NMR technology in reservoir evaluation for shale oil and gas

Since the development of unconventional oil and gas business, Nuclear Magnetic Resonance (NMR) technology has been gradually applied in the evaluation for unconventional reservoirs due to the merits such as nondestructive, sensitive and fast, this technology has become one of the important methods in shale oil and gas reservoir evaluation. Therefore, based on the experimental principle of NMR technology, this paper focuses on the applications of NMR technology in the full-scale integrated characterization of pore and fracture distribution, characterization of shale porosity, pore wettability, fluid mobility and fluid classification, etc. In addition, the applications of NMR in describing water migration, methane adsorption and desorption, carbon dioxide displacement and other fluid behaviors, obtaining organic matter information, oil shale interface area, determining organic pores and inorganic pores, analyzing pore connectivity, and obtaining information about high-viscosity asphalt and kerogen are also briefly reviewed. Finally, the shortcomings of NMR and the development trend of NMR in shale reservoir evaluation are analyzed

Effects of Simulated Heat Waves on ApoE-/- Mice

The effects of simulated heat waves on body weight, body temperature, and biomarkers of cardiac function in ApoE-/- mice were investigated. Heat waves were simulated in a meteorological environment simulation chamber according to data from a heat wave that occurred in July 2001 in Nanjing, China. Eighteen ApoE-/- mice were divided into control group, heat wave group, and heat wave BH4 group. Mice in the heat wave and BH4 groups were exposed to simulated heat waves in the simulation chamber. Mice in BH4 group were treated with gastric lavage with BH4 2 h prior to heat wave exposure. Results showed that the heat waves did not significantly affect body weight or ET-1 levels. However, mice in the heat wave group had significantly higher rectal temperature and NO level and lower SOD activity compared with mice in the control group (p < 0.01), indicating that heat wave had negative effects on cardiac function in ApoE-/- mice. Gastric lavage with BH4 prior to heat wave exposure significantly reduced heat wave-induced increases in rectal temperature and decreases in SOD activity. Additionally, pretreatment with BH4 further increased NO level in plasma. Collectively, these beneficial effects demonstrate that BH4 may potentially mitigate the risk of coronary heart disease in mice under heat wave exposure. These results may be useful when studying the effects of heat waves on humans

Potential and future exploration direction of marine shale gas resources in China

Marine shale gas, represented by the shale gas from Wufeng-Longmaxi formations in southern China, is the main field for shale gas exploration and development in China. In recent years, marine shale gas exploration and development have been constantly facing new problems and challenges. Expanding new fields of shale gas resources and increasing shale gas production are still top priorities. The distribution characteristics, resource potential, and favorable area prediction of shale gas in typical marine formations in China are sorted out, with the results as follows. The geological and recoverable resources of shale gas in Wufeng-Longmaxi formations in Sichuan Basin and its peripheral regions are (17.50-33.19)×1012 m3 and (3.50-6.14)×1012 m3, respectively, with deep shale gas resources accounting for over 50%, mainly distributed in the high and steep structural belt in eastern Sichuan and in the low steep structural belt in southern Sichuan. The geological and recoverable resources of shale gas in the Permian Wujiaping Formation are (8.7-24.6)×1012 m3 and (1.3-3.7)×1012 m3, respectively, with exploration potential in areas such as Kaijiang-Liangping, Longjuba, Jiannan, and Sanxing in eastern Sichuan. The geological and recoverable resources of shale gas in the Qiongzhusi Formation are (5.69-12.71)×1012 m3 and (0.89-1.06) ×1012 m3, respectively, with favorable areas mainly distributed in areas such as Jingyan-Jianwei-Weiyuan-Ziyang in southwestern Sichuan, Nanjiang in northern Sichuan, and Yichang in the middle Yangtze region. The ancient marine formations such as the Doushantuo Formation, Hongshuizhuang Formation, and Xiamaling Formation have certain potential of shale gas resources, which are potential continuation of shale gas resources. The favorable areas for shale gas in the Doushantuo Formation are mainly distributed in western Hunan and Hubei and southeast Chongqing, while the favorable areas for shale gas in the Hongshuizhuang Formation are mainly distributed in the Chengde-Kuancheng area of Hebei. The favorable areas for shale gas in the Xiamaling Formation are mainly distributed in the areas of Zhuozhou in Hebei, Fangshan, Mentougou, Changping in Beijing, and Lanqi-yingzi. Based on this, three suggestions are further proposed for the future exploration direction of marine shale gas: the first is to focus on deep to ultra-deep and normal pressure shale gas, move towards new layers, and expand the field of shale gas exploration; the second is to deepen and enrich the exploration theory of deep to ultra-deep shale gas, normal pressure shale gas, and shale gas of new layer in the new area; the third is to focus on the improvement and innovation of deep to ultra-deep shale gas drilling and production technology and supporting equipment, and reduce the drilling and production costs of single wells of normal pressure shale gas

