Browsing by Subject "Smectite"
Now showing 1 - 4 of 4
Results Per Page
Sort Options
Item Application of a Novel Clay Stabilizer to Mitigate Formation Damage due to Clay Swelling(2014-12-09) Clarke, TimothyClay swelling and fines migration can cause formation damage of hydrocarbon bearing zones and prevent economic realization of oil/gas wells. Identification and management of clay particles in the formation is a necessary component of production and drilling engineers? responsibilities. This research focuses on the application of a cationic inorganic Al/Zr-based polymer clay stabilizer to prevent swelling of smectite particles in a sandstone matrix. Previous work has focused on mitigating fines migration; swelling mitigation is tested here. Berea sandstone cores were injected with a montmorillonite slurry to supplement the very low concentration of naturally occurring swelling clays. The modified Berea cores were subjected to a unique aluminum/zirconium-based clay stabilizer, via coreflood, to determine the effect of the stabilizer as a clay control mechanism. Pressure differential across the core and analysis of the coreflood effluent were used to measure the effectiveness of the treatment. The Al/Zr stabilizer performed well as a means to prevent clay swelling. When compared to an untreated core, permeability loss due to clay swelling and fines migration was negligible. Performance of the stabilizer at different concentrations suggests that an increase in stabilizer concentration does not correlate directly with permeability maintenance.Item Detection and Quantification of Expansive Clay Minerals in Geologically-Diverse Texas Aggregate Fines(2012-11-28) Russell, George 1983-Expansive clay mineral contamination of road aggregate materials in Texas is a persistent problem. Hydrous layer silicate minerals - particularly smectites - in concretes are associated with decreased strength and durability in Portland cement and asphalt concretes. The Texas Department of Transportation (TXDOT) and Texas A&M Transportation Institute (TTI) evaluated the methylene blue adsorption test for its potential to identify and estimate quantities of expansive clays in aggregate stockpiles. Clay mineral quantification was completed for 27 geologically-diverse aggregate materials from Texas, Oklahoma, and Arkansas. X-ray diffraction analysis (XRD) of separated clays on glass was conducted, and NEWMOD was utilized to model the resulting diffraction patterns. Methylene blue adsorption (MBA) and cation exchange capacity (CEC) of clay fractions (< 2?m) and -40 mesh screenings (< 400 ?m) were determined for most aggregates. Many of the aggregates exhibited significant quantities of expansive clay minerals such as smectite, which are linked to deleterious performance properties in concretes. While the majority of aggregates were derived from crushed limestone or calcareous river gravel parent materials, severalexhibited uncommon origins and unusual clay mineralogy. Due to the relatively low number of aggregates tested and diverse geological origins of the different aggregates,it proved difficult to formalize any conclusions abouttrendsbetweenthedifferent aggregate performance properties.Item Mineralogy of the playa clays at the Pantex plant, Amarillo, Texas(Texas Tech University, 1996-08) Mars, Kenneth R.The Southem High Plains of Texas contains approximately 20,000 small ephemeral lake basins called playas. Recentiy, these playas have received considerable attention due to the realization that focused recharge to the Ogallala Aquifer can occur through these basins (Wood and Osterkamp, 1984, 1987; Scanlon et al., 1994; Wood et al., 1996). The Pantex Plant, located 16 miles northeast of Amarillo, Texas, in Carson County, has five playa lakes on property owned or leased by the Department of Energy. Potential contamination of the Ogallala Aquifer from Pantex has created much concern. Measurable contamination has been detected in the soils underlying the Plant (Laun, 1995). A sufficient knowledge of soil properties in playa basins is necessary to properly characterize the potential of contamination. Playa basins are a major focus of surface mnoff on the Southem High Plains. Playa basins have a distinctive surface soil, termed the Randall soil series (USDA-SCS unpublished material, 1978). Randall soils are defined as fine, montmorillonitic, thermic typic Halplustert. Playa basins collect mn-off from agricultural fields, roads, pavement and other man-made stmctures that can be sources of contamination. Mineralogy influences factors such as recharge and contaminant attenuation through these basins.Item Smectite clay adsorbents of aflatoxin B1 to amend animal feed(2009-05-15) Kannewischer, InesSmectite clay has been shown in studies over the past 20 years to sorb aflatoxin B1 (AfB1) in animal feed and thereby reduce its toxic influence on animals. In this study, 20 smectite samples were selected from industrial products or reference minerals. In the initial steps, it was shown that AfB1 entered the interlayer galleries of smectites and a 10-fold range in sorption ability was observed in a set of 20 smectite samples. Yet, it was not clear which clay properties (CEC, pH, base saturation) influenced this variation. In an effort to further explore properties that might influence the sorption of AfB1, three good sorbent samples were chosen from our set of 20 samples along with one sample of low sorption capacity. Those samples were fractionated into sand, silt, coarse clay (CC), and fine clay (FC) fractions. From all sample fractions, sorption isotherms and X-ray diffraction patterns were obtained. Additionally, a vermiculite and a palygorskite were examined with regard to sorption capacity. Concentration of smectite and their adsorption test suggest that differences in smectite composition are responsible for difference in sorption, not so much their relative abundance or other mineral phases. Initial infrared analysis indicates that weathered aluminous smectites, which have no octahedral iron or magnesium, belong to the poor AfB1 sorbents. Palygorskite and vermiculite are not effective sorbents. Based on the findings in this study, tentative quality criteria of sorbent selection for their use in animal feed were established. These criteria are: pH between 6.5 and 8.5, CEC > 75cmolc/kg, organic carbon < 2.5 g/kg, expression of XRD smectite peak and AlFeOHbending in FTIR and Langmuir adsorption capacity for AfB1 > 0.40 mol/kg.