The Effect of Casing Ovality on Fracture Plug Sealing Element Performance

Sealing element of frac plugs have crucial roles to isolate target zones of the well in hydraulic fracturing. If the zonal isolation by the sealing element is not adequate, it can result in erosion of the casing. The effect of casing deformation on sealing performance of sealing element is not well researched or understood. To study the effect of casing deformation on sealing performance, finite element analysis of sealing element in deformed casing was conducted in this study to assess the effect of casing deformation on sealing performance. In this study, finite element simulation of a full frac plug with three different casings ovalities (0%, 2%, and 5%) and three different sealing element designs (O-ring type, short type, traditional long type) was conducted to evaluate deformation behavior and sealing performance of the sealing elements in the deformed casings. Compression pressure on the casing by sealing element after the plug is set in the casing and the risk of leak were discussed and compared for each design. In the casing with 0% ovality, all the sealing element designs established contact with inner surface of the casing when setting force is applied. However, for the O-ring type design, area in contact with the casing was small and it may result in leak and erosion in the actual well if there is a small dent or deformation on the casing. When there is deformation and ovality in the casing, the minor ID has a smaller ID and a major ID has a larger ID compared to nominal ID of the casing. In the casing with 2% and 5% ovality, neither O-ring type nor short type sealing element could contact the major ID of the casing and there was a gap between inner surface of the casing and the sealing element. This gap can cause erosion of the frac plugs and casing when fluid passes through the gap. In contrast, traditional long type sealing element contacted both major and minor IDs of the casing and no gap was observed. This result indicates that there is a potential risk of insufficient isolation of target zones and erosion of casings in actual well condition if frac plugs with small sealing element is used. Since there are various types of frac plugs with different sealing element designs, this study helps to select proper frac plugs with good sealing element design and mitigate the risk of erosion of casings and plugs.

Modeling of hydraulic fracturing in ultra-low permeability formations: The role of pore fluid cavitation

North American market with growing trend of unconventional shale gas reservoirs has warranted rapid development in hydraulic fracturing technology. The long horizontal wells are completed using multi zone plug and perf method that requires multiple zones to be fracked optimally to minimize nonproductive time (NPT). Frac plugs plays vital role in hydraulic fracturing in isolating the multiple zones of the wellbore for operations up to 10,000 psi pressure and 250°F temperature. In this paper advanced computational analysis is conducted to optimize the composite frac plug design for successful operations. Comprehensive laboratory testing is conducted, and digital solutions are compared against the test data to validate the new composite frac plug design. The traditional frac plug design requires effort in milling out the plug and further flushing out the cuttings that adds to the operational time. An alternative is to utilize composite plug that allows ease in milling and reduction in cuttings than traditional design. Numerical analysis is conducted to evaluate the feasibility of composite frac plug design utilizing three-dimensional finite element analysis (FEA) simulations to predict the slip holding capacity. Extensive laboratory testing is conducted for the composite frac plug to validate the digital analysis results. FEA simulations are performed for different configurations of frac plug design by varying number of slip buttons and composite material for slips. FEA results underscored best possible slip button configuration that can successfully work at desired pressure and temperature. Laboratory testing corroborated with digital analysis results and indicated as efficient design that reduced NPT and ensured successful hydraulic fracturing operations. This work assisted in optimizing design quickly and reduced time and cost associated with laboratory testing. This work elucidates use of digital solutions along with laboratory testing for design optimization of composite frac plug. This frac plug has been successfully utilized for several jobs in Marcellus shale play.

Tong type mechanisms have been used in industry to lift many types of loads where the clamping force generated in the tong mechanism along with friction and indentation prevent the load from slipping out of the tongs. There are several types of tong designs, lifted load geometries and levels of hardness resulting in numerous variations of clamping forces and grip/load geometries which makes the design of the tong mechanisms extremely challenging. The purpose of this work is to develop a Finite Element Analysis (FEA) simulation of the grip behavior under the multitude of variables that occur in the practical use of tongs to lift loads. Variables include tong mechanism geometry and load size resulting in different tong grip angles relative to the lifted load and resulting clamping force. Other variables include the hardness of the lifted load and the style of grips. With an FEA simulation methodology developed, a multitude of different variables affecting tong effectiveness can be evaluated. To verify the FEA simulation, a series of actual laboratory tests were conducted. These tests measured the load slip force as a function of clamping force, grip geometry, and load and grip hardness. Also measured was the grip indentation into the load and deflection versus slip force. A comparison of the results of the FEA simulation and the experimental tests is given. In some cases the correlation is good and in others more work is needed. A plan for further improvement of the FEA simulation technique is given.

