Theses
http://nur.nu.edu.kz:80/handle/123456789/4781
2024-03-29T14:40:36ZINVESTIGATION OF SURFACE CHEMISTRY, MICRO-TOPOGRAPHY, AND WETTABILITY ALTERATION OF CALCITE-ASPHALTENE INTERFACE IN PRESENCE/ABSENCE OF NIO AND MGO NANOPARTICLES USING ATOMIC FORCE MICROSCOPY AND X-RAY PHOTOELECTRON SPECTROSCOPY
http://nur.nu.edu.kz:80/handle/123456789/7379
INVESTIGATION OF SURFACE CHEMISTRY, MICRO-TOPOGRAPHY, AND WETTABILITY ALTERATION OF CALCITE-ASPHALTENE INTERFACE IN PRESENCE/ABSENCE OF NIO AND MGO NANOPARTICLES USING ATOMIC FORCE MICROSCOPY AND X-RAY PHOTOELECTRON SPECTROSCOPY
Rakhmetullin, Alisher
2023-01-01T00:00:00ZREDUCING POLYMER ADSORPTION DURING CHEMICAL ENHANCED OIL RECOVERY IN UZEN FIELD
http://nur.nu.edu.kz:80/handle/123456789/7378
REDUCING POLYMER ADSORPTION DURING CHEMICAL ENHANCED OIL RECOVERY IN UZEN FIELD
Maratbekkyzy, Laila
This research investigated the potential of nanomaterials and alkaline in diminishing polymer adsorption on terrigenous rock formations. Polymer injection has been examined as a tertiary recovery technique in the Uzen field, which has favorable reservoir characteristics for this technology implementation. Nonetheless, the occurrence of polymer adsorption can considerably limit the usefulness of the method, reducing the permeability of the layers and the viscosity of the injection fluid, and consequently decreasing the oil recovery. Therefore, polymer adhesion may be adjusted by modifying the system's chemical and physical properties using nanoparticles. In particular, silica nanoparticles are widely employed due to their large surface area and ability to connect with polymeric chains. In addition, alkali can improve the repelling forces between the polymer and minerals by making the rock surface more negative.
This research aimed to determine the influence of silica nanoparticles and lye on HPAM-based ASP3 polymer adsorption at the interface of Uzen rock. It was investigated by performing tests on static and dynamic adsorption.
The first step was to evaluate different concentrations of polymers and nanoparticles by zeta potential measurement in order to achieve stable chemical conditions. ASP3 (2500 ppm) – SiO2 (0.1 wt. %) and ASP3 (2500 ppm) – NaOH (0.03%) solutions were utilized for the static adsorption tests, showing a noticeable influence on adsorption reduction. It should be highlighted that alkali was less efficient in prolonged durations, such as 24 and 36 hours.
When silicon dioxide was applied for dynamic adsorption studies, the adsorption of ASP3 was decreased by around 18%. At the same time, alkali was ineffective in reducing the polymer's dynamic adsorption, leading to a 5% increase in adsorption. Polymer-nanoparticle flooding as an enhanced oil recovery technique was successful, achieving a total recovery factor of around 96%, where incremental recovery was 5% higher than only the polymer injection case. Ultimately, it is recommended that the project plan for the Uzen field can be improved in consideration of the findings of the study.
2023-04-01T00:00:00ZECONOMIC IMPACT OF MINING IN KAZAKHSTAN
http://nur.nu.edu.kz:80/handle/123456789/7377
ECONOMIC IMPACT OF MINING IN KAZAKHSTAN
Kizatov, Yeskendir
Kazakhstan is a country that economically relies on the export, especially on the export of the products of mining. Review of recent publications has proven the claim above. That is why mining sector has a significant impact on national economics. The research of data from the report, ordered by Minisrty of Industry and Infrastructure Development of Kazakhstan has shown that generally sector of mining in Kazakhstan is growing, however the taxation system has significant drawbacks, that are restraining it from sustainable development. These drawbacks are needed to be worked on.
2023-03-31T00:00:00ZAPPLICATION OF SEQUENTIAL INDICATOR SIMULATION TO MODEL NON-STATIONARY GEOLOGICAL DOMAINS COMBINING WITH A MACHINE LEARNING ALGORITHM
http://nur.nu.edu.kz:80/handle/123456789/7376
APPLICATION OF SEQUENTIAL INDICATOR SIMULATION TO MODEL NON-STATIONARY GEOLOGICAL DOMAINS COMBINING WITH A MACHINE LEARNING ALGORITHM
Amirzhan, Almas
Resource estimation is an essential aspect of the development process for any mining project. The geological domains are defined based on data obtained from boreholes, with the goal being to determine the mineral grades in the geological domains. Geostatistics assumes that the joint distribution of geological attribute values is consistent across homogeneous domains and is defined by a stationary covariance function. However, the nature of geological systems often contains uncertainties and variations in structure and behaviour.
Sequential Gaussian and Sequential Indicator Simulation are one of several methods used for simulating continuous and categorical variables in 3D geological modelling. Despite its advantages, this method and other conventional techniques have been criticized for not effectively capturing local mean values, variance, and spatial continuity changes.
