in acidic deposits with similar diagenetic maturity. Our LDCHIP200 and SOLID-like instruments may be excellent tools for the search for molecular biomarkers on Mars or other planets.

Influence of sediment transport dynamics and ocean floor morphology on benthic foraminifera, offshore Fraser Island, Australia

The extensive longshore sediment transport system along the SE margin of Australia transports yearly 500,000 m 3 of sand from the Gold Coast of southern Queensland north towards Fraser Island. Fraser Island, which consists of 203 km 3 of quartz sand, is presently not increasing in size and north of the island quartz sand is replaced by carbonate sand. Recent multibeam sonar seafloor imagery and sediment analysis has established that the transported sand is being diverted by strong ebb tidal flow over the continental shelf edge onto the Tasman Abyssal Plain through a series of active gullies that incised the continental slope. Foraminiferal distribution patterns on the shelf and slope are closely linked to the variable ocean floor morphology and associated physical processes. In sample locations outside the continental slope gullies, areas unaffected by downslope sediment transport, foraminiferal assemblages gradually change in accordance with bathymetric zones and their prevailing ecological parameters. Species diversity, evenness, the proportion of infaunal species and the abundance of agglutinated taxa all increase with depth. Assemblages within gullies of the clastic sand transport route are significantly different. Estuarine and shelf species are transported over the shelf break and mix with typical slope species along the transport path, resulting in continued high species diversities. As the sediment and faunal load enters the abyssal plain, a faunal portion continues to travel within the Capricorn Sea Valley to over 4000 m depth. The erosional nature of gullies results in reduction of agglutinated species. Subtle topographic features such as ridges or levees within the canyon and deep-sea valley act as protection from the main erosional sand transport pathway and support the presence of fragile and erect suspension feeders. Foraminiferal distribution patterns would have received an entirely different biofacies interpretation without linking them to ocean floor processes as revealed through multibeam sonar imagery.

Siliciclastic biolaminites indicative of widespread microbial mats in the Neoproterozoic Nama Group of Namibia

Siliciclastic biolaminites are thinly laminated sediments resulting from the interaction of epibenthic microbial mat growth and sediment supply. A thick succession of ancient siliciclastic biolaminites consisting of alternating thin layers of siltstone and sericitic argillite is reported here from the Ediacaran Vingerbreek Member (Schwarzrand Subgroup) of the Nama Group in Namibia. The succession was laid down in a low-energy, intertidal environment, behind a sheltering sand barrier or shoal. Intercalated are sandstone beds and bodies originating from storm events or representing tidal channel fills. The participation of microbial mats in the accretion of the siliciclastic biolaminites is indicated by mat growth and destruction structures, like ‘elephant skin’, circular cracks with involute margins, and sand clasts, and by microstructures like ‘coated grains’ and isolated silt-sized grains ‘trapped’ in mat-derived sericitic argillite. Typical features of the biolaminites are isolated, tepee-like, antiformal structures and isolated upturned packages of the laminated sediment, overlain by undisturbed layers. By comparison with modern examples, these structures are interpreted as upturned margins of major shrinkage cracks developed once in thick microbial mats, partly involving underlying biolaminated sediment. Microbial mats inducing accretion of siliciclastic biolaminites act as barriers and retain sediments, locally leading to sizeable sedimentary successions, in the intertidal zone. This may be expected particularly in the Precambrian where mats were widespread due to the absence of predators.

Guano-derived deposits within the sandy cave fills of Naracoorte, South Australia

Geochemical and mineralogical data suggest that bat guano has made a major contribution to the development of several separate sedimentary layers, in the predominantly clastic sand and coarse silt deposits of the Naracoorte Caves, South Australia. A 20 cm thick group of reddish fine silt sediments located in Robertson Cave contains the phosphate minerals whitlockite and apatite, significant concentrations of SO3, P2O5, and CaO, and organic matter with low C/N ratios and highly enriched δN values. These data suggest that accumulations of bat guano and weathered cave limestone contributed significantly to the red silts formation. Sedimentary deposits located in Wet and Blanche Caves also contain horizons that exhibit increased concentrations of SO3, P2O5 and CaO, relatively lower C/N ratios and enriched δN values, suggesting that bat guano may have also contributed to their formation. Physical attributes evident for both these horizons further support this interpretation. A milky-white material that appears...

