The transportation of wet gas fluid in carbon steel pipelines for onshore processing offers an economically attractive strategy. Although a substantial saving in capital cost can be realised, the risks of hydrate formation and corrosion damage are two of the main issues with such an approach. The standard industrial practice is to apply chemical solutions to reduce the risks. A thermodynamic hydrate inhibitor, such as monoethylene glycol (MEG) and corrosion inhibitors are commonly utilized to provide hydrate and corrosion control, respectively. Other production chemicals, such as an oxygen scavenger, may also be deployed as part of the risk management process. Consequently, the main challenge to the corrosion inhibitor is to provide corrosion protection throughout the production and processing facility while subjected to high temperatures in the MEG regeneration process and exposure to other production chemicals. Thermal stability and performance assessments should be an important aspect of the qualification process in the selection of corrosion inhibitors. This paper presents data from laboratory corrosion inhibitor evaluation programs, using thermally stressed MEG/chemicals under simulated wet gas pipeline operating conditions, which resulted in the successful qualification of a corrosion inhibitor for the production facility. In addition, the performance of oxygen scavengers for use in MEG systems is reviewed, including details of an oxygen scavenger that performs in lean MEG.

Generally, the most economical material for construction in oil and gas pipeline systems is carbon steel. Besides the safety and environmental issues, downtime caused by corrosion related failures and hydrate-induced blockages in pipelines can be costly to the operator. Asset integrity and flow assurance are, therefore, recognised to be critical issues in oil and gas production and transportation. Chemical inhibitors to protect pipelines from metal degradation and hydrate blockages are commonly utilised but compatible corrosion inhibitor (CI) and kinetic hydrate inhibitor (KHI) combinations are often difficult to formulate for sour gas applications. It is often found that either the KHI has an adverse affect on the CI function or vice versa. Before field deployment, extensive inhibitor testing and evaluation is conducted to ensure that the most appropriate products are selected. This paper presents data from a laboratory programme which was instigated to develop and assess new corrosion inhibitor formulations. Performance was evaluated in terms of the corrosion inhibition of the CI and its KHI compatibility and performance in supplementary secondary property tests under simulated sour gas pipeline operating conditions. From this work two CI/KHI combinations exhibiting excellent compatibility in terms of corrosion inhibition performance (both general corrosion inhibition as well as, more importantly, pitting corrosion inhibition), hydrate inhibition performance and high temperature injection performance have been developed. 1. INTRODUCTION The oil and gas industry commonly employs offshore and subsea technology for the economic extraction of hydrocarbon. Offshore processing facilities incorporating dehydration units have enabled multiphase streams to be treated before transportation to nearby platforms or onshore. The shipping of dry fluids is advantageous since this helps to reduce the hydrate formation tendency and internal corrosion of steel pipelines. However, substantial financial savings can be made in the initial investment of new platforms and their subsequent operating costs when these treatment amenities are omitted and, as a result, an increasing number of offshore assets involve the direct transportation of unprocessed wet fluids to onshore processing and storage facilities.

Introduction Coronavirus disease 2019 (COVID-19) had spread to over 200 countries and regions across the world since early 2020. Travel bans had been implemented in Hong Kong to control the spread of virus. Despite the burden to the healthcare system brought by COVID-19, there was also an increase in number of hiking-related injuries requiring inpatient care. The aim of this study is to report the incidence of hiking-related injuries admitted to the orthopaedic wards during the COVID-19 pandemic and comparison with statistics from the past years. Methods Data was retrieved from the admission books of the orthopaedic wards and Electronic Patient Records. The number of admissions, patients’ demographics and details of hospitalisation were compared between February to May 2020 (COVID-19 study period) and 2019. Secondary analysis was performed on admissions for tibia and/or fibula fractures with or without operation during the study period and compared with the past five years. Results 48 patients were admitted due to hiking-related conditions during the COVID-19 study period, which was 2.4 times more than 2019. 23 patients suffered from tibia and/or fibula fractures and was higher than the past five years (average 5.8, p = 0.0001). Among patients operated for tibia and/or fibula fractures, the percentage of hiking-related injuries was 41.9% in 2020 and 6.9% in the past five years (p = 0.0002). Conclusions An increase in incidence of hiking-related orthopaedic injuries was observed during the COVID-19 pandemic. Healthcare workers, public health experts and government officials should work together to raise awareness on safety in hiking for effective prevention of injury.