A mechanical loading technique for reliability assessment of flip-chip BGA interconnects was developed as a rapid alternative to traditional temperature cycling methods. Sinusoidal shear loading was used to accelerate fatigue cracking within the solder interconnects of a chip-scale test while shear force and circuit resistance were monitored in situ with resistance increases of 30% considered the point of failure in tested devices. Test parameters were selected and optimized by leveraging finite element analysis (FEA) simulations of mechanical cycling and temperature cycling to select shear force, frequency, and test duration such that the inelastic strain energy density (plastic work density per cycle) achieved in the mechanical cycling test agreed closely with that predicted by FEA for more traditional temperature cycling tests. These FEA simulations were conducted using Anand's constitutive material model to make accurate predictions of the inelastic strain energy density, accumulation per cycle, and therefore fatigue lifetimes of chip-scale devices containing Sn63/Pb37 solder interconnects using energy based fatigue models. With optimized test parameters, this mechanical loading method was able to induce the same inelastic strain energy density into the flip-chip interconnects as traditional temperature cycling (as predicted by FEA simulations). By monitoring resistance in situ, determinations were made as to the affects this amount of damage had on the performance and reliability of the studied device. Failure localization and crack visualization was achieved using MicroCT imaging to study interconnect cross-sections. Thus, the total amount of damage predicted for a thermal cycling test by FEA simulation can be generated in flip-chip interconnects at a much higher rate by utilizing the mechanical loading technique, reducing overall test time duration and associated testing costs. Assessments can then be made as to the impact the fatigue damage has had on the electrical performance of the device. Additionally, inexpensive mechanically analogous Si test vehicles were used to make predictions about the reliability of more expensive SiC devices using this mechanical cycling technique.

The evaluation of torque transmission capacity for centrifugal compressor impellers can be complicated due to the unique geometric characteristics of the impeller wheels. The existing analytical method for keyless interference fit only works for simple geometries like cylinders. In general, finite element analysis (FEA) simulations are needed to obtain the torque capacity of centrifugal compressor impellers for a specific setup (rotational speed/geometric scale/interference fit rate). However, when the torque capacity needs to be evaluated in multiple working conditions, the time cost of FEA simulations can be an issue if each case is evaluated individually. In this study, a methodology is provided to obtain the torque capacity of centrifugal compressor impellers instantly for any given working conditions with pre-generated data from FEA simulations, especially with scaling of the interference fit rate. If the interference fit rate (ratio of interference fit to diameter) is kept the same as the pre-generated FEA data, the results can be directly scaled by rotational speed and geometric scale factor which is covered by the existing method and not the focus of this study. If the given interference fit rate is different than the setup in pre-generated FEA simulations, then an engineering approximation is used to calculate the contact pressure and torque capacity based on impeller bore deformation. In this methodology, the FEA simulations are performed before knowing the working conditions which can be very useful in many time-sensitive industrial applications.

Drilling specialty tools and accessories are often machined with large Inside Diameters (IDs) so that the necessary electronic packages can fit within the component. As the ID of the component increases, the wall thickness of the pin connection is reduced. It has been established that the machining of a Stress Relief Groove (SRG) on the pin connection with a standard-sized ID will greatly improve the fatigue performance of that connection. However, no such consensus has been reached regarding the machining of SRGs on the pin connections of these special-purpose tools with large IDs. The common concern is that the wall thickness of the pin connection has been reduced so much by the large ID that the machining of a SRG would drastically deteriorate the performance of the connection. This paper addresses that concern by providing in-depth analysis of various API connection sizes tested over a broad range of IDs. Finite Element Analysis (FEA) was used to quantify the difference in fatigue life between connections with stress relief features versus without stress relief features. Additionally, calculations were performed to understand the reduction in the capacity of the connection that results due to machining stress relief features. This paper gives the comparative fatigue life for each of the connections modeled where the API recommended Make-Up Torque (MUT) is adjusted to compensate for the increasing ID of the connection. In every case, the benefits of machining SRGs on large ID connections are significant. Allowing larger IDs in connections where SRGs are required will bring the technical benefit of allowing larger electronics packages to fit within the bore and increased hydraulic performance, among other benefits. Additionally, the drawbacks to SRGs are considered and quantified whenever possible. Possible solutions to these drawbacks are proposed as a way to lessen their effects so the full benefit of cutting the SRGs can be realized. In total, by looking at the potential gain in fatigue life against the trade off in lost capacity, this paper provides operators with the ability to determine the suitability of stress relief features on their components with large IDs. For those connections where a SRG is required, this paper provides guidance as to the connection's performance at various large IDs.

