This article deals with the stability analysis of a drilling system which is modelled as a coupled ordinary differential equation / string equation. The string is damped at the two boundaries but leading to a stable open-loop system. The aim is to derive a linear matrix inequality ensuring the exponential stability with a guaranteed decay-rate of this interconnected system. A strictly proper dy...

Embedded sensors, connected to the industrial internet of things (IIoT), have increased the granularity and frequency of data collected during the drilling process – but the data is often siloed and underutilized. This lack of integration can lead to expensive, time-consuming problems during the drilling process. Inefficient drilling programs can have an even greater aggregate financial impact,...

The Hawaiian-Emperor hotspot track has a prominent bend, which has served as the basis for the theory that the Hawaiian hotspot, fixed in the deep mantle, traced a change in plate motion. However, paleomagnetic and radiometric age data from samples recovered by ocean drilling define an age-progressive paleolatitude history, indicating that the Emperor Seamount trend was principally formed by th...

In this paper, we consider linear dynamics subject to a distributed state-dependent delay and a pointwise input-delay. We propose a prediction-based controller which exponentially stabilizes the plant. The controller design is based on a backstepping approach where delays are reformulated as hyperbolic transport PDEs. Infinity-norm stability analysis of the corresponding closed-loop system is a...

Drilling holes into concrete or metal ceilings is one of the most physically demanding tasks performed in construction. The work is done overhead with rotary impact hammer drills that weigh up to 40 N. The task is associated with pain and musculoskeletal disorders at the wrist, forearm, shoulder, and back. The mechanism of injury is thought to be the high forces and non-neutral shoulder and wri...

High-frequency measurements can provide much more new insights for drillstring dynamics compared to traditional instruments, leading a realm of understanding behaviors in great detail than before. In this paper, data acquisition tools with high-frequency sample rates and the processing are introduced. Based on data, progress drilling is summarized, including understandings low-frequency dynamic...

Although pneumatic down-the-hole (DTH) hammers have good performance of high penetration rate and minimal deviation tendency in the vertical section oil gas wells, they not been successfully used directional drilling due to drill tool wear wellbore disturbance. Herein, we developed a novel type DTH hammer with self-propelled round bit overcome technical difficulties drilling. Nonlinear dynamic ...