Access status: Open Access ,
The modified Dräger probe to the geochemical research of the soil gases composition
(2015) Fąfara, Zbigniew; Ilkiv, Igor; Solecki, Tadeusz
The Dräger probe in the measurement set to the geochemical research of the soil gases composition is inconvenient to use. It's heavy, which are reąuired to operate at least two people. Cumbersome and time-consuming is to place it into the soil by impact method, and often there is fail to reach the planned measurement depth. For this reason, there was designed and made the new modified Dräger probe. The new probe has significantly lower mass and outer diameter. In principle it should be possible to introduce it into the soil by pushing, which will greatly facilitate and accelerate conducting the geochemical research of the soil gases composition.In the autumn of 2014 has been tested the modified Drager probe. The purpose of this study is to assess it suitability to conduct the geochemical research of the soil gases composition. In total there were performed 374 measurements of the soil gases composition at different depths in the 247 measurement points. In 99 cases (26.5%) there was failed to perform the measurement because the soil gases flow rate through the meter was too little. Pulling probe usually allowed to perform the research - in only 6 measurement points (2.4%), it was impossible. The average depth of the measurement point is equal to 0.78 m.
Access status: Open Access ,
Badanie bezpieczeństwa rurociągu ze względu na uderzenie hydrauliczne
(Wydawnictwa AGH, 2023) Fąfara, Zbigniew
The paper presents the results of a study of the effect of hydraulic hammer on the sudden increase in internal pressure in the “Druzhba” trunk pipeline transporting crude oil. The subject of the investigation is a path of one section of the pipelines with a length of 103.5 km. During the analysis, nine selected events were taken into account, during which one of the pump stations was completely stopped. Practice shows that the effects of hydraulic hammer occurring in pipeline systems transporting liquid media are the cause of their failure in more than 80% of cases. The results of direct measurements of pressure changes inside the pipeline accompanying a complete stoppage of the flow of crude oil indicate an up to three-fold increase in the pressure of the transported medium at the entrance of the stopped pump station, which is particularly dangerous and may result in leakage of the “Druzhba” pipeline. Despite the recent changes in the market for crude oil supplies to Europe and the reduction of its import from Russia due to the aggression against Ukraine, the trunk pipeline “Druzhba” is currently still the primary installation supplying oil to Ukraine, Slovakia, the Czech Republic and Hungary, while in Poland its part is used to transport oil to refineries located in the eastern part of Germany. The main pipeline “Druzhba” was built 60–70 years ago and currently its technical condition may leave much to be desired, so its safety is a very important issue.
Access status: Open Access ,
The study of unsteady operation mode of the crude oil trunk pipeline in case of a sudden stop flow
(2017) Fąfara, Zbigniew; Mazur, Roman; Matuła, Rafał
Media pipeline transportation, in particular energy commodities has a very high share in the world economy. It has many advantages over other methods of transmission of the products on land but there are concerns about the safety of the pipeline system. When we are designing the pipeline, we take into consideration maximal discharge pressure of medium, but any change in pumping parameters results the appea rance of an unsteady (transient) process, which in some cases may lead to a rapid increase in pressure. The largest increase in pressure in the pipeline comes at a time of a complete stop fluid flow. There is formed a water hammer, which may cause a major accident up to pipeline leaks inclusive. Subject of considerations in the paper is the analysis of changes in pressure over time in the pipeline obtained in 12 experiments of stop oil pump unit in the trunk pipeline for different pumping parameters and properties of the medium. Based on the recorded changes of pressure in measurement points were fitted regression models allowing to forecast an increase in pressure along the pipeline route caused by water hammer.
