Experimental investigation of dynamic characteristics of leaching tubing for solution mining of salt cavern carbon and energy storage

Salt caverns are extensively utilized for storing various substances such as fossil energy,hydrogen,compressed air,nuclear waste,and industrial solid waste.In China,when the salt cavern is leached through single-well water solution mining with oil as a cushion,engineering challenges arise with the leaching tubing,leading to issues like damage and instability.These problems significantly hinder the progress of cavern construction and the control of cavern shape.The primary cause of this is the flowinduced vibration instability of leaching tubing within a confined space,which results in severe bending or damage to the tubing.This study presents a model experimental investigation on the dynamic characteristics of leaching tubing using a self-developed liquid-solid coupling physical model experiment apparatus.The experiment utilizes a silicone-rubber pipe(SRP)and a polycarbonate pipe(PCP)to examine the effects of various factors on the dynamic stability of cantilevered pipes conveying fluid.These factors include external space constraint,flexural rigidity,medium outside the pipe,overhanging length,and end conditions.The experiments reveal four dynamic response phenomena:water hammer,static buckling,chaotic motion,and flutter instability.The study further demonstrates that the length of the external space constraint has a direct impact on the flutter critical flow velocity of the cantilevered pipe conveying fluid.Additionally,the flutter critical flow velocity is influenced by the end conditions and different external media.

Analysis of Maximum Liquid Carrying Capacity Based on Conventional Tubing Plunger Gas Lift

China’s unconventional gas fields have a large number of low-productivity and low-efficiency wells, many of whichare located in remote and environmentally harsh mountainous areas. To address the long-term stable productionof these gas wells, plunger-lift technology plays an important role. In order to fully understand and accurately graspthe drainage and gas production mechanisms of plunger-lift, a mechanical model of plunger-liquid column uplift inthe plunger-lift process was established, focusing on conventional plunger-lift systems and representative wellboreconfigurations in the Linxing region. The operating casing pressure of the plunger-lift process and the calculationmethod for the maximum daily fluid production rate based on the work regime with the highest fluid recovery ratewere determined. For the first time, the critical flow rate method was proposed as a constraint for the maximumliquid-carrying capacity of the plunger-lift, and liquid-carrying capacity charts for conventional plunger-lift withdifferent casing sizes were developed. The results showed that for 23/8 casing plunger-lift, with a well depth ofshallower than 808 m, the maximum drainage rate was 33 m3/d;for 27/8 casing plunger-lift, with a well depth ofshallower than 742 m, the maximum drainage rate was 50.15 m3/d;for 31/2 casing plunger-lift, with a well depthof shallower than 560 m, the maximum drainage rate was 75.14 m3/d. This research provides a foundation for thescientific selection of plunger-lift technology and serves as a decision-making reference for developing reasonableplunger-lift work regimes.

CATIA Tubing Design模块客户化研究

采用CATIA Tubing Design模块进行管路设计必须按设计标准进行客户化定制。研究了CATIA Tubing Design模块客户化定制的方法,包括项目定制、系统文件定制及管路零部件库定制。研究了管路零部件端头属性的兼容性规则及零部件的自动摆放规则,以实现管路零部件自动摆放;阐述了直硬管、弯硬管及软管的建模方法。

Tubing Dimension Optimization for the Development of an Offshore Gasfield

L1 is one of the largest offshore gas fields currently under development.In order to optimize the related design,nodal analysis is applied(including proper consideration of the plant productivity,sensitivity to the tubing size,erosion effects,liquid carrying performance,and tubing string).As a result of such approach,it is shown that 13Cr material should be chosen as the appropriate tubing material.Moreover,3-1/2 inches 9.3 lb/ft N80 tubing,4-1/2 inches 12.75 lb/ft N80 tubing,5-1/2 inches 17 lb/ft N80 tubing should be used for a gas production rate under 80×10^(4)m^(3)/d,between 80×10^(4)m^(3)/d and 120×10^(4)m^(3)/d and above 120×10^(4)m^(3)/d,respectively.

