accelerated corrosion
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2022 ◽  
pp. 136943322110737
Author(s):  
Nariman Fouad ◽  
Mohamed A Saifeldeen

This article proposes a new technique of monitoring neutral axis positions and deflection of Reinforced Concrete (RC) beam during corrosion of steel reinforcement using macro-strain measurements of distributed long-gauge sensors. A different group of distributed long-gauge Packaged Carbon Fiber Line (PCFL) sensors with self-compensation and effective packaging system is installed on the compression and tension fibers of the concrete surface and steel reinforcements of RC beam to verify the proposed method experimentally. An accelerated corrosion method utilizing a salt solution and the constant current was used to achieve the required corrosion levels. The estimated deflection measured by the developed method is compared with the results using Linear Variable Displacement Transducer (LVDTs). It has been demonstrated that long-gauge PCFL sensors could provide the same accuracy. The distributed measured strains were utilized to evaluate the deterioration of the structure’s health with the advance of corrosion. Based on corrosion monitoring experimental results, it can be confirmed that using distributed PCFL sensors mounted on steel reinforcements or concrete surface, the locations and progress of the damage with corrosion time can be detected effectively. The maximum error in the estimated deflection from PCFL sensors mounted on the concrete surface compared to the LVDTs before the onset and after 24 h of accelerated corrosion was 0.5% and 2.5%, respectively.


2022 ◽  
Vol 69 (1) ◽  
Author(s):  
Lamiaa M. Omer ◽  
Mohamed S. Gomaa ◽  
Waleed H. Sufe ◽  
Alaa A. Elsayed ◽  
Hany A. Elghazaly

AbstractThe durability of reinforced concrete (RC) pipes depends upon the corrosion resistance of the reinforcing steel and the resistance of concrete mixes against an aggressive environment. This research paper aims to compare the performance of R.C. pipes made of ordinary Portland cement (OPC) concrete mixtures with others made of two different geopolymer concrete mixes based on different ratios of granulated blast furnace slag (GBFS), fly ash (FA), and pulverized red brick (RB) subjected to three different environments, ambient, tap water (TW), and an aggressive environment, and a solution of 10% magnesium sulfates + 5% chloride (MS-CL). An accelerated corrosion setup has been applied to accelerate the corrosion process in the tested samples. The evaluation of change of compressive strength of concrete and microstructure of different mixes was investigated too. Fourier transform infrared (FTIR) spectroscopy has been studied on all pipes. Geopolymer concrete mixes based on 90% GBFS and 10% RB show better results in all cases. Geopolymer concrete mixes based on 63% GBFS, 27% FA, and 10% RB increase the concrete compressive strength in the magnesium sulfate and chloride environment by 5% compared to tap water. It can be concluded that the geopolymer concrete mixes produced of 90% GBFS and 10% RB perform well under all environments, and its microstructure shows stable behavior in an aggressive environment.


2022 ◽  
Vol 165 ◽  
pp. 108620
Author(s):  
Abdelmagid E.A. Ali ◽  
Andrea Cioncolini ◽  
Dominique Laurence ◽  
Hector Iacovides

2021 ◽  
Author(s):  
Peter Levison Mwansa ◽  
Esha Narendra Varma ◽  
Victor Jose Aguilar ◽  
Alexander Amorocho ◽  
Daniel McPherson ◽  
...  

Abstract Inability to effectively isolate depleted aquifer formations due to severe losses during cementation leads to accelerated corrosion of the production casing. Per current practice, a top job is performed from surface to fill the annulus with cement, but with limited success in a severe losses’ scenario. The objective is to improve zonal isolation by applying V0 rated multiple stage cementation technology with inner string thus enhancing well integrity during the life cycle of the well. A metal expandable annular sealing system was selected as a reliable isolation mechanism for effective cementation behind aquifers due to its ability to provide high expansion in potentially washed-out wellbores and the feature of long multi-element sealing systems with built in redundancy. The inner string operated stage cementing system provides a reliable solution to selectively and accurately place cement above the metal expandable packer whilst maintaining V0 casing integrity once closed. Additionally, the unique combination of technologies provides a cost-effective life of well solution compared to current stage cementing methodologies. Following successful execution of three trial jobs, the multi-stage cement using V0 rated tools and an inner string was compared to similar jobs done per current cementing practices. Analysis involved reviewing the cement bond column coverage and quality (CBL) with offset wells. Cement bond log results showed that this technique enhanced the cement column quality behind the 9 5/8" casing across the aquifer zones with moderate to good cement for the most part. Contaminated cement was observed just below the previous casing shoe and this could be addressed by adding another stage tool just above the previous casing shoe. Overall results show improved cement column quality for this section when compared to conventional jobs with similar conditions and is recommended for future use in severe to total losses scenario. In a situation where losses are seen at the previous casing shoe, a three-stage job is recommended. Other benefits include: Security and confidence in gas tight sealing capability and mechanical integrity Precise and conclusive operation for open, close and lock with no risk of accidental lock Ability to squeeze cement below the metal expandable packer No reduction in pressure rating regardless of OH ID and full bore ID of casing No post operation drill out required of the stage tools V0 stage cementing tools with inner string and metal expandable annular sealing system are not available on Oil & Gas market as a single tool. Therefore, this combined technology application of solutions from different technology providers to access a dedicated solution is totally novel and creates an opportunity for future applications across the industry.


2021 ◽  
Author(s):  
Mahesh S. Picha ◽  
M. Azuan B. Abu Bakar ◽  
Parimal A. Patil ◽  
Faiz A. Abu Bakar ◽  
Debasis P. Das ◽  
...  