Fostering creative design within the curriculum in engineering and engineering technology is often both daunting and time-consuming. This paper describes the efforts in the Engineering Technology Department at Western Washington University to foster creative design within the curriculum by using TRIZ, parametric modeling, finite element analysis (FEA) simulation, and rapid prototyping. First, the paper describes how assessment enabled the faculty to create a collaborative environment. Second, the introduction to the design process using parametric modeling and 3D printing rapid prototyping technology during the freshman experience is described. Next, the paper describes TRIZ, the Theory of Inventive Problem Solving, in detail and how that philosophy can be used within an academic setting to foster both creativity and efficient product and process design. Then the paper details how TRIZ, FEA simulation and Fused Deposition Modeling (FDM) are actually used in the senior year. The paper concludes with the results of the department's assessment efforts and plans for future.

To evaluate the risk points and levels of display panels caused by manufacturing variations, a numerous number of simulations are required. Traditional reliability assessment method, such as Finite Element Analysis (FEA) are time‐consuming for this purpose. Therefore, this study has developed an AI‐based model that can predict panel defects, enabling efficient simulations for numerous scattered cases within a short timeframe, serving as a practical alternative to FEA. Initially, structural analysis are conducted following the reliability evaluation technique through conventional FEA simulations. The likelihood and location of defects are determined by examining strain contours derived from the FEA results. In the panel layout, manufacturing tolerances that may occur include critical dimension (CD), overlay, thickness, and taper angle. To secure data, all manufacturing tolerances are assumed to randomly occur in each layer, and 100 cases of panel structures are modeled and analyzed. The solving time for a FEA simulation takes about 3 hours. The finite element (FE) model used in FEA simulation is preprocessed to be input data into the neural network model. And strain contours derived from FEA simulation results are preprocessed to be output data into the neural network model. We developed and optimized an AI model capable of taking input from the preprocessed data. Input and output data are highdimensional, and a fully convolutional network (FCN) model is employed to handle these data. After completing the training of the AI model, we input a panel with a new structure into the AI model and predicted the strain contour. We compared the predicted contours with the ground truth strain contours by performing FEA on a panel of the same structure. The results revealed an inference accuracy of 92.02% for the AI model, with a prediction time of around 17 seconds. This indicates a significant time‐saving effect of 99.84% compared to FEA. It is expected that a faster structural reliability assessment will be conducted through this method.