INTRODUCTION TO INCONEL ALLOY 740: AN ALLOY DESIGNED FOR SUPERHEATER TUBING IN COAL-FIRED ULTRA SUPERCRITICAL BOILERS

Chinese utilities as well as those worldwide are facing increased demand for additional electricity, reduced plant emissions and greater efficiency. To meet this challenge will require increasing boiler temperature, pressure and coal ash corrosion resistance of the materials of boiler construction of future coal-fired boilers. A new nickel-based tube alloy, INCONEL^R alloy 740, is described aiming at meeting this challenge. Emphasis will be on describing the alloy＇ s mechanical properties, coal-ash and steam corrosion resistance. Microstructural stability as a function of temperature and time is addressed as well as some of the early methodology em- ployed to arrive at the current chemical composition.

Investigations into the coiled tubing partial underbalanced drilling (CT-PUBD)technique for drilling hard formations

To improve the rate of penetration(ROP) in drilling deep and hard formations, this paper proposes a new drilling method called coiled tubing partial underbalanced drilling(CT-PUBD). As a preliminary investigation into the new drilling method, this paper presents predictions of hole cleaning efficiency, drilling speed, cuttings migration and pressure loss in the drilling process with CT-PUBD. Based on numerical simulation and full-scale experimental studies, we conclude that using CT-PUBD, an underbalanced drilling condition can be achieved near the bit while maintaining wellbore safety at the same time. This condition can be achieved using a cuttings discharge device, a rotary packer and a backflow controller.According to the numerical simulations performed in this study, CT-PUBD can achieve high efficiency of hole cleaning.Along the cuttings migration process, the fluid velocities can reach the maximum values in the backflow holes. A full-scale laboratory experimental system was used to test the hydraulic characteristics and obtain the drilling performance of the new technology. The result shows that CT-PUBD significantly improves the ROP compared to the conventional drilling method.

Influence factors on stress corrosion cracking of P 110 tubing steel under CO2 injection well annulus environment

Stress corrosion cracking （SCC） behavior of P 110 tubing steel in simulated C02 injection well annulus environments was investigated through three-point bent tests, potentiodynamic polarization and EIS measurements. The results demonstrate that SCC of P110 tubing steel could occur in acidulous simulated environment, and the sensitivity of SCC increases with the decrease ofpH, as well as increase of sulfide concentration and total environmental pressure. Both anodic dissolution and hydrogen embrittlement make contributions to the SCC. Adequate concentration of corrosion inhibitor can inhibit the occurrence of SCC on account of the inhibition of localized anodic dissolution and cathodic hydrogen evolution.

Outcomes of revision external dacryocystorhinostomy and nasal intubation by bicanalicular silicone tubing under endonasal endoscopic guidance

AIM: To evaluate the long-term treatment outcomes in patients who underwent revision of external dacryocysto- rhinostomy (DCR) and nasal intubation by bicanalicular silicone tubing (BSTI) under endonasal endoscopic guidance. · METHODS: Data from 28 patients with recurrent dacryocystitis were retrospectively reviewed. Revision external DCR and bicanalicular nasal intubation by silicone tubing under endonasal endoscopic guidance was performed in 28 eyes of 28 patients. The patients were evaluated with respect to the reason of recurrence, time to recurrence, time to revision, duration of follow-up and surgical success. · RESULTS: Endoscopic endonasal examination detected an osteotomy-side obstruction by the excessive granulation tissue in 24 patients (86%), nasal septal deviation in three patients (10%) and nasal polyp in one patient (4%). Recurrence occurred after a mean duration of 5.3±3.7 months following the first operation. The mean time between the first DCR operation and the revision DCR was 11.5 ± 9.3 months. After a mean follow-up of 14.9±7.8 months, the rate of anatomic success alone was 85% (24/28); the rate of subjective success was 78% (22/28). · CONCLUSION: Revision external DCR and bicanalicular nasal intubation by silicone tubing under endonasal endoscopic guidance can be recommended in patients with recurrent dacryocystitis as a surgical approach that achieves satisfactory objective and subjective success rates.

