An Engineered Fit-For-Purpose Polymer Nanocomposite Seal Repair Material for Wellbores

Seal integrity of wellbores has become of significant interest due to repeated leakage and spill incidents occurring worldwide that jeopardize both human health and the environment in addition to causing significant economic burden. This is attributed to the fact that wellbores intersecting geographical formations contain potential leakage pathways. The cement-steel and cement-rock formation interfaces are recognized as two critical leakage pathways. A seal repair material that has good bond strength with both steel and rock formations in addition to the ability to completely fill thin microcracks is needed to restore the seal integrity of wellbores. In this research, engineered polymer nanocomposites are proposed for use as seal repair materials for wellbores. Novolac epoxy polymer nanocomposites (PNCs) show more than 200% and 250% higher bond strength with steel and shale, respectively, when compared with microfine cement. In addition, it was found that Novolac epoxy PNCs have up to 545% and 761% higher displacement at peak load and toughness than microfine cement respectively. Moreover, Novolac epoxy PNCs was able to completely fill 800 mm microcracks that microfine cement were not able to completely fill. Microstructural investigations using Fourier-Transform Infrared spectroscopy (FTIR) and Dynamic Mechanical Analysis (DMA) showed that incorporating aluminum nanoparticles (ANPs) in Novolac epoxy PNCs interrupted the polymerization process, which allowed free epoxy groups to improve the bond strength of PNCs with both shale and steel surfaces. On the other hand, penetrability calculations based on contact angle and surface tension of seal repair materials showed that nanomodified methyl methacrylate (NM-MMA) incorporating 0.5 wt.% ANPs has higher potential to penetrate thin microannuli than microfine cement and Novolac epoxy PNCs. NM-MMA was able to seal thin microcracks as small as 30 mm while microfine cement has very limited penetration in such small microcracks. Furthermore, NM-MMA showed more than 1000%, 460%, and 8000% higher apparent bond strength, displacement at failure, and toughness than microfine cement respectively. Microstructural investigation using XRD analysis showed that incorporating ANPs in MMA increased the degree of polymer crystallization enabling significant improvement in polymer ductility, toughness, and reduced creep compliance. A performance study of seal repair materials was evaluated based on their efficiency to seal the cement-steel interface, their ability to withstand cyclic casing pressure, and their ability to withstand harsh environmental conditions. The results showed that microfine cement efficiency was limited to 24%. On the other hand, NM-MMA was able to achieve seal efficiency as high as 103%. Moreover, NM-MMA was able to withstand casing pressure cycles two orders of magnitude higher than microfine cement. Finally, a durability investigation using a weight loss study showed that all PNC seal repair materials have higher resistance to harsh environmental conditions than microfine cement

A New CFRP-UHPC System for Strengthening Reinforced Concrete T-Beams

Since Fiber Reinforced Polymer (FRP) was introduced to the construction field, strengthening of reinforced concrete beams using FRP laminates became a common repair and retrofit technique. Traditionally, Reinforced Concrete (RC) beams are strengthened by adhering FRP laminates to the tension side of the beam to work as an additional tensile reinforcement. Although this technique has been proven as an efficient strengthening technique, in many cases reaching the tension side of the beam is challenging due to the existing of ducts, pipes or cables underneath the beam in buildings. This challenge is magnified in bridges crossing water canals or major highways where expensive scaffolding is needed to reach the underside of beams. This research investigates a flexural strengthening system for T-beams that avoids the need to reach the tension underside. In this technique, the top 51 mm cover of the beam is removed, and Carbon Fiber reinforced polymer (CFRP) laminates are attached to the existing concrete surface after which an Ultra High performance Concrete (UHPC) overlay is then cast on top of the CFRP. The hypothesis of this technique is that the very high compressive strength of the UHPC overlay will push the neutral axis up and allow the CFRP laminates to be under tension. Four RC beams were cast and tested under four-point bending until failure. The proposed strengthening technique showed an increase in the load capacity while strengthening beam with only UHPC overlay had no significant effect on the load capacity of the beam. Unlike the expected, replacing the UHPC overlay with Latex Modified Ultra High Performance Concrete (LMUHPC) overlay did not increase the bond between the overlay and the T-beam and resulted in low load capacity. These results indicate that the proposed technique might be beneficial for shallow to medium T-beams and slabs.Department of EnergyCivil EngineeringMastersUniversity of New Mexico. Dept. of Civil EngineeringReda Taha, MahmoudMaji, ArupShen, Yu-Li

Fly Ash-Based Geopolymers as Lower Carbon Footprint Alternatives to Portland Cement for Well Cementing Applications

