Rubber Cylinder Research Articles

Technical Status and Development Trends of Difficult Throttles Treatment Technology in Gas Wells

Abstract In order to promote the development of treatment technology for difficult throttles in gas wells and assist in solving the problem of gas well shutdown caused by the failure of difficult throttle treatment, this paper delves into the structural principles of preset throttles and slip-type throttles, introducing various types such as preset wire deployment and fishable throttles, preset non-wire deployment and fishable throttles, mechanical slip-type throttles, and electric throttles. It systematically analyzes the difficulties in retrieving difficult throttles, including wire breakage, fishing head breakage, deformation and breakage of slips, eccentric fishing head, non-release of inflated rubber cylinder, jamming, sand burial, scaling, fluid accumulation, falling objects underground, tubing deformation, and complex production tubing strings. Furthermore, it sequentially introduces weighted steel wire fishing treatment, coiled tubing fishing treatment technology, milling and fishing stuck throttles treatment, snubbing operation treatment technology, and well killing and workover treatment technology, which encompass punching holes in the tubing treatment technology, tubing cutting technology under pressure and sand flushing technology. The shortcomings of each treatment technique are also highlighted. Taking into account the current challenges faced in the treatment of difficult throttles, such as high cost and low efficiency in low-pressure gas wells, poor technical adaptability, and high risk of operational failure, it is pointed out that future difficult throttle processing technology should focus on two key directions. Firstly, it should aim for non-well-killing and low-cost development. Secondly, it should strive to reduce the occurrence and treatment difficulty of difficult throttles from the source design. And it provides technical references and ideas for the design of the next generation throttles.

Application Research of Bridge Plug Packer Rubber Tube Ablation Technology in Gas Storage

In the production process of oil and gas fields, for old wells, sealed wells, etc., if the bridge plug or packer is inserted into the well for a long time, the sealing cylinder will harden under the high-temperature and high-pressure environment of the wellbore. The sealing cylinder cannot contract normally and tightly adhere to the inner wall of the casing. During the tool unsealing and lifting process, impurities such as scale and rust on the casing wall will be scraped off and continuously accumulated, ultimately causing the bridge plug or packer to jam and unable to successfully complete the tool unsealing and salvage. During construction, the method of repeatedly moving the pipe column and suspending it is usually used for unblocking, and nitrogen gas lifting and lowering liquid construction is added, but the results are not ideal. During the process of moving the tubing, fatigue damage to the tubing increases the risk of well control and complex wellbore conditions, while significantly prolonging the construction period and increasing construction costs. Therefore, it is urgent to develop a degradation and ablation agent for hardened rubber parts, which can degrade and soften the hardened rubber cylinder, ensuring the smooth operation of tool salvage. Rubber products obtained through normal cross-linking reactions exhibit a regular grid like molecular structure, which can resist the invasion of organic molecules and oxidant molecules. This is also the reason why rubber products are resistant to organic solvents and acid-base corrosion. The experiment proposes to use a combination of "dissolution" and "destruction" methods to soften and melt the excessively cross-linked and hardened rubber cylinder.

Mechanical comprehensive evaluation model and sealing performance research of rubber cylinder at large pressure and high temperature

Mechanical comprehensive evaluation model and sealing performance research of rubber cylinder at large pressure and high temperature

Establishment of constitutive model and simulation study on sealing performance of special-shaped rubber cylinder for inner packer in deepwater pipeline

It’s important to improve the sealing performance of the inner packer in deepwater pipelines, which is an emergency sealing and oil control equipment. The deformation characteristics and sealing stress conditions of the packer’s sealant cylinder are analyzed, and the hyperelastic constitutive model is determined based on uniaxial tensile experiments. The effective contact stress and effective contact range between the rubber cylinder and the pipe wall are the main parameters for evaluating the sealing performance. Through simulation, it was found that the rubber cylinder on the force application side plays a major sealing role, and severe stress can lead to shoulder protrusions. The location of fatigue damage on the rubber cylinder’s shoulder is consistent with the sea trial. Therefore, special-shaped rubber cylinders with different structures are designed to address the shoulder protrusion. The simulation shows that the sealing performance of the right-angled trapezoidal double-layer rubber cylinder with force applied on the slope side(S-RARC) is significantly better than the original rubber cylinder(ORC), and it does not produce shoulder protrusions.