Access status: Open Access ,
Geomechanical characterization by estimating the Vp/Vs ratio of sedimentary rock samples
(Wydawnictwa AGH, 2019) Matuła, Rafał; Lewandowska-Śmierzchalska, Joanna; Fąfara, Zbigniew
The velocity ratio V$_{p}$/V$_{s}$ and elastic parameters are effective quantities for describing various physical parameters and lithological properties of rock samples. Ultrasonic measurement was used to evaluate the V$_{p}$/V$_{s}$ ratio. Ultrasonic velocity estimation is widely used in the quantitative evaluation of rock materials. Ultrasonic P and S-wave travel times were studied in one direction of cylindrical core samples with a length and diameter of 100 mm. Wave velocity analysis was carried out on 20 crystalline drill cores taken at depths ranging from 10 m to 80 m. The cores were then tested for their ultrasonic velocity. The studied samples were also geomechanically characterized using ultrasonic testing. In this paper, the method used and a brief description of the measurement geometry are presented. The results of the calculations of P and S wave velocities, V$_{p}$/V$_{s}$ ratio, Young's modulus and Poisson's coefficient are given. Finally, the studied samples were geologically classified and the V$_{p}$/V$_{s}$ ratio was discussed.
Access status: Open Access ,
Recent developments of non-direct methods of pipeline and leak detection
(Wydawnictwa AGH, 2018) Fąfara, Zbigniew; Lewandowska-Śmierzchalska, Joanna; Matuła, Rafał; Lewińska, Paulina
Industrial pipelines are used as a low-cost method of transport of various types of substances. In the last decades the number of transmission and distribution pipelines increased considerably, leading to an increased number of failures and rising the need for better and more accurate non-destructive methods of their detection and prevention. Leakage in pipeline networks causes a loss of valuable resources in the form of oil and gas. Repairing the infrastructure requires significant additional financial resources. Therefore, any damage to the pipeline network must be detected and repaired as soon as possible. Indirect methods for leak detection and localization uncover the presents of leaks from outside the pipeline by visual observation or by using appropriate equipment. Pipelines are often underground installations or run for many kilometers in areas where there are no roads, and access is extremely difficult or impossible. The underground occurrence of pipelines makes regular inspection difficult. It is also not possible to examine all pipeline sections simultaneously. Pipeline preventive maintenance or replacement program should be conducted based on detailed assessment of its technical and environmental conditions. Thus, safe and non-destructive techniques are needed, which would allow for pipeline periodical inspection without disturbing their operation.
Access status: Open Access ,
Evaluation of adsorption of petroleum products in the soil depending on its granulation
(2013) Fąfara, Zbigniew; Stępień, Agnieszka
Thanks realized in 2011 in a wide range of laboratory investigations of adsorption of selected petroleum products in different models of soil author has an extensive set of experimental data. They lead to a series of qualitative and quantitative analysis. They confirm the generally known fact that the intensity of the adsorption of hydrocarbons strongly depends on some features of the oil products (mainly viscosity) and soil (especially grain). It is possible to fit the regression equation using statistical methods, which permits to estimate the adsorption coefficient of different oil products on the basis of parameters describing the granulation of soil. Those obtained equations are characterized by a high degree of suitability to the experimental data and can be successfully used in numerical modeling of hydrocarbon migration in the soil.
Access status: Open Access ,
The analysis of the soil gases on the chosen example of oil mine
(2015) Fąfara, Zbigniew; Ilkiv, Igor; Przybyłowicz, Joanna
In the autumn of 2014 were performed the geochemical research of the soil gases composition in the area of selected oil mine in southern Poland. For a total were carried out of 75 individual analysis at 55 measuring points. The average depth of the measuring point was about 84.4 cm. The grid selection of the measurement points was made ad hoc, taking into account arrangement the existing mine installation and the location of the abandon wells. Finally, geochemical studies were performed in the vicinity of 6 exploitation wells (1 liquidated, one flowing well and 4 pumped periodically), on the route of transmission pipelines and in the area of group centers. The free choice of the measurement point location was limited by buildings and agricultural crops. In the area of the analyzed deposit were drilled more than 100 wells, most of which were liquidated and usually did not stay after them no trace on the surface. Based on the results of the geochemical research of the soil gases composition there was determined the spatial distribution of the methane concentration in the soil in the nodes of a regular grid by geostatistical methods using kriging. On this bases there were developed the maps of the methane concentration. Generally, on the oil deposit site there were detected two areas with the increased methane concentration in the ground. The distribution of the methane concentration in soil on the first one shows the installation leak in the vicinity of several wells. In the second much smaller area it may suspect that the pipeline transporting crude oil to the group centre is leaky. In the research area are vast cultivated fields of high oxygenation and small wet ground. There are no permanently wetlands areas. This means that in soil occur at most aerobic rot and decay processes, resulting in the production of carbon dioxide but not methane. There is no reason to assume that occur also the natural anaerobic putrefaction processes. Therefore, the detected abnormally high methane concentration in the ground is not of biological origin. To confirm formulated hypothesis should also be do the chromatographic research of C14 carbon isotope content in the taken methane samples from the soil to determine his age and confront it with the age of methane produced from the deposit. In general, the results analysis of the geochemical research of the soil gases composition leads to the conclusion that the rock mass is hermetic from the geological point of view, but there are occasional leaks in the production system of several wells and transmission pipeline, that can remove.
