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Collaborating Authors
Improved Ultrasonic Piezoceramic Sandwich Transducer
Jiang, Lin (School of Naval Architecture Engineering, State Key Laboratory of Structural Analysis for Industrial, Equipment, Dalian University of Technology) | Hong, Ming (School of Naval Architecture Engineering, State Key Laboratory of Structural Analysis for Industrial, Equipment, Dalian University of Technology)
ABSTRACT This paper presents an improved ultrasonic piezoceramic sandwich transducer, utilised for ultrasonic field in narrow lift stations, wet well, flumes and filter beds. The piezoceramic sandwich transducer powered by a signal generator and it is suitable to generate ultrasound with two piezoceramics and the exponential horn at 35 kHz resonance frequency. From the experiments it can be proved that the ultrasonic piezoceramic transducer acoustical power and vibration amplitude mainly depends on the piezoceramic tores and the ratio between the diameter of the horn ends and material elasticity coefficient. The advantage of the exponential horn is that the beam angle is narrower which is suitable for narrow lift stations measurement. The piezoceramic sandwich transducer and the air-coupled transducer are modeled in order to optimize output with material physical parameter changing. The simulation results show good agreement with experiments and based on the numerically modeling trials, more robust design would become true without extensive cutting or trying prototype. The polar pattern results in lab are prominent. INTRODUCTION Increasing concern for ultrasonic piezoceramic sandwich transducer has, in recent years focused studies of energy transmission. Royster (1969) explained that the ultrasonic piezoceramic sandwich transducer is used near its resonance frequency, which yields the highest acoustic output power and efficiency. The signal power generator supplies the ultrasonic piezoceramic sandwich transducer, which converts the electrical oscillation into mechanical vibration. Wevers (2005), Berlincourt (1964) and Wilson (1985) have designed more. Ultrasonic transducer is applied to various purposes because of these beneficial effects. For example, it can be used to enhance reaction rates, clean glass bath, and form nano-particles of metals and level measurement pharmaceutical products. It is used in the in narrow lift stations, wet well, flumes and filter beds and even on the sea. The energy transmission depends on piezoceramic crystal design and mechanism structure design.
The measurement of reflection coefficient dispersion in the ultrasonic frequency range
Li, Min (China University of Petroleum) | Tang, Genyang (China University of Petroleum) | Dong, Chunhui (China University of Petroleum) | Zhao, Liming (China University of Petroleum) | Sun, Chao (China University of Petroleum) | Han, Xu (China University of Petroleum) | Wang, Shangxu (China University of Petroleum)
ABSTRACT Reflection coefficient is a significant parameter in seismic exploration and closely related to seismic velocity contrast between different layers. In this paper, the reflection coefficient dispersion at the interface of a cap and a reservoir (saturated with different fluid) is studied. The ultrasonic pulse reflection method is used to measure the waveform of a tight sandstone (acting as a cap layer). Besides, we also recorded the waveforms of an extra conventional sandstone (to simulate reservoir) placed under the cap and saturated with different fluids (gas, water and oil #2/oil #68). With the waveforms of reflections at top and bottom interfaces of the cap both with and without reservoir placed underneath it, a simple ratio is derived and calculated to estimate the dispersion of reflection coefficient. We find the reflection coefficient has no dispersion or weak dispersion when the reservoir is dry; nonetheless, dispersion appears when the sandstone is water and oil-saturated. It is likely that the difference of frequency dependence between dry and water/oil saturation is caused by pore-fluid flow. Furthermore, the whole procedure in this paper for reflection coefficient ratio calculation can detect its dispersion under different conditions (change of pore fluid or reservoir properties) with a uniform standard. Presentation Date: Tuesday, September 17, 2019 Session Start Time: 1:50 PM Presentation Start Time: 2:40 PM Location: 305 Presentation Type: Oral
A Novel Ultrasonic Cased-Hole Imager for Enhanced Cement Evaluation
van Kuijk, Robert (Schlumberger) | Zeroug, Smaine (Schlumberger) | Froelich, Benoit (Schlumberger Riboud Product Center) | Allouche, Michael (Schlumberger) | Bose, Sandip (Schlumberger) | Miller, Douglas (Schlumberger-Doll Research) | Le Calvez, Jean-Luc (Schlumberger Riboud Product Center) | Schoepf, Virginie (Schlumberger) | Pagnin, Andrea (Schlumberger Riboud Product Center)
Abstract Current acoustic (sonic and ultrasonic) techniques for cement evaluation have proved to be limited in providing unambiguous answers to the zonal isolation issue. This is especially true in lightweight cements where they often fail to differentiate cement from mud. Also, as far as imaging of the cement sheath is concerned, ultrasonic pulse-echo tools fail to image beyond the cemented region adjacent to the casing, thus providing limited diagnosis of the annulus. A new ultrasonic imaging tool has been developed to address these limitations. The new imager combines the classical pulse-echo technique with a new ultrasonic technique that provides temporally compact echoes arising from propagation along the casing and also reflections at the cement-formation interface. Processing these signals yields unprecedented characterization of the cased hole environment in terms of the nature and acoustic velocity of the material filling the annulus between casing and formation, the material immediately behind casing, the position of the casing within the hole, and the geometrical shape of the hole. Different wells cemented with conventional and light cements were logged with the new experimental tool. The results demonstrate enhanced cement evaluation for both cement types and significant reduction in the uncertainty in making a squeeze or no-squeeze decision. Introduction Cement evaluation logging tools have been used successfully for many years to evaluate casing and cement conditions. These tools, which use sonic or ultrasonic1 techniques, are designed for conventional steel casing and cements. The sonic tools, commonly known as Cement Bond Log or CBL, operate at frequencies of about 20 kHz and measure the amplitude or the attenuation of a wave traveling along the casing. The wave loses energy mainly though shear coupling to the surrounding cement, so that well-bonded solid cement attenuates more quickly than a fluid. Due to the low frequency, the CBL logs made with these tools lack azimuthal resolution, which makes it difficult to distinguish channeling from poor cement properties.
