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Prussian blue (PB) nanoparticles possess excellent physicochemical properties, including imaging features, robust photothermal conversion ability, catalytic activity, surface modifiability, effective drug loading, good stability, biocompatibility and biodegradability. With the advancement of nanotechnology, diverse PB-based nanoplatforms have been developed for biomedical applications. This review systematically summarized recent studies on PB-based nanoplatforms in the treatment of tumor (photothermal therapy, photodynamic therapy, chemotherapy, immunotherapy, theranostics, etc.), cardiovascular and cerebrovascular diseases (restenosis, atherosclerosis, thrombosis, ischemic stroke, etc.), bacterial infections (photothermal sterilization, biofilms disruption, etc.), and other inflammation-related diseases (liver injury, acute pancreatitis, inflammatory bowel disease, osteoarthritis, etc.). Finally, the existing challenges associated with current studies are discussed, and the future possible research and application directions for PB-based nanoplatforms are proposed, providing paradigms for subsequent development.

In order to cope with the global climate crisis, carbon capture, utilization, and storage are the key technologies to achieve carbon neutrality, and it is an elegant geological utilization method for the oil and gas industry to improve the recovery rate of crude oil by using CO2. However, in practical applications, the problem of low miscibility of CO2 and crude oil, resulting in low oil displacement efficiency, cannot be avoided. Thus, finding an appropriate method to increase the utilization rate of CO2 is a worth in-depth study. In light of this, this paper carries out the study on improving the CO2 flooding efficiency by using oil and gas amphiphilic surfactants. First of all, according to the molecular structure theory and the solubility experiment of surfactants in CO2, five kinds of surfactants and two kinds of additives with good performance of oil and gas were selected. Then, three experiments were conducted to explore the mechanism of the selected surfactants. The main mechanism of promoting the miscibility of CO2–crude oil is to reduce the interfacial tension of the oil and gas phases, followed by increasing the volume expansion of crude oil and reducing the viscosity of crude oil. Finally, through the slim tube displacement experiment, the oil displacement efficiency effect of adding the compound systems of SPO5/n-pentanol was simulated. The results show that the oil displacement efficiency is significantly higher than that of pure CO2 flooding, and the pressure of miscibility reduces at the same time. The selected reagents have a good effect of promoting miscibility. Therefore, this is an effective method to improve the geological utilization of CO2.

History matching and quantifying uncertainty in hydrocarbon production forecasts are considered important steps in reservoir simulations and are key processes for providing crucial information for decision making in the development of oil and gas fields. However, history matching of unconventional reservoirs with complicated fracture system is very computationally expensive and time consuming, and most of the data used are subject to high uncertainty. In addition, the objectives of history matching are usually conflicting, such as improving match of oil rate will deteriorate match of water rate. Previous studies on assisted history matching have mainly focused on optimizing a single-objective function, where the production and pressure data are combined as a single misfit value. In this study, the proposed algorithm extends the application of the proxy model to deal with multiobjective optimization in the context of reservoir history matching. Then, the resulted proxy model were conducted to analyze history-matching quality and obtain uncertainty prediction. Result suggests that the multiobjective surrogate reservoir model scheme not only could obtain reliable history matches and provide accurate uncertainty estimation, but the complexity of gridded fractures is mitigated through the workflow. The benefit of using the multiobjective surrogate reservoir model is to obtain a various set of history matched models while reducing the number of expensive reservoir simulation runs. The proposed methodology might also be useful for reservoirs in which simulation models could not reflect the production history and for those with high uncertainties in reservoir characterization.

