Browsing by Subject "cement slurry"

Now showing 1 - 9 of 9

Access status: Open Access ,
Application of fluidal ashes as a component of cement slurry used in carbon dioxide injection wells - possibility analysis
(Wydawnictwa AGH, 2018) Formela, Małgorzata Maria; Gonet, Kamil; Stryczek, Stanisław; Wiśniowski, Rafał
One of the most important environmental issues bothering scientists nowadays are greenhouse gases, mainly carbon dioxide, and the possibility of limiting their emission and utilization. Many countries have been actively trying to limit the greenhouse gases emission, mainly carbon dioxide, and implement the Carbon Capture and Storage (CCS) technology for years. One of the essential aspects of geological injection is constant monitoring of carbon dioxide, especially its pressure and temperature. Those parameters have an impact on viscosity, density and phase alterations during the flow. It is of vital importance to maintain the supercritical state of the fluid because it is the most efficient way of $CO_2$ storage. The negative impact of $CO_2$ on the properties of the cement slurry may disturb the exploitation of the well and create considerable hazard for the geological storage of carbon dioxide. Therefore, the cement slurry should be appropriately selected and the role of $CO_2$ in the development of technological properties of fresh and hardened cement slurry should be determined. The aim of this research is to select the most appropriate cement slurry composition exhibiting optimal properties with respect to the phase changes of carbon dioxide. The first part of the research consists in creating cement slurries of various compositions and investigating its thermal conductivity and sogginess under in-situ conditions. The second part concerns a possibility of utilization of fluidal ashes from combustion of lignite as a component of cement slurry.
Access status: Open Access ,
Comparison of gas migration test and building structural strength of slurry in the aspect of limiting gas invasion
(2016) Kremieniewski, Marcin; Rzepka, Marcin; Stryczek, Stanisław; Wiśniowski, Rafał
The problem of eliminating natural gas microflows through the cement slurry while bonding has been investigated by scientists in a number of scientific and research centers. Works have been undertaken to define the causes of gas migration and predict possibilities of interchannel communication in the hardened cement slurry. In the course of bonding cement slurry changes its state from liquid through gel to solid. Accordingly, the gas migration effects should be taken into account in the formation of these phases.The results of tests of gas migration in the course of binding and building structural strength have been presented in this paper. Both research methods have been compared and a high dependence of parameters defined by each of them has been found. The research works were conducted with the use of innovative apparatuses thanks to which the phenomena taking place in the course of binding can be observed. This gives the possibility of working out recipes of sealing slurries applicable to deposits where the risk of occurrence of gas migration is high.
Access status: Open Access ,
Determining the actual temperature of the side of a borehole heat exchanger
(Wydawnictwa AGH, 2017) Złotkowski, Albert; Druzgała, Angelika
Borehole heat exchangers (BHE) are made as hydraulic systems consolidated by cement slurry in boreholes. They mediate in heat exchange between the receiver on the surface (heat pump), and the reservoir of thermal energy (rock mass). In the analytical description of temperature changes accompanying energy download and return to the rock mass, the temperature of the entire borehole heat exchanger is assumed to be the same. In fact, the exchanger temperature changes both in the vertical and horizontal cross-sectional view of the exchanger. Accordingly, the temperature of the interface of the hardened cement slurry and the rock mass differs from the one which was adopted for design calculations. The article shows the differences between the theoretical and actual state, when the temperature was measured with a thermal imaging camera. It also includes suggestions regarding the mathematical description of temperature changes on the side surface of the heat exchanger. Measurements were made by a model of a BHE equipped with a single U-tube.
Access status: Open Access ,
Microstructure of porous space in cement sheath used for sealing oil wells
(Wydawnictwa AGH, 2018) Kremieniewski, Marcin; Rzepka, Marcin; Stryczek, Stanisław; Wiśniowski, Rafał
The effect of cement slurry modification on the microstructure of the annular space in a wellbore is presented in this paper. An admixture of macromolecular copolymer GS was used, which is usually applied in cement slurry technology to counteract gas migration by the binding cement slurry. The copolymer addition also results in sealing up the cement matrix at the stage of the binding and formation of hardened cement slurry. The modification of a slurry composition with this admixture results in the fact that the cement matrix has low porosity and is strongly compact. Consequently, a significantly higher number of micropores with small diameters are formed than those with larger micropores in the analyzed hardened cement slurry sample. An admixture of a macromolecular copolymer (7 wt.% of the cement) was added and 10% of the latex was removed from the recipe to show the influence of the modified recipe on the microstructure of the cement sheath. Thanks to this modification, the microcement participation could be reduced by 50% with the simultaneously improved quality of the most important technological parameters of fresh and hardened cement slurry. The basic and modified recipes were analyzed. The following parameters of the slurry were determined: rheology, filtration, water settlement, and time of densification. The influence of the modified slurry on the parameters describing the microstructure of the hardened slurry was analyzed for the hardened slurry (i.e., porosimetric porosity and microtomographic porosity). The microstructure of a sample fracture was also investigated. The analyses were conducted for recipes of slurries to be used for sealing wells at a temperature of 40°C and pressure of 10 MPa.
