Zonal isolation and cement sheath integrity are vital for a consistent oil and gas production process in an economic and environmentally conscious manner. However, cement is a brittle material that can fail under repeated application of stresses. The objective of this research is developing a novel material Complex micro-containers (CMC) to induce autonomous self-healing properties to the cement using the mechanism of a self-expanding polyurethane foam formation in a crack area. Complex micro-containers (CMC) consist of polyol-loaded polyurea (PUa) micro- and nanocapsules loaded inside the isocyanate-filled core of larger polyurethane (PU) microcapsules. The method of CMC creation includes several steps. During the first step, an oil-in-oil emulsion, composed of organic solvent and polyol-polyamine solution, is created. The second step is made of a polyurea shell formation directly at the surface of the polyol droplets controlled by an addition of isocyanate. As the result of the interfacial polymerization process, micro- and nanocapsules are formed. Then, they are mixed with the isocyanate solution and further emulsified in the water-based media. The droplets of isocyanate with micro- and nanocapsules are encapsulated through polyurethane shell formation by adding polyol. A variety of factors alter the morphology and size of the micro- and nanocapsules including parameters of emulsion's creation, core/shell ratio, and dispersion speed. The optimal content of isocyanate and polyols in cores of polyurea and polyurethane microcapsules, mechanical mixing parameters, and concentration of emulsifiers in oil-in-oil and oil-in-water emulsions were determined. FTIR-spectroscopy was used to identify the chemical structure and to demonstrate encapsulation of the isocyanate core and the polyurethane shell and the polyol core and polyurea shells. TGA-analysis, optical microscopy, and scanning electron microscopy methods were used to determine the core content of micro- and nanocapsules and their size. The peeling strength test proved that the release of the microcapsules’ core content occurs by pressure application and the diisocyanate reacts with polyol and water and creates the polyurethane material. The main advantage of CMC is its expandable properties due to the formation of a polyurethane foam in the presence of water that can effectively fill the micro-cracks directly in a place of cement breakage. Integration of developed new material into the cement body will allow for improving a long-term wellbore isolation and mitigating a leakage potential in the cemented annuli.

Produced water is by far the largest by product by volume associated with oil and gas production. To minimize environmental impact of the produced water disposal, reuse produced water, and fulfill the targeted Zero-Liquid-Discharge approach, it is necessary to develop new economically viable technologies for water purification. The objectives of the research enclose development of the sustainable ion-exchange resin from the discarded expanded polystyrene via a multi-stage process with plasma treatment. The process of sustainable ion-exchange resins’ preparation includes several consecutive steps. At first, a polystyrene waste is collected and dissolved in an organic solvent.After that the polymeric beads are prepared using a microdroplet precipitation mechanism. Then, one part of the polystyrene beads is modified with the green gas-liquid interfacial plasma (GLIP) sulfonation process producing a strong acidic cation exchange resin. The other part is functionalized by amine groups in cyclopropylamine medium producing strong basic anion exchange resin. Robust and self-sustained process for creating the polystyrene beads was developedusing the «solvent-non-solvent» system. The bead formation process is realized by a controlled, laminar liquid jet broken into equally sized beads by vibrations at optimized frequency value. This process was performed using the in-house state-of-the-art encapsulator instrument. The concentration of waste expanded polystyrene and a filler in a solution was optimized. The size of obtained porous beads was measure around 750-1000 micron and can be controlled by the nozzle size and frequency of vibration. The research describes a new method of sustainable ion-exchange resin creation. The utilization of this novel material is a beneficial approach to re-use plastic waste and reuse it to clean produced water from dissolved salts. Moreover, plasma technology that is used for polystyrene treatment is probably the most versatile surface treatment technique and, moreover, it is environmentally friendly.