Research on nanotechnology application in the oil and gas industry has been growing rapidly in the past decade, as evidenced by the number of scientific articles published in the field. With oil and gas reserves harder to find, access, and produce, the pursuit of more game-changing technologies that can address the challenges of the industry has stimulated this growth. Nanotechnology has the potential to revolutionize the petroleum industry both upstream and downstream, including exploration, drilling, production, and enhanced oil recovery (EOR), as well as refinery processes. It provides a wide range of alternatives for technologies and materials to be utilized in the petroleum industry. Nanoscale materials in various forms such as solid composites, complex fluids, and functional nanoparticle-fluid combinations are key to the new technological advances. This paper aims to provide a state-of-the-art review on the application of nanoparticles and technology in the petroleum industry, and focuses on enhanced oil recovery. We briefly summarize nanotechnology application in exploration and reservoir characterization, drilling and completion, production and stimulation, and refinery. Thereafter, this paper focuses on the application of nanoparticles in EOR. The different types of nanomaterials, e.g., silica, aluminum oxides, iron oxide, nickel oxide, titanium oxide, zinc oxide, zirconium oxide, polymers, and carbon nanotubes that have been studied in EOR are discussed with respect to their properties, their performance, advantages, and disadvantages. We then elaborate upon the parameters that will affect the performance of nanoparticles in EOR, and guidelines for promising recovery factors are emphasized. The mechanisms of the nanoparticles in the EOR processes are then underlined, such as wettability alteration, interfacial tension reduction, disjoining pressure, and viscosity control. The objective of this review is to present a wide range of knowledge and expertise related to the nanotechnology application in the petroleum industry in general, and the EOR process in particular. The challenges and future research directions for nano-EOR are pinpointed.

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Short-term gas migration during the cementing process has been a challenge in the oil and gas industry. During the curing process, the cement slurry will slowly lose its hydrostatic pressure allowing gas from the formation to enter the annulus. The ideal cement should generate gel structure rapidly after the pumping is finished to hold gas from entering the slurry. Therefore, the rheological properties of cement play a key role in designing reliable gas tight cement. Sets of rheological evaluations were performed on four different zonal isolation materials (neat G cement, geopolymer, gas tight cement, and rapid hardening cement). The cement samples used in the evaluation are industrially used for cementing jobs in the North Sea. The flow rotation and oscillation test were executed at 25°C by using a rheometer. The flow rotation test was performed initially and followed by the oscillation test. In the flow rotation test, the slurry was pre-sheared at 100 1/s for 60 sec, continued ramp-up (0.01-511 1/s) and ramp-down (511-0.01 1/s). The hysteresis area between ramp-up and ramp-down shows the degree of thixotropy of each material. Afterward, an amplitude sweep test was performed at a constant frequency of 10 rad/sec under oscillation movement. The test showed the behavior of materials under a deformation phase. The set of tests measured the storage modulus (G′) and loss modulus (G″) at elevated strain. It also shows the elasticity of the material and its internal strength which could be important parameters for handling the gas invasion. Of four different types of cementitious material, the commonly used gas tight cement had the highest thixotropy and good elasticity compared to other cementitious materials which could explain how it has been widely used for shallow gas cementing. This paper provides an in-depth rheological evaluation of gas tight cementitious material to better understand the importance of rheological parameters for shallow gas and water bearing zones.

Methane gas leaks from shallow gas zone have been reported in some areas in the North Sea. In the North Sea, shallow gas zones can have temperatures below 25°C with relatively low pore pressure. It is necessary to prevent the flow of this gas behind casings by performing proper zonal isolation with cementitious materials. A series of experiments were performed on three different types of industrially used and state-of-the-art cementitious materials and a rock-based geopolymer to evaluate their performance for shallow gas zonal isolation. Neat class G Portland cement, industrial rapid-hardening cement, gas-tight cement, and granite-based geopolymer were the selected materials. The research aims to reveal the performance of these zonal isolation materials and their potential shortcomings due to the low-temperature effect. Material characterizations were performed on three states of the materials: liquid-state, gel phase, and solid-state. Rheological properties and consistency are evaluated at the liquid state of the materials. Static gel strength tests were performed to evaluate the strength of gel structure and transition time. The compressive strength of samples was evaluated using an ultrasonic cement analyzer (UCA) and unconfined compressive strength (UCS). In addition, the scanning electron microscopy (SEM) technique was utilized to reveal microstructure of the materials. To have a similar hydration process as in the low-temperature shallow gas zone, slurries were mixed and pre-conditioned at temperatures of 4 and 25°C. The experiment shows that the hydration process of the cement is less optimum in the low-temperature condition, which affects the gel strength development of the cement during the transition from liquid to a solid phase. It also resulted in the lower final compressive strength of the cured specimens.