Under-deposit/scale, pitting and weld corrosion are a major cause of localised corrosion failure in oil and gas production systems. Since advancement in instrumentation and the successful development of the localised corrosion test protocol in 2002, the technique has been widely used to study the inhibition of localised corrosion. The latest examples of its application are presented. Green corrosion inhibitors have been screened and their ability to inhibit under scale pitting has been determined. The work has allowed the key monitoring parameters in the inhibition of localised corrosion to be identified, which has resulted in a refinement of the test protocol. Additionally, the ability of corrosion inhibitors in preventing weld corrosion was also assessed. The ability of the corrosion inhibitors to be effective against weld corrosion and under deposit corrosion was demonstrated. The results established that specialised laboratory tests should be used to qualify inhibitors prior to field deployment. Introduction Corrosion inhibitors are widely used within the oil and gas industry to prevent corrosion within pipelines due to the presence of CO2 and H2S. Laboratory corrosion inhibitor selection traditionally uses electrochemical techniques that determine inhibitor effectiveness in preventing general corrosion. Such tests include kettle tests, rotating cylinder electrode (RCE) and jet impingement1,2,3. However, within oil field pipelines and downhole tubing, carbon steel can be susceptible to several types of corrosion. These include pitting, under deposit and corrosion of weldments. Field experience suggested that not all inhibitors are effective in inhibiting these forms of corrosion. In fact it is possible that some inhibitors, if injected at insufficient quantity, can accelerate the pitting rate and weld corrosion. Care must be taken when changing out inhibitors or starting inhibitor injection for the first time that the inhibitor will prevent or reduce the type corrosion that is present. For fields where general corrosion is not the predominant type of corrosion present it is advisable that other tests be performed to investigate inhibitor performance against the form of corrosion present. For example, it is possible to assess inhibitor performance against pitting corrosion in sour environments by using weight loss coupons and visually inspecting coupons with a microscope for the presence of pits4,5. It is also possible with this technique to measure the maximum pit depth present in treated and untreated coupons. With this information it is possible to qualify inhibitor performance. Additionally, an ambient pressure technique has been developed where an artificial pit electrode has been used to evaluate corrosion inhibitor performance in preventing localised corrosion6. Tests were able to distinguish between inhibitors which gave similar levels of protection against general corrosion. The use of corrosion inhibitors can also enhance weld corrosion. Rothwell7 has reported based on field data, that corrosion inhibitors can have a detrimental affect on weld corrosion at low dose levels. Furthermore, a considerably higher dose level of inhibitor was required to inhibit weld corrosion compared to inhibiting the general corrosion rate. Corrosion of weldments and under deposit pitting corrosion beneath barium sulphate scale deposits were recognised to be an important aspect of corrosion risk in an oil and gas production facility in the North Sea. Due to the awareness of minimising environmental impact, a laboratory test programme was initiated to identify more environmental friendly candidate corrosion inhibitors as potential replacements for the incumbent inhibitor. This paper gives details of how the artificial pit technique, weldment corrosion test and traditional test methods have been used in selecting a ‘green’ corrosion inhibitor that is effective against under deposit and weldment corrosion.

Study background: A retrospective study to compare the rate of facet joint violation (FJV) in lumbar posterior spinal instrumentation using open pedicle screw, percutaneous pedicle screw, and cortical bone trajectory (CBT) technique. CBT is a new posterior spinal instrumentation technique in which a more caudal entry point can minimize iatrogenic damage to the cranial facet joint. Only one recent study reports incidence of FJV of 11%; however, no previous reports comment on radiological outcomes comparing to traditional open and percutaneous screws. Methods: We reviewed 90 patients who underwent lumbar posterior spinal instrumentation from January 2016 to June 2017. Postoperative computer tomography scans were performed to evaluate FJV. Incidence of FJV was graded by three reviewers according to Seo classification. Results: Totally, 446 screws (open 43.4%, percutaneous 37.8%, CBT 18.9%) were inserted. Among these, 6.3% (28/446) had screw head or rod in contact with facet joint and 0.9% (4/446) had screws directly invaded the facet joint. Overall, FJV was 7.2% (CTB = 3.4%, open = 10.4%, and percutaneous = 4.5%, p = 0.075). Conclusion: CBT technique has potential advantage in reducing FJV. It has a unique entry site at lateral aspect of pars interarticular with a caudomedial to craniolateral pathway. It is a reasonable alternative to open or percutaneous techniques in lumbar posterior spinal instrumentation.