Waste Injection Research Articles

Numerical simulation of the stress-strain state near the injection well at deep disposal facilities for liquid radioactive waste

Relevance. The need to predict deformations of the earth's surface near injection wells pumping liquid radioactive waste, as well as their stability when pressure changes in the well during injection. Aim. To perform a numerical analysis of the stress-strain state of the structural elements of the injection well and the surrounding rock mass using the finite element method, to determine the magnitude of the deformations of the earth's surface and define the stability of the well and the strength of the cement stone at the maximum injection pressure of liquid radioactive waste. Objects. Near-wellbore zone of one of the injection wells located at the liquid radioactive waste injection site. Methods. Numerical finite element method for calculating the stress-strain state of the near-wellbore zone, taking into account the distribution of the elastic properties of rocks along the simulated section and the main structural elements of the well. Results. The authors have developed the numerical finite element scheme of one of the injection wells, taking into account its main structural elements, as well as allowing you to set the pressure distribution within the exploited horizon during the injection of waste. In the model, the distribution of the elastic properties of rocks along the section was set, taking into account their lithological features. The authors carried out the analysis of the hydrodynamic parameters of the well operation and determined the maximum pressure at the wellhead during the injection of liquid radioactive waste, equal to 1.71 MPa. Numerical modeling of the stress-strain state of the near-wellbore zone was performed in two stages: for the conditions of an idle well and taking into account the pressure distribution at the maximum waste injection pressure. The distribution of vertical displacements at the level of the earth's surface, as well as at the top of the operational horizon at the maximum pressure of liquid radioactive waste injection, is obtained. It is shown that at such a pressure, the largest uplifts will be: on the earth's surface – 4.5 cm, on the top of the production horizon – 11 cm. An assessment of the stability of the well structural elements at a maximum waste injection depth of 280 m, corresponding to the maximum pressure, showed that the stresses in the well and cement stone are much lower than the values that can lead to their violation. For cement stone, the safety factor at a maximum pressure of 1.71 MPa was equal to 7.8.

Episodic fluid venting from sedimentary basins fueled by pressurized mudstones

Subsurface sandstone reservoirs sealed by overlying, low-permeability layers provide capacity for long-term sequestration of anthropogenic waste. Leakage can occur if reservoir pressures rise sufficiently to fracture the seal. Such pressures can be generated within the reservoir by vigorous injection of waste or, over thousands of years, by natural processes. In either case, the precise role of intercalated mudstones in the long-term evolution of reservoir pressure remains unclear; these layers have variously been viewed as seals, as pressure sinks, or as pressure sources. Here, we use the geological record of episodic fluid venting in the Levant Basin to provide striking evidence for the pressure-source hypothesis. We use a Bayesian framework to combine recently published venting data, which record critical subsurface pressures since ∼2 Ma, with a stochastic model of pressure evolution to infer a pressure-recharge rate of ∼30 MPa/Myr. To explain this large rate, we quantify and compare a range of candidate mechanisms. We find that poroelastic pressure diffusion from mudstones provides the most plausible explanation for these observations, amplifying the ∼3 MPa/Myr recharge caused primarily by tectonic compression. Since pressurized mudstones are ubiquitous in sedimentary basins, pressure diffusion from mudstones is likely to promote seal failure globally.

Wastewater leakage identification in WWTP and concrete pipelines using integrated geophysical imaging methods

Industry and mining activities covers a broad spectrum of processes that dispose an abundant amount of wastewater. Given the vast array of industries, there are equally large number of heavy metals, organic solvents, and hydrocarbons pollutants associated with its wastewater, posing a great threat to aquifers, especially groundwater. Main contributor of this polluting scheme are from the leakage of underground/surface storage tanks, effluent pipework, industrial sewers, and waste injection system. To ascertain the presence of pollution in the subsoil and groundwater resources, an integrated geophysical method can be the alternative of non-invasive methods. The presence of contaminants in subsoil alters the physical properties of rock formations and decrease pore-water resistance, therefore it can be mapped by geoelectrical resistivity. In this paper, study case was conducted in Medan Industrial Estate, Indonesia, to identify potential leakage under the Wastewater Treatment Plant (WWTP) and its pipework, using Geoelectrical Wenner and Magnetotelluric Method with 5 lines in the interval of 40-60 meters and Magnetotelluric Method throughout the 175 meters of pipework in the production area. Based on the Geoelectrical Method, an anomaly with a low resistivity value was detected within 7 meters of the ground depth. Meanwhile, in the Magnetotelluric Method, a moderate permittivity value was detected that is local and located within 2 meters depth which is where the pipe and the bottom of the WWTP storage tank is located. In conclusion, based on the results obtained from the Geoelectrical and Magnetotelluric Methods that have been carried out in the WWTP area and along the wastewater pipeline leading to the WWTP, no anomalies were found that lead to waste water leakage.