Access status: Open Access ,
Model stanowiska laboratoryjnego przeznaczonego do pomiarów przepuszczalności stwardniałego zaczynu uszczelniającego, zbudowany w oparciu o dynamiczną prasę filtracyjną HTHP
(2011) Hendel, Jacek; Złotkowski, Albert; Stryczek, Stanisław
The qualification of permeability cement rock is very difficult process, which success depends from good tightening and correct measuring value of liquid by sample filtration. Lower permeability, typical for cement rock, requires use high pressure. Investigation then will be exact, if the volume of liquid filtration will be considerable. Therefore to get high volume liquid to measurement was adapted filtration press HPHT (High Pressure, High Temperature), which give possibility to make this research in pressure 8 MPa.
Access status: Open Access ,
Możliwości zastosowania iniekcji wykonywanych otworami wiertniczymi głębokimi w celu ograniczenia dopływu wód do podziemnych wyrobisk górniczych
(Wydawnictwa AGH, 2024) Rado, Robert
One of the unwanted effects of mining activities is the formation of secondary changes in the rock mass in the surroundings of the mine workings. The rock mass in the areas where mining is carried out is most often also affected by primary dislocations due to geological processes occurring over time. The combination of both undesirable effects leads to various complications accompanying the mining of minerals. One such occurrence is the inflow of water from the rock mass into the underground mine. Uncontrolled water inflow into mines is dangerous from the point of view of mining safety and environmental protection. The dewatering of mines requires financial investments and engagements of technical and human resources. The article presents efforts to reduce the water inflow into the mine workings of a copper ore mine. To reduce the inflow of water into the mine sites, drilling methods were applied by using deep borehole injection. To reduce the permeability of the primary and secondary disturbed rock mass, mineral-based slurries and the waste products from the energy industry were used. The injection slurry recipes used were different in composition and their setting time selected according to the current state of the rock mass and the evolution of the inflow to the mine workings.
Access status: Open Access ,
Prevention of gas migration in the area of the Carpathian Foothills in the laboratory tests
(Wydawnictwa AGH, 2018) Uliasz, Małgorzata; Kremieniewski, Marcin
In the area of the Carpathian Foothills, gas exhalations are a frequently observed phenomenon. It is connected with the presence of many shallow gas horizons in the autochthonous Miocene. In addition, gas migration effect is intensified due to the complicated geological structure in this region. During drilling boreholes, one of the most important requirements is to ensure adequate tightness in the annular space. In connection with the above, laboratory tests were carried out in the Oil and Gas Institute - National Research Institute, whose aim was to assess the impact of applied drilling fluids on the degree of sealing the annular space on the contact hardened cement slurry - rock formation, for specific geological and technical conditions. The result of the conducted research work was a modification of the composition of washing fluids in terms of improving the efficiency of their impact on the wall of borehole and removal of mudcake formed by the drilling muds, as well as modification of cement slurry formulations by application appropriate additives to prevent gas migration. During research work have been indicated potential causes of gas migration from the annular space in the selected holes drilled in the Carpathian Foothills and preventive actions aimed at reduction gas migration and exhalation.
Access status: Open Access ,
Selecting recipes of cement slurry for sealing casing columns in wellbores used for CCS
(2016) Formela, Małgorzata Maria; Stryczek, Stanisław; Wiśniowski, Rafał; Pikłowska, Anna
Cement sheath serves primarily as a zonal isolation for the life of the well while protecting and supporting the casing. Nowadays, more and more solutions in the term of different cement slurries compositions appear on the market. One of them is application of fluid ashes as an alternative substitution of cement itself. The purpose of it is to overcome a challenging environment where a high concentration of corrosive gases or fluids exist. An example of that aggressive substance is carbon dioxide. Moreover, this is how it might reduce the cost of the cementing process. Laboratory research was conducted at the Drilling, Oil and Gas Faculty and Materials Science and Ceramics Faculty at AGH University of Science and Technology in Krakow.
Access status: Open Access ,
Technological parameters of innovative cement slurries used for sealing wellbores in shale formations
(2016) Kremieniewski, Marcin; Rzepka, Marcin; Stryczek, Stanisław; Wiśniowski, Rafał; Kotwica, Łukasz; Złotkowski, Albert
In the years 2014–2016 two scientific units, i.e. Faculty of Drilling, Oil and Gas, AGH UST and Oil and Gas Institute – National Research Institute cooperated on the realization of a project called Optidrilltec. A group of innovative recipes of slurries to be used for sealing wellbores in shale formations were worked out. Both fresh and hardened cement slurries should meet restrictive technological requirements, therefore this issue was in the focus of the conducted research. Laboratory experiments were performed on high-class research and control/measurement equipment, thanks to which innovative recipes of cement slurries for sealing casing in shale gas formations could be worked out. These recipes comply with standards and can be successfully used as read-made applications for sealing casing installed in shale formations.