NOVEL APPROACHES FOR COST-EFFICIENT WIRELINE WELL INTERVENTION

The slickline technology goes beyond pass decades in ensuring proper well intervention operation to operate successfully. Plenty of operations that works and operate by using the slickline technology which referring to the light load intervention that require less manpower, minimum load usage and less data requirement. . Its portability has allowed it to be cost efficient for performing these services in remote locations and on satellite platforms. In order to perform a much complicated operations via the well intervention, the option of using the slickline technology is off the hook which bring to much more manpower involvements, higher load usage and details data requirements which leads to more than one unit of wireline crew needed on board. By using more than one crew on board and others additional requirements, it will lead to the increment of cost of the operation

Structural Health Monitoring and Damage Identification of Bridges Using Triaxial Geophones and Time Series Analysis

This study uses the vibration data of two full-scale bridges, subjected to controlled damage, along the I-40 west, near downtown Knoxville, TN, to evaluate the feasibility of time series-based damage identification techniques for structural health monitoring. The vibration data was acquired for the entrance ramp to James White Parkway from I-40 westbound, and the I-40 westbound bridge over 4th Avenue, before the bridges were demolished during I-40 expansion project called Smartfix40. The vibration data was recorded using an array of triaxial geophones, highly sensitive sensors to record vibrations, in healthy and damaged conditions of the bridges. The vibration data is evaluated using linear stationary time series models to extract damage sensitive-features (DSFs) which are used to identify the condition of bridge. Two time series-based damage identification techniques are used and developed in this study. In the first technique, the vibration data is corrected for sensor transfer function suitable for given geophone type and then convolved with random values to create input for autoregressive (AR) time series models. A two-stage prediction model, combined AR and autoregressive with exogenous input (ARX), is employed to obtain DSFs. An outlier analysis method based on DSF values is used to detect the damage. The technique is evaluated using the vertical vibration data of the two bridges subjected to three controlled amounts of known damage on the steel girders. In the second technique, ARX models and sensor clustering technique is used to obtain prediction errors in healthy and damaged conditions of the bridges. DSF is defined as the ratio of the standard deviations of the prediction errors. The proposed technique is evaluated using the triaxial vibration data of the two bridges. This study also presents finite element analysis of the I-40 westbound bridge over 4th Avenue to obtain simulated vibration data for different damage levels and locations. The simulated data are then used in the ARX models and sensor clustering damage identification technique to investigate the effects of damage location and extent, efficacy of each triaxial vibration, and effect of noise on the vibration-based damage identification techniques

Wide area condition monitoring of power electric drives in wind power generation system using radiated electromagnetic fields

Electric components in numerous applications (particularly wind generation) are not straightforwardly accessible for monitoring. Therefore, the monitoring and protection through voltage/current measurement may not be dependable since the current value passes numerous segments to reach the observing element. Accordingly, finding an unusual phenomenon of a specific element is difficult. To resolve this issue, using transmitted electromagnetic field of an element for wide area condition monitoring is proposed. It is planned to diagnose and locate short-circuit in induction generator drive such as interturn, intercoil and terminal-to-turn failures. The frequency characteristics of the propagated field is then utilized for finding the short-circuit. The theoretical foundation that relate the behavior of each elements to their frequency response is analyzed and used. To utilize the derived technique for different practical circumstances, two distinctive methods are used for locating the short-circuit. As the experimental test of major fault cases could destruct the winding, the full three-dimensional finite element analysis is used in these cases and some are verified experimentally through the wide area communication. Identifying the areas of partial faults Prevents the whole winding failure prior to a massive destruction, which is costly especially for cases in inaccessible situations such as offshore wind towers