Study of Atmospheric Plasma-Based Mass Separation System for High-Level Radioactive Waste Treatment

Study of Atmospheric Plasma-Based Mass Separation System for High-Level Radioactive Waste Treatment

Strontium transport modeling in high-concentrated nitrate solution in DEEP liquid radioactive waste repository

This article focuses on modeling 90Sr migration in strong nitrate solutions in aquifers used for radioactive waste disposal. This type of radioactive waste disposal is typical only for the Russian Federation and is a unique object of study. The calculations are based on the laboratory study of strontium sorption in nitrate solutions on sandy, loamy and clayey rocks under biotic (with natural microbial communities obtained from Seversky repository) and abiotic conditions. To obtain a strontium sorption model, first, an ion exchange model in PHREEQC software is fitted to the experimental data both manually and automatically (using MOUSE software). Since real nitrate-ion concentrations at radioactive waste injection sites can reach values of hundreds of grams per liter, strontium Kd values are predicted for high ionic strength (for which no experimental study of strontium sorption efficiency has been carried out) with PHREEQC-model. The strontium transport models accounting for sorption and the nitrate reduction processes have been developed using two numerical software packages: the GeRa 3D hydrogeological simulation code and the PHREEQC reactive transport code. Reactive transport modeling under different conditions shows a high sensitivity to dispersion. A significant effect of sorption of nitrate ion on Sr sorption is shown and a relatively small contribution of microbial processes to strontium transport is noted for liquid radioactive waste injection sites.

Utilization of Palm Oil Mill Effluent (POME) Liquid Waste to Increase Density and Growth Rate of Microalgae Chlorella Pyrenoidosa

Microalgae Chlorella pyrenoidosa is a microalgae that has the potential to have various roles, especially as a bioabsorbant for organic waste. The growth of the oil palm plantation industry is also directly proportional to the increase in waste generated from the CPO production process, namely POME Waste (Palm Oil Mill Effluent). POME waste has a high nutrient content so that it can be utilized by the microalgae Chlorella pyrenoidosa. This study aims to utilize POME waste to increase the growth of Chlorella pyrenoidosa. Microalgae cultivation had a significant effect on the 1:2 treatment and 1:3 treatment when compared to the control cultivation medium with the highest cell density values ​​of 263(106cells/ml) and 279(106cells/ml) respectively. Injection of POME waste into microalgae rearing media will have an impact on increasing the growth of Chlorella pyrenoidosa microalgae.

Evaluation of the impact of injection of liquid radioactive waste on the change in the stress-strain state of a rock mass

Evaluation of the impact of injection of liquid radioactive waste on the change in the stress-strain state of a rock mass

Lessons Learned to Avoid Formation Damage Development During Waste Slurry Injection Operations

The injection of oil and gas wastes produced during the exploration and production phases have been proven to be an effective technique towards achieving zero discharge. However, several challenges are associated with the injection of slurry into an underground formation. The most common challenge during waste slurry injection (WSI) is the loss of well injectivity and pre mature formation damage due to a poor engineering and operational design. For the WSI operation, near wellbore formation damage is one of the major risk and is created by the injected solids. The real time injection monitoring of the ongoing operations is important to make amends to the injection procedure in order to avoid the formation damage and ensure the well longevity. Three different case studies are presented to highlight the operational mistakes that caused a significant formation damage in injectors in Eagle Ford, Haynesville, and Permian Basin shale plays of Texas, United States. Certain guidelines depending on the monitoring results are provided like modifying the slurry rheology, injection pressure, injection strategy etc. that are helpful in maintaining the injectivity. The presented case studies show that the wells with good monitoring program maintained its injectivity during its operation compared to the other wells that lost its injectivity sooner. The paper discusses the importance of injection monitoring and steps necessary to maintain the injectivity and perform a healthy WSI operation.

