Failure Modes and Mechanism Analysis of Downhole Tool Seals

Abstract Packer rubber, O-rings, and screw pump stators are important downhole tool seals, and their sealing performance directly affects the production of oil and gas wells. This paper systematically summarizes the failure forms of packer rubber, O-ring, and screw pump stators sealing elements and analyses their failure mechanisms. The packer rubber mainly exhibits stress concentration, stress relaxation, temperature aging, medium corrosion, rubber swelling, casing damage, and fretting wear. The failure mechanisms involve cracks caused by local stress, permanent deformation due to long-term pressure, changes in material properties, chemical erosion, and volume changes, etc. The main failure forms of O-rings include permanent deformation, gap bite, particle wear, twisting, and surface wear, and their failure mechanisms are closely related to pressure influence, improper installation, and abrasion. The failure of the screw pump stator is manifested in swelling, chemical erosion, and mechanical wear, mainly resulting from liquid absorption, chemical action, and material loss caused by friction. Through the analysis of the failure forms and mechanisms of packer rubber, O-ring, and screw pump stator sealing elements, the summary can provide various helps for subsequent research and optimization. Firstly, by deeply understanding different failure forms and their root causes, the material selection can be optimized to improve product durability and adaptability. Secondly, the design can be improved to enhance the structural strength and reduce the damage caused by stress concentration and uneven pressure. In addition, optimizing the manufacturing process helps to reduce the defect rate and ensure product consistency; and formulating targeted maintenance strategies can detect potential faults in advance and reduce maintenance costs. Finally, through carrying out targeted experiments and reliability assessments, the effectiveness of new materials and designs can be verified, thereby improving the overall reliability and operating efficiency of the sealing equipment.