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1

Acoustic Full Waveforms as a Bridge between Seismic Data and Laboratory Results in Petrophysical Interpretation

Wawrzyniak-Guz K.

Acta Geophysica

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2016

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Vol. 64, no. 6

2356--2381

EN

Mutual relationships between geological and geophysical data obtained by using methods of different scale are presented for the Miocene sandy-shaly thin-bedded formation and for the Zechstein carbonate formation. The common basis of laboratory results, well logging and seismic data was a recognition of elastic and reservoir properties of rocks. The common basis of laboratory results, well logging and seismic data were elastic and reservoir properties of rocks. Seismic attributes calculated from acoustic full waveforms were a link between the considered data. Seismic attributes strongly depend on small changes observed in rock formation related to lithology variations, facies changes, structural events and petrophysical properties variability. The observed trends and relationships of high correlation coefficients in the analysed data proved the assumption made at the beginning of research that common physical basis is a platform for data scaling. Proper scaling enables expanding the relationships determined from laboratory and well logging of petrophysical parameters to a seismic scale.

2

Determination of seismic wave attenuation based on acoustic full waveforms

Święch E., Wandycz P.

Mining Science

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2015

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Vol. 22

55--63

EN

The loss of elastic energy to the medium can be quantified by the quality factor Q. Acoustic full waveforms log from Winna Góra1 borehole were used to estimate P-wave quality factor. Data used in this paper were analyzed with usage of GeoWin software. Interpretation of acoustic full waveforms was performed for the one pair of waveforms. The most important part in the interpretation of data is manual picking of P wave arrival, calculation of semblance function, and picking anomalies of P wave on amplitude spectrum. Using data from interpretation of acoustic full waveforms, we calculated quality factor. Based on provided analysis it is concluded that the highest attenuation ( so the lowest Q) is observed in Rotliegend strata.

3

Multi-method approach to velocity determination from acoustic well logging

Jarzyna J., Bała M., Krakowska P.

Annales Societatis Geologorum Poloniae

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2013

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Vol. 83, No. 2

133–-147

EN

Three different methods of building detailed velocity models for seismic interpretation are explained and discussed in terms of their advantages and limitations. All of the proposed methods are based on the analysis of acoustic well logs. An application of acoustic full waveform measurements, as well as the FalaFWS and Estymacja software, is presented as a tool for determining P-wave and S-wave slowness (transit time interval, velocity reciprocal). Well log data from several wells, located near the special research seismic transect in the Polish Lowland, were processed using the methods proposed. The results of data analysis are presented for a depth section of up to 3623 m for the lithostratigraphic units, recorded from the Środa Wielkopolska 5 (SW5) well. The results of P-wave and S-wave slowness filtering, used to upscale well log data to a seismic scale of resolution, are shown for the entire geological profile of the SW5 well.

4

Elastic parameters of rocks from well logging in near surface sediments

Jarzyna J., Bała M., Cichy A.

Acta Geophysica

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2010

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Vol. 58, no. 1

34-48

EN

Acoustic full waveforms recorded in wells are the simplest way to get the velocity of P, S, and Stoneley waves in situ. Processing and interpretation of acoustic full waveforms in hard formations does not generate problems with identification packets of waves and calculation of their slowness and arrivals, and determination of the elastic parameter of rocks. But in shallow intervals of wells, in soft formations, some difficulties arise with proper evaluation of the S-wave velocity due to the lack of refracted S wave in case when its velocity is lower than the velocity of mud. Dynamic approach to selection of a proper value of semblance to determine the proper slowness and arrival is presented. Correlation between the results obtained from the proposed approach and the theoretical modeling is a measure of the correctness of the method.

5

Application of time-frequency transforms to processing of full waveforms from acoustic logs

Wawrzyniak K.

Acta Geophysica

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2010

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Vol. 58, no. 1

49-82

EN

The paper deals with the application of time-frequency methods, Continuous Wavelet Transform (CWT) and Matching Pursuit algorithm (MP), to acoustic full waveform processing. The goal of the research is to present possible ways of application of these methods, particularly for the precise identification of selected acoustic waves, waveform decomposition into separate waves, and determination of zones of different elastic parameters in the geological profiles. The simulations, developed methodology, and results of each method are discussed in detail. The Continuous Wavelet Transform is used to improve qualitative interpretation. Time-depth-frequency plots for a given frequency are constructed to distinguish the waves and identify gas-bearing zones. The Matching Pursuit has a better resolution in timefrequency space than CWT; thus, it is used to extract individual waves from the whole acoustic waveform, i.e., decompose the signal. For the extracted waves, the slowness is calculated. Results from MP methods are compared with their counterpart parameters obtained from the original waveforms. Additionally, time-frequency decompositions are used for the determination of the frequency content of each wave packet to get unique information about formation in situ.