Sensors: A Key to Successful Robot-Based Assembly

Computer controlled robots offer a number of significant advantages in manufacturing and assembly tasks. These include consistent product reliability and the ability to work in harsh environments. The programmable nature of robotic automation allows the possibility of applying them to a number of tasks. In particular, significant savings can be expected in batch production, if robots can be applied to produce numbers of products successfully without plant re-tooling. Unfortunately, despite considerable progress made in robot programming [Lozano-Perez 83] [Paul 81] ;Ahmad 84] [Graver et al. 84] [Bonner & Shin 82] and in sensing [Gonzalez & Safabakhsh 82] [Fu 82] [Hall et al. 82], [Goto et al. 80], [Hirzinger & Dietrich 86], [Harmon 84], kinematics and control strategies [Whitney 85] [Luh S3] [Lee 82], a number of problems still remain unsolved before en-mass applications take place. In fact, in current applications, the specialized tooling for manufacturing a particular product may make up as much as 80% of the production line cost. In such a production line the robot is often used only as a programmable parts transfer device. Improving robots ability to sense and adapt to different products or environments so as to handle a larger variety of products without retooling is essential. It is just as important to be able to program them easily and quickly, without requiring the user to have a detailed understanding of complex robot programming languages and control schemes such as RCCL [Hayward & Paul 84], VAL-II [Shimano et al., 84], AML [Taylor et al., 83], SR3L-90 [Ahmad 84] or AL [Mujtaba & Goldman 79]. Currently there are a number of Computer Aided Design (CAD) packages available which simplify the robot programming problem. Such packages allow the automation system designer to simulate the assembly workcell which may consist of various machines and robots. The designer can then pick the motion sequences the robot has to execute in order to achieve the desired assembly task. This is done by viewing the motions on a graphical screen from different viewing angles to check for collisions and to ensure the relative positioning is correct, much the same way1 as it is done in on-line teach playback methods (see Figure 1). Off-line robot programming on CAD stations does not always lead to successful results due to two reasons: (i) The robot mechanism is inherently inaccurate due to incorrect kinematic models programmed in their control system [Wu 83] [Hayati 83] [Ahmad 87] [Whitney et ■ al. 84]. (ii) The assembly workcell model represented in the controller is not accurate. As a result parts and tools are not exactly located and their exact position may vary. This causes a predefined kinematic motion sequence program to fail, as it cannot deal with positional uncertainties. Sensors to detect real-time errors in the part and tool positions are obviously required with tailored sensor-based motion strategies to ensure assembly accomplishment. In this chapter we deal with how sensors are used to successfully ensure assembly task accomplishment. We illustrate the use of various sensors by going through an actual assembly of an oil pump. Additionally we illustrate a number of motion strategies which have been developed to deal with assembly errors. Initially, we discuss a number of sensors found in typical robotic assembly systems in Section 1. In Section 2 we discuss how and when sensors are to be used during an assembly operation. Issues relating to sensing and robust assembly systems are discussed very briefly in Section 3. Section 4 details a sensor-based robot assembly to illustrate practical applications

Medical Robotics for use in MRI Guided Endoscopy

Interventional Magnetic Resonance Imaging (MRI) is a developing field that aims to provide intra-operative MRI to a clinician to guide diagnostic or therapeutic medical procedures. MRI provides excellent soft tissue contrast at sub-millimetre resolution in both 2D and 3D without the need for ionizing radiation. Images can be acquired in near real-time for guidance purposes. Operating in the MR environment brings challenges due to the high static magnetic field, switching magnetic field gradients and RF excitation pulses. In addition high field closed bore scanners have spatial constraints that severely limit access to the patient. This thesis presents a system for MRI-guided Endoscopic Retrograde Cholangio-pancreatography (ERCP). This includes a remote actuation system that enables an MRI-compatible endoscope to be controlled whilst the patient is inside the MRI scanner, overcoming the spatial and procedural constraints imposed by the closed scanner bore. The modular system utilises non-magnetic ultrasonic motors and is designed for image-guided user-in-the-loop control. A novel miniature MRI compatible clutch has been incorporated into the design to reduce the need for multiple parallel motors. The actuation system is MRI compatible does not degrade the MR images below acceptable levels. User testing showed that the actuation system requires some degree of training but enables completion of a simulated ERCP procedure with no loss of performance. This was demonstrated using a tailored ERCP simulator and kinematic assessment tool, which was validated with users from a range of skill levels to ensure that it provides an objective measurement of endoscopic skill. Methods of tracking the endoscope in real-time using the MRI scanner are explored and presented here. Use of the MRI-guided ERCP system was shown to improve the operator’s ability to position the endoscope in an experimental environment compared with a standard fluoroscopic-guided system.Open Acces

