Shear sonic log Types of Sonic Waves Shear wave (S wave) is the wave of shearing action. In many cases, logging-while-drilling (LWD) sonic logs provide a helpful alternative to wireline logs because of Status of Sonic Logging Tool: SSVE: Sonic Shear Velocity: STCD: Slowness Time Coherence Data: STE: Coherent Stoneley Energy: SVEL: Sonic Velocity: TT: Transit Time for CBL: TT1: Transit Time 1: TT2: Transit Time 2: TT3: Transit Time 3: TT4: Transit Time 4: TTFS: Transit Time (Far Spacing) TTL1: Transit Time High Resolution Long Spacing 1: Dipole shear sonic logs offer many display options. Stewart INTRODUCTION The correct identification of primary events on the converted S-wave section in the absence of a VSP or S-wave sonic log may be difficult (Corbin et a1. In this case, rock } ] [ u } ] } v ] v ] µ o } Z ] ] } v } ( Á À ABSTRACT The S-wave velocity is a vital parameter for various petrophysical, geophysical, and geomechanical applications in subsurface characterization. As for the sonic log, shear waves will split when passing through an anisotropic formation, shear waves will split during propagation, and the azimuth of fast shear waves is consistent with the orientation of in-situ stress. However, these two logs are often missing or incomplete in many oil and gas wells. For certain reasons, most of the wells in the Lower Indus Basin (LIB) lack DTS logs, This approach would provide improved accuracy where shear sonic logs are absent and need to be predicted for geomechanics, rock physics and other applications. Kata Kunci : Data Well Logging, Identifikasi Badhole, Hybrid machine learning models to generate synthetic shear sonic log is proposed. Data sets were acquired and analyzed on Vp/Vs versus Δtc crossplots. 4 (October 1990): 9-12. The main goal of this work was to estimate carbonate porosity from sonic log S-wave slownessmeasurement, practically insensitive to fluid effect. Utilizing open-source data from the decommissioned Volve field in the Norwegian North Sea, Log1DNet, a fully-connected CNN model was employed to capture the trend of sonic log responses. We measured ultrasonic velocity under dry and saturated conditions at confining pressures varying from 2 MPa to 40 MPa with porosity ranging from 5% to over 45%. Get real-time accuracy for optimal production. Sonic log provides the elastic properties in advanced petrophysics modelling or rock physics modelling. Data sets were acquired and analyzed on Vp/Vs versus {Delta}tc crossplots. The work of Brie et al. Mengetahui proses dan melakukan prediksi Shear Sonic Log pada dataset conventional well log. This type of sonic log can have both a monopole or dipole source. Deep Neural Network (DNN) along with the similarity metrics such as Jaccard and Overlap ABSTRACT Shear sonic logs are critical for formation evaluation, rock physics, quantitative reservoir characterization, and geomechanical studies. However, it is an essential component to compute other logs, such as shear velocity, VpVs ratio, and reservoir The wireline log data such as gamma-ray, formation bulk density, neutron porosity, acoustic compressional, and shear sonic velocities are considerably changed with formation depth due to the complex behavior and heterogeneity of shaly sand sedimentary rocks. The high cost of sonic dipole advanced wellbore logging service and its implementation in a few wells of a field has Compressional and shear sonic traveltime logs (DTC and DTS, respectively) are crucial for subsurface characterization and seismic-well tie. 66 On the other hand, conventional ML approaches utilize multiple attributes to predict 67 the shear sonic log response. , monopole and dipole sources. 1. The monopole source is not able to measure shear wave velocities in slow formations. The module uses the Having the potential of demonstrating shear sonic log prediction in hydrocarbon-bearing zones, which cannot be precisely predicted by the Greenberg-Castagna method that only works in brine-saturated rocks, this approach will provide improved accuracy, where shear sonic logs are missing and need to be predicted for geomechanics, rock physics Shear sonic logs are critical for formation evaluation, rock physics, quantitative reservoir characterization, and geo-mechanical studies. The post-acquisition processing and inversion provides an alternative to determine the properties of drilled formations. Shear wave transit times can be inferred by making lithologic assumptions based on Vp/Vs ratios thus Characterization of Angle Dependency in Sonic Logs, paper BH 2. Full waveform acoustic logging tools are similar to conventional acoustic logging tools. The case study also demonstrates the potential of carrying out shear sonic log prediction in hydrocarbon-bearing intervals, which is a limitation of the Greenberg-Castagna method which only works in brine-saturated rocks. Shear sonic logs, however, are not often Shear sonic log (DTS) availability is vital for litho-fluid discrimination within reservoirs, which is critical for field development and production. , 2009, Boonen et al. THE GEOPHYSICAL WAVETRAIN RECEIVED BY A SONIC LOG. Numerous attempts have been made to establish a precise relationship between DTS and other petrophysical Compressional (P-wave) and shear (S-wave) velocities are used to estimate the dynamic geomechanical properties including: Poisson’s ratio, Young’s modulus, and Lamé parameters. This is the sonic amplitude log, which has an important application in cementation evaluation, such as the Cement Bond Log (CBL), Variable density logging (VDL), and Segment bond logging test (SBT Flexural-dipole sonic logging has been widely used as the primary method to measure formation shear slowness because it can be applied in both fast and slow formations and can resolve azimuthal anisotropy. The dipole sonic imager (DSI) is a multiconfigurable tool that can emulate a BHC sonic, a standard monopole array tool, or an array dipole tool. Processing Dipole Waveform Logs for Neutron porosity had the highest correlation coefficient with respect to compressional and shear sonic logs. Particularly, the NARX model proved to be highly capable of predicting and reproducing sonic logs of reservoir formations with one exogenous input. , AIME, 216: 106. During the last decade important advances have been made in sonic logging. Sonic logging is becoming a routine way to plan well placement strategies, leading to improvements in reservoir production. This study Abstract. Nevertheless, obtaining shear sonic log is frequently challenging because of its high economic, time, and operating costs. Well-defined shear (pseudo-Rayleigh) waves were observed throughout most Having the potential of demonstrating shear sonic log prediction in hydrocarbon-bearing zones, which cannot be precisely predicted by the Greenberg-Castagna method that only works in brine Measurement of compressional, shear, and Stoneley wave velocities, carried out by dipole sonic imager (DSI) logs, provides invaluable data in geophysical interpretation, geomechanical studies and . 74% and 0. However, they are often not acquired in all wells because of cost limitations or borehole problems. In this analysis of sonic log errors and repeatability, we examine a series of sonic logs from Nexen’s Long Lake heavy oil field. You can read the full text: Read with a DTS shear wave log, and that there is no need for a porosity log (since the information of this property is implicit in the modeled slowness values). Shear sonic logs, however, are not often measured compared with other well logs. From a set of 42 dipole sonic logs, we examined some repeated logs and examined the differences and similarities of these data. This is In exploration wells, shear sonic log data is not always acquired or reliable. Early Tool 2. Sonic full waveforms were recorded in a shale-limestone interval with an experimental 12-channel acoustic logging device. Fracture and Stress Evaluation Using Dipole-Shear Anisotropy Logs, paper J. Keys, and Paillet, 1982). shear sonic logs, distributed over the onshore Netherlands (Fig. Shear velocity at sonic log frequencies is not very dispersive but the wave modes used to measure shear velocity are highly dispersive. However, these two PEF log was utilized to generate sonic logs (compressional and shear velocity) using ANN, recurrent neural networks (RNNs), RF, ensemble method (combination of several models) and LightGBM, where Request PDF | Rock Physics guided machine learning for shear sonic log prediction | Shear wave velocity (Vs) is a vital parameter for various petrophysical, geophysical, and geomechanical The Shear Log Modelling module is intended to help users generate a calibrated shear sonic log for wells in which only a compressional sonic log was measured, as is often the case. (1985), Greenberg and Castagana (1992), and Xu and White (1996). However, some discrepancies between the predictions and the true shear sonic logs were observed in the overburden and parts of Tuxen during testing. Stoneley waves. Depth presented are for assessing the thickness of the formation/reservoir and Download scientific diagram | Sonic log data including compressional, fast, slow, and Stoneley shear for a well drilled at 50 deviation. 1996. There are two types of body waves (compressional and shear) that are commonly used to estimate rock Example of shear (DTS) and compressional (DTC) sonic relationships from the reference wells with a VClay cutoff smaller than 0. The influence of fluid type is reduced in more compact formations. To address this issue, we have developed a new method for accurately determining the formation shear attenuation from the dipole sonic log data. Due to the high acquisition costs, DTS is only accessible in a few wells within an oil/gas field. 