Parametric Effects on the Deployment Dynamics and Passability of the Inner Assembly of a 216-Type Wireline Coring Tool in Ultra-Deep Wells

Wireline coring enables efficient core recovery in deep and ultra-deep wells. However, the deployment of slender inner assemblies through curved drill pipes is often affected by wall contact, friction, and localized stress, potentially leading to deployment arrest. This study investigates the deployment dynamics and passability of the inner assembly of a 216-type wireline coring tool. A nonlinear transient finite-element model was developed in ANSYS 2022 to characterize axial motion, bending deformation, repeated wall contact, and local stress within a prescribed S-shaped drill pipe. Drilling-fluid conditions were incorporated indirectly through Fluent-derived initial deployment velocities, while Hertz contact theory and mesh sensitivity analysis were employed to assess the physical plausibility and numerical consistency of the model. Parametric simulations examined the effects of annular clearance, core-barrel wall thickness, assembly length, and initial deployment velocity. The results show that deployment arrest occurs at annular clearances of 5.0, 5.5, and 6.0 mm, whereas successful deployment is achieved at 6.5 mm. At a clearance of 5.0 mm, the equivalent stress peak reaches 934.44 MPa, exceeding the material yield strength and indicating a potential risk of local yielding. Increasing wall thickness from 5 to 7 mm intensifies localized stresses, while extending assembly length from 10 to 20 m accelerates velocity attenuation. Nevertheless, successful deployment is achieved in all four cases. Within the investigated initial velocity range of 3.4–3.6 m/s, successful deployment is achieved in all cases, although transient contact responses vary. These findings provide insights into contact-induced deployment arrest and offer guidance for improving the structural design and deployment performance of wireline coring tools under the investigated conditions.