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CO2 capture， utilization， and storage （CCUS） can achieve a win-win situation of carbon emission reduction and oil production increase， and it is a key technology for the green and low-carbon transformation of the fossil energy industry. The petroleum and petrochemical industries have accelerated the large-scale application of CCUS technology after China proposed the goals of “peaking carbon emissions before 2030 and achieving carbon neutrality before 2060” in September 2020. It has gradually been revealed that CO2 flooding has contradictions such as a low impact， short effective time， and rapid increase in the gas-oil ratio in the field practices of SINOPEC Shengli Oilfield and CNPC Jilin Oilfield. It is necessary to strengthen the optimization design of reservoir engineering further. This article systematically analyzed field practices of CO2 flooding to enhance oil recovery in sandstone reservoirs in China and abroad and key issues in the optimization design of reservoir engineering， such as the matching between reservoir pressure maintenance level and miscible pressure， between well pattern direction and formation stress direction， between well spacing and reservoir permeability， and optimization of gas-water alternative displacement methods combined with the research results of the million-ton CCUS demonstration project in Shengli Oilfield. Then， the article summarized the latest progress in reservoir engineering research， such as reservoir pressure maintenance level during CO2 flooding， well network， well spacing， and gas-water alternative displacement， and analyzed the increasing pressure method， well pattern， well spacing， and gas-water alternative displacement optimization design for high-pressure miscible flooding. Finally， it indicated that the research direction of CO2 flooding reservoir engineering design should focus on the phase and flow laws of crude oil， CO2， and water in porous media under high-pressure conditions， the synergistic mechanism of CO2 flooding and storage， and the gas channeling mechanism of CO2 flooding under complex reservoir conditions. This article provides technical support for large-scale CO2 flooding in China.

A three-dimensional simulation model of the electromechanical control system was built using the fuzzy control proportional–integral–derivative (PID) adjustment algorithm after an automatic electromechanical control system based on programmable logic controller (PLC) technology was optimized to achieve the practical use of electromechanical program control. First, the hardware of the electromechanical control system is discussed and designed. The findings demonstrate the viability of the mechanical and electrical integration PLC program optimization solution based on three-dimensional (3D) model. The system has a higher control and management efficiency, which is 30% greater than that of the conventional system. The mechatronic manufacturing system’s continuous operation efficiency enhancement can significantly lower the investment costs and boost the financial gains of industrial organizations. Traditional systems have a control and management efficiency of around 30%, but automatic electromechanical control systems based on PLC technology and created using 3D models have a control and management efficiency between 60 and 70%.

There are various issues for CO2 flooding and storage in Shengli Oilfield, which are characterized by low light hydrocarbon content of oil and high miscible pressure, strong reservoir heterogeneity and low sweep efficiency, gas channeling and difficult whole-process control. Through laboratory experiments, technical research and field practice, the theory and technology of CO2 high pressure miscible flooding and storage are established. By increasing the formation pressure to 1.2 times the minimum miscible pressure, the miscibility of the medium-heavy components can be improved, the production percentage of oil in small pores can be increased, the displacing front developed evenly, and the swept volume expanded. Rapid high-pressure miscibility is realized through advanced pressure flooding and energy replenishment, and technologies of cascade water-alternating-gas (WAG), injection and production coupling and multistage chemical plugging are used for dynamic control of flow resistance, so as to obtain the optimum of oil recovery and CO2 storage factor. The research results have been applied to the Gao89-Fan142 in carbon capture, utilization and storage (CCUS) demonstration site, where the daily oil production of the block has increased from 254.6 t to 358.2 t, and the recovery degree is expected to increase by 11.6 percentage points in 15 years, providing theoretical and technical support for the large-scale development of CCUS. [ABSTRACT FROM AUTHOR]

The aim of this study is to investigate the status of laboratory practice of organic acid (OA) analysis using gas chromatography–mass spectrometry in China.

The standardization of cystatin C (CysC) measurement has received increasing attention in recent years due to its importance in estimating glomerular filtration rate (GFR). Mass spectrometry-based assays have the potential to provide an accuracy base for CysC measurement. However, a precise, accurate and sustainable LC–MS/MS method for CysC is still lacking. The developed LC–MS/MS method quantified CysC by detecting signature peptide (T3) obtained from tryptic digestion. Stable isotope labeled T3 peptide (SIL-T3) was spiked to control matrix effects and errors caused by liquid handling. The protein denaturation, reduction and alkylation procedures were combined into a single step with incubation time of 1 h, and the digestion lasted for 3.5 h. In the method validation, digestion time-course, imprecision, accuracy, matrix effect, interference, limit of quantification (LOQ), carryover, linearity, and the comparability to two routine immunoassays were evaluated. No significant matrix effect or interference was observed with the CysC measurement. The LOQ was 0.21 mg/L; the within-run and total imprecision were 1.33–2.05 % and 2.18–3.90 % for three serum pools (1.18–5.34 mg/L). The LC–MS/MS method was calibrated by ERM-DA471/IFCC and showed good correlation with two immunoassays traceable to ERM-DA471/IFCC. However, significant bias was observed for immunoassays against the LC–MS/MS method. The developed LC–MS/MS method is robust and simpler and holds the promise to provide an accuracy base for routine immunoassays, which will promote the standardization of CysC measurement. [ABSTRACT FROM AUTHOR]