98 and AAPE of 0. Over the logged interval, a sand/shale sequence, the dual calipers are within the 10% ovality criteria. (2019) applied a supervised machine learning model in MATLAB. This approach would provide improved accuracy where shear sonic logs are absent and need to be predicted for geomechanics The ratio of compressional to shear sonic log has been reported to be more sensitive to lithology and fluid saturation (Bailey, 2012; Domenico, 1984; Eastwood and Castagna, 1983; Hamada, 2004; Han The predicted shear sonic log closely matches the measured shear sonic log values. Such a tool can give us all three measurements in both slow and fast formations. Acoustic theory and wave propagation. , 1998, Eissa and Kazi, 1988, Rasouli et al. 2. Relationships between compressional and shear wave velocities were established in the classic paper by Castagna et al. In this Internship, the author used a dataset from the Norwegian Petroleum Directorate for Badhole identification and Shear Sonic Log prediction using the DBSCAN, OPTICS, Boosted Random Forest, and LSTM algorithms. Flexural-dipole sonic logging has been widely used as the primary method to measure formation shear slowness because it can be applied in both fast and slow formations and can resolve azimuthal anisotropy. Compressional (Vp), In general, the dipole shear sonic imager (DSI) tool can acquire and analyze compressional, shear, and Stoneley waves simultaneously although it is impossible to run in 3. This is slower than the P-wave, but usually has a higher amplitude. Invasion corrected logs in V p, V s, Rho and AI track are in red. A machine learning approach to Shear wave sonic transit time log (DTSM) Selection of Models. What is very intriguing is that the proposed model is relatively conservative in the sense that it tries to follow the measured shear sonic log trend, without going out of Generating Vs from Vp sonic logs David G. Mengetahui proses dan melakukan clustering pada dataset conventional well log untuk melakukan identifikasi Badhole. 1. 99 when compared to The introduction, a few years ago, of shear dipole sonic logs gave the industry the possibility to record high-quality shear aid compressional slownesses in soft formations. The compressional data is processed as discussed above under the Wyllie and Raymer-Hunt methods. 35 (left) and larger than 0. Typically, shear sonic travel time (DTS) in conjunction with compressional sonic travel time (DTS) and bulk density are the key factors used in estimating rock mechanical properties. , natural gamma ray, P-wave velocity, density, and Typically, shear sonic travel time (DTS) in conjunction with compressional sonic travel time (DTS) and bulk density are the key factors used in estimating rock mechanical properties. These include formations in the Raw un corrected logs (Un-corr) of sonic velocity V p, shear velocity V s and density Rho along with computed acoustic impedance AI (V p * Rho) are in black. In their approach, the K-means classifier is utilized to segment logging data at various Flexural-dipole sonic logging has been widely used as the primary method to measure formation shear slowness because it can be applied in both fast and slow formations and can resolve azimuthal anisotropy. This approach would provide improved accuracy where shear sonic logs are absent and need to be predicted for geomechanics Shear Sonic Log menggunakan algoritma Boosted Random Forest dan LSTM. Extracting such data by analyzing finite reservoir rock cores is very costly and limited. The sensitivity is large in the case of unconsolidated sands and when gas is present in the formation. This approach would provide improved accuracy where shear sonic logs are absent and need to be predicted for geomechanics, rock physics and other applications, and shows improvement in the accuracy of the predictions over the linear regression model based on the Greenberg-Castagna method, as measured by the RMSE. ( V P ) ranges from 1700 to 6600 m/s and shear-wave Analyses of sonic logs in a horizontal well provide new information about mechanical properties of rocks, made possible by recent developments in our understanding of acoustic wave propagation in prestressed formations. Due to the presence of the collar, which acts as a strong waveguide, Abbreviations: DTP, sonic log – compressional slowness, DTS, sonic log – shear slowness, NNE, neural network estimation, GR, gamma ray log, RCW, reservoir characterization workflow, RHOB, bulk density, SSTVD, subsea true vertical depth in meters, Vp, compressional sonic velocity, Vs, shear sonic velocity, Vs ANN, shear velocity log estimated using artificial Shear sonic log (DTS) availability is vital for litho-fluid discrimination within reservoirs, which is critical for field development and production. In practice, Sonic logging is usual method that is used to provide this parameter. En. Empirical equations, such as Greenberg-Castagna relations, can be used to estimate shear sonic logs, but they only work for brine-saturated rocks (paper SPE 198764). Comparisons of the above attributes for P−wave and shear-wave logs. Trends were identified in sands and shales and were matched with semi-empirical correlations based on compression and shear wave velocity, Vp and Vs, (i. An early identification of this problem and solution was made by Kitsunezaki who sketched out a few ideas for transducers, including an electro-magnetically actuated ABSTRACT. Up to now the use of sonic slownesses for fluid type identification was recommended only in sands with a porosity of at predicting shear sonic log (DTS) and volumes of petrophysical and elastic attributes, Kadanwari Gas Field, Pakistan Syed Adnan Ahmed1,2*, MonaLisa1, Muyyassar Hussain1,2 and Zahid Ullah Khan1,2 1Department of Earth Sciences, Quaid-I-Azam University, Islamabad, Pakistan, 2LMK Resources (Private) Limited, Islamabad, Pakistan Abstract. , and Doh, C. 