Effects of Different Concentrations of Sulfate Ions on Carbonate Crude Oil Desorption:Experimental Analysis and Molecular Simulation

Low salinity water containing sulfate ions can significantly alter the surface wettability of carbonate rocks.Nevertheless,the impact of sulfate concentration on the desorption of oil film on the surface of carbonate rock is still unknown.This study examines the variations in the wettability of the surface of carbonate rocks in solutions containing varying amounts of sodium sulfate and pure water.The problem is addressed in the framework of molecular dynamics simulation(Material Studio software)and experiments.The experiment’s findings demonstrate that sodium sulfate can increase the rate at which oil moisture is turned into water moisture.The final contact angle is smaller than that of pure water.The results of the simulations show that many water molecules travel down the water channel under the influence of several powerful forces,including the electrostatic force,the van der Waals force and hydrogen bond,crowding out the oil molecules on the calcite’s surface and causing the oil film to separate.The relative concentration curve of water and oil molecules indicates that the separation rate of the oil film on the surface of calcite increases with the number of sulfate ions.

Synthesis and molecular recognition characteristics of a tetrapodal benzene cage

In this contribution,we describe the preparation and recognition characteristics of a novel tetrapodal benzene cage(1).The cage can express a wide recognition range without losing selectivity for the object of appropriate size and functional groups.The key to obtaining the desired structural isomer of 1 is the synthesis and isolation of the o-bis(bromomethyl)benzene precursor(5).Three distinct guests,F^(−)(ex-tremely small size),d-lactate(appropriate size)and l-Asp(branched shape),were selected as examples to demonstrate the recognition characteristics of 1.By NMR titration studies,they all expressed good binding affinity(K>10^(5) L/mol)in competitive medium(10%DMSO/THF),indicating that 1 has a wide recognition scope.The highest binding constant was observed for d-lactate,revealing that 1 has good selectivity for d-lactate versus F^(−)and L-Asp.Moreover,the NMR titration study of F^(−)in DMSO indicates 1 can achieve different binding modes(1:1 and 2:1 guest-host)for small-sized guests,which allows for the further development of binary binding properties and thereafter applications in the field of catalysis.

Intelligent Recognition Method of Insufficient Fluid Supply of Oil Well Based on Convolutional Neural Network

Traditional methods for judging the degree of insufficient fluid supply in oil wells have low efficiency and limited accuracy. To address this problem, a method for intelligently identifying the degree of insufficient fluid supply in oil wells based on convolutional neural networks is proposed in this paper. Firstly, 5000 indicator diagrams with insufficient liquid supply were collected from the oilfield site, and a sample set was established after preprocessing;then based on the AlexNet model, combined with the characteristics of the indicator diagram, a convolutional neural network model including 4 layers of convolutional layers, 3 layers of down-pooling layers and 2 layers of fully connected layers is established. The backpropagation, ReLu activation function and dropout regularization method are used to complete the training of the convolutional neural network;finally, the performance of the convolutional neural network under different iteration times and network structure is compared, and the super parameter optimization of the model is completed. It has laid a good foundation for realizing the self-adaptive and intelligent matching of oil well production parameters and formation fluid supply conditions. It has certain application prospects. The results show that the accuracy of training and verification of the method exceeds 98%, which can meet the actual application requirements on site.

Synergetic process between wind power and sewage sludge pyrolysis in a novel renewable-energy microgrid system

To relieve the stress of sewage sludge(SS)disposal and effectively increase the use of renewable energy,a novel renewable-energy microgrid system(REMS)was developed,specifically designed to integrate a wind power plant(WPP)with energy storage and the SS pyrolysis process for heat and power generation.Based on a lab-scale pyrolysis experiment and 7-day numerical analysis,we studied the energy-recycling potential of SS and simulated the operational behaviours of REMS.According to the results,the calorific values of the pyrolytic gaseous and liquid products were better than those of the raw material,at 16.19 and 33.53 MJ/kg,respectively.The proposed REMS performed well in power supply and energy utilization with a design performance index of 99.23 when the WPP capacity was 200 MWe and the initial wind-energy curtailment rate was 30%.It indicates that by converting SS into flammable gas,condensable liquid and carbon-rich solid residue,curtailed wind energy could be saved and the synergy between wind power and the SS pyrolysis process enabled the proposed microgrid system to effectively utilize renewable energy and provide reliable on-demand power service.The REMS installed with a 155-MWe WPP achieved the optimal design in system performance,environmental benefit and construction cost under the initial wind-curtailment rate of 34.12%.The design scheme makes REMS capable of satisfying the 15.10-GWh power demand of end users and the 1700-t/day SS disposal need,and the curtailed wind energy could be reduced to zero.