6

Wykorzystanie aplikacji FalaFWS w systemie GeoWin do wyznaczania parametrów sprężystych skał na podstawie rejestracji sondą FWST (Halliburton)

Jarzyna J., Bała M., Cichy A., Stadtmüller M.

Prace Instytutu Nafty i Gazu

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2008

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nr 150 wydanie konferencyjne

215--220

PL

W pracy pokazano możliwości aplikacji FalaFWS, przygotowanej do przetwarzania akustycznych obrazów falowych rejestrowanych sondą FWST (Halliburton). Przedstawiono wyniki interpretacji w utworach miocenu oraz w skałach podłoża na obszarze przedgórza Karpat, w aspekcie wyznaczania prędkości fal sprężystych P i S oraz dynamicznych parametrów sprężystych. Wybrano skały o zmiennej litologii (piaskowce, mułowce i iłowce), występujące na zróżnicowanych głębokościach.

EN

A characteristics of FalaFWS program in GeoWin system for processing of acoustic full waveforms recorded with FWS Tool (Halliburton) is illustrated. Results of interpretation of the Miocene sediments and basement rocks in the Carpathian Foredeep in aspect of velocity of P- and S-waves and elastic parameters determination are presented. Rocks of various lithology (sandstone, mudstone and claystone) occurred in different depths are chosen as examples.

7

Analiza czasowo-częstotliwościowa akustycznych obrazów falowych za pomocą transformaty falkowej

Wawrzyniak K.

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

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2005

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T. 31, z. 3/4

309-335

PL

Interpretacja akustycznych obrazów falowych opiera się na identyfikacji fal sprężystych rejestrowanych w otworze. Problem z określeniem czasów przyjścia i trwania pakietów falowych może być rozwiązany dzięki zastosowaniu analiz czasowo-częstotliwościowych, takich jak transformata falkowa. Do rozdzielenia pola falowego rejestrowanego na akustycznych obrazach falowych zastosowano dyskretną i ciągłą transformatę falkową. Prowadzone badania dowiodły, że z uwagi na nieduże zróżnicowanie częstotliwości w pakietach fal P i S dyskretna transformata falkowa nie nadaje się do rozwiązania postawionego zadania. Jest za to bardzo dobrym narzędziem do odfiltrowania szumów z rejestrowanych sygnałów. Wykorzystanie ciągłej transformaty falkowej, która charakteryzuje się większą rozdzielczością, daje szansę na wydzielenie fal z akustycznych obrazów falowych

EN

Interpretation of acoustic full waveforms is based on identification of elastic waves recorded in boreholes. Determination of arrival time and duration of wave packets can be solved using time-frequency analyses such a wavelet transform. Discrete and continuous wavelet transform were applied to decomposition of wave field. Research showed that discrete wavelet transform is not a proper tool to solving the problem. However, it allows denoising signals. Research on continuous wavelet transform, which has better resolution, are carried out and gives a chance to decompose wave field into separate waves

8

Model prędkościowy fal P i S opracowany przy zastosowaniu programu ESTYMACJA i danych geofizyki otworowej w rejonie wschodniej części zapadliska przedkarpackiego

Bała M., Witek K.

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

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2004

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T. 30, z. 3

299-310

PL

Obliczono czasy interwałowe fal podłużnych i poprzecznych (DPEQ i DSEQ) oraz prędkości (Vp i Vs) z głębokością, stosując teoretyczne modele ośrodków porowatych oraz pomiary i wyniki interpretacji ilościowej geofizyki otworowej. Do obliczeń wykorzystano program o nazwie ESTYMACJA opracowany przez M. Bałę i A. Cichego w ramach projektu badawczego nr 8 T12B 046 20. Program ten wylicza parametry sprężyste skał na podstawie teoretycznych modeli ośrodków porowatych, wiążących własności sprężyste skały z parametrami takimi jak: porowatość, spectrum przestrzeni porowej, nasycenie porów wodą, ropą lub gazem, składem mineralnym szkieletu oraz zawartością frakcji ilastej. Obliczone Vp i Vs stanowiły podstawę do opracowania "modelu" prędkościowego dla wschodniej części zapadliska przedkarpackiego rejonu Żołynia - Dębno - Chałupki Dębniańskie.

EN

P-wave and S-wave interval times (DPEQ and DSEQ) and velocities (Vp and Vs) were calculated for different depth using theoretical models for porous media and results of quantitative interpretation of well-logging data. The ESTYMACJA program, developed by M. Bała and A. Cichy as a result of the research project No 8 T12B 046 20, was applied to calculations. The program calculates elastic parameters of rock based on theoretical model of porous media that relate rock elastic properties with: porosity, pore space spectrum, water, oil and gas saturation, mineral composition of rock matrix, and shale content. The calculated Vp and Vs values were the basis to determine a velocity model for the Żołynia - Dębno - Chałupki Dębniańskie region of the eastern part of the Carpathian Foredeep.