Noise Logging Research Articles

Measurement of wellbore leakage in high‐pressure gas well based on the multiple physical signals and history data: Method, technology, and application

AbstractLeakage is one of the most serious challenges for the safe production of high‐pressure gas wells for its high risks, including abnormal annular pressure, natural gas accumulation, and environment pollution, but available methods can hardly accurately measure the leakage type and depth, which are the key parameters for the rigless leakage repair and risk assessment. Therefore, this paper proposes a method to measure the leakage based on the characteristics, which combines qualitative and quantitative measurement together. Qualitative measurement considers the annular pressure, tubing pressure, liquid level, cement quality, and workover history. Quantitative measurement is determined by noise logging, electromagnetic logging, pressure logging, and temperature logging. The logging should be optimized according to the qualitative measurement. The method was successfully applied in high‐pressure gas well belonging to Tarim Oilfield. Two potential leakage types are provided based on the annular pressure, liquid level, cement quality, and workover history, including tubing leakage and linger hanger leakage. Based on the potential leakage types, the pressure difference, logging devices string, stopping length, and time are optimized to make the engineering logging reliable. Through measurement, two leakage points are found in tubing string. One is tubing body crack at the depth of 2724 m and the other is tubing thread leakage at the depth of 5211.7 m, which well matches the production data.

Cleaned Hydrophone Array Logging Data Aids Identification of Wellbore Leaks

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 201512, “Enhanced Wellbore-Leak Localization With Estimation and Removal of Guided Wave Noise Using Array Hydrophone Logging Data,” by Yao Ge, Ruijia Wang, and Yi Yang Ang, Halliburton, et al. The paper has not been peer reviewed. Leaks in wellbore tubulars emit acoustic waves in the borehole that can be captured by a hydrophone array. Processing the array data yields location and energy level of the wellbore leaks; however, the hydrophones also may capture other coherent noise propagating as guided waves along the borehole. The complete paper describes an approach to estimate and subsequently remove the guided-wave noise from the hydrophone array data to improve the accuracy of leak-source locations. Estimating the propagation direction and amplitude of leak-induced guided waves aids logging operations to locate a leak source efficiently. Noise Logging and Well Integrity Well integrity has become a focused area for most operators given the long life cycle and complex structure of a wellbore. Noise-logging tools have been developed to detect flow or leak in a wellbore. A typical noise-logging tool consists of one or two acoustic sensors logged through the depth of the well that produce the amplitude and frequency spectrum-log of the received acoustic signals. A noise-logging tool usually operates in two modes—the continuous (or dynamic) mode and the stationary mode. In the continuous mode, the tool usually is logged through all accessible depths at a constant speed. Based on the data from the continuous pass, specific depths are identified and additional stationary mode passes are performed to stop the tool at selected depths and acquire higher-quality data. A major issue of the data from continuous logging is the presence of road noise, which is created by the centralizer, cable, or any part of the tool strings scratching against the casing or tubing. To reduce the effect of the road noise, a high-pass filter usually is applied to remove the signal from the lower-frequency range corresponding to the range of the road noise. However, this procedure could affect the quality of the leak signal when a portion of the leak signal lies in the lower-frequency range. The logging data taken when the tool is stationary for 1 minute or more at a target depth is free from road noise, but this approach prolongs logging time and limits depth resolution. Aside from road noise, other forms of propagating noise exist in the wellbore, such as noise from surface or downhole equipment or propagating noise induced by a leak source. Road noise and all forms of propagating noises are referred to as guided-wave noise in the complete paper. The guided waves usually propagate along the borehole’s axis for a long distance with low attenuation. However, traditional noise-logging tools with one or more omnidirectional hydrophones are unable to distinguish guided-wave noise from leak signals. Recent advances in noise-logging-tool design use array hydrophones to provide not only depth but also radial location of downhole leaks. The array hydrophones also enable an advanced array-processing method to measure and suppress the guided-wave noise.