Guano-derived deposits within the sandy cave fills of Naracoorte, South Australia

Geochemical and mineralogical data suggest that bat guano has made a major contribution to the development of several separate sedimentary layers, in the predominantly clastic sand and coarse silt deposits of the Naracoorte Caves, South Australia. A 20 cm thick group of reddish fine silt sediments located in Robertson Cave contains the phosphate minerals whitlockite and apatite, significant concentrations of SO3, P2O5, and CaO, and organic matter with low C/N ratios and highly enriched δN values. These data suggest that accumulations of bat guano and weathered cave limestone contributed significantly to the red silts formation. Sedimentary deposits located in Wet and Blanche Caves also contain horizons that exhibit increased concentrations of SO3, P2O5 and CaO, relatively lower C/N ratios and enriched δN values, suggesting that bat guano may have also contributed to their formation. Physical attributes evident for both these horizons further support this interpretation. A milky-white material that appears to be whitlockite is present in the Wet Cave horizon, while similarities are identified by thin section petrography, between the Blanche Cave horizon and the guano layer in Robertson Cave. The development of such horizons relies on minimal sediment input from outside the cave system; hence their presence may serve as an indicator of periods of landscape stability in the palaeoenvironmental record.

Benthic foraminifers and paleoecology of a Holocene shelly concentration, Salado Basin, Argentina

Foraminiferal fossil assemblages of the shelly concentration, which represents the type section of Cerro de la Gloria Member of Las Escobas Formation, were analyzed for the first time. Taxonomic, quantitative and taphonomical analyses were made in order to obtain paleoenvironmental (physical as well biological) information. The complexity of the internal structure of the taphocoenoses was analyzed to infer the history of the final concentration process. The shell bed of Channel 15 corresponds to a shoreface longshore bar deposited in a brackish, unstable, wave-dominate coast. Shoreface and beach (foreshore) regressive facies were recognized. Taphonomic processes have modified the paleobiocoenoses by the selective preservation of autochthonous elements and by the addition of parautochthonous fauna from relict beachs and lagoons. Thus, the taphocoenoses is a within-habitat time-averaged assemblage composed of species that inhabit shallow shelf marine environments. Discrimination of autochthonous and parautochthonous fauna was possible based on taphonomic signatures of tests. The addition of the parautochthonous elements was related with longshore currents and littoral drift, and with high-energy events, probably with storm-waves, when erosion of the Pre-Mid Holocene substrate was more intense. Thus, the contribution of parautochthonous fauna is directly related with lithology and therefore, with dynamic of the paleoenvironment: in the shoreface, autochthonous fauna dominates in clastic sands with lamination and parallel stratification, whereas parautochthonous elements dominate in shoreface shelly gravels and in the foreshore sands. In the upper part of the section (beach facies), mainly parautochthonous elements related with erosion of the Pre-Mid Holocene substrate was recognized, since the shoreface was only periodically affected by marine processes, i.e., during storms.

Comparative scanning electron microscopy study of oriented till blocks, glacial grains and Devonian sands in Estonia and Latvia

Samples of Middle Devonian (Eifelian age; 387–380 Ma) indurated and non‐cemented sandstone were compared with Pleistocene basal tills in Estonia and Latvia to test a hypothesis that glacial SEM (scanning electron microscopy) microtextures are distinctly different from those produced in a fluvial depositional environment. The deposits of Middle Devonian Aruküla Stage were emplaced in a continental water basin close to sea level and well away from any glacial source. Therefore, the SEM microtextures on quartz grains from the Aruküla Stage should show mainly the effect of stream transport. The basal tills are of Late Weichselian age deposited as ground moraine directly over the sandstone. Additional glaciofluvial and glaciolacustrine samples were included with the tills to determine whether glacial and fluvial‐lacustrine transport could be differentiated by the SEM microtextures. Samples of oriented blocks of till from a limited number of sites were studied without pretreatment to determine whether sand clast orientation could provide a method for determining glacial flow vectors. While there are some microtextural similarities between grains from glacial and glaciofluvial‐lacustrine depositional environments, the vast majority of grains from till deposits (50%–60%) are faceted, sharp edged, angular to subangular, and comprised of numerous and distinct microfeatures including abraded surfaces over microfractures, deep linear and curved troughs (striations), step features, and a preponderance of conchoidal and linear microfractures. Glaciofluvial and lacustrine grains contain abundant abrasion features and v‐shaped percussion cracks that make them very distinct from glacial grains. Fluvial transport produces primarily rounded grains, well abraded, with v‐shaped percussion scars dominating. Thus, it is possible to use microtextural differences between the three sample suites to identify particular depositional environments. Oriented till blocks provide information on sand clast orientation. Although carbonate coatings often obscure sand clasts in untreated blocks, it is possible to determine some microfabric information that can be useful in determining flow direction of the ice.

