In recent times, particularly in the 21st century, there has been an alarming increase in the demand for global energy, along with continuous depletion in conventional oil reservoirs. This necessity has incentivized interested scholars and operators worldwide to seek alternative oil resources. To secure such accelerating energy demand, considerable effort has been directed toward the development of previously unconventional oil formations that, in past decades, had remained sidelined. Although shale oil reservoirs have seen tremendous success over the past decade, the continued challenges of rapidly declining oil flow rates and oil retention in the pores continuously persist. Substantial attempts have been made to improve shale-bypassed oil recovery; however, there is little data about the accessibility on recovery mechanisms, especially in the oil field. Furthermore, approachesparticularly, Huff-n-Puff (H-n-P) experiments using conventional proceduresfail to properly represent field conditions and they generate deceptive findings, because the utilized cores are not simulated under realistic reservoir conditions, leaving the significance of critical factors unclear. Therefore, this review study comprehensively and specifically discusses the feasibility of enhanced oil recovery (EOR) methods in unconventional oil reservoirs. Beside addressing the validity of the currently applied H-n-P technology in shale/tight oil reservoirs and underlining some critical gaps regarding laboratory results, modified technology is proposed in this paper for a better field future performance. The study is divided into sections, and each section analyzes the role of one specific H-n-P portion in detail, such as preferable injected solvents, their mechanisms, and critical factors affecting H-n-P recovery. The exceptions to this are the first and second sections, which provide a brief introduction about shale and tight oil reservoirs, a history of applied technology, and the method’s current problem statement. In the Introduction section, the authors will justify why this Review fills a critical gap in the field. Within the assessment study, great focus is given to the H-n-P technique, its parameters, and effective processes. In the final sections, carefully chosen experimental results and tools are reviewed to highlight the controversy and state “the gap”.

After drilling each section of a well, cement is placed in the annulus of the casing and the formation. The cement integrity must be ensured during the life cycle of the well or after abandonment. If for any reason, the cement lost its integrity, the consequences could be severe for personnel, equipment, and the environment. When the cement fail, leakages may occur through the cement pathways and sealant materials are used to plug these pathways. This study investigates a temperature activated epoxy resin sealant to evaluate the potential use of this sealant as an alternative to Portland cement in oil and gas wells. This study focuses on analyzing the rheological behavior of the sealant, the effect of temperature on the rheology and the curing time of the sealant, the penetrability of the sealant into small voids, and the blocking efficiency of the sealant. Experimental tests were conducted to evaluate the epoxy resin sealant including rheological measurements, density, injectivity, blocking efficiency, and mechanical properties. The findings of this study show that this sealant has low viscosity and Newtonian rheological behavior, low density as low as water, high injectivity and penetrability even in small gaps, ability to resist differential pressure higher 1000 psi, and extremely high compressive strength. This work demonstrates that epoxy resin sealant can be used effectively and safely in sealing cement voids.

Ceramic membranes offer considerable promise for future industrial applications due to their superior chemical, mechanical, and thermal stabilities, resistance to harsh operating conditions, and long‐term operating processes. However, several bottlenecks still limit their commercial scale‐up in filtration and separation applications, including brittleness, the high costs of conventional ceramic materials, and fouling. Despite several articles in the literature on ceramic membranes, this review focuses on recent progress, technical strategies, and methods to mitigate these limitations that significantly impact their separation and filtration performance. The use of alternative naturally occurring ceramic materials to mitigate the high costs of conventional ceramic materials is discussed, as well as strategies to improve the mechanical strength of brittle ceramic membranes by increasing sintering temperatures and using support materials. Additionally, advanced techniques to mitigate fouling accumulation and wetting in the pores and on the ceramic membrane surface, such as increasing membrane hydrophilicity and surface modification, are addressed. Despite progress in technical solutions for mitigating the bottlenecks of ceramic membranes, these limitations persist. Therefore, the present limitations and future research directions are highlighted.

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