Awareness and attitude of fecal microbiota transplantation through transendoscopic enteral tubing among inflammatory bowel disease patients

BACKGROUND Transendoscopic enteral tubing(TET)has been used in China as a novel delivery route for fecal microbiota transplantation(FMT)into the whole colon with a high degree of patient satisfaction among adults.AIM To explore the recognition and attitudes of FMT through TET in patients with inflammatory bowel disease(IBD).METHODS An anonymous questionnaire,evaluating their awareness and attitudes toward FMT and TET was distributed among IBD patients in two provinces of Eastern and Southwestern China.Question formats included single-choice questions,multiple-choice questions and sorting questions.Patients who had not undergone FMT were mainly investigated for their cognition and acceptance of FMT and TET.Patients who had experience of FMT,the way they underwent FMT and acceptance of TET were the main interest.Then all the patients were asked whether they would recommend FMT and TET.This study also analyzed the preference of FMT delivery in IBD patients and the patient-related factors associated with it.RESULTS A total of 620 eligible questionnaires were included in the analysis.The survey showed that 44.6%(228/511)of patients did not know that FMT is a therapeutic option in IBD,and 80.6%(412/511)of them did not know the concept of TET.More than half(63.2%,323/511)of the participants stated that they would agree to undergo FMT through TET.Of the patients who underwent FMT via TET[62.4%(68/109)],the majority[95.6%(65/68)]of them were satisfied with TET.Patients who had undergone FMT and TET were more likely to recommend FMT than patients who had not(94.5%vs 86.3%,P=0.018 and 98.5%vs 87.8%,P=0.017).Patients’choice for the delivery way of FMT would be affected by the type of disease and whether the patient had the experience of FMT.When compared to patients without experience of FMT,Crohn’s disease and ulcerative colitis patients who had experience of FMT preferred mid-gut TET(P<0.001)and colonic TET(P<0.001),respectively.CONCLUSION Patients’experience of FMT through TET lead them to maintain a positive attitude towards FMT.The present findings highlighted the significance of patient education on FMT and TET.

Non-symmetric distributions of solids deposition for solid-water stratified flow in deviated tubing strings

Dynamic performance on solids flow with water in deviated tubing is essential for the reliability of pump and normal operation of horizontal and directional wells.Compared with coal-water flow in vertical tubing and sand-oil flow with high production in deviated tubing,solids deposition with water shows obvious non-symmetric distributions in deviated tubing from simulations and experiments.The mathematical model of two phase flow was developed under coupling conditions of deviated tubing,low flow rate and viscosity based on the kinetic theory of granular flow and first-order discrete scheme.The results show that solid-water stratified flow in deviated tubing can be divided into two zones of suspension bed and the moving bed throughout the flow field.The solid flowing velocity with water is negative and particles slide down at the bottom of moving bed zone.The process of solids flow with water in deviated tubing will produce pressure loss and consume the kinetic energy.The thickness of deposited layer and the flowing velocity of solids flow downward with water at the moving bed zone enhance with the decreased inlet flow rate and the increased particle size,tubing inside diameter(ID)and inclination angle.Solids are easier into suspension from the upper part of moving bed zone to suspension bed zone and more solid particles flow with water towards the tubing outlet with the increase of inlet flowing velocity.The decision is made to reduce the screen width,tubing ID and inclination angle to maintain to be greater than critical deposition velocity in order to prevent solids settling.And it provides the theoretical basis and technical reserves for solid control and offers an effective approach to enhance tubing cleaning in deviated strings.

Progress and future prospects of application technology for tubing and casing

The main failure modes of tubing and casing in current service conditions are represented in this study.The progress of the tubing and casing application technology and the problems that should be focused on during application are introduced,with special attention paid to the reliability of the pipe string design and the connection sealing properties.The necessary work that should be undertaken in future research is also summarized.