The CO2 water-alternating-gas flooding (CO2-WAG) is a key technology to improve the oil recovery of low permeability reservoirs. The effect of CO2 flooding to enhance the oil recovery is affected by geological conditions and production systems. The effect of CO2 flooding parameters on the enhanced recovery factor should be clarified to optimize the production system. In this paper, the machine learning algorithms are used to carry out the study and establish a set of procedures for optimizing CO2 flooding parameters based on the artificial neural network (ANN) and the particle swarm optimization (PSO) algorithm. Firstly, large amounts of basic data are generated by the Monte Carlo sampling method. Then, the recovery factor by the water flooding and the CO2-WAG and the enhanced recovery factor by CO2-WAG in different models are calculated in the reservoir numerical simulator. Moreover, the machine learning method is used to establish a neural network model, and analysis of the sensitivity of parameters of the enhanced oil recovery (EOR) is carried out by combining with the Sobol method. Finally, the neural network model and the particle swarm algorithm are combined to optimize the parameters of CO2-WAG flooding. The results show that the established model has a good prediction accuracy (97.6%), thus it could be used to predict the enhanced recovery factor by CO2-WAG, and it is applicable in potential evaluation of enhancing the oil recovery and optimization for parameters in the CO2-WAG well group.

In the late 1990s, large amounts of low permeability resource plays in the south of Songliao basin have been discovered and made a great contribution to regional development, so far most of them need to be made efforts to improve recovery factors by tertiary method, CO2 flooding has an effective way for this kind of reservoir. CO2 injection pilot was implemented in 2008, it provided invaluable information for extensive areas to make gas injection and production scheme including produced gas recycling. Most low permeability reservoirs in Song Liao basin have no nature flow, the economic productivity could not be obtained except fracturing. Therefore, it leads to CO2 breakthrough early and produced gas profile variation greatly during the CO2-EOR process. CO2 is from the deeper natural gas field with CO2 concentration over 20%, after separation, the CO2 purity reaches 99% for injection. So how to treat the EOR produced gas is an environmental and economic issue to achieve zero emissions for the whole operations. According to the actual field test data, the vast majority of composition of produced gas are lighter hydrocarbon and CO2. This paper will analyze the composition of gas samples from Jilin oil field, understanding the components of the output gas variation with time. The phase behavior and mass transfer will be characterized by the minimum miscibility pressure (MMP) test and core flood experiment, and the quantitative description method will be obtained through the relationship between the individual component or segment components and sweep efficiency. Consideration the effect of CO2 impurities on MMP and displacement efficiency, the critical value of CO2 concentration of produced gas is 85%~95%, according to this study, all the produced gas can be reinjection without separation, the value for field application is approximately 90%. That means it would require mixing with pure CO2 for reinjection when CO2 concentration of produced gas is below 90%, otherwise, it could re-inject to oil field directly. All these results have been applied to achieve reasonable CO2 recycle.

The parallel reservoir perforating technology enables each shot hole in the gun to be fired in a direction parallel to the reservoir at a set angle, realizing a new technique in which the perforating projectile and the reservoir are parallel. The technology can be combined with the azimuth perforating technology. For the oblique angle of the reservoir and the wellbore, the oil pipe conveying type azimuth perforating technology, the inclined well self-orientation perforating technology and the modular cable perforating technology can be used for construction. The technology can effectively reduce the fracture pressure of reservoir construction, improve the productivity of medium and low permeability reservoir oil wells, and meet the needs of low permeability, thin poor layer and special well development and transformation.

Three homodinuclear lanthanide complexes [Ln2(μ-L)3] [Ln = La (1), Nd (2), Sm (3)] were synthesized by the reaction of Ln[N(SiMe3)2]3 (Ln = La, Nd, Sm) with 1.5 equiv. of the salen-type ligand N,N-bis(3, 5-di-tert-butyl-salicylidene)-1, 3-diaminobenzene (H2L) in THF at room temperature. X-ray diffraction studies revealed that the coordination arrangement around each lanthanide atom could be best described as distorted octahedral for complexes 2 and 3 and the two lanthanide metal ions are linked together by the three rigid m-phenylenediamine-based ligands. The ring-opening polymerization (ROP) of ϵ-caprolactone (ϵ-CL) was carried out using the complexes 1–3 as catalysts. The catalytic activities of dinuclear lanthanide complexes were greatly affected by ionic radii and the increased active order is Sm < Nd < La.