State of the art of advanced spectral noise and high-precision temperature logging technology utilization in Iraqi oil fields: an integration approach to diagnose wells performance complications

In this study, an integrated approach of advanced spectral noise and high-precision temperature logging with production logging tool was used for the understanding of leak detection, fluid cross-flow, flow below spinner threshold, packer failure, fluid channeling in patchy and bad cement bond behind the casing, flow quantification in complex SSD completion, production detection and quantification in recirculation intervals in deviated wells. Various case studies from Southern and Northern Iraqi oil fields have been presented in this paper.

Data processing method of noise logging based on cubic spline interpolation

Abstract Noise logging is a method to determine the natural noise in a well. In the actual production logging process, it is a common situation that the noise data is not continuous with depth, which can be solved by the cubic spline interpolation method. This method is a piecewise interpolation method, which fits with a three-time polynomial in each segment interval, and adds up the polynomials on all intervals to get the interpolation formula. The interpolated data points are a smooth transition with good stability. In this article, the original noise data is interpolated to continuous noise data by cubic spline interpolation method, and then evaluated by noise imaging logging, which presents good results. The cubic-spline interpolation method ensures the internal connection of noise data, and also realizes the fine description and recognition of the characteristics of the output layer. This method will provide a low-cost and effective logging evaluation method for production logging, which has a wide range of applications.

Monitoring and surveillance of subsurface multiphase flow and well integrity

With maturing oil fields, there is an increasing focus on improving the oil recovery factor and pushing the envelope towards a 70% target. This target is indeed very challenging and can be reached by fully understanding the reservoir characteristics before using an enhanced oil recovery method. These include reservoir heterogeneities, displacement efficiency, horizontal sweep, vertical sweep due to flow behind the casing, and the presence of conductive faults or fractures. Therefore, a proper surveillance should be performed to evaluate the injectant plume front, reservoir conformance, well connectivity, and the assessment of well integrity, which can be crucial for the success of the project and its future development. This paper discusses a special downhole logging technique including a set of conventional multiphase sensors alongside high precision temperature (HPT) and high-definition spectral noise logging (SNL-HD). It was run for an injector and producer pair near the wellbore area to provide complete assessment of the integrity issues that might impair the lateral sweep of injectants into the target layer. The operation was carried out with a tool string that contained no mechanical parts and was not affected by downhole fluid properties. It was also conducted under both flowing and shut-in conditions to identify flow zones, to check fracture signatures and to provide multiphase fluid velocity profiles. The results of the survey allowed for in-depth assessment of borehole and behind casing flow, confirming lateral continuity, and allow for better well planning and anticipation of possible loss of well integrity. Combining the behind casing flow assessment with borehole multiphase flow distribution can be used for production optimization by sealing unwanted water contributing zones that might impair production in the future.

EXPERIMENTAL STUDY OF THE NATURE OF ACOUSTIC NOISE SPECTRAL CHARACTERISTICS DISTURBANCE AT A LAB WELLBORE MOCKUP WITH STEEL CASING

Background The possibility of using passive acoustic noise logging in the study of operating wells is considered. Currently, there are several companies on the geophysical services market that offer to implement the method of broadband wellbore noise logging for solving practical problems in wells of various categories. Aims and Objectives Lab experimental study devoted to investigating the nature of acoustic noise spectral characteristics disturbance in a wellbore mockup with steel casing in presence of the acoustic source behind the casing. Methods The study is performed using the reference high-accuracy hydrophone and a wide frequency band wellbore logging tool at a close to real scale lab wellbore mockup. Results It is established the fact that acoustic resonances appear inside the casing volume with respective disturbances of the original signal that are also affected by the parameters of the specific wellbore tool.