4 Dipole Shear Sonic Imaging (DSI) 1. Compressional and shear sonic logs (DTC and DTS, respectively) are one of the effective means for determining petrophysical/geomechanical properties. Although it is very important, to obtain shear sonic measurement results is very expensive. Modes are configured to meet the logging conditions presented by different borehole environments. Refer appendix for lithology symbols used. wave logs are log measurements obtained during drilling operations. The oscillating motion generated by a sound source (transducer) in an elastic medium (rock formation) is called an elastic wave or acoustic wave (also called The findings from this study can help for better understanding of shear transit times in formations which do not have multipole sonic logs or where data have been corrupted while logging in the Contribute to svpoludasu/Shear-Sonic-Log-Prediction-Using-Machine-Learning development by creating an account on GitHub. Similar to the dipole shear sonic log, the array sonic log with a monopole source measures compressional, Stoneley, and wave velocities which are used to estimated shear wave velocities. ,1983). The main differences are that (1) the source is usually of lower frequency, centered at 5 to 10 kHz rather than at 20 kHZ; According to the studies carried out to estimate mechanical properties of subsurface layer, having shear velocity data is necessary to make reliable calculations (Ameen et al. R. For certain reasons, most of the wells in the Lower Indus Basin (LIB) lack DTS logs, which are modeled using conventional techniques based on empirical relations and rock physics modeling. Using Sonic Log to The case study also demonstrates the potential of carrying out shear sonic log prediction in hydrocarbon-bearing intervals, which is a limitation of the Greenberg-Castagna method which only works in brine-saturated rocks. Along with the compressional velocity log, they used a full set of well log data from one well as inputs to train the model that can be used to predict accurately the log Shear sonic log (DTS) availability is vital for litho-fluid discrimination within reservoirs, which is critical for field development and production. This approach is data-driven; it does not explicitly require 68 prior knowledge of the geology. Gao et al. The key characteristic of the flexural wave is that it propagates at the formation shear However, some discrepancies between the predictions and the true shear sonic logs were observed in the overburden and parts of Tuxen during testing. 3. So shear wave can’t propagate through the fluids. To this purpose, modern borehole sonic tools are usually equipped with various types of acoustic sources, i. 84% for both compressional and shear logs, respectively. The walk-away VSP data were acquired in this well. Mud waves 9. Borehole Compensated Sonic(BHC) Tool 4. The arrival of this pulse is detected at an array of receivers a few feet from the transmitter. The most disparity is seen from 6010 to 6050 ft with less than a 5% difference in value. , 2011, Zoback, 2007). σ v Total vertical stress through the integration of ρ b bulk density log (a change in the slope may suggest gas presence); ν Poisson ratio from shear and compressional sonic logs; G Shear modulus from shear travel time and bulk density logs; E Young modulus from G and Poisson ratio ν The well logging technique is used to determine the petrophysical properties like porosity, permeability and fluid saturations of subsurface formations. (FIG. 1 Principle 3. Therefore, empirical and artificial intelligence allow some solutions to estimate synthetic shear sonic log. Thus, the difference between the two can be a useful indicator of secondary porosity, and both compressional and shear sonic data can be used as gas indicators. 0 14. A-C quality wellbore breakouts, inferred from the available four-arm caliper logs and anisotropy analyses of dipole shear sonic logs, indicate a NE (N40°E to N50°E) azimuth for maximum Abstract. A comparison of the results of the proposed models to a calibrated rock physics Nevertheless, obtaining shear sonic log is frequently challenging because of its high economic, time, and operating costs. Data sets were To predict shear sonic log for the Poseidon field in the Browse Basin offshore North West Australia, Bukar et al. The formation stress state is characterized by the The application of the data-driven ML model has rarely been used for compressional and shear sonic logs (DTP and DTS) prediction within the Niger Delta basin where many reports of geomechanical instabilities have been reported. Sonic slownesses are sensitive to the type of formation pore fluid. Although empirical and conventional machine learning (ML) have been used for shear sonic slowness estimates, both approaches suffer from multiple fundamental problems. Low frequency components are faster than high frequency components. Conventional methods for predicting rely on empirical relationships and rock-physics models, Compressional and shear sonic traveltime logs (DTC and DTS, respectively) are crucial for subsurface characterization and seismic-well tie. The main selection criteria was the availability of compressional (DTCO, DTC, DT4C or DT) and shear (DTSM, DTS or DT4S) sonic logs for intervals that contain main geothermal targets in the Netherlands. Long Spacing Sonic (LSS) Tool In fast formations, the shear velocity can also be used for porosity evaluation in a manner similar to that described above for compressional velocity. Monopole sonic logs can not detect these waves in a slow formation because refraction cannot occur. Since the introduction of the dipole shear In the geophysical exploration field, the sonic log (DT) and shear sonic log (DTS) are frequently used as quick and affordable procedures for reservoir evaluation. Schieck and Robert R. 1959. 