Performance Evaluation of Multistage Fractured Horizontal Wells in Tight Gas Reservoirs at Block M, Ordos Basin

Block M of the Ordos Basin is a typical low-permeability tight sandstone gas accumulation. To develop these reservoirs, various horizontal well fracturing technologies, such as hydra-jet fracturing, open-hole packer multistage fracturing, and perf-and-plug multistage fracturing, have been implemented in practice, showing greatly varying performance. In this paper, six fracturing technologies adopted in Block M are reviewed in terms of principle, applicability, advantages, and disadvantages, and their field application effects are compared from the technical and economic perspectives. Furthermore, the main factors affecting the productivity of fractured horizontal wells are determined using the entropy method, the causes for the difference in application effects of the fracturing technologies are analyzed, and a comprehensive productivity impact index (CPII) in good correlation with the single-well production of fractured horizontal wells is constructed. This article provides a simple and applicable method for predicting the performance of multi-frac horizontal wells that takes multiple factors into account. The results can be used to select completion methods and optimize fracturing parameters in similar reservoirs.

Silencing of ATP Synthase β Impairs Egg Development in the Leafhopper Scaphoideus titanus, Vector of the Phytoplasma Associated with Grapevine Flavescence Dorée

Scaphoideus titanus (Hemiptera: Cicadellidae) is the natural vector of Flavescence dorée phytoplasma, a quarantine pest of grapevine with severe impact on European viticulture. RNA interference (RNAi) machinery components are present in S. titanus transcriptome and injection of ATP synthase β dsRNAs into adults caused gene silencing, starting three days post injection (dpi) up to 20 dpi, leading to decrease cognate protein. Silencing of this gene in the closely related leafhopper Euscelidiusvariegatus previously showed female sterility and lack of mature eggs in ovaries. Here, alteration of developing egg morphology in S. titanus ovaries as well as overexpression of hexamerin transcript (amino acid storage protein) and cathepsin L protein (lysosome proteinase) were observed in dsATP-injected females. To evaluate RNAi-specificity, E.variegatus was used as dsRNA-receiving model-species. Different doses of two sets of dsRNA-constructs targeting distinct portions of ATP synthase β gene of both species induced silencing, lack of egg development, and female sterility in E. variegatus, indicating that off-target effects must be evaluated case by case. The effectiveness of RNAi in S. titanus provides a powerful tool for functional genomics of this non-model species and paves the way toward RNAi-based strategies to limit vector population, despite several technical and regulatory constraints that still need to be overcome to allow open field application.

Eco-Friendly Electric-Powered Hydraulic Fracturing Towards Shale-Gas Recovery: Efficiency, Economics and Field Application

The recovery of unconventional gas fields especially the shale gas is of great significance to clean energy supply. High productivity of shale gas is attributed to the large-scale hydraulic fracturing with high operating pressure (80-100MPa) and discharging rate (14-18m3/min). More high-horsepower fracturing vehicles driven by diesel engines result in higher CAPEX. The low operation efficiency and unexpected maintenance negatively affected the economics performance of operators due to unacceptable OPEX. The fully electric-powered hydraulic fracturing solution was proposed as the alternative to the diesel-engine fracturing vehicles in this article. The skid-based electric pumping units were newly developed with advantages of high power density (6000HP per unit), Variable Frequency Drive (VFD) modules integration, fuel cost saving, low maintenance expenditure and eco-friendly operation. The field application was conducted in one pad of N209 in shale gas field, Sichuan, China. The electric-powered system, consisting of pumping units and blenders with other facilities, was deployed on the operation site. One large-capacity electric power grid (35kV and 30000kVA) was constructed for both drilling and massive multistage fracturing. The operation team successfully performed all hydraulic fracturing jobs as required with 7.4×105 kWh of total power consumption. The system functioned reliably without large faults occurred. The electric-powered solution was comprehensively evaluated and compared to the diesel-engine fracturing solution in terms of CAPEX, operational efficiency, power consumption, maintenance and fleet crew cost. The novelty of the technology is the fully electric-powered hydraulic fracturing system with large-capacity electric power grid. It is concluded from the field application that the electric-powered fracturing technology is qualified for unconventional reservoirs development.

Control Of Plant Diseases By An Allium-based Antimicrobial Formulation

The objective of this work was to determine the antimicrobial properties of an allium-based antimicrobial formulation named VEG’LYS (https://phytoauxilium.com/) on the growth of plant pathogenic microorganisms such as fungi, oomycetes, and bacteria. Two anthracnose-related species of the fungal genus Colletotrichum, C. gloeosporioides, and C. fragariae, the oomycete Phytophthora cactorum and the bacterium Xanthomonas fragariae associated with strawberry plants and two fungi Alternaria dauci and Botrytis cinerea, associated with carrot plants were tested in vitro. In in planta experiments, A. dauci and B. cinerea were used.. VEG’LYS inhibited the growth of all plant pathogens tested. We found that both curative and preventive in planta treatments with VEG’LYS inhibited the growth of A. dauci and B. cinerea in carrot. Furthermore, after spraying VEG’LYS on carrot plants the expression of the Pathogenesis-related (PR) 10 gene correlated with the magnitude of infection both in treated and untreated plants. Additionally, it has been shown, that the field application of VEG’LYS on strawberry plants results in a reduction of bacterial and fungal pathogens of strawberry fruits stored in refrigerator. In summary, VEG’LYS is a potential resistance inducer that seems to be suitable for use in both curative and preventive treatments to reduce the diseases and rotting of fruits and vegetables caused by different plant pathogens.

Protective immunity induced by oral vaccination with a recombinant Lactococcus lactis vaccine against H5Nx in chickens

Background The development of an influenza vaccine for poultry that provides broadly protective immunity against influenza H5Nx viruses is a challenging goal. Results Lactococcus lactis (L. lactis)/pNZ8149-HA1-M2 expressing hemagglutinin-1 (HA1) of A/chicken/Vietnam/NCVD-15A59/2015 (H5N6) and the conserved M2 gene of A/Vietnam/1203/2004 (H5N1) was generated. L. lactis/pNZ8149-HA1-M2 could induce significant humoral, mucosal and cell-mediated immune responses, as well as neutralization antibodies. Importantly, L. lactis/pNZ8149-HA1-M2 could prevent disease symptoms without significant weight loss and confer protective immunity in a chicken model against lethal challenge with divergent influenza H5Nx viruses, including H5N6 and H5N1. Conclusions L. lactis/pNZ8149-HA1-M2 can serve as a promising vaccine candidate in poultry industry for providing protection against H5Nx virus infection in the field application.

Virtual and Augmented Reality Awareness Tools for Universal Design

This chapter will be focused on contributing to the increase of universal design competencies of future engineers, educators, and designers through the use of mixed reality technologies, closing the gap between theory and field application of principles, towards a more inclusive world and promoting health and wellbeing for all. The experience of a situation where limitations arise in relation to what is taken for granted is an important experience that leads to a personal knowledge of the difficulties. By the use of simulators, especially virtual (VR) and mixed reality (MR) technologies, it is possible to create such experiences. Training based on MR can prepare future and current professionals for up-to-date requirements of the labor market. In addition, it can ensure that the standards such as barrier-free concepts, broader accessibility, adaptive and assistive technology will be familiar to trainees.