CURRENT PREDICTION OF RESERVOIR PARAMETERS UNDER THEIR OPTIMIZATION CONTROL DYNAMICS. PART 2. RESERVOIR POROSITY AND PERMEABILITY PREDICTION IN THE INTERWELL ZONES

In this part of the work, spectral methods for predicting such basic parameters of reservoir properties as residual oil saturation and piezo conductivity of the controlled objects of reservoir exploitation by their volumes are considered. Based on the materials of part I of this work, methods for modeling inter-well zones were determined using the Dupuis-Forchheimer and Bernoulli equations. This approach establishes the possibility of determining the residual oil saturation and piezo conductivity at controlled points of «collapse» in certain areas of remote zones. It becomes possible in transient processes of cyclically alternating operation modes and oil displacement in elastic and rigid states of reservoir exploitation. Linear values of piezo capacity as a function of residual oil saturation and piezo inductance as a function of piezo conductivity are in the characteristics of the integral steepness of the leading and trailing edges of the controlled «collapse» point respectively. It is shown that the results of the current forecasting are largely confirmed by geophysical methods of spectral noise logging, barometry and flow metering. It has been established that in the considered approach of the current prediction of the qualitative indicators of the development of the operational object of the deposit, methods for predicting their parameters in the form of development stability values are also implemented. First of all, this concerns the selective-coordinate forms of parametric resonance in the theory of oscillations. It becomes possible due to the implementation of metatechnology of oil extraction in controlled quanta of time and space along the trajectory of the oil displacement flow tube. These circumstances lead to the resolution of the contradictions of modern theories of systems, controls and oscillations in objects with distributed parameters.

Modulation-Domain Kalman Filtering for Monaural Blind Speech Denoising and Dereverberation

We describe a monaural speech enhancement algorithm based on modulation-domain Kalman filtering to blindly track the time–frequency log-magnitude spectra of speech and reverberation. We propose an adaptive algorithm that performs blind joint denoising and dereverberation, while accounting for the inter-frame speech dynamics, by estimating the posterior distribution of the speech log-magnitude spectrum given the log-magnitude spectrum of the noisy reverberant speech. The Kalman filter update step models the non-linear relations between the speech, noise, and reverberation log spectra. The Kalman filtering algorithm uses a signal model that takes into account the reverberation parameters of the reverberation time $T_{60}$ and the direct-to-reverberant energy ratio (DRR) and also estimates and tracks $T_{60}$ and the DRR in every frequency bin to improve the estimation of the speech log spectrum. The proposed algorithm is evaluated in terms of speech quality, speech intelligibility, and dereverberation performance for a range of reverberation parameters and reverberant speech to noise ratios, in different noises, and is also compared to competing denoising and dereverberation techniques. Experimental results using noisy reverberant speech demonstrate the effectiveness of the enhancement algorithm.

Sound levels in movie theaters: is there a potential for hearing loss?

Purpose: The goal of this study was to determine the frequency of attendance at movie theaters, the most popular genres of movies, the sound levels inside movie theaters, and if, based on frequency of attendance, a relationship could be established between temporary threshold shift and noise levels inside movie theaters. Method: A survey was first distributed to moviegoers at several different venues. Movies were selected based on the most popular genres. A noise logging dosimeter was utilized during the viewing of 16 movies in two different multiplex theaters to determine if sound levels exceed those deemed hazardous by the Occupational Safety and Health Administration. Results: Results indicated that most surveyants go to the movie theater about once a week. The noise levels obtained for 16 movies did not exceed those established by OSHA as hazardous in nature. Conclusion: Given that the maximum dose recorded by any movie viewed was 7.6% (out of 100%), it is highly unlikely that the average person would sustain a temporary threshold shift from movie viewing alone. Even if a person attended the movie theater on a daily basis, there is no evidence to suggest that movie viewing alone could cause a temporary shift in hearing.

Noise Exposure and Self-reported Hearing Impairment among Gas-fired Electric Plant Workers in Tanzania.

