In addition to the light oil which is easy to be exploited, there are many heavy oil which can not be directly exploited in the underground oil reservoir. The heavy oil reservoir is usually exploited by means of steam injection and thermal recovery. Steam dryness is an important parameter to measure the quality of wet saturated steam in heavy oil thermal recovery process, which has an important impact on the efficiency of heavy oil thermal recovery. In this paper, a new method of measuring the dryness of wet saturated steam in steam injection pipeline matrix conductance method was proposed. Based on this method, combining the thermodynamic properties of water and steam, an algorithm model of matrix conductance method for measuring the dryness of wet saturated steam was established. The causes of measurement errors and the methods to reduce the errors were analyzed. The calculation of the edge area of the instantaneous cross⁃section water area under the matrix was interpolated. Finally, the absolute error of the algorithm model was less than ±3.0%. This study also provided a reliable method for real⁃time monitoring of steam dryness, which was of great significance for improving the efficiency of heavy oil thermal recovery.

Low⁃carbon alloy steel is widely used in industrial design such as pressure vessels, vehicles, bridges, etc.By studying the influence of high pressure abrasive water jet on the cutting of low carbon alloy steel, the influence of water jet cutting characteristics on the cutting effect is analyzed, which has certain reference significance for improving cutting efficiency and reducing cutting cost.In the experiment, the five⁃axis linkage NC water cutter cutting machine is used，take Q345B as an example and the effects of cutting pressure, target distance and transverse speed on cutting depth and width are analyzed. The experimental results show that: with the increase of cutting pressure, the depth of cutting increases greatly. but the effect on cutting width is not obvious. Under certain conditions, there is an optimum target distance to maximize the cutting depth, the cutting depth decreases with increasing mobile speed. The target distance has a great effect on the cutting width, but the moving speed has little effect on the cutting width.