Exploring Wave–Vegetation Interaction at Stem Scale: Analysis of the Coupled Flow–Structure Interactions Using the SPH-Based DualSPHysics Code and the FEA Module of Chrono

Aquatic vegetation in the littoral zone plays a crucial role in attenuating wave energy and protecting coastal communities from hazardous events. This study contributes to the development of numerical models aimed at designing nature-based coastal defense systems. Specifically, a novel numerical application for simulating wave–vegetation interactions at the stem scale is presented. The numerical model employed, DualSPHysics, couples the meshfree Smoothed Particle Hydrodynamics (SPH) fluid solver with a structural solver to accurately capture the two-way interactions between waves and flexible vegetation. The proposed numerical model is validated against experimental data involving a submerged rubber cylinder representing an individual vegetation stem, subjected to regular waves. The results demonstrate excellent agreement in hydrodynamics, force transfer, and the swaying motion of the flexible cylinder. Importantly, the approach explicitly captures energy transfer between the fluid environment and the individual stem. The numerical results indicate persistent turbulent flow along the vegetation stem, even when its swaying speed matches that of the surrounding environment. This reveals the presence of vortex shedding and energy dissipation, which challenges the concept of passive swaying in flexible aquatic vegetation.

Simulating the sealing performance of the double rubber cylinder assembly in an intelligent pipeline isolation tool

Intelligent pipeline isolation tools (IPITs) are widely used for pipeline maintenance and repair. Therefore, authors mainly study the sealing performance of double rubber cylinder IPIT. This study first analyzed the material and geometric properties of the rubber cylinders in an IPIT to establish a numerical finite element model of cylinder mechanical behavior. The influence of the cylinder hardness, camber angle, and short-side length on the sealing performance was subsequently investigated by systematically altering the established model according to the control variable method. Next, the response surface methodology was employed to evaluate the change in model sealing performance according to the coupled action of multiple rubber cylinder parameters and identify their optimal values.

Effectiveness of displacement compensation units for integral abutment bridges

Integral abutment bridges (IAB) have become increasingly popular in the past few decades due to their design simplicity. UK design rules limit the length of IABs to 60 m, due to the issues associated with thermal strains, settlement, and pressure build-up behind the abutment. A cyclic loading test, representing seasonal thermal fluctuations, was conducted on a 1/12 scaled-down retaining wall of a conventional full-height IAB. The test was then repeated with the inclusion of displacement compensation units (DCU) in the form of conical disc springs (CDS) and hollow rubber cylinders (HRC), which operate in a pre-deformed shape. The results show some remarkable improvements in the IAB performance with DCUs. The soil backfill pressure was reduced to 30% and 47% with CDSs and HRCs, respectively. Furthermore, no settlement was observed, as compared to the conventional IAB test which recorded a 20 mm settlement after 100 cycles. Non-linearity in the force-deflection behaviour of DCUs enables expansion and contraction of the deck to be accommodated with minimal fluctuation of backfill pressure. Finally, a finite element (FE) model of an HRC applied with two temperatures has been analysed and compared with the IAB wall test, which suggests that both analyses showed some correlation.

Research on dynamic sealing performance of sealer structure under the influence of temperature

Affected by the extreme environment of high temperature and high pressure downhole, the mechanical behavior of the sealer rubber sleeve undergoes significant changes during service, leading to a sharp decline in the mechanical properties of the rubber material within the high-temperature environment. To address the issue of seal failure in the sealer rubber barrel under high-temperature loads, experimental investigations were conducted to analyze the compression properties of rubber materials at various temperatures. The constitutive parameters of the rubber were then fitted using the Reduce-Polynomial model. Subsequently, a finite element model was employed to study the sealing performance and mechanical response of the three-compartment rubber-tube structure sealer at different temperatures. The findings demonstrate that temperature fluctuations have a substantial impact on the sealing performance and bearing strength of the sealer. Consequently, this research holds crucial guiding significance for the structural design of the sealer rubber cylinder under high-temperature conditions.

Fundamental experiments of bird-strike, and derivation of empirical equations for damage

Bird-strikes against aircrafts and against wind generator blades are urgent issues. In addition, their effects on flying cars are beginning to be highlighted. As it is assumed that birds vary in size, impact experiments using projectiles that take into account the characteristics and shapes of birds are unavoidable for material screening during their development stage. However, such kinds of experiments have not been sufficiently carried out. In this study, to elucidate the effect of the shape and the properties of projectiles on the impact behaviors of CFRPs, a fundamental study was done by three-dimensional measurement using various projectiles including a gelatin cylinder, rubber cylinders and rubber spheres for mainly two types of CFRPs with different laminate configurations (stackings) at the impact velocities below 370 m/s. The difference in the elapsed-time dependence of the largest displacement of deformation (vertex displacement) due to the stackings was slight, but the deformation behavior changed depending on the shape of the projectile, i.e. especially, large deformable or large-diameter projectiles resulted in a wider bottom area. To determine the penetration and delamination, the contacted area, related to the projectile’s diameter, should be considered. The deformation of CFRPs by a spherical projectile just after the impact could be described by a quartic/quintic-function and after a certain period of time (30–50 μs) by a quadratic-function. Empirical equations for the kinetic energies of penetration and delamination for aircraft structural grade CFRP were proposed.

