Genesis and microscopic characteristics of tight reservoirs in the Fengcheng Formation, at the southern margin of the Mahu Sag

The tight reservoirs of the Fengcheng Formation at the southern margin of the Mahu Sag have strong heterogeneity due to the diversity in their pore types, sizes, and structures. The microscopic characteristics of tight reservoirs and the mechanisms that generate them are of significance in identifying the distribution of high-quality reservoirs and in improving the prediction accuracy of sweet spots in tight oil reservoirs. In this paper, high-pressure mercury intrusion (HPMI) and nuclear magnetic resonance (NMR) experiments were carried out on samples from the tight reservoirs in the study area. These experimental results were combined with cluster analysis, fractal theory, and microscopic observations to qualitatively and quantitatively evaluate pore types, sizes, and structures. A classification scheme was established that divides the reservoir into four types, based on the microstructure characteristics of samples, and the genetic mechanisms that aided the development of reservoir microstructure were analyzed. The results show that the lower limit for the tight reservoir in the Fengcheng Formation is Φ of 3.5% and K of 0.03 mD. The pore throat size and distribution span gradually decrease from Type I, through Type II and Type III reservoirs to non-reservoirs, and the pore type also evolves from dominantly intergranular pores to intercrystalline pores. The structural trend shows a decrease in the ball-stick pore-throat system and an increase in the branch-like pore-throat system. The dual effects of sedimentation and diagenesis shape the microscopic characteristics of pores and throats. The sorting, roundness, and particle size of the original sediments determine the original physical properties of the reservoir. The diagenetic environment of ‘two alkalinity stages and one acidity stage’ influenced the evolution of pore type and size. Although the cementation of authigenic minerals in the early alkaline environment adversely affected reservoir properties, it also alleviated the damage of the later compaction to some extent. Dissolution in the mid-term acidic environment greatly improved the physical properties of this tight reservoir, making dissolution pores an important reservoir space. The late alkaline environment occurred after large-scale oil and gas accumulation. During this period, the cementation of authigenic minerals had a limited effect on the reservoir space occupied by crude oil. It had a more significant impact on the sand bodies not filled with oil, making them function as barriers.

Cambering of Four High Cold Mill with the View of Reducing Roller Ends Contact and Preventing Complex Waves

Based on lots of field experiments and theoretical research, fully thinking the equipment and production craft characters of four high cold mill, a new cambering scheme for four high cold mill is advanced in this paper. This scheme considered the need of production of multi-specification products, as well as the control of roller ends contact. The most homogeneous transverse distribution of front tension is the control target and the homogeneous pressure distribution between rollers is the constraint condition. In this technology, working roll curve adapt the combination of cosine curve and high order curve, backup roll adapt the combination of cosine curve, straight line and high order curve. The cosine subentry of working roll and the high order curve subentry are used to control edge wave, the high order curve subentry of working roll is used to control the roll contact, the cosine subentry of backup roll is used to reduce the center wave. That’s the features of this technology. On-site testing shows that the new cambering and combination can not only manage the complex waves of normal four high cold mill effectively, but also will reduce the contact between roller ends and minish roll consumption. This technology has created economic benefits for enterprises.

Characteristic Analysis and Comprehensive Control for the Horizontal Stripes of High-Grade Automotive Panels in Continuous Annealing

As to the horizontal stripes defect which exist on the surface of the high-grade automotive panels in continuous annealing process, an effective comprehensive control method is proposed on the basis of full consideration of the equipment and technological features of continuous annealing line. With five field tests as basis, the generation mechanism of the defect was analysised in detail and the comprehensive control measures were put forward. According to actual situation, a detailed technical plan was worked out .Then the relevant technologies were applied to a 1850 continuous annealing line. The statistics shows that this program acquired good effects. The incidence of horizontal stripes defect decreased from 100% to 2.78%. Meanwhile, the surface quality of strip also improved effectively, which created a larger economic benefit.

Development of Roller Ends Forced-Contact Model and Cambering Technology for UCM Temper Mill (II)——Development of cambering technology for UCM temper mill

Roller ends forced-contact and overmuch roll consumption are the widespread problems in temper rolling process of thin strip for two-stand UCM temper mill. Fully thinking the equipment and technology characteristics of UCM temper mill, we took the newly-built 1220 UCM temper mill of Baosteel as the research object in this paper. A model of roller ends forced-contact and a calculation model of flatness for UCM temper mill are established after a great deal of site tracing and theoretical researches. On this basis, an optimal mathematical model of roll shape which is suited for UCM temper mill is developed. Working roll curve is the combination of cosine curve and high order curve. The cosine subentry is used to control edge wave, the high order curve subentry is used to control roller ends forced-contact. Furthermore, the chamfering curve of middle roller end is optimized. Those are the innovations. Through the above-mentioned technology, pressure distribution between rollers caused by the shift of middle roll becomes more homogeneous, pressure peak disappeared, working life of roll is improved effectively as well. Relevant technologies have been used to the practice of 1220 UCM temper mill of Baosteel and have achieved good use effects, which is of further extending application value.

Development of Roller Ends Forced-Contact Model and Cambering Technology for UCM Temper Mill (I)——Development of Roller Ends Forced-Contact Model and the Computational Model of Flatness for UCM temper mill

Roller ends forced-contact and overmuch roll consumption are the widespread problems in temper rolling process of thin strip for two-stand UCM temper mill. Fully thinking the equipment and technology characteristics of UCM temper mill, we took the newly-built 1220 UCM temper mill of Baosteel as the research object in this paper. A model of roller ends forced-contact and a calculation model of flatness for UCM temper mill are established after a great deal of site tracing and theoretical researches. On this basis, an optimal mathematical model of roll shape which is suited for UCM temper mill is developed. Working roll curve is the combination of cosine curve and high order curve. The cosine subentry is used to control edge wave, the high order curve subentry is used to control roller ends forced-contact. Furthermore, the chamfering curve of middle roller end is optimized. Those are the innovations. Through the above-mentioned technology, pressure distribution between rollers caused by the shift of middle roll becomes more homogeneous, pressure peak disappeared, working life of roll is improved effectively as well. Relevant technologies have been used to the practice of 1220 UCM temper mill of Baosteel and have achieved good use effects, which is of further extending application value [1].

Highly efficient catalytic performances of nitro compounds via hierarchical PdNPs-loaded MXene/polymer nanocomposites synthesized through electrospinning strategy for wastewater treatment

The problem of water pollution has become increasingly serious,and it has already threatened the survival of mankind and has become an obstacle to the healthy development of human health.Here,we prepared a novel polyvinyl alcohol(PVA)/polyacrylic acid(PAA)/MXene fiber membrane by electrospinning.After heat treatment of film and subsequent modification with Pd nanoparticles,PVA/PAA/MXene@PdNPs composite nanofiber membrane with high specific surface area and excellent catalytic performance was finally prepared.The uniform distribution of MXene sheets in the composite fiber membrane not only solves the problem that the MXene sheet is not easy to be monolayerized,but also can grow the self-reduced Pd nanoparticles on the MXene sheets.In addition,the composite nanofiber membrane exhibits excellent catalytic ability and cycle stability for 4-nitrophenol(4-NP)and 2-nitrophenol(2-NA),providing new strategy for the study of catalytic composite materials related to degradation of wastewater.