The traditional algorithms used in the industry are not suitable for non-stationary geological domains, as they are designed for stationary target simulation variables. This thesis proposes using Multinomial Logistic Regression as an alternative method for simulating the spatial properties of non-stationary geological domains. The technique will be applied to a copper-porphyry deposit that shows clear signs of non-stationarity.
The mineral resource model will be created by weighting the copper grade estimates based on the probability of occurrence of different rock types in various geo-domains. The generated probability maps will be evaluated using various criteria, including visual inspection of realizations, probability maps, replicas of each geo-domain fraction, connectedness metrics, and trend analysis.
2023-04-17T00:00:00ZPOLYMER SCREENING TO IMPROVE ACID SWEEP EFFICIENCY IN URANIUM ISR PROCESS
http://nur.nu.edu.kz:80/handle/123456789/7372
POLYMER SCREENING TO IMPROVE ACID SWEEP EFFICIENCY IN URANIUM ISR PROCESS
Veintimilla, Santiago
In-situ leaching (ISL) is a widely used technique for the extraction of uranium from ore bodies.
The ISL process involves the injection of a leaching solution into the ore body through wells
drilled into the formation. The leaching solution dissolves the uranium from the ore, and the
resulting solution is then pumped to the surface for processing.
One of the main challenges in the ISL process is the heterogeneity and anisotropy in the
petrophysical properties of the reservoir. The ore body may contain multiple zones with varying
permeability values and a constant porosity value making it difficult for the acidic solution to
reach the main objective zones for production. As a result, a large volume of acidic solution is
often injected to ensure that the solution reaches the targeted zones by density differentiation.
However, this solution leads to a higher volume of injection solution needed, and the
operational costs of the process become prohibitive.
This study attempts to provide a new direction in the production of uranium through the ISR
process and a practical solution to improve acidic solution use and enhance its sweep efficiency
by the use of polymer flooding. The aim of this study is to screen the performance of different
polymers to identify the most effective ones in enhancing sweep efficiency. The study
investigates the effects of polymer concentration on the viscosity of the polymer on the surface
of the ore. The use of polymers can enhance the viscosity of the acidic solution, reduce the
heterogeneity between the layers on the reservoir and displace the desired resulting solution as
uniform as it can be.
The results of polymer screening will provide data to a simulation of polymer flooding under
determined parameters. The main objective of this simulation is to demonstrate that polymer
can enhance the sweep efficiency of the injected fluid even being under extreme conditions as
low pH values, enabling it to reach the main objective zones for production. This can reduce
the operational costs of the process and increase the sustainability of uranium extraction from
ore bodies. As a result the sweep efficiency was improved from 0.72 in the first case scenario,
only acidic solution injection, to 0.80 after polymer flooding. Furthermore, the study can
contribute to the understanding of the mechanisms of polymer flooding in the ISL process,
providing a foundation for further research on this topic.
2023-04-01T00:00:00ZUSING MULTIPLE-POINT STATISTICS FOR MODELING A VEIN TYPE GOLD DEPOSIT
http://nur.nu.edu.kz:80/handle/123456789/7371
USING MULTIPLE-POINT STATISTICS FOR MODELING A VEIN TYPE GOLD DEPOSIT
Zhexenbayeva, Aida
The main causes of geological uncertainty in development of mines consist of inaccuracy from geological domains and uncertainty in metal grades (Emery, 2007). Because geological domains typically influence how the grade is distributed, these two types of uncertainty impossible to model separately. Creating geological domains and assessing the grade of metal inside them are often first steps in the resource estimation process in the mining sector. Legacy drill hole data samples taken decades ago contain a vast quantity of geological information, but there is no proof that accurate QA/QC was done on those specimens (Abulkhair and Madani 2022). In this case, it is important to build an appropriate block model that can be used as a representative training image for conducting a multiple-point geostatistics. Because complex, curved, continuous structures such as vein-type deposits unable to be defined with traditional two-point statistics, variogram-based stochastic modeling are frequently unable to represent the spatial distribution of gold veins.
This thesis proposes a unique method for stochastic simulation of a Mineral Resource in a structurally complicated gold deposit. Multiple-point geostatistics tries to overcome the variogram's limitations. While creating deterministic geological models of the subsurface, information from boreholes and expert subject knowledge are frequently used as cognitive or explicit geological modeling techniques. Such cognitive geological models, however, are unable to convey the ambiguity of layer boundaries. Also, there are typically only a few boreholes available throughout the research area, although it is still unclear where the facies boundaries exactly are. To quantify the uncertainty in these boundaries, however, probabilistic modeling enables the creation of numerous realizations of facies that can be thought of as equiprobable outcomes. We suggest a novel stochastic methodology that combines the efforts of probabilistic data integration to address the flaws in this approach.
Multiple-point geostatistics is based on the idea of going beyond two-point correlations between variables and obtaining (cross) correlation moments at three or more places at the same time utilizing training images to identify patterns of geological heterogeneity ( in our case veins). Since the Multiple-point statistics approach based on training image, also this work was investigated the appropriateness of using geological model produced in Leapfrog as a training image. Furthermore findings demonstrated that direct sampling (DeeSse) is a feasible multiple-point geostatistics approach for replicating the long-range connectivity and the structure of veins in gold deposit
2023-04-03T00:00:00Z