Cone bit bearing seal failure analysis based on the finite element analysis

To improve the performance of the cone bit bearing seal, experimental study and simulation analysis of seal failure were carried out, and optimization of the seal was conducted. Results show that d...

https://journals.sagepub.com/doi/pdf/10.1177/1687814018767485

Optimization of cone bit bearing seal based on failure analysis

Abstract Three-cone bit is the key equipment in the exploration of the oil in offshore drilling and exploration, the bearing system and the seal system are the critical components for the bit. Especially in the offshore drilling environment, the seal design need to be carefully considered. A multi-objective optimization design including orthogonal design method and F-test with finite element analysis for a three-cone bit seal is proposed. Firstly, the calculation method of optimization targets are given, including the minimization of maximum contact pressure and leakage rate analyzed by ANSYS and MATLAB respectively, to maximize seal life and reliability. Then, an orthogonal experiment approach is used to investigate the effects of the eleven parameters on the seal performance, and the influence degrees of the seal factors on the optimization targets have been confirmed by F-test, and the reasonable factors can be determined by the trend of the targets. Finally, in order to validate the analysis results, a new seal was designed and tested on a seal tester compared to the previous seal. In this test, the seal maximum interface temperature that reflects the position of maximum contact pressure can be obtained by using three high precision thermocouples. Both the experiment results and the numerical analyses proved that the maximum contact pressure and leakage rate of the improved seal have been reduced compared to the previous.

Experimental and optimization design of offshore drilling seal

Purpose The paper aims to clarify the relationship between the cone bit seal failure and the down-hole drilling fluid pressure and high temperature that occur during ultra-deep well drilling. It proposes the contact pressure distribution under low pressure is favourable for lubrication, and the seal inner wear is serious under the high-pressure condition. Furthermore, the more reliable cone bit seal can be obtained using the BP neural network and genetic algorithm to reduce the drilling cost. Design/methodology/approach The wear morphologies of the seal surface were analyzed using Contour GT-K to determine the seal contact pressure distribution. Then, the influences of the drilling fluid pressure and high temperature on the metal seal interface were analyzed using FEM. The structural parameters of the seal under high pressure were optimized based on the BP neural network and genetic algorithm. Findings This paper proposes that the inner seal contact pressure increases rapidly with an increase in the drill...

Wear morphology analysis and structural optimization of cone bit bearing seals

Rubber parameters of single metal floating face seals are gained accurately by adapting the theoretical analysis and tests, and the problem that uncertainty of rubber parameter make theoretical analysis impossible quantitative is solved. Axial force-displacement curve calculated by finite element analysis model is close to the experimental curve at the overall tendency, which shows that finite element analysis model can simulate the assemble process of single metal floating face seal accurately. Based on stress analysis of the finite element analysis model, it is pointed that back-up ring can improve contact stress distribution of static seal face and dynamic metal seal face, improve sealing ability and deduce seal wear, but have little effect on O-ring.

Tamer Waheed

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