Thickness and spatial distributions of clastic dykes, northwest Sacramento Valley, California

The geometry and distribution of the clastic dykes of the Ono district, North Sacramento Valley are examined within stream sections. Five traverses along dry stream beds provide good exposure allowing the spacing, thickness and geometry of the dykes to be recorded. The spatial and thickness distribution of the dykes are considered using cumulative frequency plots, allowing a visual estimation of a best fit distribution. Dyke thickness conforms best to a log-normal distribution. There is also a characteristic minimum dyke thickness in a traverse and this is attributed to the minimum aperture that a fluid with sand clasts is able to exploit. Dyke spacing, however, shows a good correlation with a power-law distribution for four traverses, suggesting that there is a mechanistic control on the spatial distribution. Plotting dyke thickness against minimum dyke spacing reveals that thin dykes do not generally intrude in isolation. Unlike veins and igneous dykes, clastic dykes continue to provide preferential pathways for fluid flow, subsequent to their intrusion, thus inhibiting intrusion in the area surrounding a pre-existing dyke. A combination of this process and dyke branching provides the best model for the observed spatial and thickness distribution of clastic dykes seen in the Ono district, California.

A sound-probe for real-time checking of physical bottom characteristics

A new, handy sound-probe for simple, real-time checking of physical bottom characteristics in shallow waters is described. The device consists of an underwater sensor and an amplifier unit, connected by a strong cable. Observations are made by lowering the sensor, and listening to the sound generated when it touches the bottom, either by gentle lowering, free-fall dropping or slow dragging. Barren rock and coarse clastic deposits, finer pebbles and sand, and mud, are three easily recognized bottom types. Mixed deposits can also be identified. We have used the instrument for several years as a means to map bottom characteristics in coastal marine areas, with satisfactory results.

Textural and Compositional Variability Across Littoral Segments of Lake Tanganyika: The Effect of Asymmetric Basin Structure on Sedimentation in Large Rift Lakes

Lake Tanganyika, part of the East African rift system, represents one of the most widely cited modern analogs for interpreting ancient rift lakes. To date, few published detailed sedimentologic studies of the modern sediments allow for comparisons to outcrop- and well-bore-scale observations within ancient strata. Four recurrent structural margin types exist along the alternating half-graben structure of the lake: hinged margins, axial margins, accommodation zone margins, and escarpment margins. The hinged margin consists of a series of structurally controlled benches over which long, continuous tracts of bioclastic lag deposits predominate; clastic sands are limited to moderate-size silty deltas and long, narrow shoreface sands. The axial margin is dominated by a wave-dominated, silt-rich delta system. Accommodation zone margins consist of bioclastic lag deposits atop structural highs, whereas carbonate and clastic mud accumulates farther offshore. Escarpment margins contain small fan-delta deposits alternating along shore with talus deposits; offshore carbonate and clastic mud is present away from active gravity-flow deposition. Total organic carbon (TOC) and pyrolysis data from fine-grained samples subtly reflect the contrasts in margin types, but these values are controlled more directly by water depth. Although facies are similar among all margin types, their spatial distribution, in particular the degree to which facies tracts trend parallel to shore, best discriminates among the different margin types. These data suggest that unique but predictable associations of reservoir, seal, and source facies exist along each of the different margin types.

Integrated, Multidisciplinary Reservoir Characterization, Modeling and Engineering Leading to Enhanced Oil Recovery from the Midway-Sunset Field, California: ABSTRACT

The Pru Fee property is developed in a heavy oil, Class III (slope and basin clastic sand), reservoir of the Midway-Sunset field, San Joaquin Basin, California. Wells on the property were shut-in with an estimated 85% of the original oil remaining in place because the reservoir failed to respond to conventional cyclic steaming. Producibility problems are attributed to the close proximity of the property to the margin of the field. Specific problems include complex reservoir geometry, thinning pay, bottom water, and dipping beds. These problems are likely common at the margins of the Midway-Sunset and other Class III reservoirs. This project forms the first step in returning the property to production and explores strategies that might be applied elsewhere. Reservoir characterization, modeling, and engineering methods are integrated to design, simulate, and implement a pilot steam flood. A new drillhole provides good quality, core through the pay zone and a full suite of geophysical logs. Correlations between geological and petrophysical data are used to extrapolate reservoir conditions from older logs and yield a 3-dimensional petrophysical model. Numerical results illustrate how each producibility problem might influence production and provide a framework for designing the pilot steam flood. This first phase illustrates howmore » a multidisciplinary team can use established technologies in developing the detailed petrophysical, geological, and numerical models needed to enhance oil recovery from marginal areas of Class III reservoirs.« less