Wyniki wyszukiwania - BazTech

1

Sonar surveys under challenging conditions in gas at very low pressure and in crude oil

Hasselkus F., Reitze A.

Przegląd Solny

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2015

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T. 11

109--115

EN

Sonar surveys have for decades been the established technique for the regular monitoring of gas and oil storage caverns. So as to have the best possible basic physical conditions gas caverns should be under the highest possible pressure at the time they are surveyed. This is all the more important the greater the distances to be measured. With regard to caverns located deeper than 1000 m pressures > 150 bar provide a good basis for achieving qualitatively reliable and focused measurements. Surveying shallow caverns with a low maximum pressure < 100 bar or caverns that for operational reasons have to be under low pressure is considerably more challenging than a “standard survey” under high pressure. The lower the pressure the higher the attenuation of the acoustic waves. Consequently to be able to interpret these reflections the measuring system must be in a position to amplify the significantly attenuated signal reflections by a suitable amplifier technology and by applying mathematical correlation techniques. Furthermore special transducer technology is necessary when working at such low pressures. Surveys in caverns at pressures between 80 and 90 bar had been carried out successfully for years. Then the task of surveying gas caverns with a pressure of just 45 bars presented a new challenge. Indeed, to obtain qualitatively usable results under these demanding basic conditions it was essential to have sophisticated transducer technology as well as high performance transmitter and receiver equipment. By carrying out special developments and modifications in this area equipment has been designed which enables distances of more than 85 m to be measured even if the pressure is as low as 45 bar. This provides the customer with a means of monitoring all parts of those caverns which previously were internally regarded as “unsurveyable” without having to flood the cavern with brine. The technical changes that have been made not only bring about advantages in terms of measuring greater distances at low pressure, but also provide extra performance. In caverns with an extremely long extension (e.g. elongated fingers due to leached potash zones, steeply inclined bedding and so on) it is now possible to measure considerably longer distances. In some cases it is even possible to measure distances of well over 100 m in gas or crude oil.

2

Sonar surveying of caverns and 3D modelling of entire cavern fields

Hasselkus F., Reitze A.

Geology, Geophysics and Environment

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2012

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Vol. 38, no. 2

251-262

EN

The echometric surveillance of caverns is especially important with regards to their safe and effective operation. As opposed to brine production caverns, storage caverns are generally subject only to convergence and they do not undergo large and irregular changes of shape under normal conditions. Echometric surveillance is therefore primarily employed to obtain proof of the cavern stability and convergence. Applying the state-of-the-art sonar technology it is possible during an echometric survey to measure and process the geometry of relevant parameters such as speed of sound, pressure and temperature with a single tool run. Today, specialized software allows us to present all the cavern field data in a common computer model, starting from the sonar survey results over the surface situation, and the well courses until the geology. In the first instance of the presentation the techniques used for surveying caverns as well as the survey procedure are described in general. Subsequently some interesting results of individual sonar surveys are presented. In the paper it is shown by means of a practical example what benefits cavern operators can derive from 3D-models of cavern field sites. Besides being useful for presentation purposes, such models can among other things help in the correlation of the survey results with the geology and support planning. Modeling is done with the CavWalk Professional software, which has been specially developed for the presentation of cavern fields. The software allows the user to undertake virtual excursions through the 3D-model at the surface as well as underground. In the spatial representation of one or several caverns the observer can move around outside and inside the caverns.

PL

Akustyczne (echometryczne) badania kawern są szczególnie ważne ze względu na zapewnienie bezpieczeństwa i efektywności ich pracy. W przeciwieństwie do kawern ługowanych w celu pozyskania solanki kawerny magazynowe ulegają zasadniczo jedynie konwergencji i nie następują w nich duże i regularne zmiany kształtu w normalnych warunkach. Nadzór echometryczny jest podstawową metodą pozyskiwania informacji o stabilności i konwergencji kawern. Podczas badania echometrycznego możliwy jest pomiar i geometryczne przetworzenie takich istotnych parametrów, jak prędkość sygnału, ciśnienie i temperatura. Obecne wyspecjalizowane oprogramowanie umożliwia przedstawienie wszystkich danych polowych z kawerny w formie modelu komputerowego, począwszy od wyników powierzchniowego profilowania akustycznego, przez profilowania otworowe aż do danych geologicznych. W pierwszej części pracy przedstawiono podstawowe techniki badań kawern i wymagane procedury, a następnie - wybrane wyniki profilowań akustycznych. Wykorzystując rzeczywiste przykłady, wykazano korzyści płynące ze znajomości modelu powierzchni kawerny dla jej operatora. Model taki jest także pomocny przy korelacji wyników profilowań akustycznych z danymi geologicznymi i przy planowaniu dalszych prac. Modelowanie wykonywane jest za pomocą oprogramowania CavInfo Professional, opracowanego specjalnie dla kawern. Oprogramowanie umożliwia użytkownikowi wirtualne podróże w modelu z powierzchni terenu i pod nią w perspektywie konwencjonalnej i rzeczywistej 3D (ujęcie stereoskopowe).

3

Importance of sonar surveying in the monitoring and operation of natural gas caverns

Reitze A., Krieter M., Tryller H. von

Geologia / Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie

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2010

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T. 36, z. 3

419-430

EN

It is becoming increasingly important to carry out thermodynamic calculations starting from the very first stage of storage planning and continuing right on up to the actual storage operation in gas caverns. The reason for this is that on the one hand the availability of gas quantities and the efficiency of the storage facilities need to be determined and on the other hand these have to be predicted as reliably and as quickly as possible. History match methods and particularly the predictions (on a daily or hourly basis) of pressures, temperatures and operating gas amounts in relation to the existing storage situation are therefore important tools for the storage operator to enable him to react to short and medium-term market needs. SOCON Sonar Control Kavernenvermessung GmbH recognized the need for and so developed a software package that, based on the SOCON sonar survey in caverns under gas with the accompanying logs, answers the remaining thermodynamic and rock mechanics questions. This provides the cavern operator with the opportunity to increase operational safety and at the same time allows the capacities and performance profiles during injection and extraction to be assessed (history match) and predicted.