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Chemical-assisted steam flooding (CASF) is a promising method for heavy oils. However, few researches have investigated the CASF performance on offshore heavy oil reservoirs recovery after water flooding. In this study, a numerical simulation model was developed to simulate CASF processes for offshore heavy oil reservoirs after water flooding. Then, a comparison of CASF and various thermal methods was made to assess the feasibility of CASF in an offshore heavy reservoir of Bohai Bay, China. Finally, sensitivity analysis was performed to evaluate the effects of the gas-liquid ratio, foaming agent concentration, surfactant concentration, the size of nitrogen foam slug, the size of surfactant slug, and the number of chemical injection round on CASF performance by the developed model. The results showed that the developed numerical method can precisely simulate the CASF processes. CASF is a potential and effective method for offshore heavy oil reservoirs after water flooding. The most suitable gas-liquid ratio was around 2 : 1 under the simulation conditions. Considering the economic benefit, it is significant to optimize the CASF parameters, such as foaming agent concentration, the size of nitrogen foam slug, and the number of chemical injection round. [ABSTRACT FROM AUTHOR]

Background: A biosimilar needs to demonstrate its similarity to the originator reference product (RP) in terms of structural and functional properties as well as nonclinical and clinical outcomes. Objectives: The aim was to assess the analytical similarity between the trastuzumab biosimilar HLX02 and Europe-sourced Herceptin® (EU-Herceptin®) and China-sourced Herceptin® (CN-Herceptin®) following a quality-by-design (QbD) quality study and tier-based quality attribute evaluation. Methods: A panel of highly sensitive and orthogonal methods, including a novel Fc gamma receptor IIIa (FcγRIIIa) affinity chromatography technique that enables quantitative comparison of glycan effects on effector function, was developed for the assessment. To ensure the full product variability was captured, ten batches of HLX02 were compared with 39 RP batches with expiry dates from August 2017 to March 2021. Results: The extensive three-way similarity assessment demonstrated that HLX02 is highly similar to the RPs. Furthermore, the %afucose, %galactose, and FcγRIIIa affinity of the RPs were observed to first decrease and then return to the original level in relation to their expiry dates, and the RP batches can be subgrouped by their FcγRIIIa affinity chromatograms. HLX02 is demonstrated to be more similar to the RPs of the high FcγRIIIa affinity group. Conclusion: Besides having an overall high analytical similarity to both EU-Herceptin® and CN-Herceptin®, HLX02 is more similar to Herceptin® with high FcγRIIIa affinity, a result that demonstrates the power of the novel FcγRIIIa affinity chromatography technology in biosimilarity evaluation. [ABSTRACT FROM AUTHOR]

Graphical abstract In order to evaluate reservoir adaptability of the ASP (alkali/surfactant/polymer) system, its field tests have been carried out in Saertu, Xingshugang and Lamadian Oilfield of Daqing. The results show that crude oil compositions have a great effect on the agent concentration in produced liquid and oil recovery increment. Therefore, this paper researches crude oil composition of three oilfields in Daqing, and the interaction between oil and ASP system. The effect of crude oil compositions on the oil recovery increment and the properties of produced liquid are also further studied. Abstract In order to evaluate reservoir adaptability of the ASP (alkali/surfactant/polymer) system, its field tests have been carried out in Saertu, Xingshugang and Lamadian Oilfield of Daqing. The results show that crude oil compositions have a great effect on the agent concentration in produced liquid and oil recovery increment. Therefore, this paper researches crude oil composition of three oilfields in Daqing, and the interaction between oil and ASP system. The effect of crude oil compositions on the oil recovery increment and the properties of produced liquid are also further studied. Results show that, the active components of crude oil from three oilfields have the peak feature of typical saturated monocarboxylic acids (fatty acid and naphthenic acid). And there are larger types of organic acids in Lamadian oil active components, from nonane acid to nonacosane acid. In addition, the content of n -alkanes with high carbon component in Lamadian raffinate is larger, and its composition is closer to that of heavy alkylbenzene sulfonate. After the interaction between various crude oil and ASP system, the partition coefficients of surfactant and alkali in Lamadian oil is higher. Besides that, the interfacial tension between ASP system and active components or raffinate are both higher. However, there is ultra-low interfacial tension between ASP system and crude oil. This indicates that synergistic effect exists among the colloid and asphaltene in crude oil and surfactant component, which jointly promotes the substantial decrease in interfacial tension. Furthermore, the field tests have proved the results of laboratory physical simulation experiments. [ABSTRACT FROM AUTHOR]

Based on the thermodynamic stabilities and molecular simulation, two trimethyldibenzothiophene molecular indicators, that is, 2,4,6-/(1,4,6 + 1,4,8 + 3,4,6)-trimethyldibenzothiophene (TMDBT) and (2,4,7 + 2,4,8)-/(1,4,6 + 1,4,8 + 3,4,6)-TMDBT (the numbers indicate the position of methyl-substitute), were proposed to trace subsurface oil migration orientations and reservoir filling pathways. In this paper, we successfully applied the aforesaid parameters both in an Ordovician carbonate reservoir of the Tuoputai region of the Tarim Basin (NW China), and in an Eocene clastic lacustrine reservoir of the Fushan Depression in the Beibuwan Basin, South China Sea. Besides the migration fractionation is proven the main control factor for the relative contents of TMDBT isomers in corresponding oils, which indicates that the trimethyldibenzothiophene molecular parameters can serve as the effective oil migration tracer in an oil reservoir, especially in high to over mature and severely biodegraded oils. [ABSTRACT FROM AUTHOR]