Petroleum and natural gas industries. Steel drill pipe

With the increasing intensity of oil and gas field exploration and development, oil and gas wells are also drilling into deeper and more complex formations. Conventional steel drilling tools can no longer meet the requirements of ultra-deep, high-temperature and high-pressure wells. The paper first analyzes the advantages of titanium alloy drill pipe based on basic performance of titanium alloy drill pipe. The experimental results show that the basic properties of titanium alloy drill pipes meet the operating standards of the petroleum industry. Then the buckling performance of titanium alloy drill pipe and steel drill pipe is compared, the calculation results show that the buckling performance of titanium alloy drill tools is slightly lower than that of steel drill tools. Secondly, the maximum allowable buildup rate of titanium alloy drill pipe and steel drill tool is studied. The research shows that under the same condition of the drill pipe outer diameter, titanium alloy drill pipe can be used for a smaller curvature radius and greater buildup rate. This advantage of titanium alloy drill pipe makes it more suitable for short radius and ultra-short radius wells. Finally, taking a shale gas horizontal well as an example, with the goal of reducing drill string friction and ensuring drill string stability, a comparative study on the application of titanium alloy drill pipe and steel drill pipe is carried out. The results show that titanium alloy drill pipe has a wider application in the field, and is suitable for operations under various complex working conditions.

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Changes of Microstructure and Properties of G105 Drill Pipe in H2S Environment

Materials Science Forum ◽

10.4028/www.scientific.net/msf.814.303 ◽

2015 ◽

Vol 814 ◽

pp. 303-312

Author(s):

Ben Sheng Huang ◽

Xiang Chen ◽

Long Peng Huang

Keyword(s):

Oil And Gas ◽

Drill Pipe ◽

Hardness Test ◽

Immersion Test ◽

Metallographic Analysis ◽

Key Factors ◽

High Concentration ◽

Microstructure And Properties ◽

Steel Drill ◽

Pipe Materials

H2S corrosion has become one of the key factors that has impact seriously on the exploration and development of high-sulfur oil and gas. In order to study the change of microstructure and properties of G105 steel drill pipe in H2S environment, different concentrations of H2S (300ppm, 400ppm, 500ppm, 600ppm) were used respectively at room temperature to make corrosion immersion test on the G105 drill pipe, and then tensile test, impact test, hardness test, metallographic analysis, scanning electron microscopy (SEM) observation and EDS spectrum analysis. The results showed that in the range of H2S concentration provided in tests, pipe materials was corroded quite seriously, microstructure changed obviously, comprehensive mechanical properties decreased significantly, and the range decreased first and then increased and decreased again. The type of fracture is classified as the pore ductile fracture, some of them appear prospective cleavage characteristics, and, fracture place exist severe solute partial clustering phenomenon. In addition, high concentration of Sulfur was found in impact fracture surface. The results would provide a reference for our understanding of the corrosion behavior of the drill pipe materials in H2S environment and the development of new anti-corrosion materials drill pipe.

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