Background:Gas-fired electric plants are equipped with heavy machines, which produce hazards including noise pollution. Exposure to high level of noise of above 85dB(A) is known to bring about Noise-Induced Hearing Loss (NIHL). This study aimed to assess noise exposure level and reported prevalence of noise-induced hearing loss among workers in gas-fired electric plants.Material and Methods:This cross-sectional study was conducted in three gas-fired electric plants in Dar es Salaam (Plant A, Plant B and Plant C) from July to August 2017. A noise logging dosimeter was used to measure personal noise exposure level. A questionnaire was used to collect information on managerial factors, individual factors, socio-demographic factors and history of the participants. A short screening validated questionnaire was used to obtain noise exposure score. Frequency distribution, Chi-square test and Regression analyses were done using SPSS version 20.Results:One hundred and six participants were involved in the study. Noise exposure level among gas-fired electric plant workers was above 85dB(A), n = 37. The equivalent sound level (LAeq) measured over 8 hours was (98.6 ± 9.7) dB(A). The mean noise peak level was (139.5 ± 9.4) dB(A). Plant C had higher mean noise exposure level (TWA) of (96.9 ± 5.1) dB(A) compared to plant B 96.4 ± 3.7dB(A) and plant A 78.7 ± 11.9dB(A). Participants in both operation and maintenance had higher equivalent sound level (LAeq) measured over eight hours of 101.980 ± 3.6dB(A) compared to maintenance alone 98.5 ± 12.4dB (A) or operation 97.7 ± 8.8dB (A). Proportion of participants with reported hearing loss was 57(53.8%) where 44(41.5%) participants reported difficulty hearing people during conversations. Hearing protective devices (HPDs) were reported to be used by a majority, 101(95.3%).Conclusion:Workers in gas-fired plants are exposed to high noise levels that could damage their hearing. Hearing conservation programs should be established and maintained in this work environment.

Technology Trends in Evaluating Cement Jobs Using Logging Tools

This article, written by Special Publications Editor Adam Wilson, contains highlights of paper SPE 188274, “Technology Trends in Cement-Job Evaluation Using Logging Tools,” by Mahmoud Khalifeh, SPE, University of Stavanger/IRIS; Dave Gardner, SPE, IRIS; and Muhammad Yasser Haddad, University of Stavanger, prepared for the 2017 Abu Dhabi International Petroleum Exhibition and Conference, Abu Dhabi, 13–16 November. The paper has not been peer reviewed. Cement-job evaluation is a process that identifies whether the objectives of a cement-job operation have been achieved after cement placement. This paper reviews the technology trends in cement-job evaluation using logging tools and considers the main advantages and concerns associated with each technology. The technologies covered are acoustic tools, temperature logging, noise logging, resistivity logs, oxygen-activation logs, X-ray measurements, gamma/gamma density measurements, neutron/neutron logging, and fiber-optic measurements. Introduction After a cementing operation has been performed and the cement has set, cement evaluation is conducted either through hydraulic testing or by using various well-logging methods. Verification of casing-cement quality by logging tools has been a contentious subject for the past few decades. On one hand, some experts claim that current technologies are not sufficient to show the sealing capacity and quality of casing cement. On the other hand, others claim that data processing and misinterpretation of the obtained data from cement-job evaluations are the crucial challenges, not the logging technologies. However, another critical element must be considered as a limiting factor—downhole condition. The downhole condition, which includes well parameters and well design, has a major influence on technology development and data interpretation. The well parameters include downhole temperature, downhole pressure, wellbore-fluid properties, casing size and thickness, cement thickness and type, fast formation, slow formation, and unconsolidated formation. Fig. 1 shows the most-likely well design and the worst-case scenarios that need to be considered when developing technology with an assumption that there is no formation washout. As shown in Fig. 1, cement sheaths may be relatively thin but they are very long, especially in the case of surface and intermediate casings. This means that extensive vertical defects along the bore-hole axis would be necessary to create a leakage pathway. Cement defects that can cause leakage include low top of cement (TOC), mud channels, chimneys, and microannuli. Acoustic and ultrasonic logging tools are the standard tools used for indirect cement-quality measurement and for finding TOC. However, limitations exist concerning the measurement and interpretation accuracy that can be achieved using standard cement-bond logs. In addition, logs do not provide continuous, real-time, long-term monitoring of cement-barrier quality. Therefore, different technologies have been proposed that might have the potential to address the limitations of acoustic and ultrasonic logging tools.