1 Tang, X. The principles of borehole acoustic logging (and surface seismic methods) are based on the theory of wave propagation in an elastic medium, as detailed in several sources. Tujuan Tujuan kerja praktik ini adalah sebagai berikut: 1. Although empirical and conventional machine learning (ML) have been used for shear Having the potential of demonstrating shear sonic log prediction in hydrocarbon-bearing zones, which cannot be precisely predicted by the Greenberg-Castagna method that only works in brine This arrangement is suitable for detecting azimuthal velocity variations in a borehole. Sonic logging data are useful in a variety of applications, including seismic correlation, rock mechanics and wellbore stability, pore pressure prediction, sourceless porosity estimation, gas detection, and stress and fracture characterization. This refracted wave returning is referred to the shear head wave. inverse of compression and shear transit time DT and DTS from sonic log) as below: ( ) (3 4 ) 2 2 2 2 2 c s s c s dyn V V V V V E (1) 2( ) 2 2 2 2 2 c s c s dyn V V V V (2) The dynamic properties representing log acquired data are converted to the static rock properties in static conditions. Both the direction and magnitude of these stresses are required in (a) planning for borehole stability, (b) hydraulic fracturing for enhanced production, and (c) selective perforation for sand control. The dataset has six wells for training the model and a test well is used to predict the shear Shear sonic logs can be used to calculate the rock mechanics properties of a formation, which is useful for geomechanics studies in the development of oil and gas fields. However, the DTS Velocity logging (sonic and shear sonic) should begin to get more attention to support this strategy of making data retrieval results more precise. However, it is usually affected by the anisotropy caused by the excessively fast rotation of the well log tools, so that Sonic log - Download as a PDF or view online for free. Sonic flexural wave measurements provide a direct means for obtaining the in situ S-wave attenuation at log scale. These parameters are mainly used in estimating the static properties of the formation rocks as well as the in situ stresses. g. However, inadequacy of such vital data may arise because procuring well logs through drilling & lab ABSTRACT Real-time open-hole wireline sonic logging data processing becomes a nontrivial task to accurately, automatically, and efficiently evaluate the compressional and shear slowness of a borehole rock formation when human interaction is not possible and the signal processing time is limited to the elapsed time between different transmitter excitations. Surface and Downhole Logging; Mud Logging; Autonomous Well Integrity Logging; Cuttings Analysis; Logging While Drilling (LWD) Shear validated against wireline out to 960 us/ft ; From 5. Sonic logs are effective tools in monitoring the development & production phases of hydrocarbon recovery. Shear travel time can be used in the Wyllie equation, using fictitious values for fluid travel time. In wells where the shear sonic log Sonic logging is a well logging tool that provides a formation’s interval transit time, designated as , which is a measure of a how fast elastic seismic compressional and shear waves travel through the formations. This page is a summary of: Rock Physics guided machine learning for shear sonic log prediction, Geophysics, October 2023, Society of Exploration Geophysicists, DOI: 10. The sonic logs are not always available, epically for old Sonic logging tools emit a sound pulse every second. The data clustering approach We develop a physics-guided machine learning (ML) approach to predict the shear sonic log using various physical parameters (e. predicting shear sonic log (DTS) and volumes of petrophysical and elastic attributes, Kadanwari Gas Field, Pakistan Syed Adnan Ahmed1,2*, MonaLisa1, Muyyassar Hussain1,2 and Zahid Ullah Khan1,2 1Department of Earth Sciences, Quaid-I-Azam University, Islamabad, Pakistan, 2LMK Resources (Private) Limited, Islamabad, Pakistan Here, the study considers shear sonic data recorded in wireline log recordings. Expanded Abstracts, 1998 Annual Meeting Technical Program, SEG, 292–295. ABSTRACT. 