A solids-free brine drilling fluid system for coiled tubing drilling

There are many problems associated with coiled tubing drilling operations, such as great circulation pressure loss inside pipe, difficulties in weight on bit(WOB) transferring, and high probability of differential sticking. Aiming at these problems, solids-free brine drilling fluid system was developed on the basis of formulation optimization with brine base fluid experiment, which was evaluated and applied to field drilling. Based on the optimization of flow pattern regulator, salt-resisting filtrate reducer, high performance lubricant and bit cleaner, the basic formula of the solids-free brine drilling fluid system was formed: brine +(0.1%-0.2%) Na OH +(0.2%-0.4%) HT-XC +(2.0%-3.0%) YLJ-1 +(0.5%-2.0%) SDNR +(1.0%-2.5%) FT-1 A +(1.0%-5.0%) SD-505 + compound salt density regulator. Lab evaluation showed that the fluid had satisfactory temperature resistance(up to 150 ℃), excellent cuttings tolerance(up to 25%), and strong inhibition(92.7% cuttings recovery); Moreover, its lubrication performance was similar to that of all oil-based drilling fluid. The wellbore could be fairly cleaned at annular up-flow velocity of more than 0.8 m/s if the ratio of yield point to plastic viscosity was kept above 0.5. This fluid system has been applied in the drilling of three coiled tubing sidetracking wells in the Liaohe Oilfield, during which the system was stable and easy to adjust, resulting in excellent cuttings transportation, high ROP, regular hole size, and no down hole accidents. In summary, the solids-free brine drilling fluid system can meet the technical requirements of coiled tubing drilling.

Tubing管在海洋平台中的应用

Tubing管在海洋平台中应用较广泛。本文主要介绍了Tubing管在海洋平台中的应用领域、Tubing管分类、组成以及选型时应遵循的原则。总结了Tubing管安装工艺、敷设原则、管线的检查和试压程序。

Strength Design Method for Tubing Hanger of Subsea Christmas Tree Against Big Temperature Difference

The tubing hanger is an important component of the subsea Christmas tree, experiencing big temperature difference which will lead to very high thermal stresses. On the basis of API 17D/ISO 13628-4 and ASME VIII-1, and by comprehensively considering the erosion of oil and the gravity load of the tubing, a calculation model is established by regarding design pressure and thermal stress, and the method for designing the tubing hanger of the horizontal Christmas tree under big temperature difference condition is developed from the fourth strength theory. The proposed theory for strength design of the tubing hanger in big temperature difference is verified by numerical results from ABAQUS.

Effect of abrasive blasting on the internal surface of L80-13Cr tubing and casing

In this study,two sandblasting textures,namely,quartz and high-chromium(Cr)stainless steel sands,were used for sandblasting of the internal surface L80-13Cr tubing and casing.The contrastive analysis on the properties of the pipes before and after abrasive blasting was conducted,including the metallographic phase detection of the internal surface,simulating accelerated corrosion tests,and residual stress tests for the pipe after abrasive blasting.Based on the analysis results,it is explained why the API standard requires that no scale appears on the internal surface of L80-13Cr and iron contamination when internal sandblasting media are applied.The results show that abrasive blasting can effectively remove scales on the internal surface of L80-13Cr tubing and casing and improve corrosion resistance.The abrasive blasting process does not produce obvious residual stress on the internal surface of the tubing and casing.Also,the de-rusting effect of stainless sand is better than that of quartz sand,and the former does not produce iron contamination.

Preliminary build and application of a data analysis platform for coiled tubing steel strips

To solve the problems in the quality control and improvement of coiled tubing steel strips production, such as scattered and inefficient production data, difficult performance fluctuation factor analysis, complex multivariate statistical analysis, and low accuracy and difficulty in mechanical property prediction, an industrial data analysis platform for coiled tubing steel strips production has been preliminarily developed.As the premise and foundation of analysis, industrial data collection, storage, and utilization are realized by using multiple big data technologies.With Django as the agile development framework, data visualization and comprehensive analyses are achieved.The platform has functions including overview survey, stability analysis, comprehensive analysis(such as exploratory data analysis, correlation analysis, and multivariate statistics),precise steel strength prediction, and skin-passing process recommendation.The platform is helpful for production overviewing and prompt responding, laying a foundation for an in-depth understanding of product characteristics and improving product performance stability.

