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The application of Vacuum Insulated Tubing in Deep Borehole Heat Exchangers

Śliwa T., Kruszewski M., Assadi M., Sapińska-Śliwa A.

AGH Drilling, Oil, Gas

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2017

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Vol. 34, no. 2

597--617

EN

The world’s demand for energy is constantly increasing mainly due to population growth and improved living standards. Currently, the share of electricity generation is 37 of the global primary energy consumption. Fossil-based electricity production is accounted for 68 of the total generation with coal, the most carbon-intensive fossil fuel, being the largest contributor (41) to the world’s electricity supply in 2012. Electricity demand is projected to grow rapidly and is also expected to be 70 higher in 2035, than the current demand. The Polish energy sector is heavily dependent on coal, resulting in large CO2 emission per capita. Poland has considerable potential for geothermal energy production, as there is a large number of deep, abandoned wells that might be utilized for geothermal energy production. Utilizing these resources would contribute to the CO2 emission reduction without negative impact on security of energy supply. Following paper describes method of reconstructing negative or abandoned oil and gas wells for Deep Borehole Heat Exchangers (DBHE). In many old boreholes, exploiting underground geothermal waters is impossible, thus adaptation for DBHE is sometimes the only option to utilize geothermal heat reservoirs. The insulated coaxial inner column which enables the circulation of heat carrier plays the crucial role in effective functioning of DBHE systems. Vacuum Insulated Tubing (VIT) can improve heat production as well as increase efficient energy use. This technique found plethora of applications in offshore and onshore deep drilling and production. Throughout recent years, VIT technology is being more commonly applied in geothermal industry. Negative or abandoned wells could be reconstructed for DBHE. To maximize the heat uptake from such boreholes, it is advised to use inner column made from material with lowest possible thermal conductivity coefficient. Article deals with possible application of vacuum pipes as inner column in deep coaxial borehole heat exchangers.

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Slimhole well casing design for high-temperature geothermal exploration and reservoir assessment

Kruszewski M., Thorhallsson S., Assadi M., Śliwa T.

AGH Drilling, Oil, Gas

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2017

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Vol. 34, no. 2

465--493

EN

It is anticipated that utilization of geothermal resources for renewable energy production will continue to grow globally. Since cost of drilling and well construction constitutes a considerable share of the total cost of the geothermal installations, development and evaluation of low-cost alternatives is crucial for expansion of this industry. This paper describes slimhole casing design for geothermal exploration wells, as an alternative for reduced cost and improved environmental performance. The main goal of the paper is to contribute to cost effective casing design program that satisfies severe reservoir conditions of geothermal wells. A case study is presented for casing design for a 2000 m deep vertical well with water level at 200 m, where the New Zealand Code of Practice has been applied. The “worst case scenario”, i.e. when temperature and pressure follow the boiling point depth curve (BPD), has been considered as base case for the casing design, when drilling in a high-temperature geothermal area. Alternative methods are also presented for determining the minimum casing setting depths and the results are compared. Pressure and temperature conditions inside the well were established using X-steam program, an Excel add-in, and the final results, establishing loading criteria that the casing has to withstand i.e.: burst, collapse and tension/compression are presented.

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The Thermodynamic Studies of the Molecular Interactions of Diphenyltin(IV) Dichloride and Dibromide with meso-Tetraarylporphyrins

Zabardasti A., Salehnassaje M., Assadi M., Karimivand V.

Polish Journal of Chemistry

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2006

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Vol. 80, nr 9

1473-1481

EN

The thermodynamic parameters for interactions of Ph2SnCl2 and Ph2SnBr2 with para-substituted meso-tetraphenylporphyrins (H2T(4-X)PP; X = OCH3, CH3, H, Cl) have been studied. The formation constants have been calculated using UV-Vis titration spectra and computer SQUAD program. The adducts show the composition 2:1 of Ph2SnX2 to porphyrin. Formation constants decreased with decreasing electron donation of porphyrins and with decreasing electron withdrawing property of X group on the diphenyltin compound, as follow: H2T(4-OCH3)PP > H2T(4-CH3)PP > H2TPP > H2T(4-Cl)PP; and Ph2SnCl2 > Ph2SnBr2.