Magnetic Position Sensor: Modeling a DC Electric Motor’s Magnetic Interference

Measuring where an object is located is an invaluable tool across many disciplines. An emerging technology utilizes the magnetic field readings of a known source to locate where the object is in space. This type of sensor is useful since the target object can be measuring without contact, such as measuring the position of a piston through a cylinder wall. However, many problems arise since magnetic fields combine and distort when multiple fields are present. The magnetic disturbance has not been characterized for magnetic sensors in close proximity to DC electric motors. By modeling the known magnetic field source and gathering data of the distorted signal, a model of the DC motor field can be developed and later filtered out of the raw signal. In this thesis, a model for the magnetic field of a dipole magnet combined with that of a DC motor is explored in order to filter out the magnetic disturbances and regain the dipole field necessary for accurate position measurements. A characteristic DC magnetic field offset along with oscillations of the measured field has been shown to be attributed to the DC electric motor’s influence and has been modeled

Electromagnetic measurements of steel phase transformations

This thesis describes the development of electromagnetic sensors to measure the phase transformation in steel as it cools from the hot austenite phase to colder ferritic based phases. The work initially involved investigating a variety of sensing configurations including ac excited coils, C-core arrangements and the adaptation of commercial eddy current proximity sensors. Finally, two prototype designs were built and tested on a hot strip mill. The first of these, the T-meter was based on a C-shaped permanent magnet with a Gaussmeter measuring the magnetic field at the pole ends. Laboratory tests indicated that it could reliably detect the onset of transformation. However, the sensor was sensitive to both the steel properties and the position of the steel. To overcome this, an eddy current sensor was incorporated into the final measurement head. The instrument gave results which were consistent with material property variations, provided the lift off variations were below 3Hz. The results indicated that for a grade 1916 carbon- manganese steel, the signal variation was reduced from 37% to 2%, and the resulting output was related to the steel property variations. The second of these prototypes was based on a dc electromagnetic E-core, with Hall probes in each of the three poles. 'Cold' calibration tests were used to decouple the steel and the lift-off. The results indicated that there was an error of 3-4% ferrite/mm at high ferrite fractions. At lower fractions the error was higher due to the instrument’s insensitivity to lift-off. The resulting output again showed a relationship with varying steel strip properties. ft was also shown that a finite element model could be calibrated to experimental results for a simple C-core geometry such that the output was sensitive to 0.2% of the range. This is required to simulate the sensor to resolve to 10% ferrite

NOVEL APPROACHES FOR COST-EFFICIENT WIRELINE WELL INTERVENTION

The slickline technology goes beyond pass decades in ensuring proper well intervention operation to operate successfully. Plenty of operations that works and operate by using the slickline technology which referring to the light load intervention that require less manpower, minimum load usage and less data requirement. . Its portability has allowed it to be cost efficient for performing these services in remote locations and on satellite platforms. In order to perform a much complicated operations via the well intervention, the option of using the slickline technology is off the hook which bring to much more manpower involvements, higher load usage and details data requirements which leads to more than one unit of wireline crew needed on board. By using more than one crew on board and others additional requirements, it will lead to the increment of cost of the operation

Casing structural integrity and failure modes in a range of well types: a review.

This paper focus on factors attributing to casing failure, their failure mechanism and the resulting failure mode. The casing is a critical component in a well and the main mechanical structural barrier element that provide conduits and avenue for oil and gas production over the well lifecycle and beyond. The casings are normally subjected to material degradation, varying local loads, induced stresses during stimulation, natural fractures, slip and shear during their installation and operation leading to different kinds of casing failure modes. The review paper also covers recent developments in casing integrity assessment techniques and their respective limitations. The taxonomy of the major causes and cases of casing failure in different well types is covered. In addition, an overview of casing trend utilisation and failure mix by grades is provided. The trend of casing utilisation in different wells examined show deep-water and shale gas horizontal wells employing higher tensile grades (P110 & Q125) due to their characteristics. Additionally, this review presents casing failure mixed by grades, with P110 recording the highest failure cases owing to its stiffness, high application in injection wells, shale gas, deep-water and high temperature and high temperature (HPHT) wells with high failure probability. A summary of existing tools used for the assessment of well integrity issues and their respective limitations is provided and conclusions drawn

Detection, Diagnosis and Prognosis: Contribution to the energy challenge: Proceedings of the Meeting of the Mechanical Failures Prevention Group

The contribution of failure detection, diagnosis and prognosis to the energy challenge is discussed. Areas of special emphasis included energy management, techniques for failure detection in energy related systems, improved prognostic techniques for energy related systems and opportunities for detection, diagnosis and prognosis in the energy field