Определение зон выноса проппанта методом спектральной шумометрии

Определение зон выноса проппанта методом спектральной шумометрии

Применение геофизического комплекса спектральной шумометрии на солевой скважине, пробуренной на ассельский (рассольный) водоносный горизонт

Применение геофизического комплекса спектральной шумометрии на солевой скважине, пробуренной на ассельский (рассольный) водоносный горизонт

Determining Process Model Using Time-Based Process Mining and Control-Flow Pattern

Determining right model of business process from event log is the purpose of process discovery. However some problems i.e the inability to discover OR, noise and event log incompleteness are emmerged while determining right model of business process. First, OR relation is often discovered as AND relation. Second, noise problem is occured when there are truncated and low frequency traces in event log. Thus control-flow pattern is used to solve issues of same noise relation frequency hence it discovers relation based on transaction function of activity. Consequently, it can refine non noise relation in business process model. Third, incompleteness leads to incorrect discovery of parallel process model; therefore we used Timed-based Process Mining which utilized non-linear dependence to solve the incompleteness. Finally this paper proposed combination of Timed-based Process Mining and control-flow pattern to discover OR and handle same frequency noise and incompleteness. From the experiment in section 3, this proposed method manages to get right process model from event log.

Выявление негерметичности муфтовых соединений насосно-компрессорных труб, обсадных и технических колонн для скважин ПХГ в соляных кавернах методом спектральной шумометрии

Выявление негерметичности муфтовых соединений насосно-компрессорных труб, обсадных и технических колонн для скважин ПХГ в соляных кавернах методом спектральной шумометрии

Seepage pathway assessment for natural gas to shallow groundwater during well stimulation, in production, and after abandonment

Hydraulic fracture stimulation (HFS) of unconventional oil and gas reservoirs is of public concern with respect to fugitive gas emissions, fracture height growth, induced seismicity, and groundwater quality changes. We evaluate the potential pathways of fugitive gas seepage during stimulation, in production, and after abandonment; we conclude that the quality of the casing installations is the major concern with respect to future gas migration. The pathway outside the casing is of particular concern as it likely leads to many wells leaking natural gas from thin intermediate-depth gas zones rather than from the deeper target reservoirs. These paths must be understood, likely cases identified, and the probability of leakage mitigated by methods such as casing perforation and squeeze, expanding packers of long life, and induced leakoff into saline aquifers. HFS itself appears not to be a significant risk, with two exceptions. These occur during the high-pressure stage of HFS when (1) legacy well casings are intersected by fracturing fluids and when (2) these fluids pressurize nearby offset wells that have not been shut in, particularly offset wells in the same formation that are surrounded by a region of pressure depletion in which the horizontal stresses are also diminished. This paper focuses on the issue of gas migration from deeper than the surface casing that occurs outside the casing caused by geomechanical processes associated with cement shrinkage, and we review the origin of the gas pulses recorded in noise logs, landowner wells, and surface-casing vents.

Geometric Anisotropic Spatial Point Pattern Analysis and Cox Processes

ABSTRACTWe consider spatial point processes with a pair correlation function, which depends only on the lag vector between a pair of points. Our interest is in statistical models with a special kind of ‘structured’ anisotropy: the pair correlation function is geometric anisotropic if it is elliptical but not spherical. In particular, we study Cox process models with an elliptical pair correlation function, including shot noise Cox processes and log Gaussian Cox processes, and we develop estimation procedures using summary statistics and Bayesian methods. Our methodology is illustrated on real and synthetic datasets of spatial point patterns.