Neptunium behavior in conditions of deep stratum-collector of liquid radioactive waste

237Np isotope is one of the long-lived and hazardous components of the accumulated liquid radioactive waste (LRW). The potential for environmental contamination when the LRW is directly disposed of in deep geological stratum is a matter of concern. Np(V) is highly mobile in the groundwater, and numerous studies are focused on its interaction with natural geological systems and prospective engineered barriers for the radioactive waste repositories. In this work, we studied the neptunium behavior in simulated conditions of acidic liquid radioactive waste injection to the deep permeable stratum collector. To determine components of the host rock preferentially binding the neptunium, and to estimate the effect of elevated temperature on its mobility, a series of laboratory experiments on sorption and leaching of neptunium was carried out using synthetic acid LRW solution and real stratum-collector sand along with individual component simulants. It was found that neptunium sorption on stratum collector sands in the conditions of acidic waste injection is quite low. Clay minerals turned out to be the sorption-dominating components of the host rock for neptunium. Increase in temperature significantly enhances the retention of neptunium on solid phase. Solid-bound neptunium species are sufficiently stable over the two-year experimental time under ambient conditions.

Enhanced Water Resources Risk from Collocation of Disposal Wells and Legacy Oil and Gas Exploration and Production Regions in Texas

ABSTRACTAn existing probabilistic risk assessment (PRA) for Class I hazardous waste (Class IH) injection well systems is extended for dynamic risk analysis and modified for Class II disposal well systems, which inject large volumes of “exempt” oil and gas (OG) exploration and production (E&P) waste. Disposal system failure is release of waste to the biosphere, including underground sources of drinking water. Comparative PRA analysis of generic Class IH and generic Texas Class II disposal systems suggests Class II systems are 50 times more likely to fail than Class IH systems due to different requirements for pressure monitoring, waste migration monitoring, and number of confining layers. The generic Texas Class II disposal well PRA was extended to portray a generic disposal system in Dimmit County, Texas, which is a legacy OG E&P region, and to account for the increased likelihood of waste migration pathways from unknown wells and plug failure of abandoned wells. Legacy oil‐related activities increase the probability of waste migration pathways because well construction, regulatory protections, and information tracking technologies have improved during the last 40 years. The system failure likelihood for Class II disposal well systems, collocated with legacy and active OG activities, is twice that for generic Texas Class II disposal systems, and failure likelihood increases with the assumed proportion of unknown wells to known wells.