Ordinary Portland cement (OPC) is currently the preferred material for the creation of barriers in wells during their construction and abandonment globally. OPC, however, is a very carbon-intensive material with some inherent technical weaknesses. These include a low casing-to-cement bond strength which may allow for the formation of micro-annuli, which in turn can become a conduit for greenhouse gas transport (primarily of methane, a powerful greenhouse gas) to surface. Alkali-activated materials (AAMs), also known as geopolymers, have a much lower manufacturing carbon footprint than OPC and can be a good alternative to OPC for primary and remedial well cementing applications. This paper reports on a comprehensive study into the use of Class F fly ash-based geopolymers for a large variety of downhole well conditions, ranging from lower-temperature surface and intermediate casing cementing conditions to much higher temperature conditions (up to 204 °C (400 °F)) that can be encountered in high-pressure, high-temperature (HPHT) wells and geothermal wells. The rheological and mechanical properties of alkali-activated fly ash with six different sodium and potassium-based hydroxide and silicate activators were measured and compared to OPC. The results show that geopolymer formulation properties can be tuned to a variety of downhole cementing conditions. With the application of a suitable alkaline activator, geopolymers exhibit good compressive and tensile strength and an outstanding casing-to-cement bond strength of up to 8.8 MPa (1283 psi), which is more than an order of magnitude higher than OPC. This has important implications for preventing the creation of micro-annuli as a result of casing-to-cement interface debonding, thereby preventing the potential leakage of methane to the atmosphere on future wells that use geopolymers rather than OPC for barrier creation

Polymer Concrete for Bridge Deck Closure Joints in Accelerated Bridge Construction

Prefabricated concrete bridge deck panels are utilized in Accelerated Bridge Construction (ABC) to simplify bridge deck construction. Concrete with good bond and shear strength as well as excellent flowability is required to fill bridge deck closure joints. This paper discusses the use of polymer concrete (PC) for bridge deck closure joints in ABC. PC produced using poly methyl methacrylate and standard aggregate was tested. Test results of PC are compared to Ultra-High Performance Concrete (UHPC). Development length, lap splice length and shear strength of unreinforced PC were tested. It is shown that PC has a development length of 3.6 to 4.1 times the reinforcing bar diameter that is close to one-half the development length of 6 to 8 times the bar diameter required with UHPC. PC also showed a shorter splice length compared with that reported for UHPC. Finally, unreinforced PC showed shear strength that is twice that of UHPC. It is evident that using PC in bridge deck closure joints in ABC can improve constructability and provide cost-savings and eliminate reinforcing bar congestion

Improving Fatigue Performance of GFRP Composite Using Carbon Nanotubes

Glass fiber reinforced polymers (GFRP) have become a preferable material for reinforcing or strengthening reinforced concrete structures due to their corrosion resistance, high strength to weight ratio, and relatively low cost compared with carbon fiber reinforced polymers (CFRP). However, the limited fatigue life of GFRP hinders their use in infrastructure applications. For instance, the low fatigue life of GFRP caused design codes to impose stringent stress limits on GFRP that rendered their use non-economic under significant cyclic loads in bridges. In this paper, we demonstrate that the fatigue life of GFRP can be significantly improved by an order of magnitude by incorporating Multi-Wall Carbon Nanotubes (MWCNTs) during GFRP fabrication. GFRP coupons were fabricated and tested under static tension and cyclic tension with mean fatigue stress equal to 40% of the GFRP tensile strength. Microstructural investigations using scanning electron microscopy (SEM) and Fourier Transform Infrared (FTIR) spectroscopy were used for further investigation of the effect of MWCNTs on the GFRP composite. The experimental results show the 0.5 wt% and the 1.0 wt% MWCNTs were able to improve the fatigue life of GFRP by 1143% and 986%, respectively, compared with neat GFRP

Roadway Embedded Smart Illumination Charging System for Electric Vehicles

Inspired by the fact that there is an immense amount of renewable energy sources available on the roadways, such as mechanical pressure, this study presents the development and implementation of an innovative charging technique for electric vehicles (EVs) by fully utilizing the existing roadways and state-of-the-art nanotechnology and power electronics. The developed Smart Illuminative Charging is a novel wireless charging system that uses LEDs powered by piezoelectric materials as the energy transmitter source and thin film solar panels placed at the bottom of the EVs as the receiver, which is then poised to deliver the harvested energy to the vehicle’s battery. The piezoelectric materials were tested for their mechanical-to-electrical energy conversion capabilities and the relatively large-area EH2N samples (2 cm × 2 cm) produced high output voltages of up to 52 mV upon mechanical pressure. Furthermore, a lab-scale prototype device was developed to testify the proposed mechanism of illuminative charging (i.e., “light” coupled pavement and vehicle as a wireless energy transfer medium)