Research on key technology of packer rubber barrel for integrated fracturing and completion of gas well

The staged and layered fracturing technology plays an important role in unconventional tight reservoirs. And the gas well fracturing and completion integration is the core component to realize the fracturing and completion integration process, which can realize the integration of acid fracturing and later drainage production so as to reduce the secondary pollution to the reservoir. The packer rubber barrel’s performance directly affects the long-term effective sealing reliability itself in high temperature and high pressure environment. In this paper, the constitutive model of rubber tested from high temperature and high pressure curing kettle to simulate the high-temperature and highly corrosive environment of the formation. On this basis, the structure of the packer’s shoulder and the protective ring of the rubber barrels are optimized through Abaqus to reduce its stress failure under high pressure, and its corrosion resistance is improved by improving the rubber material. The sealing performance of the packer rubber cylinder under the field underground requirements is tested through laboratory evaluation test and field test. The results show that the protective ring and rubber tube shoulder at 30° angle are a reasonable result of optimization, and the optimized packer can meet the requirements of 154 °C temperature resistance, 79 MPa pressure bearing and long-term effective sealing. The successful development of packer rubber and the integrated analysis process can lay a solid foundation for the realization of integrated fracturing and completion process for exploration and development of deep volcanic or carbonate reservoirs.

Rubber genocide in Joyce and Beckett: from Roger Casement’s Congo to Vél d’Hiv and Auschwitz

This essay argues that the political imaginations of both James Joyce and Samuel Beckett were shaped by their familiarity with Roger Casement’s official reports on the catastrophic atrocities that accompanied rubber extraction in the Congo Free State (1904) and Putumayo Amazon (1912). Joyce recognized the depopulation in the Congo as of a structural pattern with Ireland’s long history under British imperialism. But in Dubliners, Joyce clothes characters in consumer rubber to ask whether pursuing much-needed Irish autonomy through economic liberalism also risks backsliding into structural racism. Beckett extends the ethics of Joyce’s racial critique to Le dépeupleur (The Lost Ones), in which novella a “little people” are housed in a rubber cylinder. Here an anthropological narrator describes with French colonial tropes and humanist education why this entire population should die. Beckett’s story borrows elements from Casement and Joyce. But it also takes structure and detail from Vél d’Hiv and Drancy, Parisian holding camps for rounded-up Jews, who were then transported to Auschwitz. (Exterminatory labour from Auschwitz III-Monowitz built a factory to produce synthetic rubber, still in use today.) Beckett reworks Joyce’s caution to confront French society with its complicity in Nazi genocide, an evasion of responsibility that he suggests was prepared in colonial racism and the evisceration of intention in humanist and liberal logics. This essay shows, then, an Irish modernist tradition grappling with an ethical basis for understanding comparative genocide.

Structural Design and Sealing Performance Analysis of a Nanofluidic Self-Heating Unsealing Rubber Cylinder

As a crucial component for temporary blocking of layer segments in the segmental fracturing process, bridge plugs are difficult to unseal by conventional methods and may cause major downhole accidents if not handled properly. In this paper, a nanofluidic self-heating unsealing rubber cylinder is designed, which is equipped with a nanofluidic self-heating unsealing sandwich inside the conventional rubber cylinder, consisting of a nanofluidic system and an annular flexible heater. When unsealing, the nanofluidic self-heating unsealing sandwich is heated by the annular flexible heater, and the nanofluidic system can help the bridge plug rubber cylinder shrink in volume and unseal smoothly by the characteristics of heat shrinkage and cold expansion. The nanofluidic system, consisting of porous carbon with an exceptionally large specific surface area and glycerol, serves as a prime example for filling the sandwich layer, and the design parameters calculation was carried out. The sealing performance of the designed nanofluidic self-heating unsealing rubber cylinder was analyzed based on the Mooney–Rivlin principal structure by finite element modeling. The results show that the maximum contact stress between the nanofluidic self-heating unsealing rubber cylinder and the casing wall increases by 9.73%, the compression distance reduces by 24.47%, and the maximum equivalent force decreases by 12.17% on average compared with a conventional rubber cylinder under the same seating load. The designed nanofluidic self-heating unsealing rubber cylinder can satisfy the requirements of pressure-bearing capacity and sealing performance and performs better than a conventional rubber cylinder.