- Geophysics > Borehole Geophysics (1.00)
- Geophysics > Seismic Surveying > Seismic Processing (0.47)
- Geophysics > Seismic Surveying > Seismic Modeling > Velocity Modeling (0.47)
High-Resolution LWD Acoustic Borehole Imaging in WBM and OBM
Ritzmann, Nicklas (Baker Hughes, a GE company) | Steinsiek, Roger (Baker Hughes, a GE company) | Dymmock, Stephen (Baker Hughes, a GE company) | Moody, Brian (Baker Hughes, a GE company) | Morris, Stephen (Baker Hughes, a GE company) | Oldervoll, Alf (Baker Hughes, a GE company) | Aarnes, Ingelinn (Baker Hughes, a GE company)
Abstract This paper introduces high-resolution acoustic borehole imaging as a new service available in logging-while-drilling (LWD). Borehole images (BHI) are an important part of the formation evaluation portfolio and contribute significantly to the understanding of subsurface structures and formation characteristics throughout the entire lifecycle of a field; from exploration, where BHIs yield detailed information about the depositional environments and the inferred depositional trends, to late field life where the accuracy of the estimated hydrocarbons in place are determined by the precision of the geological model. This information is crucial for the planning phase of new wells, determining recoverable reserves in place, analysis in production behaviour and a detailed understanding of the target formations. Acoustic images can also provide a detailed picture of the borehole shape that is used to reduce well construction and completions risk on a well and provides valuable geomechanical information. The new method is based on ultrasonic transducers that scan the borehole wall with acoustic signals, while the tool is rotating in the borehole. The tool sends a high frequency acoustic signal towards the wellbore wall and measures the travel-time and the amplitude of the returning signal. Each measurement is recorded with its azimuthal position and can therefore be used to create a borehole image. Whereas the amplitude image contains information about the scanned formation, the traveltime represents the borehole shape and can be converted into a distance when the borehole environmental conditions are known. Both images can be acquired while drilling or tripping (reaming/washing). Since the selected transducers are highly focused they can reveal small scale features such as fractures, cross-bedding and mud-cracks. The high acquisition frequency enables the tool to acquire high resolution images for almost any ROP/RPM combination and the physical acquisition method results in an independence of the used mud type. High resolution images significantly improve the understanding of reservoir architecture, presence and type of fractures or faults and are now available in WBM and OBM.
- Geology > Sedimentary Geology (0.69)
- Geology > Geological Subdiscipline > Geomechanics (0.54)
- Geology > Geological Subdiscipline > Stratigraphy (0.34)
- Geology > Rock Type > Sedimentary Rock > Clastic Rock (0.30)
- Geophysics > Seismic Surveying > Borehole Seismic Surveying (1.00)
- Geophysics > Borehole Geophysics (1.00)
Abstract In highly deviated or horizontal wells, the performance of existing flow meters for production logging is severely limited. Oil and water tend to separate and flow at different rates up the borehole. Ultrasonic flow measurement technology has been developed which can measure over a large velocity range from I mm/s to 5m/s. Ultrasonic beams projected into the surrounding medium can resolve the different velocities of the components of the flow. A prototype production logging tool for the measurement of liquid flows in horizontal or deviated wells using ultrasound has been constructed. The tool is able to measure the variation of velocity over the crosssection of the borehole in oil/water flows. Results of flow measurements in oil and water flow covering stratified to mixed flow and at different pipe inclinations are included in this paper. The tool can also provide diagnostic information relating to the identification of the flow regimes, reverse flow and the location of the oil/water/gas interfaces. The prototype production logging tool includes a fixed array of flow measurement transducers with signal processing carried out downhole. It is designed to be positioned at any point along the string. The tool has been tested in the laboratory and in the field. Introduction The Requirement. Accurate quantitative determination of the rate of the fluid moving into or out of the production zones of a reservoir is important for reservoir modelling and production planning. Flow rate data can also give indications of other operational parameters such as leaks in the borehole, or cross flow situations where fluid may be flowing out of one producing zone and into another. If problems in the borehole can be identified, and remedial actions taken, then operators can benefit from large cost savings Improvements in drilling technology has led to an increase in the number of horizontal production wells being drilled. In horizontal wells phase separation can occur along the well bore, which makes interpretation of data from production logging tools, especially flow meters, increasingly difficult. An instrument capable of measuring flows downhole would ideally be required to provide a reliable and repeatable measurement of the individual flow rates of the fluids in the borehole (oil, water and gas) with depth. Ideally, it would also identify the perforated regions from which the fluids are flowing into the well. Current Downhole Technology. Current methods of flow measurement downhole mainly involve mechanical spinners placed in the flow where the rotation rate of the spinner is related to the fluid velocity. These devices have their limitations I; one major drawback is that they do not have a predictable response in multiphase flow, especially in inclined wells or horizontal wells. In addition, the spinner rotation rate is not only dependent on fluid velocity but also fluid viscosity. Moreover the technique relies on moving mechanical parts that are prone to clogging and failure. Ultrasound for flow measurement. The limitations that current downhole flow meters have in their ability to measure flow rate accurately and reliably has led to investigations into a number of other methods and a range of development projects.
- North America > United States > Texas (0.28)
- Europe > United Kingdom (0.28)