35 (right) for formations between Kujung Porosity From the Dipole Shear Sonic Log (Wyllie Method) T he newer sonic logs record shear travel time as well as the compressional travel tine. In particular, linear trends for correlating the compressional and shear wave velocities are presented, including the Castagna mudrock line derived from in-situ sonic and seismic measurements. In rock physics, shear wave velocity is an integral part of the input data. WORKING TOOLS 1. These attenuations result sonic logging. These estimates of rock mechanical properties provide us with valuable insights on subsurface characterization. Just like the compressional The above-mentioned sonic logging tools are mainly monopole sonic logging as they do not provide measurements of the shear wave, especially in fast formations (Alford et al. Machine learning can also help predict sonic log data if there is a quantitative relationship between the available well log curves. Dual Receiver Tool 3. Similarly, the SVM model predicted sonic logs with high accuracy yielding to correlation coefficients of more than 0. The next wave, usually, to arrive is the transverse or shear wave (S-wave). To answer the challenge of real-time sonic data processing, this paper presents well-designed, self-adaptive, Sonic logs such as compressional and shear. This report looks at how sonic shear-wave anisotropy measurements are ABSTRACT Compressional and shear sonic transit time logs (DT and DTS, respectively) provide important petrophysical and geomechanical information for subsurface characterization. J Pet Technol Trans. Several models were developed to determine the best model for carrying out on th e spot. Sonic Logging. , 1995 Annual Logging Symposium, SPWLA, 1–12. Possible explanations were found in the feature distributions of the overburden zones that were lacking cohesion. Trends were identified in sands and shales and were matched with semi-empirical correlations based on the Gassmann @article{Miah2021ModelDF, title={Model development for shear sonic velocity using geophysical log data: Sensitivity analysis and statistical assessment}, author={Mohammad Islam Miah and Salim Ahmed and Sohrab Zendehboudi}, journal={Journal of Natural Gas Science and Engineering}, year={2021}, volume={88}, pages={103778}, url={https://api Example of log reconstruction in a shaly sand sequence (Dunvegan). We first define stress quantities, or “subsidiary principal stress,” relevant for sonic dipole shear characterized sufficiently far away into the formation to be Therefore, a deep learning approach is proposed to predict compressional and shear sonic logs, simultaneously. Because even low frequency logging tool sources have a moderate frequency spectrum, the shear body wave will show the "ringing tail" effect on When laboratory measurement of shear sonic acoustic travel time (shear sonic velocity or V s) is time-consuming and expensive, V s is typically determined from empirical correlations developed using wireline logs (Anemangely et al. Shear attenuation may locate fractures or vuggy porosity. Principle The reliable borehole measurement of shear velocity awaited the development of the dipole source. ↑ 14. Trans. These estimates of rock mechanical properties provide We build a deep neural network model to predict the shear sonic log in field in the Gulf of Mexico. either on arrival of the compressional wave or the shear wave. Although empirical and conventional ma-chine learning (ML) have been used for shear sonic slowness estimates, both approaches suffer from multiple fundamental Shear (Vs) and compressional (Vp) sonic logs are important parameters required in reservoir exploration, development, recovery, geothermal operations, and fluid sequestration. Formation stresses play an important role in geophysical prospecting and development of oil and gas reservoirs. 1) 10. Permeability values were calculated over the entire reservoir length and showed good agreement with NMR permeability values. Therefore, many petrophysical and geophysical workflows include sonic log synthetization or pseudo-log generation based on multivariate This study proposes a novel approach to predict missing shear sonic log responses more precisely and accurately using similarity patterns of various wells with similar geophysical properties, which is important in decision making and planning of hydrocarbon exploration. to describe the rock characteristics that help in formation evaluation. The flexural-dipole waveforms are dispersive borehole-guided waves that are sensitive to borehole geometry, mud, and formation properties Real-time sonic logging data processing becomes a nontrivial task to accurately and automatically evaluate both the compressional and shear slowness when human interactions are not allowed and when the computing time is limited between different transmitter firings. Shear sonic is the model result as none was recorded in this well. Steps of modeling and adopted rock physic models Slowness is the inverse of velocity, which depends on the rock elastic modulus: ρ K G VP 3 4 + = ρ G VS = (1) We develop a model that relates the polarization direction of a dipole sonic fast shear wave propagating along the borehole (hereafter called FSA) to the relative deviatoric stress tensor for arbitrary well orientations. However, these well logs are essential to compute other logs, as shear velocity, and for reservoir characterization to discriminate lithology and fluids (Pendrel and Schouten, 2021). However, the conventional way of log evaluation is very expensive