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EN
Oil and natural gas exploration is performed using geophysical methods and drilling works. In areas initially identified as prospective for the occurrence of accumulation oil or natural gas based on the analysis of geological data carried out geophysical surveys. The aim of this works is to identify geological structures that could constitute hydrocarbons traps. In the case of finding the appropriate structures, the next stage of exploration work is drilling well for further recognition of the structure. These works allow to explore not only the geological profile but also the physico-chemical properties of drilled rocks and reservoir fluids. Geophysical (mainly seismic) surveys and drilling works can affect the individual elements of the environment: the atmosphere, underground and surface water, ground surface and land and rock environment in different degrees. In order to estimate the risks, threats to all elements of the environment related to the prospection of hydrocarbon deposits have been analyzed (seismic and drilling works). Environmental risk is estimated based on a modified methodology contained in the norm PN 18002. For risks associated with the exploration referred to the consequences of adverse events in relation to the individual elements of the environment and the frequency thereof (by determining the probability of their occurrence). The risk was estimated by multiplying the weight of the likelihood of adverse events weights and consequences. Risk evaluation, indicating danger tolerated, acceptable and unacceptable was also evaluated
PL
Prawidłowe odwzorowanie rozmieszczenia oraz zachowania się szczelin w utworach łupkowych, przy wiernym opisie własności geomechanicznego ośrodka geologicznego, wymaga wykonania analiz i interpretacji na danych sejsmicznych z uwzględnieniem anizotropii. Azymutalne i wieloskładnikowe pomiary pionowego profilowania sejsmicznego PPS 3C są najbardziej użytecznym narzędziem, spośród stosowanych metod sejsmicznych, do badania anizotropii ośrodka geologicznego. Analizy prędkościowe oraz polaryzacyjne azymutalnych wieloskładnikowych pól falowych PPS 3C są podstawą do określania kierunków oraz ilościowej oceny anizotropii. Przetwarzanie danych sejsmicznych w oparciu o azymutalne śledzenie zmian prędkości oraz AVO, w połączeniu z geomechanicznymi własnościami skał, obliczonymi dla ośrodków izotropowych, może być użyte do predykcji in-situ naprężeń, występujących w zbiornikach łupkowych. Poprawne wyznaczenie oraz zorientowanie naprężeń, umożliwia określenie głównych kierunków szczelin w strefie złożowej i pozwala na optymalne zaprojektowanie usytuowania otworów poziomych.
EN
Correct imaging of distribution and behavior of cracks in shales formation, with a faithful description of the geomechanical properties of the geological medium, requires the analysis and interpretation of seismic data, taking into account the anisotropy. Multi-offset and multi-component Vertical Seismic Profiling VSP 3C measurements are most useful tool, from among current seismic methods, to investigation of the anisotropy of geological medium. Velocity and polarization analyses of multi-azimuth and multi-component wave fields of VSP 3C are base to defining of directions and quantitative estimation of the anisotropy. Processing of seismic data based on the azimuth tracking in velocity and AVO changes, in combination with geomechanical properties of rocks, calculated for isotropic medium, can be used for prediction of in-situ stresses, occurring in shale reservoirs. Correct determination and orientation of the stress, allows to define the main directions of cracks in the reservoir zone and allows too for optimal design location of horizontal wells.
EN
The complex tectonic history of Central Europe (Fig. 1a) reflects the break-up of a Neoproterozoic supercontinet(s) (Rodinia/Pannotia) to form the fragment Baltica and the subsequent growth of continental Europe beginning with the Caledonian orogeny. Caledonian and younger Variscan orogenesis involved accretion of Laurentian and Gondwanan terranes to the riftet margin of Baltica. (East European craton, EEC) during the Paleozoic. From Central Poland northward, the region also experienced volcanic activity during the Permian and tectonic inversion during the Alpine orogeny, which in the south continues today. The Trans-European Suture Zone (TESZ) is a term used to refer to the suite of sutures and terranes that formed adjacent to the rifted margin of Baltica, and these features extend from the British Isles to the Black Sea region (Fig. 1a and 2). Understanding the structure and evolution of the TESZ region is one of the key tectonic challenges in Europe north of the Alps. The TESZ is far more complex than a single suture but in a broad sense is the boundary between the accreted terranes and Baltica. The TESZ includes the Teisseyre-Tornquist Zone (TTZ), which has several definitions. Here, we will use the term TTZ to refer to a structural zone associated with the southwestern edge of the EEC. Beginning in 1997, Central Europe, between the Baltic and Adriatic Seas, has been covered by an unprecedented network of seismic refraction experiments (Fig. 1b). These experiments - POLONAISE’97, CELEBRATION 2000, ALP 2002, and SUDETES 2003 - have only be possible due to a massive international cooperative effort. International Consortium consisted of 35 institutions from 16 countries in Europe and North America - Austria, Belarus, Canada, Croatia, Czech Republic, Denmark, Finland, Germany, Hungary, Lithuania, Poland, Russia, Slovakia, Slovenia, Turkey and the United States. The majority of the recording instruments was provided by the IRIS/ PASCAL Instrument Center and the University of Texas at El Paso (USA), the Geological Survey of Canada and other countries. For example, in the CELEBRATION experiment, the total number was 1230 stations ands 147 shot points located along seismic lines of a total length of about 9000 km. A large number of seismic sources and stations in all experiments means that besides 2 - D approach along profiles (Fig. 3 and 4), also 3 - D approach (Fig. 5 and 6) could be implemented in data interpretation. Total length of seismic profiles in all experiments is about 20 000 km (Fig. 1b).
