Light-weight carbon fiber/silver-coated hollow glass spheres/epoxy composites as highly effective electromagnetic interference shielding material

Highly effective electromagnetic interference shielding materials with light-weight feature are urgently demanded for releasing electromagnetic pollution. In this study, the hollow glass spheres were coated with silver particles to produce electrically conductive microspheres. The Carbon fiber/silver-coated hollow glass spheres (Ag@HGMs)/epoxy composites were manufactured by composites liquid molding process. The electromagnetic interference shielding properties of the composites were investigated in the X-band (8.2–12.4 GHz) range. The Ag@HGMs play a role in filling up the vacancy of the conductive network of carbon fibers in the composites, which not only form new conductive pathways but also act as bridges to connect CFs and provide additional channels for the electron transfer within the composites thus improving the electrical conductivity. The total shielding effectiveness (SET) increases with increasing Ag@HGMs loadings and the maximum SET is high as 88.1 dB. The increased SET dominated by absorption loss SEA is attributed to the high conductivity and multilayer construction of carbon fiber veil. The maximum specific SE of the carbon fiber/Ag@HGMs/epoxy composites can achieve 128.8 dB cm3/g, simultaneously the tensile strength and modulus can reach 95.6 MPa and 2.71 GPa, which provides a facile and promising strategy for designing and developing light-weight and high performance electromagnetic interference shielding materials.

Drilling with Glass and Air: Using Hollow Glass Spheres to Address a Wide Ranging Drilling Challenge in a Safe, Efficient and Cost-Effective Manner

A major development with multiple rigs delivering extensive multi-laterals encountered a pervasive mud-window issue within the reservoir. The resulting severe mud losses, extensive NPT and formation-damage was also deteriorating with time due to depletion. Conventional approaches to stem losses had failed and adoption of an energized mud-system with acceptable Effective Circulating Density (ECD) was not considered cost effective, pragmatic nor safe. Instead a novel application using Hollow-Glass-Spheres (HGS) was trialled, that demonstrated an effective and highly successful outcome. With 10 rigs drilling 60-70 wells per-year, each with 5,500 to 6,750m in the reservoir, quick resolution of the issue was required. For these reasons the Team at bp Russia looked carefully at alternatives that might fit the mud-window, but that offered a realistic approach for the environment and conditions in Eastern Siberia. The Team identified HGS as an approach to lighten the mud, often used for cementing ECD, application for drilling has been limited. For this approach we required an option with broad capabilities that could be scaled-up and exported to other development areas where such issues existed. This paper will report on the planning, delivery, and execution of a pilot on the Sb. field at TYNGD, in Eastern Siberia. Initially deployed on three wells, including multi-laterals, the paper will walk through the engineering considerations, during the planning and execution phases. Reporting comprehensively on the data gathered and the many lessons learned during the incremental and stepwise deployment. Data will be provided that demonstrated loss-free drilling was achieved where this had not occurred before, with a dramatic reduction in NPT, FLA needs and costs. The paper will also report on the post drilling productivity and comparison with offset wells drilled with conventional mud systems and suffering severe losses. The results of this pilot have beaten all expectations, there have been many insights and the Team are now looking to set a timetable to scale-up across the NOJV. Much has been learned, waste HGS material has been demonstrated to be an effective FLA pill in other sections of the well and centralisation of mud process may offer additional cost savings and improvements. Further efficiencies are expected to be achieved and potential across the Company portfolio could be a major game changer. HGS for cementing is well documented, application for drilling fluids has been less reported and almost exclusively applied to one-off sections/wells. The TYNGD application is novel as this is a major new development with 10 drilling rigs. Application is on multi-laterals and prior offset wells are available for direct comparison. The results of the approach demonstrate a new way of performing well construction in an effective manner for major Field Developments where losses are prevalent.

Impact of Silica on Geotechnical Properties of Clayey Soil Present in Edfu- Aswan, Egypt

It may be necessary to improve the engineering properties of clayey soils to make them suitable for construction by using some kind of stabilization methods. Treatment with lime, cement or waste materials such as silica fume (SF) has traditionally been used for the stabilization of clayey soils. The soil chosen in this research was extracted from a site in Edfu- Aswan, Egypt. Investigating the effect of properties of cohesive soils when mixed with SF is the main objective of this study. Silica fume is a mineral made up of ultra-fine solid, amorphous silicon dioxide glass spheres (SiO2) from the metallurgical industries company (E.JS.C) in Edfu. A series of laboratory experiments for samples prepared with different percentages were implemented of SF 0%, 2%, 4%, 6%,8%, and 10%. The results show that the blend will increase the maximum dry density of clayey soils. Their Plasticity Index and the liquid limit would increase, the permeability of clayey soil decreases, the unconfined compression strength will increase. All of these results can be summarized to say that the engineering properties of cohesive soils can be improved by combining Silica Fume and clayey soils together.

Treatment of hollow glass bubbles with silane coupling agent. sem on hollow glass bubbles, before and after treatment with silane coupling agent

In this study will be presented, how 20 millilitres of Silane Coupling Agent, adhered on 5 grams of Hollow Glass Bubbles (HGB), how the micro bubbles are looking before and after mixing, how to filter the hollow spheres from the agent and what needed to be taken in consideration when using coupling agents in processes. This paper will show how Silane Coupling Agent (3-Aminopropyl) triethoxysilane, adhered on the Hollow Glass Bubble (HGB). It is expected to observe at HR-SEM (High- Resolution Scanning Electron Microscopy) how the Hollow Glass Bubbles looks when the Silane Coupling Agent (KH-550) is applied on the filler vs when is not. During the process will be concluded, what risks should be taken in consideration, when using Silane Coupling Agents on Hollow Glass Spheres and what important information/ steps are needed to be taken in consideration before and after coupling treatment.