A Review of Soil Injection of Liquid Organic Wastes: Potentials and Challenges

A Review of Soil Injection of Liquid Organic Wastes: Potentials and Challenges

Alternative Disposal Options for High-Level Radioactive Waste

Abstract. Are alternatives to the disposal of high-level radioactive waste in a geology repository conceivable? We present the results of the first phase of a research project on the state of the art in science and technology for alternative disposal options. The project is financed by the Federal Office for the Safety of Nuclear Waste Management. Most recently, in 2015, the German Commission on the Storage of High-Level Radioactive Waste (Endlagerkommission) evaluated possible disposal technologies and classified them as either promising, conceivable, or to be pursued further. Only final disposal in a geological repository was considered promising. Conceivable, but not immediately available or not advantageous, were storage in deep boreholes (DBs), long-term interim storage (LTIS), and partitioning and transmutation (P&T). All other alternative disposal options by burial, dilution, or removal from the planet were determined not to be worth pursuing. The Disposal Commission did conclude that none of the three conceivable methods (DBs, LTIS, P&T) would result in earlier disposal of high-level radioactive waste than the preferred final disposal in a mine. However, it recommended continued tracking and regular monitoring of the future development of alternative disposal options, e.g., disposal in deep boreholes. Finally, in 2017, with the amended Site Selection Act, the federal government specified disposal in a repository mine with the option of retrieval during operation or recovery for 500 years after closure. In a learning site selection process, the Federal Office for the Safety of Nuclear Waste Disposal (BASE) reviews the proposals of the project managing company, the Federal Company for Radioactive Waste Disposal (BGE), and prepares a reasoned recommendation to the federal government for a site with the best possible safety. Part of the reasoned recommendation is, among other things, a discussion of alternative disposal options to final disposal in deep geological formations. In the presentation, we report on the status of international research on alternative disposal options, discuss advantages and disadvantages of the technologies, and evaluate the potential of the technologies for the disposal of high-level radioactive waste in Germany. The LTIS is designed as dry storage in a building to be constructed above ground or near the surface and is expected to last for a period of several hundred years. With LTIS it would be possible to gain time for the development of a suitable final disposal option; however, this also postpones the disposal issue indefinitely into the future with undetermined methods. DB storage would involve sinking the storage containers into boreholes with depths of up to 5000 m. This could reduce the expense and be particularly advantageous for smaller inventories, although the potential for the use of engineered barriers would be limited and retrievability precluded according to the current state of the art in science and technology. P&T is primarily intended to separate long-lived transuranic elements from high-level radioactive waste and then convert them to short-lived fission products by neutron irradiation in reactors. The main goal is to reduce the necessary containment times in the repository by changing the inventory, but the effort to treat the waste would be significant and a repository for high-level nuclear waste is still needed. More exotic ideas for alternative disposal include deep geological injection of liquid waste, waste forms that melt themselves into rock, storage inside the ocean floor or subduction zones, shipment to space, burial in ice sheets, or dilution in the atmosphere and oceans. None of these exotic options is currently being actively pursued.

Design Of Portable Injection Waste Destruction Machine With Sterilization System

The Community Health Center (Puskesmas) does not yet have special facilities for treating medical waste such as hospitals. Hospital/Puskesmas waste and waste generated by hospital activities and other supporting activities. Make a machine that destroys waste injection equipment equipped with a knife made of SKD as a plastic syringe destroyer. Design of a syringe crushing machine in the form of needles and syringes, Analyze the von misses stress received by the frame structure of the syringe crusher, Analyze the displacement by the load received by the frame structure of the syringe crusher, Analyze the safety factor of the frame structure of the crusher syringe. Analyzing using solidworks 2016 software, the results obtained are the maximum value of von misses, displacement, and safety of factor from the lower frame of the syringe waste crusher machine. Von misses stress obtained in the analysis using Solidworks 2016 gets a value of 48.54 Mpa in software calculations, while in theoretical calculations it is 48.01 Mpa. The percentage of errors calculated by software and theory is 1%. The displacement obtained in the analysis using Solidworks 2016 software is 0.34 mm in theoretical calculations of 0.35 mm. The percentage of errors calculated by software and theory is 2%. The safety factor obtained in the solidwork analysis gets a value of 4.7 ul (upper limit), while the theoretical calculation is 5.2 ul (upper limit) which means this frame is declared safe when the engine is operating.

Технологии безопасного обращения с отходами бурения при строительстве скважин в Обской губе