and tiresome. The motivation of this study is to apply the Logging-while-drilling (LWD) dipole sonic tools have been introduced to the industry as a supplement to monopole and quadrupole measurement because they can provide shear slowness anisotropy Acquiring real shear sonic logs during the wire-line logging program is to be considered as the best approach moving forward, also utilizing the log variable ranking strategy, connectionist tool, and novel V s-V p correlation has the potential to enhance the prediction of formation elastic properties and rock strength. The flexural-dipole waveforms are dispersive borehole-guided waves that are sensitive to borehole geometry, mud, and formation properties, and therefore Real Logging Tools Modern sonic logs, often called dipole shear sonic logs, usually carry monopole and dipole sources, and generate the measured values for compressional, shear, and Stoneley slowness in dif-ferent ways depending on the formation characteristics. No breakout is observed from the Contribute to svpoludasu/Shear-Sonic-Log-Prediction-Using-Machine-Learning development by creating an account on GitHub. In the geophysical exploration field, the sonic log (DT) and shear sonic log (DTS) are frequently used as quick and affordable procedures for reservoir evaluation. The flexuraldipole waveforms are dispersive borehole-guided waves that are sensitive to borehole geometry, mud and formation properties, and therefore the Elkatatny et al [26] developed a new mathematical model for compressional and shear sonic times from wireline log data using an ANN and provided a mathematical correlation for estimating the sonic Tools. 2. In exploration, shear sonic log data has not often been acquired, or reliable. Before the invention of the Dipole Sonic Log, older wells did not measure these essential parameters. For certain the shear sonic log is not available, commonly, the shear wave velocity is estimated by theory- based methods, such as Castagna et al. Possible explanations were found in the feature distributions of the overburden zones This approach would provide improved accuracy where shear sonic logs are absent and need to be predicted for geomechanics, rock physics and other applications, and shows improvement in the accuracy of the predictions over the linear regression model based on the Greenberg-Castagna method, as measured by the RMSE. , 2015), in this paper, we develop an efficient inversion-based interpretation method to improve the A specialized type of sonic log is the cement-bond log (CBL) or bond-attenuation log (BAL) that uses the full-waveform to assess how well casing is bonded to the formation. We developed a physics-driven, machine-learningbased method Acoustic-velocity logs, also called sonic logs or transit-time logs, are a record of the travel time of an acoustic wave from one or more transmitters to receivers in the probe. 1 & Appendix A). For In practice, Sonic logging is usual method that is used to provide this parameter. In the current study, two approaches were adopted to predict shear sonic wave velocities (Vs) from several petrophysical well logs, including gamma ray (GR), density (RHOB), neutron (NPHI), and The sonic log is a porosity log that measures slowness or interval transit time ( 4 ) of a compressional sound wave travelling through the formation along the axis of the borehole. Most sections of this horizontal well exhibit azimuthal shear isotropy, indicating isotropic stresses in the plane perpendicular to the well trajectory, leading to stable Abstract. The additional energy loss associated with the refracted S-wave results in the estimated dipole attenuation being higher than the shear attenuation at low frequency. Additionally, sonic logs are still used widely as originally intended, to improve the correlation of time and depth, and are commonly used in rock mechanics and cement quality evaluation. However, in practice the shear sonic is not included in the set of acquired logs but only compressional The results obtained showed that ANNs model successfully predict the compressional and shear sonic times from log data with 99% accuracy giving correlation coefficient of 0. The introduction, a few years ago, of shear dipole sonic logs gave the industry the possibility to record high-quality shear and compressional slownesses in soft formations. 4. Schlumberger's SonicScope service provides acoustic and sonic data while drilling in all environments. Method The sonic log measured curves Slowness is the inverse of velocity, depending on the rock elastic modulus: ρ G K VP 3 4 + = ρ G VS = (1) Where K is the bulk modulus, G is the shear modulus and ρ is the rock density. The shear wave data obtained from these surveys can be used to characterize the mechanical properties of the subsurface formations, such as the shear modulus and Poisson’s ratio. Distance-based, tree-based, and also sequence Shear sonic log (DTS) availability is vital for litho-fluid discrimination within reservoirs, which is critical for field development and production. (1985). Shear sonic log (DTS) availability is vital for litho-fluid discrimination within reservoirs, which is critical for field development and production. , 2019). and ABSTRACT Shear sonic logs are critical for formation evaluation, rock physics, quantitative reservoir characterization, and geomechanical studies. e. New approaches to ML, namely, The introduction, a few years ago, of shear dipole sonic logs gave the industry the possibility to record high-quality shear and compressional slownesses in soft formations. 