Abstract Oil & Gas Operators are focusing on zero carbon emission to comply with government's changing rules and regulations, which play an important role in the encouragement of carbon capture initiatives. This paper aims to give insights on the world's first offshore CCS project in carbonate reservoir, where wells will be drilled to inject CO2, and store produced CO2 from contaminated fields. To safeguard the storage containment, the integrity of all wells needs to be scrutinized. Development wells in the identified depleted gas field are more than 40 years old and were not designed with consideration of high CO2 concentration in the reservoir. In consequence, the possibility of well leakage due to accelerated corrosion channeling and cracks, along the wellbore cannot be ignored and require careful evaluation. Rigorous process has been adopted in assessing the feasibility for converting existing gas producers into CO2 injectors. The required defined basis of designs for gas producer and CO2 injection wells differs in a great extent and this governs the re-usability of wells for CO2 injection or necessity to be abandoned. Three (3) new CO2 injectors with fat to slim design approach, corrosion resistant alloy (CRA) material and CO2 resistant cement are designed in view to achieve lifecycle integrity. Optimum angle of 53 deg and maintaining the injection pressure of 50 bar at 90 MSCFD rate is required for the injection of supercritical CO2 for 20 years. During well execution, challenges such as anti-collision risk, total loss scenarios while drilling in Carbonate reservoir need to be addressed before execution. The completion design is also focusing on having minimal number of completion jewelries to reduce pressure differential and potential leak paths from tubing hangar down to the end of lower completion. The selection of downhole safety valve (TRSV) type is of high importance to accommodate CO2 phase attributes at different pressure/temperature. Fiber Optic is included for monitoring the migration of CO2 plume by acquiring seismic survey and for well integrity by analyzing DAS/DTS data.


2021 ◽  
Author(s):  
◽  
Hannah Robinson

<p>Marine biofouling is the accumulation of biological material (e.g. microorganisms, soft- and hard-fouling organisms) on the surface of an object submerged in seawater, and it remains a worldwide problem for shipping industries. The fouling of ship hulls results in a reduction of speed and manoeuvrability due to frictional drag, as well as increased fuel consumption and accelerated corrosion, and the exorbitant expenses and losses of efficiency attributed to biofouling have prompted the development of antifouling coatings. Current antifouling paints use copper as a biocidal agent, but copper-based paints are increasingly being banned due to environmental concerns about the non-target effects of leached copper. This project aims to circumvent these concerns and tightening regulations via a revolutionary concept: the development of marine antifouling paints that incorporate Cu(II)-selective ligands to draw the biocidal ingredient (i.e. Cu(II)) from seawater. A multistage strategy emerged for the development of this technology. First, criteria were established for the project’s ideal ligand, and ligands were synthesised or selected based on these criteria. Second, the ligands were incorporated in coatings through covalent modification of the paint binder or additives. Third, methodology was developed and implemented to test each coating’s ability to coordinate and retain Cu(II), as well as its subsequent ability to prevent microfouling by marine bacteria.   The suitability of two ligand classes was assessed: acylhydrazones and tetraaza macrocycles, specifically cyclen. Unlike the acylhydrazones, cyclen met the established criteria and was initially evaluated as a curing agent and/or surface-modifier in a two-pack epoxy system with resin Epikote™ 235. However, the Cu(II)-loading by these coatings was relatively low, being at most ~0.05% w/w, and the modification of silica, a common paint additive, with cyclen was explored as an alternative formulation route. The method for the functionalisation of silica with cyclen was optimised, and the maximum Cu(II)-loading achieved by the product was 2.60% w/w. The cyclen-functionalised silica was incorporated on the surface of an epoxy coating, and a bacterial adherence assay was developed to assess the cellular attachment of marine bacterium Vibrio harveyi to this coating, which was found to be undeterred. Yet, the development of the strategy and testing methodology by which the project’s goals may be achieved provides a solid foundation for future work.</p>


2021 ◽  
Author(s):  
Andrey Yugay ◽  
Hamdi Bouali Daghmouni ◽  
Andrey Nestyagin ◽  
Fouad Abdulsallam ◽  
Annie Morales ◽  
...  

Abstract Well Cementing can be divided into two phases – primary and remedial cementing. Primary cementing may have 3 functions: casing support, zonal isolation and casing protection against corrosion. First two functions are commonly recognized while the third one might be a point of discussion, as the full casing coverage with 100% clean cement is not something common in most of the fields. In fact, poorly cemented areas of the casing may become negatively charged and create a zones of accelerated corrosion rate. This paper is about main role of cementing - zonal isolation. The process of primary cementing assumes that cement slurry is being pumped into the casing and displaced outside. After wait on cement time (WOC) it becomes hard, develops compressive strength and creates impermeable seal that ensures hydraulic isolation. Old and well-known technique, it still remains one of the most challenging rig operations. It is unlikely to find a service company that would guarantee 100% cement displacement behind the casing all the way from top to bottom. Main challenges in this region are quiet common for many other fields – displacement in deviated sections, losses before and during cementing, exposure to pressure during cement settling. In case the main target is not achieved (no hydraulic isolation behind the casing) – we may observe behind casing communications resulting in sustainable pressures in casing-casing annuluses. In this situation the remedial cementing takes place. It's function is to restore isolation so the cement can work as a barrier that seals off the pressure source. Despite of the good number of sealants available on the market (time, pressure, temperature activated) that can be injected from surface to cure this casing-casing pressure, Company prefers not to do so unless there is a proven injectivity capability that would allow for the sealant to reach deep enough, to protect aquifers in case of outer casing corrosion. Otherwise that would be just a ‘masking" the pressure at surface. Therefore in general Company prefers rig intervention to cure the pressure across the cap rock in between the aquifers and the reservoir. Those aquifers are illustrated on the Figure 1 below: More details on Company casing design, cement evaluation issues, sustained casing pressure phenomena and challenges have been mentioned previously [Yugay, 2019].


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