Development of the Russian oil and gas fields in the Arctic requires ensuring industrial and environmental safety of conduct of the operations. Large and unique oil and gas condensate fields are discovered in the southern part of the Kara Sea. The Kamennomysskoye-Sea, Severo-Kamennomysskoye, Semakovskoye, Parusovoye, etc. gas condensate fields are located in the Ob Bay of the Kara Sea. The raw material base of the Severo-Obskoye gas condensate field, unique in terms of the reserves, will become the basis for future Arctic LNG projects. Based on the published data, the initial recoverable total hydrocarbon resources in the Ob and Taz bays are about seven billion tons. Active exploration and commissioning of the already discovered fields require the large volumes of well drilling in a freezing sea, the presence of permafrost, and gas hydrates. During construction of the wells and operation of the offshore ice-resistant oil and gas production platforms, it is required to ensure the disposal of drilling waste (cuttings) and domestic water. There are two technologies for waste disposal — injection into the reservoir or into the clay formations. The first one is used in onshore fields, the second one — on the shelf. Injection into a clay reservoir is successfully used in the Lunskoye gas field on the shelf of the Sakhalin island, and on the Prirazlomnoye oil field in the Pechora Sea. The possibility of using the method and the selection of a reservoir for injecting waste into it requires a geological justification, and the reservoir should ensure a stable injectivity of the required volume. The article presents the results of modeling the injection into the formation of drilling waste, and the waste of the household activities for the Kamennomysskoe-Sea gas condensate field. Calculation was made concerning the zone of absorption of the technological waste into the designed well of the offshore ice-resistant stationary platform. Formation allocation for waste injection was made according to the data of a complex of offshore wells geophysical studies. Three packs of sandy-argillaceous rocks with high reservoir properties were selected as the object of industrial waste disposal. Сalculation was carried out related to the radius of the spread of waste (effluent) in the target reservoir considering drilling and operation of twenty five wells, the construction of which is planned for five years. The results of modeling the process of pumping industrial waste of various types into an absorption well showed that the planned volumes can be successfully disposed of in the selected objects. This will allow to ensure functioning of the marine industry and its environmental safety.

Assessment of density driven convection effect on the dynamics of contaminant propagation on a deep well radioactive waste injection disposal site

The influence of density driven convection is considered when injecting high density solutions into deep aquifers on a radioactive waste injection site. The proposed mathematical model allows to take into account confined and unconfined flow regimes, variable solute density and dual porosity of the media. Time discretization is based on full implicit scheme with Picard iterations applied to solve arising nonlinear problems. The importance of density driven convection effect is studied on a 3D model of a real waste deep injection site. Also the influence of dual porosity concept and dispersion process on waste propagation is addressed.

Deep Underground Injection of Waste from Drilling Activities—An Overview

Oil and gas exploration and production activities generate large amounts of waste material, especially during well drilling and completion activities. Waste material from drilling activities to the greatest extent consists of drilled cuttings and used drilling mud with a smaller portion of other materials (wastewater, produced hydrocarbons during well testing, spent stimulation fluid, etc.). Nowadays, growing concerns for environmental protections and new strict regulations encourage companies to improve methods for the reduction of waste material, as well as improve existing and develop new waste disposal methods that are more environmentally friendly and safer from the aspect of human health. The main advantages of the waste injection method into suitable deep geological formations over other waste disposal methods (biodegradation, thermal treatment, etc.) are minimizing potentially harmful impacts on groundwater, reducing the required surface area for waste disposal, reducing the negative impact on the air and long-term risks for the entire environment. This paper gives a comprehensive overview of the underground waste injection technology, criteria for the selection of the injection zone and methods required for process monitoring, as well as a comprehensive literature overview of significant past or ongoing projects from all over the world.

Mutual impact of reservoir sands and acidic liquid radioactive waste

The work is devoted to the study of the behavior of long-lived alpha-emitting radionuclides (Pu, Am, U, Np) under the conditions of injection of acidic liquid radioactive waste into a sandy rock reservoir bed. Different mineral phases of initial reservoir sands, secondary minerals formed when interacting with waste solutions, as well as phases precipitating from the waste solution are considered in terms of their retention properties towards to actinides.

Real-time microseismic overburden surveillance at the Grane PRM field offshore Norway

