Optimization of tight gas reservoir fracturing parameters via gradient boosting regression modeling.

In China, the exploitation of most unconventional oil and gas reservoirs is dependent on hydraulic fracturing, which is a key method employed when developing tight gas formations. Numerous scholars and field engineers, both domestically and internationally, have conducted extensive numerical simulations and physical experiments to study crack propagation and predict post-fracturing productivity in hydraulic fracturing. Although some progress has been reported in this regard, it is difficult to accurately predict the well productivity using mechanistic models owing to the vertical multilayered development of tight gas reservoirs. In this study, vertical fractured wells in a block of Sulige gas field were examined. The block relied on hydraulic fracturing to produce tight gases. However, as development progressed, the available reservoir environment deteriorated, large differences emerged between wells after fracturing, and the fracturing results did not meet the expectations. In this study, geological, construction, and generation data for this block that had been collected since 2007 were analyzed. After applying multiple machine-learning methods to filter outliers and fill in missing values, k-means clustering, classification enhancement, extreme gradient enhancement, and LightGBM algorithms were used to establish a regression model. The analysis results revealed that the regression accuracy of the cluster test set was as high as 70% and that the LightGBM model had the best regression effect among the 227 stripper wells in the block. After optimizing the fracturing construction parameters (fracturing fluid volume, proppant volume, liquid-nitrogen volume, and pumping rate), the average fracturing fluid and liquid-nitrogen volumes per well decreased, whereas the unit reservoir proppant and liquid-nitrogen volumes increased. The results also revealed that 182 wells showed an improved initial production capacity during fracturing. The average gas production index per meter increased by 22.04%. This approach enabled rapid and efficient production forecasting and construction optimization. Moreover, this represents a novel fracture design method that is applicable to onsite engineers in tight gas production fields in the Ordos region.

Resistant effects determination of Lactobacillus supplementation on broilers to consecutive hydrogen sulfide exposure.

Hydrogen sulfide (H2S) is one of the most irritant gases present in rearing stalls that suppress broilers' healthy growth, which is seriously required an effective alleviation method. In this study, Lactobacillus was supplemented to investigate the alleviative effects on broilers reared under consecutive H2S exposure. A total of 180 healthy 1-day-old male AA broilers with similar body weight (40.8 ± 1.0 g) were randomly allotted into the control treatment (CON), the hydrogen sulfide treatment (H2S), and the Lactobacillus supplement under H2S exposure treatment (LAC) for a 42-d-long feeding process. Growth and carcass performances, immunity-related parameters, intestinal development and cecal microbial communities, and blood metabolites were measured. Results showed that Lactobacillus supplement significantly increased the body weight gain (BWG) while reduced the mortality rate, abdominal fat and bursa of fabricius weight during the whole rearing time compared with H2S treatment (P < 0.05). Serum LPS, IL-1ß, IL-2, and IL-6 contents were observed significantly increased after H2S treatment while remarkably decreased after Lactobacillus supplementation(P < 0.05). Intestinal morphology results showed a significant higher in the development of ileum villus height (P < 0.05). Cecal microbiota results showed the bacterial composition was significantly altered after Lactobacillus supplement (P < 0.05). Specifically, Lactobacillus supplement significantly decreased the relative abundance of Faecalibacterium, while significantly proliferated the relative abundance of Lactobacillus, Bifidobacterium, Clostridium, and Campylobacter (P<0.05). Metabolic results indicated that Lactobacillus supplement may alleviate the harmful effects caused by H2S through regulating the pyrimidine metabolism, starch and sucrose metabolism, fructose and mannose degradation, and beta-alanine metabolism. In summary, Lactobacillus supplement effectively increased BWG and decreased mortality rate of broilers under H2S exposure by enhancing the body's immune capacity, proliferating beneficial microbes (e.g., Lactobacillus and Bifidobacterium), and regulating the physiological pyrimidine metabolism, starch and sucrose metabolism, and beta-alanine metabolism.

Mechanism determination on the interactive effects between host immunity and gut microbiome to resist consecutive hydrogen sulfide inhalation of laying hens.

The study aims to investigate the underlying mechanism of the interactions between intestinal microbiota and host immunity-related parameters in response to H2S inhalation of layer hens. A total of 180 healthy 300-day-old Lohmann pink hens with similar body weight were randomly allotted into the control (CON) and the hydrogen sulfide (H2S) treatments for an 8-wk-long feeding procedure. Productive performances, antioxidant capacities, immunity-related parameters, blood metabolites, and cecal microbiota were measured to determine the physiological and gastrointestinal responses to H2S treatment. Results showed that feed intake, egg production, eggshell strength, Haugh unit, and relative yolk weight significantly declined under H2S treatment compared with CON (P < 0.05). Antioxidant and immunity-related parameters showed that glutathione peroxidase, IL-4, and TNF-α contents significantly decreased, whereas contents of IL-1ß, IL-2, and IL-6 significantly increased after H2S treatment (P < 0.05). Further metabolic results showed H2S treatment upregulated 2-mercaptobenzothiazole, D-glucopyranuronic acid, deoxyuridine, cholic acid, and mimosine, etc., which mainly enriched into the pyrimidine metabolism, beta-alanine metabolism, valine, leucine, and isoleucine biosynthesis, and pantothenate and CoA biosynthesis pathways. Meanwhile, aceturic acid, 9-oxodecenoic acid, palmitoleic acid, lauric acid, linoleic acid, oleic acid, and valeric acid mainly contributed to the downregulated metabolites, and enriched into the biosynthesis of unsaturated fatty acids, amino sugar and nucleotide sugar metabolism, tryptophan metabolism and linoleic metabolism. Moreover, H2S treatment significantly proliferated the relative abundances of Faecalibacterium, Ruminococcaceae, and Streptococcus, while decreased Prevotella, Lactobacillus, Bifidobacterium, Clostridium, and Campylobacter (P < 0.05). The altered bacteria were functionally enriched in the carbohydrate metabolism, amino acid metabolism, and metabolism of cofactors and vitamins pathways. H2S treatment also significantly downregulated the expression of ZO-1, Claudin 4, and Claudin 7 (P < 0.05). In summary, intestinal microbial communities altered significantly to make proper adaptations in interacting with the host immune systems through the immunity-related metabolites secretion, and epithelial tight-junction-related genes expressions, purposely to regulate the productive performance under hydrogen sulfide inhalation.

Agricultural Application Prospect of Fully Polarimetric and Quantification S-Band SAR Subsystem in Chinese High-Resolution Aerial Remote Sensing System.

The synthetic aperture radar (SAR) is a type of active radar that can obtain polarization scattering information of ground objects, which is an important supplement to optical remote sensing. This paper designs a high-precision quantitative SAR system that combines radiation and polarization calibration processing to achieve a subtle perception of the changes in soil moisture and straw coverage. In Yushu, Jilin, we conducted the first S-band agricultural remote sensing application experiment. The backscattering coefficient was measured under different water content and straw coverage conditions, and the results showed that the backscattering coefficient increased by about 2 dB and 6 dB, respectively. We estimated that the soil water content increased by about 0.01 cm3/cm3, which was consistent with the theoretical analysis. The polarization scattering characteristics also showed significant differences under different straw coverage. The results indicated that S-band quantitative SAR had an excellent response ability to water content and straw coverage, which provided a technical basis for further radar agricultural applications in the future.