The Edwards SAPIENTM transcatheter heart valve is designed for heart-valve replacement in patients with severe aortic stenosis without open-heart surgery. Physiological finite element analysis (FEA) has been performed to provide an assessment of the fracture and fatigue resistance of the device during deployment and operation. Experimental validation is an essential step in establishing the credibility of computational modeling and simulation [1,2]. The present study validates FEA frame models by comparing the crimping behavior of the FEA models with the results of crimping experiments. FEA models for the Edwards SAPIENTM transcatheter-heart-valve frames were created to assess the structural integrity and durability of the frame, in conjunction with a number of accelerated reliability tests. When a SAPIENTM valve is prepared for delivery, the valve is reduced in diameter onto a delivery catheter using a radial force fixture called a “crimper”. During crimping, the frame deforms elastically at the beginning of crimping, and later, the struts experience large displacements and substantial plastic deformation to achieve the desired diameter reduction. This crimping step includes all the representative deformation modes encountered during the full physiological FEA simulation. Therefore, a rigorous physical crimping experiment was developed to validate the FEA models, encompassing the full range of elastic and plastic deformation experienced during the physiological simulations. Specifically, crimping experiments were conducted using a radial force test system to compare the measured structural response of the frame to an FEA simulation. Figure 1Fig. 1Configuration of the radial force test system shows the radial force test system (MSI Radial Force tester model RX650). The results of the experiment were then compared with the predictions of the FEA models.Two FEA models of SAPIENTM valve frames were constructed using abaqus/standard [3]. These two frame models included representative design conditions in the simulation of the crimping process. The dimensional range of these models encompassed the dimensions of the physical test specimens: one at the low end and the other at the high end. After simulation, the resultant force-diameter curves were extracted from the FEA output database. Crimping experiments were performed using actual SAPIENTM valve frames as the test specimens. The radial force tester progressively reduced the diameter of each frame specimen by applying a uniform radial displacement through an array of 12 radial displacement elements [4]. The reaction force at each element was measured by instrumentation integral to the radial force test device. The radial force was continuously measured along with the outside diameter of the frame during the crimping process. After the crimp test, the resultant force-diameter curves were extracted and compared with the resultant force-diameter curves from FEA. The test system compliance was measured to compensate for the elastic deformation of the loading mechanism.The force-diameter curve defines the structural response of the frame over the complete crimping cycle. Qualitatively, by plotting the curves on the same axes, the curves of the FEA can be seen to agree well with the curves from the physical experiments (Fig. 2). Quantitatively, the curves can be compared using parameters such as radial strength, radial stiffness, and average crimping force. These parameters represent important crimping attributes and span the complete range of elastic and plastic deformation of the frame during the crimping process. A linear regression was performed for each parameter using the simulation results and the experimental data. Figure 3 shows an example of radial strength comparison for the experimental and FEA data. The radial strength represents the force at which plastic-frame deformation occurs. All experimental data points fall within 5% of the linear relationship established from the FEA simulation predictions. Validating a simulation model also aids in assuring the expected in vivo behavior of the implant. The adequacy of the radial strength is evaluated in a verified model and is confirmed clinically. Wilson et al. [5] have demonstrated the SAPIENTM and SAPIEN XTTM design success and have reported 98% circularity upon implantation.Finite element analyses of SAPIENTM valve frames were conducted to simulate the crimping process. The analogous crimping test was performed on SAPIENTM frames using a radial force test system. The force-diameter curves from FEA agree well with those from the physical experiments, capturing the important transition points and following similar slopes. Furthermore, the FEA simulation results are within 5% of the physical experiments for all three important frame characteristic parameters (radial strength, radial stiffness, and average crimping force). This good agreement validates the FEA models for the Edwards SAPIENTM transcatheter heart valve frames and demonstrates high credibility for their use in stress analyses and fatigue life analysis.

Finite Element Analysis (FEA) simulation results of sheet metal forming processes are highly sensitive to changes in component geometry, as any alteration requires a complete re-computation of the forming process. Surrogate models, trained on FEA simulation data, offer a promising alternative by providing faster, approximated solutions that mitigate these disadvantages. While being computationally efficient, surrogate models also offer other advantages like differentiability, which is crucial for optimization tasks. However, the effective processing of FEA simulation data for training data-driven surrogate models remains challenging due to their complexity and size. Existing methods often rely on low-order data such as depth images exported from FEA simulations, limiting the surrogate models’ area of application. In contrast, data like 3D point clouds extracted from the FEA mesh, are more general and extensible to complex areas. Additionally, they present opportunities for bridging the Sim2Real gap by fine-tuning the model using transfer learning with point cloud data obtained from physical sensors. This paper introduces a novel approach using 3D point cloud data from FEA forming simulations to train surrogate models. In this paper we demonstrate the effectiveness of this method based on a two stage sheet metal forming process involving deep-drawing and trimming of a box-shaped component, with the goal of predicting the springback. Using machine learning architectures such as PointNet++ and Dynamic Graph Convolutional Neural Networks, we demonstrate that 3D geometric representations not only capture problem complexity more generally than 2D images but also achieve the same results as 2D state-of-the-art surrogate models.

