Systematic Investigation of Integrating Small Wind Turbines into Power Supply for Hydrocarbon Production

In this paper, the technical and economic feasibility of integrating SWTs (Small Wind Turbines) into remote oil production sites are investigated. Compared to large turbines in onshore and offshore wind farms, SWTs are more suitable for individual power generations. A comprehensive approach based on wind energy assessment, wind power prediction, and economic analysis is then recommended, to evaluate how, where, and when small wind production recovery is achievable in oilfields. Firstly, wind resource in oilfields is critically assessed based on recorded meteorological data. Then, the wind power potential is numerically tested using specified wind turbines with density-corrected power curves. Later, estimations of annual costs and energy-saving are carried out before and after the installation of SWT via the LCOE (Levelized Cost of Electricity) and the EROI (Energy Return on Investment). The proposed methodology was tested against the Daqing oilfield, which is the largest onshore oilfield in China. The results suggested that over 80% of the original annual costs in oil production could be saved through the integrations between wind energy and oil production

R3Det: Refined Single-Stage Detector with Feature Refinement for Rotating Object

Rotation detection is a challenging task due to the difficulties of locating the multi-angle objects and separating them effectively from the background. Though considerable progress has been made, for practical settings, there still exist challenges for rotating objects with large aspect ratio, dense distribution and category extremely imbalance. In this paper, we propose an end-to-end refined single-stage rotation detector for fast and accurate object detection by using a progressive regression approach from coarse to fine granularity. Considering the shortcoming of feature misalignment in existing refined single-stage detector, we design a feature refinement module to improve detection performance by getting more accurate features. The key idea of feature refinement module is to re-encode the position information of the current refined bounding box to the corresponding feature points through pixel-wise feature interpolation to realize feature reconstruction and alignment. For more accurate rotation estimation, an approximate SkewIoU loss is proposed to solve the problem that the calculation of SkewIoU is not derivable. Experiments on three popular remote sensing public datasets DOTA, HRSC2016, UCAS-AOD as well as one scene text dataset ICDAR2015 show the effectiveness of our approach. Tensorflow and Pytorch version codes are available at https://github.com/Thinklab-SJTU/R3Det_Tensorflow and https://github.com/SJTU-Thinklab-Det/r3det-on-mmdetection, and R3Det is also integrated in our open source rotation detection benchmark: https://github.com/yangxue0827/RotationDetection.Comment: 13 pages, 12 figures, 9 table

The effect of explicit and tacit synergies on alliances radical innovation: The moderating roles of interfirm technological diversity and environmental technological dynamism

This study draws on theories of organizational inertia and relational view to examine how the pursuit of partnership synergy influences radical innovation in different technological contexts. We differentiate between two types of synergy: explicit synergy, defined as the potential to exchange interfirm operational elements to renew processes or capabilities, and tacit synergy, conceptualized as the potential to synthesize cross-boundary resources to develop new perspectives or thinking modes. We find that both explicit and tacit synergy have positive impacts on radical innovation, and such impacts are contingent on interfirm technological diversity and environmental technological dynamism in opposing ways. Specifically, environmental technological dynamism positively moderates the relationship between explicit synergy and radical innovation but not the relationship between tacit synergy and radical innovation. In contrast, interfirm technological divers ity positively moderates the relationship between tacit synergy and radical innovation but not the relationship between explicit synergy and radical innovation. Our study sheds new light on the generation of radical innovation in alliances. It also provides practitioners with useful guidelines for crafting synergy strategies that will facilitate the pursuit of radical innovation

Do land markets improve land-use efficiency? evidence from Jiangsu, China

Inefficient use of scarce and fragmented land challenges the sustainability of agriculture. Land markets may improve land-use efficiency. In recent years, China has employed various instruments to promote land markets. This paper investigates whether land markets affect households' land-use efficiency, based on data from 1,202 farm households in Jiangsu Province. The measure of land-use efficiency was derived from a stochastic frontier production function, and a control function approach was employed to correct for selection bias. The results indicated that many households are using land inefficiently. While renting in land increases land-use efficiency, it is not affected by renting out land, implying that households are not giving up land for efficiency gains. We also provide suggestive evidence that the positive effect of renting in land results from abundant agricultural labour due to labour market failure

Analysis of Contact Surface Wear Performance of O-Ring Dynamic Seal Based on Archard Model

With the development of hydraulic system to high pressure gradually, the leakage risk of sealing system increases, and it is necessary to confirm the performance parameters of sealing structure through analysis and calculation. The traditional analysis of the friction and wear performance of the seal ring is limited to the amount of wear, and cannot describe the surface wear characteristics of the O-ring in detail. Based on the Archard model, this paper constructs a model to analyse and calculate the friction and wear performance of the dynamic seal structure through the material characteristics and operating parameters, analyses the friction and wear characteristics of the O-ring seal structure under different compression ratio, medium pressure, relative slip velocity and temperature, and summarizes the influence of each single variable on the wear characteristics of the dynamic seal structure. According to the analysis in this paper, the increase of medium pressure of 5 MPa will cause the wear concentration area of the contact surface to move to the back pressure side, and the overall wear will be reduced, but the increase of contact area will lead to the weakening of sealing effect. By the action of 15 MPa, when the compression ratio is between 5% and 10%, the change of cumulative wear rate and the wear rate of each node is small

Short-term offshore wind speed forecast by seasonal ARIMA - A comparison against GRU and LSTM

Offshore wind power is one of the fastest-growing energy sources worldwide, which is environmentally friendly and economically competitive. Short-term time series wind speed forecasts are extremely significant for proper and efficient offshore wind energy evaluation and in turn, benefit wind farm owner, grid operators as well as end customers. In this study, a Seasonal Auto-Regression Integrated Moving Average (SARIMA) model is proposed to predict hourly-measured wind speeds in the coastal/offshore area of Scotland. The used datasets consist of three wind speed time series collected at different elevations from a coastal met mast, which was designed to serve for a demonstration offshore wind turbine. To verify SARIMA’s performance, the developed predictive model was further compared with the newly developed deep-learning-based algorithms of Gated Recurrent Unit (GRU) and Long Short-Term Memory (LSTM). Regardless of the recent development of computational power has triggered more advanced machine learning algorithms, the proposed SARIMA model has shown its outperformance in the accuracy of forecasting future lags of offshore wind speeds along with time series. The SARIMA model provided the highest accuracy and robust healthiness among all the three tested predictive models based on corresponding datasets and assessed forecasting horizons

Dynamic coupling modelling and application case analysis of high-slip motors and pumping units

To solve the issues and difficulties in the high-coupling modelling of beam pumping units and high-slip motors, external characteristic experiments of high-slip motors were performed where the external database and characteristic correlation equations of the motors were obtained through data regression analysis. Based on the analysis of the kinematics, dynamics and driving characteristics of the beam pumping unit, a fully coupled mathematical model of a motor, pumping unit, sucker rod and oil pump was established. The differential pumping equation system of the pumping unit used a cyclic iteration method to solve the problem of high coupling among the motor, pumping unit, sucker rod and the pumping pump. The model was verified by experimental data of field l pumping wells. Theoretical calculations and experimental tests showed that the soft characteristic of the high-slip motor can reduce the peak suspension load of the sucker rod, peak net torque of the gearbox and peak power of the motor. In addition, the results show that the soft characteristic can also decrease the high-frequency fluctuation of the motor power curve and the torque curve of the gearbox. The highslip motor can improve the smoothness and safety of the pumping well system