EN
Modern siesmic survey vessels in ‘production’, may tow twelve or more streamers, each of which can be six to eight kilometres long. Together with associated paravanes, tail-buoys and acoustic ‘guns’, the streamer spread width of such wide-tow configurations can extend to 1200 metres. The physical deploy-ment and recovery of such an extensive array is time-consuming and expensive. The entire survey operation requires the constant attendence of a suitable offshore support vessel (OSV) to act in the role of ‘chase ves-sel’, but more critically, to provide close replenishment support underway and, when required, rapid emer-gency towing assistance. While naval crews rightly claim a near monopoly on the skills-set necessary for underway replenishment, the naval RAS exercise almost never involves the supply and receiving vessels engaging ‘close-alongside’. The seismic/OSV replenishment operation, on the other hand, frequently necessitates such a demanding and stressful manoeuvre. This paper presents a training solution involving the use of a 360°full-mission bridge simulator.
PL
Polska, mimo znacznych zasobów energii geotermalnej, nie jest krajem dynamicznie rozwijającej się geotermii. Przeszkodą w zwiększaniu wykorzystania odnawialnych źródeł energii jest znaczne ryzyko geologiczne i wysokie koszty inwestycyjne, towarzyszące budowie zakładów geotermalnych. Obniżenie kosztów inwestycyjnych jest możliwe przez zaadaptowanie dla potrzeb geotermii wierceń ponaftowych, a przede wszystkim wyeliminowanie ryzyka geologicznego dzięki wiarygodnemu szczegółowemu rozpoznaniu budowy geologiczno-strukturalnej rejonu, w którym sytuujemy zakład geotermalny. Znaczący udział ilościowy i jakościowy w rozpoznaniu warunków geologicznych i ocenie zasobów geotermalnych mają badania sejsmiczne. W niniejszym artykule zwraca się uwagę na możliwość wykorzystania tych badań w dwojaki sposób: - wykonanie badań sejsmicznych, przede wszystkim 3D, ściśle dla potrzeb geotermii - wykorzystanie wyników badań sejsmicznych 3D wykonanych przez górnictwo naftowe w ostatnich latach, bądź poddanie reprocessingowi profili sejsmicznych 2D wykonanych w latach 1980-2000 Współczesne możliwości firm geofizycznych w zakresie sprzętowym, metodycznym i oprogramowania oraz wysokiej klasy specjaliści, gwarantują wykonanie badań sejsmicznych dających wiarygodne rozpoznanie struktur ze złożami wód geotermalnych.
EN
Poland is a country of moderate - developed geothermal industry, in spite of substantial geothermal resources occurrence. Main obstacles in increasing the use of renewable energy sources are both high geological risk and considerable cost of geothermal plant construction. To lower the investment costs, the old oil wells can be used for geothermal purposes. Furthermore, reliable and detailed geological and structural studies of the region of interest can be beneficial to reduce drastically the geological risk involved. Seismic exploration is effective and widely used for geothermal resources evaluation. This paper focuses on possibility of deriving this seismic method in two ways: - performing of seismic surveys, mainly 3D ones, strictly for geothermal purposes, - making use of 3D seismic surveys carried out by oil industry in recent years or reprocessing of 2D seismic lines completed within last two decades. Current technical capabilities of geophysical companies, up-to-date equipment, and technology, most advanced seismic software and highly qualified specialists enable to provide clients with reliable and detailed recognition of geothermal structures.
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