AGH Drilling, Oil, Gas
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ISSN 2299-4157
e-ISSN: 2300-7052
Issue Date
2017
Volume
Vol. 34
Number
No. 2
Description
Journal Volume
AGH Drilling, Oil, Gas
Vol. 34 (2017)
Projects
Pages
Articles
Predicting relative permeability from experimental capillary pressure porous plate test for two phase flow
(2017) Czarnota, Robert; Janiga, Damian; Stopa, Jerzy; Wojnarowski, Paweł
Relative permeabilities relationships as a function of fluids saturation are one of the most important parameters for describing multiphase flow processes in reservoir rocks. When direct laboratory tests are not available for investigating oil-water multi-phase flow in rocks, then indirect prediction techniques using relative permeability functions are widely used, e.g. from capillary pressure test. In this study the measurement of capillary pressure was performed on rocks plugs with different characteristics at reservoir conditions using porous plate method. During measurement semi-permeable membrane was used with 15 bar threshold pressure, what allowed to register formation water saturation, at changing differential pressures steps. Desaturation at each pressure stage was continued until no more produced liquid was observed. Water saturation point at maximum capillary pressure applied is assumed to be final irreducible water saturation. Application of porous plate method provides sufficient stabilization time, allowing to achieve uniform saturation distribution. In this research, Brook–Corey model was used to predict relative permeability from experimental measured capillary pressure data for oil-water phase flow in porous media. As a result, it is possible to obtain more accurate capillary pressure outcomes, and relative permeability curves for the two-phase system, than other methods used in practice. Performing capillary pressure measurements at reservoir conditions, allows to restore the processes occurring in the reservoir.
Influence of bentonite addition on parameters of fresh and hardened cement slurry
(2017) Kremieniewski, Marcin; Stryczek, Stanisław; Wiśniowski, Rafał; Rzepka, Marcin; Gonet, Andrzej
The recipe of cement slurry contains a number of additives and admixtures used for obtaining appropriate technological parameters. Some of these agents have a loose form and their density is higher or lower than that of working water, which may result in sedimentation of solid phase. For the sake of eliminating this effect, the viscosity of the working fluid should be increased to keep the fine solids over the entire volume of the slurry. This can be done with the use of appropriate high-molecular polymers. However, bearing in mind the cost of the polymers, bentonite is most frequently applied. Bentonite (montmorillonite) has a packet build and the resulting higher water-demand causes an increase of viscosity of working fluid. It is most frequently used to improve the sedimentation stability, though the presence of this additive is not neutral for the technological parameters of the slurry. During research works aimed at analyzing the influence of montmorillonite on the parameters of fresh and hardened cement slurry predefined quantities of bentonite were used in proportion to the working water. Reference recipes of slurries were worked out to trace the changes. The following properties of the slurry were defined: rheological parameters, filtration, thickening time, water settling, sedimentation stability. For hardened cement samples the bentonite addition was analyzed in view of its influence on the mechanical properties (compressive strength), physicochemical parameters (adhesiveness to steel pipes and adhesiveness to rock formation). Additionally, hardened cement slurry underwent analyses describing the microstructure of the sample porosity and permeability tests). For the sake of determining the influence of mineral additives on parameters of slurry and the hardened slurry there were performer tests for recipes of slurries to be used in wellbore conditions at temperature from 30°C to 90°C and pressure from 5 MPa to 35 MPa.
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.
Application of AHP method to assess the possibilities of using of geological structures located in the aquifers as underground storage sites
(2017) Lewandowska-Śmierzchalska, Joanna; Uliasz-Misiak, Barbara
Decision-making problem with assessing of the suitability of geological structures located in aquifers in terms of their use for carbon storage, natural gas storage or waste injection is mainly connected with the necessity of taking into consideration a large number of criteria and analyze a lot of parameters. It also connected with making many independent decisions concerning geological, environmental, social, political, technical or legal issues. This article shows the possibility of using the AHP method, ie. multi-criteria hierarchical methods to analysis of decision problems in assessment the potential of aquifers. AHP method allows to take reasonable decision. The article was divided into three parts. The first one includes a characteristics of geological structures located in aquifers, special attention was paid to the criteria describing these structures. In the second part, the basis for decision-making system based on the method of AHP, which was used to carry out the hierarchical scoping assessment of potential structures. Validation of decision-making system was realized on selected geological structures located on the Polish Lowlands. An assessment of the possibilities to use the two anticline in the Mesozoic aquifers was made. As a result, received the criteria ranking, rankings of decision variants to all criteria and global ranking of variants. Based on the results obtained can be determine which decision represents a priority way of use structure.
Analysis of Drill Stem Test (DST) results at Osobnica oil field, in terms of sampling of selected technology parameters
(2017) Dubiel, Stanisław; Rzyczniak, Mirosław; Solecki, Marek; Maruta, Michał
In this paper results of DST tests obtained in two wells at Osobnica oil field are presented. At the same time there were analyzed and reinterpreted the conditions of these results from the selection of technological parameters and geological conditions. The results of this analysis have been developed in conclusions.