Calculation of the Gas Injection Rate and Pipe String Erosion in Nitrogen Drilling Systems

Detailed information is provided for the design and construction of nitrogen drilling in a coal seam.Two prototype wells are considered.The Guo model is used to calculate the required minimum gas injection rate,while the Finnie,Sommerfeld,and Tulsa models are exploited to estimate the ensuing erosion occurring in pipe strings.The calculated minimum gas injection rates are 67.4 m^(3)/min(with water)and 49.4 m^(3)/min(without water),and the actual field of use is 90–120 m^(3)/min.The difference between the calculated injection pressure and the field value is 6.5%–15.2%(formation with water)and 0.65%–7.32%(formation without water).The results show that the Guo model can more precisely represent the situation of the no water formation in the nitrogen drilling of a coal seam.The Finnie,Sommerfeld,and Tulsa models have different sensitivities to cutting densities,particle size,impact velocity and angle,and pipe string hardness.

Sense of the Scene,Reflexivity,and New Local Writing:On Above Baiyangdian Lake by Guan Renshan

Above Baiyangdian Lake is a meticulously crafted novel by Guan Renshan nearing a million words in length.The novel offers a panoramic view of everyday life in Baiyangdian Lake and the development of the Xiong'an New Area.The novel exemplifies a genuine sense of the scene by presenting readers with a vivid,authentic depiction of our contemporary life.He employs a narrative structure that overlaps the present with the past,blending tradition and modernity to create a truly magnificent epic.Rather than avoiding the contradictions and darkness inherent to humanity,the novel embraces them and strives to accurately depict their complexity,resulting in a more profound reflection on society.Above Baiyangdian Lake expands and innovates the path of local literature by applying a genuinely realistic approach.It not only surpasses Guan's writing style,but also represents a transcendence of local writing conventions in contemporary literature.It draws upon and elevates the literary tradition of the Hehuadian School,emerging as a notable example of new local writing with distinct regional traits.

Analysis of Maintenance and Inspection Status of Aeronautical Machinery and Improvement Countermeasures

In the daily operation process of airlines,aviation machinery maintenance and inspection work play an important role.At present,the quality of life of the people in our country is constantly improving.In daily travel,we have not only used cars,trains and other means of transportation,but also started to choose airplanes as the first choice in a higher frequency.In recent years,with the improvement of living standards,more and more people choose to travel during holidays.Therefore,the traffic volume of aviation aircraft is increasing year by year,but it also increases the risk of aviation aircraft failure,so it is particularly important to do a good job in the maintenance and inspection of aviation machinery.In this paper,according to the current situation of aviation machinery maintenance and inspection,put forward targeted improvement measures to ensure the safety and stability of China's aviation aircraft operation.