Mechanical response of the sealing packer based on two rubber materials at high temperatures

The compression packer is an important downhole oil production tool, and its failure is mainly attributed to the degradation of its embedded rubber cylinders under the action of high temperatures. In the present study we have made a comprehensive investigation on the mechanical response of the sealing packer based on two rubber materials at high temperatures. Firstly, by measuring the material parameters under different temperatures, we established the constitutive relationships of the two rubber materials (Aflas and Kalrez) in consideration of the temperature effect, in the light of the Mooney-Rivlin model. Next, the sealing performances of two optimized packers were analyzed including Aflas and Kalrez rubber cylinders. The effects of high temperature and the initial setting pressure on the sealing effects of these two optimized packers were probed based on the finite element analysis (FEA), and the ranges of temperature and initial setting pressure for best sealing were determined. This study can provide some ideas for the material selection and structural optimization for sealing packers, aiming to ensure the safe operation of the packers in severe environments.

Wave Propagation in Laminated Cylinders with Internal Fluid and Residual Stress

Numerical computation of wave propagation in laminated cylinders with internal fluid and residual stress is obtained using a Wave Finite Element formulation for 2D waveguides. Only a very small segment of the system is modelled, resulting in a very low-order finite element (FE) model to which the theory of wave propagation in 2D periodic structures is applied. The method uses standard FE formulations and exploits the capability of commercial FE software to model both fluid and structure and their interaction, resulting in a very large reduction in computational time. The presented approach is general, and can be applied without the need to make assumptions related to shell theory or low-frequency analysis. In particular, the laminated structure is discretised using 3D solid elements, thus representing the through-thickness dynamics with high accuracy. Residual radial and hoop stresses are included in the model by adding the FE pre-stress stiffness matrix to the original stiffness matrix of the system. The method provides simultaneously a very substantial reduction of computational cost, accurate solutions up to very high frequency and prediction of the dispersion curves for selected circumferential orders without the need for any further analysis. Here, the formulation of the method is introduced and its application to laminated cylinders filled with an acoustic fluid is presented. A composite, reinforced rubber cylinder, pre-stressed by a circumferential tension, is also shown as an example of a laminated pipe for high-pressure applications.

Production of Biogas Using Water Waste Products (Water Hyacinth and Cow Dung)

This research was carried out to make use of water hyacinth to produce which may solve the problem of water hyacinth management as well as provide solution to the energy and power shortages. Samples of water-hyacinth were identified and collected and the cow dung was obtained from an abattoir. One (1) single 120 of improvised rubber cylinder can be used as an anaerobic. Three (3) of water was added for the 30 days retention time. The cow dung was mixed with water at a ratio of 3 : 1. The slurry of cow dung and water hyacinth substrates was then fed to the for the fermentation process to begin. Experiments were carried out during the cool season and dry season (20– 40◦C). The gas was collected and stored in the gas bag. The volume of was measured using an EL- STER HANDEL GMBH MAINZ volumetric meter, which has a limit of detection of less than 0.0010m3. The products obtained from the anaerobic digestion of water hyacinth were the compost that is removed from the at the end of the digestion process. The study’s evaluation of production potential over a 30 days period revealed marked seasonal variations in. The study revealed that it is possible to produce from a mixture of water hyacinth and cow dung. The facility’s yield of 1 kg of gas was collected. The study thereof revealed that the higher the dilution level and presence of cow dung, the higher the production yields.

The Use of a PVDF Array to Measure the Stress Field Inside an Elastic Material.

This paper reports a series of experimental and modeling investigations on two piezoelectric arrays made of polyvinylidene fluoride (PVDF) films. They were embedded inside rubber cylinders and used to directly measure the internal stresses generated by various external excitations applied to the top surface of the cylinder. Corresponding finite element (FE) models were established to reveal the relationship between the PVDF output and the stress field applied to it. This research improves the understanding of the output mechanism of the embedded PVDF and provides useful information for the design of PVDF sensors.

