Session: 01-06-01: Impact, Fatigue, Damage and Fracture of Composite Structures

Paper Number: 107457

107457 - A Numerical and Experimental Shock Study on a Logging While Drilling Mockup Assembly 

It is essential to determine formation properties surrounding the wellbore to mark the hydrocarbon producing zone and to visualize a better understanding of the subsurface before production. Logging while drilling (a.k.a. LWD) is an effective modern technique whereby the physical properties of the formation are recorded during drilling. Timely LWD data are generally sent to the surface through mud pulses and can also be used to guide well placement so that the wellbore remains within the zone of interest or in the most productive portion of a reservoir. In practice, the LWD tools are often placed in the bottomhole assembly at the lowest part of the drill string.

LWD tools operate in a harsh environment during drilling. The increasingly aggressive drilling conditions subject tools to varying degrees of shock and vibration, which have become the leading cause of mechanical failures for drilling and measurement tools. Further, the dynamic excitations can be transmitted from the collar to the internal components, which could result in premature failures of the expensive electronics or other measurement devices. These failures can have a major impact on operators and service companies, costing millions of dollars in repairs and non-productive hours of rig time. Therefore, developing a critical components-capturing assembly and a reasonably accurate numerical model that can be utilized to understand and predict the dynamic response of the LWD tool under a shock event is highly needed from drilling energy management point of view.

In this paper, a high-fidelity 3D finite element analysis (FEA) model that can describe contact interactions between the collar, the chassis, and the mounted electronic board is developed for an LWD mockup assembly. A shock test system of the same (i.e., device under test grabbed by shock arms) instrumented with multiple accelerometers is also presented to mimic such dynamics that the tool could experience while drilling in a controlled lab environment. Favorable agreement is observed between experimental measurements and the predictions from the FEA model, which validates the developed FEA model. The validated numerical model can be employed for virtual qualification of newly developed drilling and measurement tools and for post-job root cause analysis of failures. 

Presenting Author: Ke Li SLB

Presenting Author Biography: Modeling and Virtualization Manager of SLB

Authors:

Fei Song SLB
Amanda Olivio SLB
Ke Li SLB