Recently, piezoelectric materials have received remarkable attention in marine applications for energy harvesting from the ocean, which is a harsh environment with powerful and impactful waves and currents. However, to the best of the authors’ knowledge, although there are various designs of piezoelectric energy harvesters for marine applications, piezoelectric materials have not been employed for sensory and measurement applications in marine environment. In the present research, a drifter-based piezoelectric sensor is proposed to measure ocean waves’ height and period. To analyze the motion principle and the working performance of the proposed drifter-based piezoelectric sensor, a dynamic model was developed. The developed dynamic model investigated the system’s response to an input of ocean waves and provides design insights into the geometrical and material parameters. Next, finite element analysis (FEA) simulations using the commercial software COMSOL-Multiphysics were carried out with the help of a coupled physics analysis of Solid Mechanics and Electrostatics Modules to achieve the output voltages. An experimental prototype was fabricated and tested to validate the results of the dynamic model and the FEA simulation. A slider-crank mechanism was used to mimic ocean waves throughout the experiment, and the results showed a close match between the proposed dynamic modeling, FEA simulations, and experimental testing. In the end, a short discussion is devoted to interpreting the output results, comparing the results of the simulations with those of the experimental testing, sensor’s resolution, and the self-powering functionality of the proposed drifter-based piezoelectric sensor.

Finite element analysis (FEA) simulation has been performed to evaluate the scaling of the nanoelectromechanical nonvolatile memory cell. FEA simulation predicted program/erase voltage and also hysteresis voltage more accurate than the analytical modeling in our previous work. It is because FEA simulation reflects the actual memory cell structure and includes nonlinear effects such as beam-stretching effect. Additionally, in the FEA simulation, shear strain has been considered for the accurate evaluation of beam deformation.

This paper proposes using Finite Element Analysis (FEA) simulations to optimize the design structure for low-frequency Magnetically Shielded Rooms (MSRs). In constructing a multi-layer MSR, the different characteristics of the material and laminated structure will bring different levels of magnetic Shielding Effectiveness (SE). The theoretical SE of an MSR can be determined quickly. By using the method used in this paper, the ideal laminated material structure can be found without increasing the MSR construction cost. According to the simulation results and the actual MSR measurement results we built, the optimized MSR design structure can improve the SE by 13 dB. In the area where the external measurement magnetic field is 37 820 nT, the magnetic field in the MSR is as low as 28 nT, and the SE of the MSR is higher than 57.3 dB. The method proposed by this research can provide the theoretical basis for optimal design structure and the FEA simulation method for engineering practice, which can effectively improve the SE of shielded rooms and save the construction cost. The FEA simulations used in this paper can be obtained from the following URL: https://github.com/YuukiAsuna/-Finite-element-simulation-of-material-lamination-sequence.

Steam injection is a fundamental method for enhanced oil recovery (EOR) wherein the wells are drilled and steam is injected to heat the crude oil in the formation to help reduce viscosity and improve oil recovery. The best practices for zonal isolation in the Baghewala field in India are discussed in detail. For desired zonal isolation, cement should maintain long-term stability once placed. Pressure and temperature changes can cause failure within the set cement. An effective annular seal designed in these wells will be exposed to high temperature, cyclic stresses, and potentially corrosive environments caused by the injection of high-temperature steam into the wellbore. The design stage should go beyond cement placement, compressive strength, and gas-migration prevention. The solution is rooted in the synergy between diagnostic tools and engineered cement systems. Such design methodology was developed to address the challenge of the loss of zonal isolation caused by changes in the wellbore that can stress the cement sheath and cause destabilization at any point during the life of the well. Specific to the cyclic steam injection in the Baghewala field, a cement system was designed to address the following challenges: Achieving cement returns to surface without fallbackHelping ensure the cement system is thermally stable at the maximum expected temperature (i.e., no strength retrogression, radial cracking, debonding, etc.)Achieving a good cement bond throughout the open and cased holesHelping prevent wellhead growth during steam injectionEncountering different types of formations (halite, anhydrite, sand, and carbonate) in this fractured reservoirUsing a cement slurry designed to avoid strength retrogression of set cement during exposure to high-temperature injection Proprietary 2D hydraulics, finite element analysis (FEA), and 3D displacement simulators are analytical tools designed for simulations or investigative modeling to simulate fluid properties and slurry placement during operations. Additionally, they help reduce the need for costly remediation and positively affect the long-term cement sheath integrity by assessing and addressing issues before they become problematic. More than 10 wells were successfully constructed with no issues reported during/after cyclic steam injections, which is endorsed by excellent cement bond logs. This helped minimize multiple potential risks and ultimately maximize production. The cement design technology associated with FEA simulations and analysis provides the ability of the set cement to expand and contract in sync with the well's fluctuating temperature, reducing stress on the cement sheath. This occurs because these cement systems have approximately the same thermal expansion properties as the steel casing. Unlike conventional cement, particles can expand and contract thermally, thus reducing cement-sheath stress six times more than conventional systems.