Real-time microseismic detection at offshore hydrocarbon fields is on its way to becoming a standard monitoring tool. Recently, increased focus on injection and overburden surveillance for an improved health, safety and environment (HSE) and cost saving has led to this development. Several hydrocarbon fields are already equipped with permanent reservoir monitoring (PRM) systems with seismic sensors permanently installed at the seafloor (Caldwell et al., 2015), and similar installations are planned or under consideration for some other offshore fields. PRM systems are in principle designed for acquiring active time-lapse seismic data 1-2 times per years, and as such, they are not used during most of their lifetime. But apart from active seismic, PRM systems can also be used for recording passive seismic data. With appropriate processing and analysis methods, such as microseismic event detection, the continuous stream of passive data can be converted into useful real-time subsurface information. This results in improved HSE, and therefore a more valuable PRM system. In 2014, a mini-PRM system with 172 multi-component sensors was installed at the Oseberg field, offshore Norway. The mini-PRM system indeed demonstrated the feasibility of injection and overburden surveillance using real-time passive seismic (Bussat et al., 2016). Despite high installation costs, a cost/benefit evaluation shows net benefits for the Oseberg system owing to better control on waste injection rates. The next step, and topic of the current paper, is to scale up and transfer the learnings from the small Oseberg system to the large Grane PRM system, so as to enable processing and analysis of large amounts of passive data and allow for real-time injection monitoring at Grane. Compared to the Oseberg case, the microseismic data processing is distributed and optimized to be able to use many more sensors and monitor larger subsurface volumes with increased resolution. Moreover, the detection method is improved from an originally strict semblance-based method to also include signal-to-noise (S/N) analysis of the semblance-weighted stack. Crucial noise filtering is integrated into the real-time processing flow, enhancing the sensitivity of the system and ensuring the best possible detection/localization at any time. Key personnel receive an alert immediately after an event detection. This makes the monitoring fully integrated into the follow-up of the daily operation.

Índice de qualidade do solo em cultivo agroecológico e convencional no semiárido potiguar, Brasil

O uso e manejo inadequado em sistemas de cultivo na região semiárida podem declinar a capacidade do solo em sustentar a produção. O objetivo do estudo foi determinar o índice de qualidade do solo (IQS) em unidades experimentais agrícolas (UEA) irrigadas agroecológica e convencional, localizadas na comunidade de Sombras Grandes, Caraúbas, Rio Grande do Norte. As amostras simples de solo (0-20cm) foram coletadas no período de 2009 a 2012. Para determinar o IQS, utilizaram-se 11 indicadores de qualidade associados às funções do solo em manter a capacidade produtiva ao longo do tempo: densidade do solo (Ds), porosidade total (PT), resistência à penetração (RP), disponibilidade de água no solo (AD/PT), retenção de umidade a -33 kPa (UVcc/PT), pH, fósforo assimilável (P), capacidade de troca catiônica (CTC), saturação de bases (V), matéria orgânica do solo (MOS), argila dispersa em água (ADA) e grau de floculação (GF). O IQS nas UEAs agroecológica e convencional foram classificados como ótimo (0,80) e ruim (0,45), respectivamente. Na UEA convencional há necessidade de práticas agrícolas como aporte de resíduos orgânicos que melhorem o GF, pois foi o indicador que mais contribuiu para reduzir o IQS. O IQS reflete a integração dos atributos químicos e físicos, podendo ser utilizado nas tomadas de decisão sobre o uso e manejo do solo.

Industrial waste injection feasibility in North Dakota

Class I and Class II waste re-injection are the most important methods for disposing of fluid in North Dakota: in 2007, more than 96% of produced water were disposed of using underground injection, and by 2012 all produced water was being managed by underground injection. While Class II injection covers waste produced from most Exploration & Production (E&P) activities, Class I injection wells are used for disposing of a special class of industrial wastes, including waste generated by petroleum refining, metal production, chemical production, pharmaceutical production, commercial disposal, and food production. Non-hazardous industrial waste and Naturally Occurring Radioactive Materials (NORM) not associated with E&P can also be injected using Class I wells. In all cases, the primary concern for permitting and safe operations is to (1) predict the movement of the injected waste to ensure that it stays within pre-defined formations, and (2) ensure that pore-pressure increases caused by injection do not impact neighboring offset wells.Results from a geochemical study of the feasibility of disposal into the Dakota Sands (Inyan Kara formation) in North Dakota is being presented. Analyses were made using a compositional reservoir simulation (REVEAL) to predict the pore-pressure distribution, direction and movement of the injected fluid, as well as chemical reactions between formation brine/waste/formation rocks and the effect of these chemical reactions on formation injectivity and cap rock integrity. Forecasts indicate that for over 50 years of injection, the injected wastes will be completely trapped within the Dakota Sands (no fluid flow is expected to penetrate through the cap rock) and injection pressures are expected to remain well below the estimated fracture pressure. While the Inyan Kara formation is therefore a reasonable storage trap for industrial wastes, carbonate and sulfate scales may cause near wellbore formation damage and rising wellhead pressures which operators will need to address.