The Effect of Road Traffic Noise on Psychological Health Disorders of School Children at Cipinang Muara Elementary School, Jatinegara Sub District, East Jakarta City, DKI Jakarta Province, 2005

Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 The traffic noise is the main issue of the community who live in urban area because it may cause an adverse human health and psychological effects. The purpose of this study is to describe the effect of road traffic noise to psychological health disorders on school children of Cipinang Muara elementary school at Jatinegara Sub District, and other risk factors such as distance, length of exposure, learning periode in school, and age. This research applied a case-control study with sample population of elementary school students from grade 4 to 6. Total samples were 240 children, including 80 cases and 160 controls. Data were collected through a multistage of random sampling. Data analysis used a computer program of univariate, bivariate and multivariate. Road traffic noise data measure in the classroom using noise logging dosimeter Q-400/500. Bivariate analysis (Chis-Square) and multiple logistic regression analysis are applied in the analysis. Bivariate analysis showed that there were a significantly effect of traffic noise, distance of seat, and length of exposure towards psychological health problems. On the other side, the length of school period and age of respondents did not have any significantly effect to the psychological health problems on the elementary school students. Multivariate analysis indicated that the elementary school students exposed to traffic noise more than 61.8 dBLAeq   in the school area having a risk of psychological health problem 10.9 higher than those who were exposed to traffic noise less than 61.8 dBLAeq,   a long with the distance variable and the length of noice exposure. It is required to socialize and apply the regulation on noise control and its impact in a consistently manner. Also, it is necessary to conduct health promotion and integrated monitoring both with inter-sector and inter-program. At last, to ensure the presence of inferential causal temporality, it is required to conduct further study with design of cohort or experimental study. This includes the increase of variable number and location of study in order to describe the real condition.   

Applied Ultrasonic Technology in Wellbore-Leak Detection and Case Histories in Alaska North Slope Wells

Summary When operators are faced with well-integrity problems, a variety of methods may be used to detect the source of annular communication. Methods for detecting downhole leak points include spinners, temperature logs, downhole cameras, thermal-decay logs, and noise logs. However, many of these methods are ineffective when dealing with very small leaks and can result in collected data that require a significant amount of logging finesse to interpret. Ultrasonic listening devices have been used for a number of years to detect leak sources effectively in surface production equipment. Ultrasonic energy has some properties that, when compared to audible-frequency energy, make it ideal for accurate leak detection (Beranek 1972; Povey 1997; Evans and Bass 1972). Like audible-frequency energy, ultrasonic energy can pass through steel. However, ultrasonic energy propagates relatively short distances through fluids when compared to equal-energy audible-frequency sound. Thus, when an ultrasonic signal of this nature is detected, the detection tool will be in close proximity to the energy source. On this premise, an ultrasonic leak-detection tool was developed for downhole applications to take advantage of the unique properties of ultrasonic-energy propagation through various media. Data-acquisition equipment and filtering algorithms were developed to allow continuous logging conveyed on standard electric line at common logging speeds. Continuous logging has proved to be significantly more efficient in locating anomalies than static logging techniques commonly used in noise-logging operations. During development, the tool was shown to be effective in locating leaks as small as 0.026 gal/min with an accuracy of 3 ft in production tubing, casing, and other pressure-containing completion equipment. Leaks also have been detected through multiple strings of tubing and casing. The tool has proved to be effective in locating leaks that other diagnostic methods were unable to locate.

Neural-Net Identification of Flow Regime With Band Spectra of Flow-Generated Sound

Summary Multiphase production log interpretation requires that the flow regime along hole in the wellbore is known. Flow regime is the cased-hole analog of lithology. Knowledge of the flow regime will help to interpret tool signals, will help to evaluate the flow rate on a per phase basis, and will reduce post-processing load. The flow regime can be classified correctly by a neural net in up to 87% of all cases using 1/3 octave band spectra of flow-generated sound plus the pipe inclination angle. Without the inclination an 88% correct classification can be achieved. A neural net trained on commercially available tool data (noise cuts) appears to be too sensitive to the wellbore inclination. Hence, application of automated neural net interpretation of noise logs requires a new generation of noise logging tools.