Pore structure and free gas transport characteristics of deep shale: taking Longmaxi Formation shale in Sichuan Basin as an example

Deep shale gas is an important research direction for increasing shale gas storage and production in the Longmaxi Formation of Sichuan Basin. But there are differences in reservoir and seepage characteristics between shallow and medium-buried shale gas, which to some extent limits the progress of exploration and development of deep shale gas. In order to clarify the pore structure characteristics of deep shale gas reservoirs and the transport characteristics of shale free gas, this paper takes the high-quality shale of Longmaxi Formation in southern Sichuan as an example to carry out experiments on observing and quantitatively characterizing the pore structure of shale reservoirs. In addition, based on the transport mechanism of bulk gas, the transport characteristics, critical conditions, and dynamic evolution laws of shale free gas were explored. The experimental and computational results indicate that: (1) The pore morphology characteristics of deep shale reservoirs are not significantly different from those of shallow and medium-buried shale, but the pore structure characteristics of medium pores are more obvious, with pore volume accounting for 62.5%-69.7%; (2) The transport modes of deep shale free gas are divided into three types: transitional flow, slippage flow, and Darcy flow. The critical pore sizes of the three modes in the Yongchuan area are 4.2 nm and 420 nm, respectively. On this basis, a transport chart for free gas in the entire basin has been established; (3) From shallow to deep shale, the critical pore size corresponding to different transport modes of free gas decreases accordingly. The main transport mode of free gas changes from the transitional flow (up to 63.0%) to the slippage flow (up to 67.3%) and the Darcy flow accounts for no more than 2%. The transport capacity of free gas rapidly decreases from shallow to medium-buried shale, while the transport capacity of medium to deep shale free gas remains basically stable with increasing burial depth. By analyzing and comparing the pore structure characteristics and free gas transport characteristics of deep and shallow shale reservoirs, this study can effectively support the deployment of efficient exploration and development plans for deep shale gas and even shallow shale gas in the next step

Comparative proteomic analysis of two barley cultivars (Hordeum vulgare L.) with contrasting grain protein content

Grain protein contents of barley seeds are significantly different between feed and malting barley cultivars. However, there is still no insight into the proteomic analysis of seed proteins between feed and malting barley cultivars. Also, the genetic control of barley grain protein content is still unclear. Grain protein contents were measured between mature grains of Yangsimai 3 and Naso Nijo by using FOSS Kjeltec TM 2300. A proteome profiling of differentially expressed protein was established by using a combination of 2-DE, MALDI TOF MS and MS/MS. In total, 502 reproducible protein spots in barley seed proteome were detected with a pH range of 4-7 and 6-11, among these 41 protein spots (8.17%) were detected differentially expressed between Yangsimai 3 and Naso Nijo. Thirty-four protein spots corresponding to 23 different proteins were identified, which were grouped into eight categories, including stress, protein degradation and posttranslational modification, development, cell, signalling, glycolysis, starch metabolism and other functions. Among the identified proteins, enolase (spot 274) and small subunit of ADP-glucose pyrophosphorylase (spot 271) are exclusively expressed in barley Yangsimai 3, which may be involved in regulating seed protein expression. In addition, malting quality is characterized by an accumulation of serpin protein, Alpha-amylase/trypsin inhibitor CMb and Alpha-amylase inhibitor BDAI-1. Most noticeably, globulin, an important storage protein in barley seed, undergoes post-translational processing in both cultivars, and also displays different expression patterns

Overexpression of Barley Transcription Factor HvERF2.11 in Arabidopsis Enhances Plant Waterlogging Tolerance

Waterlogging stress significantly affects the growth, development, and productivity of crop plants. However, manipulation of gene expression to enhance waterlogging tolerance is very limited. In this study, we identified an ethylene-responsive factor from barley, which was strongly induced by waterlogging stress. This transcription factor named HvERF2.11 was 1158 bp in length and encoded 385 amino acids, and mainly expressed in the adventitious root and seminal root. Overexpression of HvERF2.11 in Arabidopsis led to enhanced tolerance to waterlogging stress. Further analysis of the transgenic plants showed that the expression of AtSOD1, AtPOD1 and AtACO1 increased rapidly, while the same genes did not do so in non-transgenic plants, under waterlogging stress. Activities of antioxidant enzymes and alcohol dehydrogenase (ADH) were also significantly higher in the transgenic plants than in the non-transgenic plants under waterlogging stress. Therefore, these results indicate that HvERF2.11 plays a positive regulatory role in plant waterlogging tolerance through regulation of waterlogging-related genes, improving antioxidant and ADH enzymes activities