Design and Performance Research of Single Rubber Cylinder for High Pressure Gas Injection Packer

In order to solve the problem of "gas explosion" at the end of common rubber cylinder in the process of high temperature, high pressure and gas drive operation, the rubber cylinder with new structure suitable for 51/2in casing pipe is developed. The "M" type single rubber cylinder structure is adopted in the new structure rubber cylinder, and the "gas explosion" problem of the end gas in the low-pressure side is solved by setting the double-layer staggered slotted steel cover to prevent outburst. The finite element method is used to simulate the setting of the rubber cylinder, and the structural parameters of the new rubber cylinder are obtained by single factor analysis and orthogonal optimization, simulation test and seal test were carried out to verify the sealing performance of the rubber cylinder. According to the actual working condition, the simulation test results and seal test results show that the sealing capacity of the packer reaches 50MPa under the temperature resistance of 120℃, and the end steel cover is fully opened to wrap the rubber cylinder, which meets the operation requirements of high temperature and high pressure gas injection packer.

Investigation of the properties and aging mechanisms of vulcanized hydrogenated nitrile rubber in different mediums

AbstractPacker rubber cylinders in oil drilling operations must withstand high pressure, high temperature, and destruction of mediums. To ensure the long‐term service time of the hydrogenated nitrile rubber (HNBR) packer rubber cylinders, it is essential to understand the aging mechanism of HNBR in different aging environments. Four HNBR with various acrylonitrile contents (ACN 17%, 21%, 34%, and 43%) were prepared in this work, and effect of CN content on the mechanical properties, aging resistance, and dynamic mechanical properties of HNBR were investigated respectively. It was observed that the higher the CN content, the stronger the mechanical properties of the HNBR, and the mechanical properties of HNBR with high CN content decayed rapidly at high temperatures. According to the thermo‐oxidative aging data, the cross‐linking reactions were investigated during the thermo‐oxidative aging of HNBR, leading to a decrease in the properties of HNBR. In a high temperature (180°C) aqueous medium, the chemical structure of HNBR underwent dramatic changes. The CN group is converted to CONH2 and COO− group, and the resulting COO− reacted further with CONH2 in deionized water and with metal ions (Ca2+ or Mg2+) in mineralized and oily water to form cross‐linking network, and the possible aging mechanisms of HNBR in different mediums were given.

Study on sealing behavior of corroded tubing in a high pressure environment

Tubing corrosion is becoming more and more serious due to the harsh operating environment and corrosive medium transportation. It results in frequent seal failure of plugs used for tubing lift-off in snubbing operations. This paper develops a finite element model of a plug rubber cylinder sealing a defected tubing. The sealing performance of the rubber cylinder under the defected tubing is studied. The accuracy of model is tested experimentally. The related structural parameters affecting the sealing performance of rubber cylinder are pointed out by numerical derivation. The results show that when selecting the equivalent defected tubing size, smaller depth and radius and larger axial height can be selected. The expression of sealing performance of rubber cylinder in defected tubing environment is obtained. The influence of the key parameters on the sealing performance of the rubber cylinder is the axial height, depth and radius from high to low. The research work in this paper can provide theoretical guidance for the behavior of rubber cylinder seal corroding tubing in snubbing operation.

Adaptability of hydraulic fracturing packers and optimization of their sealing performance for three common clastic rock reservoirs based on finite element analysis

In this paper, the adaptability characteristics of the packer to three types of common clastic rock reservoirs (mudstone, shale, sandstone) are analyzed systematically. Moreover, the identification and structural design of the packer in hydraulic fracturing are systematically conducted based on the finite element calculation. Finally, the nonlinear mathematical models of the packing safety factor and the pressure under the packer and the conditions of casing, mudstone, shale and sandstone are obtained. The results show that the maximum stress of the rubber cylinder in the three formation models of mudstone, shale and sandstone is lower than the compression set strength of the rubber cylinder, indicating that the rubber cylinder will not cause stress damage. At the same time, by analyzing the common rubber materials and constitutive models of the packers, the structure of the packer rubber cylinder and a new anti-shoulder protrusion device were redesigned. The Nitrile-butadiene rubber (NBR) meets the performance requirements of the rubber tube under the allowable pressure difference and temperature difference. The designed new anti-protrusion device can ensure the structural integrity and stress uniformity of the rubber tube, thereby ensuring good sealing performance. Under the three formation conditions of mudstone, shale and sandstone, the rubber cartridge can be in a safe working state, and its sealing width is close to the contact length of the rubber cartridge. In addition, the rubber cartridge is in a good elastic deformation range. The design of the packer in this study satisfies the third strength theory and the safety requirements. The deformation and sealing performance of the rubber cylinder are relatively stable, and the size of the rubber cylinder also meets the field requirements.