Partial Cases of Stressed-Deformed Condition of Casing and Pump Compressor Pipes

Threaded joints are the most technological for piling up in the fields. However, violations of standard threaded joints account for 70% of all complications in pipe processing and production. These malfunctions result in significant material losses, reduced well productivity, and contamination of the wells and environmental pollution. Particularly acute is the loss of these sealed joints during exploration and development of gas and gas condensate fields. The necessary increase in volumes and intensification of hydrocarbon energy production is envisaged by the increase of drilling depth, construction of slopes and horizontal wells. Horizontal drilling and fracturing are used to produce shale gas. The efficiency and safety of the operation of oil and gas wells in complex mining and technical conditions depend on the quality and reliability of casing and pumping columns, which requires the modernization of machinery and technology for the installation of wells. The most technological for column fitting in the fisheries sector is threaded joints. However, breach of standard threaded connections causes 70% of all complications with pump housings and columns. This leads to significant material losses, reduced production of raw materials, contamination of the interior and the environment. Therefore, the urgent task is to improve the threaded joints by increasing their reliability and efficiency under heavy workloads.

Applications of Nickel-Based Alloy for Oil Country Tubular Goods

With the development of the petroleum industry, more and more high temperature, high pressure and high corrosion wells have appeared. In order to adapt to the harsh environment of oil fields, nickel-based alloy oil country tubular goods have been developed and applied in the world. Nickel-based alloy oil country tubular goods have excellent high-temperature performance and good corrosion resistance, but their manufacturing and processing are difficult and the cost is high, which restricts their large-scale application and development in the petroleum industry. In this paper, the microstructure and properties of the commonly used nickel-based alloys were analyzed, the corrosion mechanism in the acidic environment and the pipe processing technology was discussed.

Finite Element Analysis of Tube End Forming and Process Design

Compared with forging and extrusion processes, tube end forming includes various forming methods, such as pipe expansion, bending, bulging, folding, shrinking and profile processing. Therefore, research and development of pipe processing and forming are of great importance in the industry. In this study, the authors used the finite element analysis software DEFORM to analyze the end deformation behavior of the single pass forming. The deformation behavior of the pipe end, load curve and formability are discussed. The single-pass forming die design enables the pipe ends to be formed into two different shapes. By reducing the processing procedures with the geometric design of the dies, the processing advantages of single pass forming are achieved.

Manufacturing of 42SiCr-Pipes for Quenching and Partitioning by Longitudinal HFI-Welding

In the pipe manufacturing and pipe processing industry, the demand for cost-effective pipes with high strength and good ductility is increasing. In the present study, the inductive longitudinal welding process was combined with a Quenching and Partitioning (Q&P) treatment to manufacture pipes with enhanced mechanical properties. The aim of the Q&P process is to establish a martensitic structure with increased retained austenite content. This allows for the beneficial use of both phases: the strength of martensite as well as the ductility of retained austenite. A 42SiCr steel, developed for Q&P processes, was joined at the longitudinal seam by a high-frequency induction (HFI) welding process and was subsequently heat-treated. The applied heat treatments included normalizing, austenitizing, quenching, and two Q&P strategies (Q&P-A/Q&P-B) with distinct quenching (Tq = 200/150 °C) and partitioning temperatures (Tp = 300/250 °C). Investigations of the microstructures revealed that Q&P tubes exhibit increased amounts of retained austenite in the martensitic matrix. Differences between the weld junction and the base material occurred, especially regarding the morphology of the martensite; the martensite found in the weld junction is finer and corresponds more to the lath-type morphology, compared to the base material in the circumference. In all zones of the welded tube circumference, retained austenite has been found in similar distributions. The mechanical testing of the individual tubes demonstrated that the Q&P treatments offer increased strength compared to all other states and significantly improved ductility compared to the quenched condition. Therefore, the approach of Q&P treatment of HFI-welded tubes represents a route for the mass production of high-strength tubular products with improved ductility.

Research Status and Development of Titanium Alloy Drill Pipes

Petroleum and natural gas exploration and development are deepening, and the environment and stratum conditions encountered are becoming more and more complex. There are many high-temperature, high-pressure, high-corrosion wells, and the number of ultra-short horizontal directional wells, ultra-deep wells, and extended reach wells are also increasing. The steel drill pipe has not been able to meet and adapt to these requirements. Titanium alloy drill pipe has a series of advantages such as low density, high specific strength, excellent corrosion resistance, high temperature resistance, fatigue resistance, non-magnetic and good flexibility. It is suitable for the development of modern petroleum industry. This article discusses the use of titanium alloy drill pipe in domestic and foreign drilling in horizontal wells with short radius, the design of alloy components in titanium alloy drill pipes, body pipe processing, joint connection and corrosion resistance. Combining the practical application of titanium alloy drill pipe points out the current problems. Finally, from the aspect of drilling cycle, production safety and cost saving, the development and application of titanium alloy drill pipes in deep wells, ultra-deep wells and deep-sea drilling operations are prospected.