Nonlinear Dynamic Characteristic Analysis of a Landing String in Deepwater Riserless Drilling

Abstract

The landing string is an important component of deepwater riserless drilling systems. Determination of the dynamic characteristics of the landing string plays an essential role in its design for ensuring its safe operation. In this paper, a dynamic model is developed to investigate the dynamic response characteristics of a landing string, where a landing string in a marine environment is modeled as a flexible slender tube undergoing coupled transverse and axial motions. The heaving motion of the drilling platform is taken as the upper boundary condition and the motion of the drilling bit caused by the interaction between the rock and the bit as the lower boundary condition. A semiempirical Morison equation is used to simulate the effect of the load imposed by the marine environment. The dynamic model, which is nonlinearly coupled and multibody, is discretized by a finite element method and solved by the Newmark technique. Using the proposed model, the dynamic responses of the displacement, axial force, and moment in the landing string are investigated in detail to find out the influences of driving depth of surface catheter, platform motion, bit movement, and marine environment on the dynamical characteristics of the landing string.

Reconfigurable dynamic analysis method for multilevel mechanical transmission system

“…When the structural composition of the mechanical transmission system changes, the modeling and solution need to be reconstructed, and the efficiency is not high. In response to this problem, Li [3] , Wang et al [4,5] , Liu and Wang [6,7] , Xu [8] , and Wang et al [9] proposed rapid dynamic analysis methods for specific systems, but the scope of application is limited.…”

“…If the current mechanism unit is connected to N successor mechanism units through one common component k, the equivalent moment of force𝑀 , the equivalent moment of inertia 𝐽 or the equivalent force 𝐹 and equivalent mass 𝑚 of each successor mechanism unit on the common component can be obtained by Formula (4) or Formula ( 5), where: 1 𝑖 𝑁 . The equivalent moment of force 𝑀 , the equivalent moment of inertia 𝐽 or the equivalent force 𝐹 and the equivalent mass 𝑚 of the common component k which is finally equivalent to N subsequent mechanism units can be calculated by Formula (6).…”

Three-dimensional nonlinear coupling vibration of drill string in deepwater riserless drilling and its influence on wellbore pressure field

“…The results show that the platform motion, shear flow velocity and drill bit motion have significant effects on the axial force of the pipe string. The larger the platform motion amplitude or the higher the rig speed, the larger the maximum dynamic axial force, and the higher the shear flow velocity, the smaller the maximum dynamic axial force [6]. Liu et al analyzed the overall stress of drill pipe and shallow casing in riserless drilling and established the overall static model of pipe string and wellhead and the dynamic model of drill pipe.…”

Three-dimensional nonlinear vibration model and fatigue failure mechanism of deepwater test pipe

“…However, the above models mainly focus on the vibration in a single direction, which can effectively predict the vibration of tubular structure with small aspect ratio, and its calculation accuracy decreased to predict the vibration of tubular structure with large aspect ratio. Also, some scholars [32][33][34] have found that the longitudinal/lateral coupling effects of tubular structure with large aspect ratio cannot be ignored. Therefore, in our recent work [21,22], the longitudinal/lateral coupling model of marine risers with consideration of the coupling effects of the CF and IL vibration were established.…”