The geothermal potential of the Middle Cambrian Pajūrio formation Juozas Bičkūnas Paper for the Master’s degree Geology Master’s Program Vilnius University, Faculty of Natural Sciences, Geology and Mineralogy Department Supervisor – dr. Dainius Michelevičius Vilnius, 2012 SUMMARY The purpose of this thesis is to evaluate the reservoir properties and the geothermal potential of the Middle Cambrian Pajūrio formation in western Lithuania and to produce maps of the effective thicknesses, permeability, temperature and the maximum potential for both horizontal and vertical boreholes. Firstly, a database of 34 boreholes, which had reached the Pajūrio system and were equally spread out in the area, was created. The reservoir properties of the formation have been evaluated using different methods. The shale content was evaluated using gamma-ray logging data, the porosity was calculated according sonic log data. Reservoir thickness was determined according above mentioned interpretation of shale content and porosity. Finally, the values of the permeability of the reservoir layers was taken from the laboratory core analysis. As a result, maps of the reservoir thickness and permeability of the Pajūrio formation were produced using the GeoGraphix software. To produce the temperature map, temperatures from the top of the Cambrian system were taken from the database of Lithuania‘s geological survey. Geotermal potential was evaluated calculating maximum productivities of vertical and 300m... [toliau žr. visą tekstą] / The geothermal potential of the Middle Cambrian Pajūrio formation Juozas Bičkūnas Paper for the Master’s degree Geology Master’s Program Vilnius University, Faculty of Natural Sciences, Geology and Mineralogy Department Supervisor – dr. Dainius Michelevičius Vilnius, 2012 SUMMARY The purpose of this thesis is to evaluate the reservoir properties and the geothermal potential of the Middle Cambrian Pajūrio formation in western Lithuania and to produce maps of the effective thicknesses, permeability, temperature and the maximum potential for both horizontal and vertical boreholes. Firstly, a database of 34 boreholes, which had reached the Pajūrio system and were equally spread out in the area, was created. The reservoir properties of the formation have been evaluated using different methods. The shale content was evaluated using gamma-ray logging data, the porosity was calculated according sonic log data. Reservoir thickness was determined according above mentioned interpretation of shale content and porosity. Finally, the values of the permeability of the reservoir layers was taken from the laboratory core analysis. As a result, maps of the reservoir thickness and permeability of the Pajūrio formation were produced using the GeoGraphix software. To produce the temperature map, temperatures from the top of the Cambrian system were taken from the database of Lithuania‘s geological survey. Geotermal potential was evaluated calculating maximum productivities of vertical and 300m... [to full text]

Vakarų Lietuvoje aptikus padidėjusį šilumos srautą, imta domėtis geoterminės energetikos perspektyvomis. Išmatavus geoterminės anomalijos zonos savybes pastebėta, kad šioje zonoje vyraujantis šilumos srautas yra dvigubai didesnis, nei likusioje Lietuvos teritorijoje ir yra dvigubai didesnis už vidutinį rytų Europos šilumos srautą, o aukštesnės nei 150 ºC temperatūros yra pasiekiamos kristalinio pamato uolienose. Pirminiai geoterminės anomalijos parametrai yra nustatomi geofizinių ir geocheminių metodų pagalba. Kiti parametrai – gręžinio eksploatacijos metu. Šių parametrų ţinojimas nulemia tolimesnę patobulintos geoterminės sistemos (Enhanced geothermal system, EGS) kūrimą. Aukšto slėgio geoterminis skystis spaudžiamas į porėtą uoliena, sąveikauja su ją sudarančiais mineralais ir deformuoja ją hidrosuplėšymo metu, taip praplėsdamas ir atverdamas naujus plyšius. Ši technologija yra vadinama stimuliuota sausų uolienų geoterminė sistema (Hot dry rock, HDR). Šių sistemų tikslas yra poţeminio šilumokaičio sukūrimas, pumpuojant aukšto slėgio vandens srautą į kristalinį pamatą. Taip formuojamas stimuliuotų plyšių koridorius, kuriuo cirkuliuoja gręžiniais pumpuojamas vanduo. / The geothermal energetic was found interesting for an anomalous heat flow at the west Lithuanian that is the most intense in a whole East European Platform. A higher temperature than 150 ºC is available in crystal basement at Lithuania at less than 5 km depth. To measure basic parameters of geothermal anomaly, geophysical and geochemical methods are applied. The other measurements are taken at the moment of hydrocirculation. Knowledge of these parameters will be used for the development and improvement of the enhanced geothermal system (EGS). High pressured water geothermal fluid is pumped into the rock in purpose to open old and create new cracks and fractures by exceeding rock compressive stress. For this reason there was created hot dry rock (HDR) system. The main goal of this system is to create a geothermal reservoir by pumping high pressure water flow into the rock. This way water circulates in enhanced geothermal system through the tunnel of fractures.

Darbe projektuojama geoterminė jėgainė, kuri tiekia šiluminę energiją pastatų grupei. Darbą sudaro įvadas, keturi skyriai, išvados ir rekomendacijos bei literatūros sąrašas. Įvade pateikta nagrinėjamos temos problema, aktualumas, darbo tikslai ir uždaviniai bei praktinė darbo vertė. Pirmajame skyriuje pateikiami projektiniai duomenys pastatų grupei Tauragės miesto pavyzdžiu, aprašomi geoterminės energijos tipai bei jos panaudojimas pasaulyje ir Lietuvoje. Antrajame skyriuje analizuojamas Lietuvos geoterminis laukas bei parenkama projektuojamos geoterminės stoties vieta. Analizuojamos UAB „Geoterma“ iškilusios problemos ir nustatomos jų priežastys. Trečiajame skyriuje atliekamas metinio šilumos poreikio modeliavimas bei trijų energijos šaltinių techninis vertinimas kompiuterine programa EnergyPRO. Ketvirtajame skyriuje energijos šaltiniai vertinami ekonominiu ir aplinkosauginiu požiūriu, taip pat atliekama jautrumo analizė bei aprašomos prielaidos, naudotos darbe. Išanalizavus pastatų grupės energijos poreikius, atlikus techninius energijos šaltinių vertinimus ir reikalingus skaičiavimus šilumos gamybos galimybėms įvertinti, teikiamos išvados ir rekomendacijos. Pridedama: trijų energijos šaltinių schemos. Darbo apimtis – 65 p. be priedų, 35 pav., 15 lent., 19 literatūros šaltinių. / There is designed geothermal power plant that supplies thermal energy group of buildings in this paper. The work consists of four chapters, conclusions, recommendations and references. The introduction is about the problem of the topic, the relevance, the work goals, objectives and the practical value of the work. The first chapter provides design details of buildings group using Taurage's city example, describes the types of geothermal energy and its use in the world and in Lithuania. The second chapter analyzes the Lithuanian geothermal area, also the place for designed geothermal station is selected. Analyze the problems encountered in Geoterma company and identify their causes. There is modeling an annual heat demand and performed the three technical evaluation of energy sources with a computer program EnergyPRO. There is assessed the economic sources from energy and environmental point of view in the fourth chapter. As well sensitivity analysis is produced and description of the assumptions used in the workplace. After the analysis of the building group's energy needs and performed technical evaluations and calculations of energy sources necessary to evaluate the heat generation ability, findings and recommendations are provided. Enclosure: energy sources schemes. Working volume - 65 pages without additives, 35 pic., 15 tables, 19 references.