An improved ant colony algorithm is proposed to address issues such as susceptibility to local optima and slow convergence speed. Firstly, the relationship between the current target node and the next target node and the normal distribution function are introduced into the heuristic function, enhancing the algorithm's search capability in the early stages. In addition, by introducing an inflection point factor, the diversity of directional selection is enhanced. Secondly, an adaptive dynamic pheromone volatility coefficient is proposed to adjust the pheromone evaporation rate adaptively, modifying the pheromone update rules. Finally, simulation experiments were conducted using Matlab to compare the traditional ant colony algorithm and the improved ant colony algorithm on three different grid maps. The experimental results demonstrate that, compared with the traditional ant colony algorithm, the improved algorithm exhibits advantages such as faster convergence speed, shorter paths, and fewer inflection points.

Using molecular dynamics, the lowest energy configurations of n?dodecane, n?octadecane, and n?nonadecane were constructed, and the interactions between oil molecules and wax molecules were studied at different water contents (mass fractions). The molecular dynamics model of crude oil emulsion system based on different mass fraction water content was constructed. The effect of water molecules dissolved in the system on the viscosity of waxy crude oil was studied. The radial distribution functions of wax molecules in different water content systems were compared. The results show that carbon number is the main factor to determine the interaction energy between crude oil molecules. With the increase of water content, the distance between molecules increases, while the interaction energy decreases. After water molecules are dissolved in the system, the distance between wax molecules and electrostatic interaction become larger, the distribution of wax molecules becomes disordered, and the flow characteristics of crude oil are improved.

Card sleeve joints are widely used in the connection of hydraulic and pneumatic equipment such as oil and gas pipelines, and its connection reliability has an important impact on the safety of oil and gas pipelines. However, there is no report on the influence of external working conditions on the stress characteristics of the thread of card sleeve joints in oilfield ground pipelines. A three?dimensional model of the double card sleeve joint was established using SolidWorks software; The maximum equivalent stress (Von Mises stress) of the sleeve joint was numerically analyzed using ANSYS finite element software. The results indicate that within the yield limit, the greater the axial force, the better the sealing performance of the sleeve joint, while the internal pressure has little effect on the sealing of the pipe joint, and the risk of thread sticking due to excessive stress can be ignored; The influence of thread parameters on sealing performance is significant; The optimal pitch and number of threads for a sleeve joint with an outer diameter of 12 mm and an inner diameter of 9 mm are 1.5 mm and 7, respectively. The research results can provide theoretical basis and reference for the optimization of structural performance and scientific operation in the assembly process of card sleeve joints, which has important engineering significance.

In order to study and determine the optimal compounding system that can improve the stability of heavy oil emulsion in Liaohe Oilfield and the law of emulsion stability under different conditions, a focused beam reflectometer(FBRM) and rheometer were used to pass four factors and three levels. Orthogonal experiment with three indexes explored the change law of droplet average particle size, dispersion degree and emulsion viscosity, and investigated the influence of external factors on the stability of emulsion under compound system. The results show that the compound emulsifiers with the mass fractions of OBS?50, AEO15/OS?15, OP?15, and sodium with mass fraction of 4.0%, 4.0%, 1.4% and 1.4%, respectively, are the most beneficial to improve Stability of heavy oil emulsion in Liaohe Oilfield; there is a positive synergy between average particle size and dispersion, and an inverse relationship with the viscosity of the emulsion; the increase in temperature, volume ratio of oil to water will weaken the stability of the emulsion; stirring rate, ore The increase of the degree of chemical conversion can improve the stability of the emulsion; when the mass fraction of the mineralized NaCl is 0.2% to 1.0%, the stability of the emulsion can be greatly improved, and the quality fraction of the emulsion can be further improved. The lifting effect is not obvious.