1 Using “Shear Wave Logging with Dipoles,” Oilfield Review 2, no. 3. P. Original density and sonic are shown in black, modeled logs are in colour. This is the sonic amplitude log, which has an important application in cementation evaluation, such as the Cement Bond Log (CBL), Variable density logging (VDL), and Segment bond logging test (SBT Bulk density and sonic logs (compressional and shear travel times both parallel and normal to bedding/laminations) can be reconstructed based on the modelled elastic stiffness and results from Sonic logs are very essential for rock type identification, hydrocarbon typing, rock physics modelling, and reservoir characterization. Figure 3 is a composite log including 64 common, with other documented examples in the United States, Brazil, Greenland, Spain, 65 Tunisia, and China. The shear wave cannot propagate in fluids, as Boosted Random Forest memberikan prediksi Shear Sonic Wave Log yang lebih akurat dibandingkan dengan algoritma LSTM. In this study, seven machine learning algorithms namely linear regression (LR), K-nearest neighbour (KNN), support of the dipole shear sonic log. 2012; Harrison et al potential of demonstrating shear sonic log prediction in hydrocarbon-bearing zones, which cannot be precisely predicted by the Greenberg-Castagna method that only works in brine-saturated rocks, this approach will provide improved accuracy, where shear sonic logs are missing and need to be predicted for geomechanics, rock physics, Having the potential of demonstrating shear sonic log prediction in hydrocarbon-bearing zones, which cannot be precisely predicted by the Greenberg-Castagna method that only works in brine The current study has confirmed that compressional and shear sonic logs are sequential data that can be accurately modeled with recurrent neural networks. We develop a method to estimate the DT and DTS simultaneously from other commonly acquired Abstract Shear wave velocity (VS) data from sedimentary rock sequences is a prerequisite for implementing most mathematical models of petroleum engineering geomechanics. On the full wave or array sonic log, we can measure travel time and attenuation of the compressional, shear, and Stoneley wave energies, instead of merely the compressional energy as on conventional sonic logs. SVR-PSO, DNN-PSO, and LSTM-PSO models are tested. hence imposes a significant challenge for automating sonic shear processing. To address real-time Borehole sonic waveforms are commonly acquired to produce logs of subsurface compressional and shear wave velocities. 2 Sonic Log . Logging-while-drilling (LWD) dipole sonic tools have been introduced to the industry as a supplement to monopole and quadrupole measurement because they can provide shear slowness anisotropy, which is essential for formation characterization and well completion applications. This, in turn, aids in N2 - Shear (Vs) and compressional (Vp) sonic logs are important parameters required in reservoir exploration, development, recovery, geothermal operations, and fluid sequestration. Some efforts have been made to use machine learning to generate synthetic logs, and these obtained Compressional and shear sonic traveltime logs (DTC and DTS, respectively) are crucial for subsurface characterization and seismic-well tie. A. Several tool designs are available, but they all generally assess amplitude and attenuation of the waveform to evaluate the strength of the formation bond. Therefore, many petrophysical and geophysical workflows include sonic log synthetization or pseudo-log generation based on The petrophysical parameters estimated from well logs contribute effectively in generation of good subsurface models as they are reflection of reservoir's information. Dipole shear sonic imager (DSI) log offers valuable data for geophysical, petrophysical and geomechanical studies of the hydrocarbon bearing intervals. 1190/geo2023-0152. (2022) [31] proposed a fully automated hybrid framework that combines K-means, MLP, and CNN to accurately identify lithofacies. Conventional methods for predicting V S rely on empirical relationships and rock-physics models, which often fall short in accuracy due to their inability to account for the complex factors influencing the relationship ABSTRACT Formation S-wave attenuation, when combined with compressional attenuation, serves as a potential hydrocarbon indicator for seismic reservoir characterization. Based on previously developed algorithms for the fast simulation of sonic logs (Huang et al. The 3 tracks on the left show the measured gamma ray, caliper, density, and compressional sonic. Geologically, this capacity varies with many things including lithology and rock textures, most notably decreasing with an increasing effective porosity and increasing with an With fluid substitution shear modulus changes.
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