Discussion on the Key Properties of Fiberglass Tubing Used in Oilfield

CNPC implements the call of energy conservation and emission reduction, and promotes the application of new energy conservation and emission reduction technologies and new products to achieve production and reduce pollution. As China’s oilfields enter the period of high water cut development, corrosion problem and scale formation ordinary steel tubing are becoming more and more serious in oilfield application, which influence and restrict the production and development and bring about energy waste. FRP tubing has been widely used in oil and gas fields because of its excellent corrosion resistance, small friction coefficient and less wear. With the gradual popularization of FRP tubing in oilfields, failure cases also show a growing trend as threaded release, leakage, fracture and so on, which affect the normal production of oilfields. In this paper, a series of key performance properties affecting service performance of high-pressure FRP tubing are tested which took from common failure cases. The key properties of FRP tubing, such as unloading, anti-collapse, short-term failure pressure at high ambient temperature and high ambient temperature axial tension, are tested in the research. The article provides a scientific basis for applicability evaluation of FRP tubing. This research has important significance for energy saving, decreasing pollution and safe operation of tubing pipes. Several suggestions are put forward on material selection and design of FRP tubing.

The Study of Tubing Vibration Mechanism in High Pressure Gas Well

Deep gas wells and gas fields have the characteristics of high pressure. The vibration of the tubing string during the production of gas wells causes the string to be subjected to severe stress and even dynamic fatigue failure. Therefore, this article is based on the dynamic finite element theory, aiming at the characteristics of large-size tubing strings in deep gas wells. The finite element mechanics model and mathematical model of the tubing string vibration of the packer of high-pressure gas wells were established, and the ANSYS software was re-developed. The finite element analysis program for the vibration dynamics of the unbuckled and buckled strings of gas wells was compiled with APDL, and the displacement of the longitudinal vibration of the tubing string of high-pressure gas wells was studied. According to different sizes of tubing strings currently used in deep gas wells and gas fields, simulation calculations are carried out, and the axial impact load and buckling damage laws of the tubing strings of the entire well section under different production rates are obtained. It provides a theoretical basis for the prediction of tubing string vibration law and measures to prevent tubing string vibration.

Effects of the Produced Water from a Sour Oilfield in South Kuwait on the Production Tubing

Kuwaiti oil production faces a growing challenge in the increasing quantities of produced water generated in the production of oil. The high water cut of the produced fluid from the wells and the high salinity of the produced water lead to significant degradation of subsurface equipment, specifically the production tubing. Debris generated through the degradation of the inner part of the tubing becomes a constituent of the scaling that deposits in the tubing and blocks the flow of the production fluid, inducing higher maintenance costs. This paper looks at the characteristics of the scaling in regard to the produced water and outlines the economic impact of the produced water induced degradation of the tubing structure.

Fatigue Life Analysis of Coiled Tubing in Deep Well Jet Plugging Removal

The coiled tubing plugging has become the main means of plugging in gas Wells in Xinjiang. These Wells are deep and have high pressure, which can easily affect the fatigue life of the operating coiled tubing. In order to improve the life of coiled tubing in high-pressure gas Wells, this paper studies the plugging conditions of coiled tubing in high-pressure ultra-deep Wells. Firstly, the cross section deformation of coiled tubing under high internal pressure is analyzed. Secondly, the factors influencing the fatigue life of coiled tubing and the influence of surface damage on the fatigue life of coiled tubing were studied. Finally, the mechanism of furrow damage caused by coiled tubing and the main measures to reduce furrow damage are analyzed. The following suggestions are made to improve the life of coiled tubing: select the right material and the right size coiled tubing;Use appropriate measures to prevent premature coiled tubing failure and reduce operating costs.