Smart Charging of Future Electric Vehicles Using Roadway Infrastructure

Corresponding data set for Tran-SET Project No. 18ITSTSA03. Abstract of the final report is stated below for reference: Inspired by the fact that there is an immense amount of renewable energy sources available on the roadways such as mechanical pressure and frictional heat, this study presented the development and implementation of an innovative charging technique for future electric vehicles (EVs) by fully utilizing the existing roadways and the state-of-the-art nanotechnology and power electronics. The project introduced a novel wireless charging system, SIC (Smart Illuminative Charging), that uses LEDs powered by piezoelectric nanomaterials as the energy transmitter source and thin film solar panels placed at the bottom of the EVs as the receiver, which is then poised to deliver the harvested energy to the vehicle’s battery. Through the project, the energy-harvestable 2D nanomaterials (EH2Ns) were tested for their mechanical-to-electrical energy conversion capabilities and the relatively large-area EH2N samples (2cm x 2cm) produced high output voltages of up to 52mV upon mechanical pressure. An electrically conductive glass fiber reinforced polymer (GFRP) was developed to be used as physical support in the integrated SIC system. Furthermore, a lab-scale prototype device was developed to testify the mechanism of illuminative charging. The project team was able to prove the feasibility of SIC concept and the start to end conversion efficiency was calculated to be 40%. The project team also provided field implementation recommended framework based on the results from the small-scale prototype developed. The framework discussed how the developed SIC can be implemented in the field and what are the expected outcomes. The team recommended inserting the EH2N embedded in the GFRP, the LEDs and the needed circuitry in the wheel path of the vehicles on the pavement by cutting a sawtooth compartment with a width of 18’’ and a length of 8’ every couple of miles. On the vehicle, a PV array will be placed on the underside between the wheel wells of each side of the EV to capture the illumination from the LEDs embedded in the roadway. The detailed strategy is presented in this report

Smart Charging of Future Electric Vehicles Using Roadway Infrastructure [Supporting Dataset]

69A3551747106National Transportation Library (NTL) Curation Note: As this dataset is preserved in a repository outside U.S. DOT control, as allowed by the U.S. DOT's Public Access Plan (https://doi.org/10.21949/1503647) Section 7.4.2 Data, the NTL staff has performed NO additional curation actions on this dataset. The current level of dataset documentation is the responsibility of the dataset creator. NTL staff last accessed this dataset at its repository URL on 2022-11-11. If, in the future, you have trouble accessing this dataset at the host repository, please email [email protected] describing your problem. NTL staff will do its best to assist you at that time.Inspired by the fact that there is an immense amount of renewable energy sources available on the roadways such as mechanical pressure and frictional heat, this study presented the development and implementation of an innovative charging technique for future electric vehicles (EVs) by fully utilizing the existing roadways and the state-of-the-art nanotechnology and power electronics. The project introduced a novel wireless charging system, SIC (Smart Illuminative Charging), that uses LEDs powered by piezoelectric nanomaterials as the energy transmitter source and thin film solar panels placed at the bottom of the EVs as the receiver, which is then poised to deliver the harvested energy to the vehicle\u2019s battery. Through the project, the energy-harvestable 2D nanomaterials (EH2Ns) were tested for their mechanical-to-electrical energy conversion capabilities and the relatively large-area EH2N samples (2cm x 2cm) produced high output voltages of up to 52mV upon mechanical pressure. An electrically conductive glass fiber reinforced polymer (GFRP) was developed to be used as physical support in the integrated SIC system. Furthermore, a lab-scale prototype device was developed to testify the mechanism of illuminative charging. The project team was able to prove the feasibility of SIC concept and the start to end conversion efficiency was calculated to be 40%. The project team also provided field implementation recommended framework based on the results from the small-scale prototype developed. The framework discussed how the developed SIC can be implemented in the field and what are the expected outcomes. The team recommended inserting the EH2N embedded in the GFRP, the LEDs and the needed circuitry in the wheel path of the vehicles on the pavement by cutting a sawtooth compartment with a width of 18\u2019\u2019 and a length of 8\u2019 every couple of miles. On the vehicle, a PV array will be placed on the underside between the wheel wells of each side of the EV to capture the illumination from the LEDs embedded in the roadway. The detailed strategy is presented in this report. The total size of the described zip file is 2.12 MB. Files with the .xlsx extension are Microsoft Excel spreadsheet files. These can be opened in Excel or open-source spreadsheet programs. Docx files are document files created in Microsoft Word. These files can be opened using Microsoft Word or with an open source text viewer such as Apache OpenOffice