Access status: Open Access ,
Oil pipeline leak detection using GPR method - simple case study
(Wydawnictwa AGH, 2018) Fąfara, Zbigniew; Lewandowska-Śmierzchalska, Joanna; Matuła, Rafał
Modelling experiment was used to investigate the abilities of using ground penetrating radar (GPR) to detect oil leaks in the underground pipeline system. Leaks not only waste precious natural resources but also create substantial damage to the transportation system within urban environments. Surface geophysical methods are noninvasive tools used to characterize the changes in the physical properties of the subsurface material. This characterization, in consequence, is used to interpret the geological and hydrogeological conditions of the strata. GPR is a reflection-based technique which uses high frequency electromagnetic waves to acquire subsurface information. GPR responds to changes in electrical properties, which are a function of soil and rock material and moisture content. A simple experiment was conducted to determine the validity and effectiveness of GPR technology in detecting leakage in metal pipelines. Initially, a prototype model was designed to simulate a pipe leak. A 1.5 GHz antenna modeling mode was used to collect GPR data. The test was modelled using sandy soil material that is representative for pipelines construction. Also model simulations are being used to select an appropriate equipment configuration (frequency band, type of antenna and real-time imaging software) prior to data acquisition.
Access status: Open Access ,
Prędkość rozchodzenia się w rurociągu fali ciśnienia powstałej po uderzeniu hydraulicznym
(Wydawnictwa AGH, 2024) Fąfara, Zbigniew; Matuła, Rafał
The paper presents the results of a study of the propagation speed of the internal pressure increase wave created by the hydraulic hammer caused by a stoppage of the flow of crude oil in a section of the trunk transmission pipeline “Druzhba”. The results of pressure measurements in a section of one line of the 103.5-kilometer-long pipelines, at five measurement points, were analyzed. The preassure was recorded continuously every second. The analysis included nine events occurring in one year, when one of the pump stations was stopped. Practice shows that hydraulic hammers occurring in such a situation in pipeline systems transporting liquid media are the most common cause of their failure. The results of direct measurements of pressure changes inside the analyzed section of the pipeline accompanying the stoppage of the flow of crude oil indicate an up to three-fold increase in the pressure of the transported medium at the entrance of the stopped pump station, which is particularly dangerous and may result in leakage of the “Druzhba” pipeline. It was built 60–70 years ago, so it’s safe operation is now a very important issue.
Access status: Open Access ,
Magnitude of hydrocarbon sorption capacity of sandy soils analysis
(2013) Fąfara, Zbigniew
This paper summarizes the author's previous studies on the sorption of hydrocarbons in sandy soils. Completed several independent series of measurements for various models of soil. There were used unleaded petrol and diesel fuel as petroleum products. A large amount of collected information allows you to draw some interesting conclusions, which may be the basis for generalizations. The detected regularity can afford to develop a several models that can be successfully used to describe the intensity of hydrocarbon sorption processes in soils. These processes have a significant impact on the hydrocarbon migration in the soil by reducing the pollution zone and extending the time of migration. Inaccurate description of the magnitude sorption capacity will lead to large differences between the actual scenario of hydrocarbon migration in soil and its numerical simulation.

Fąfara, Zbigniew

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