Rotational drilling was a revolution in drilling technology. It made the drilling process more efficient and faster and more depth of well could be achieved through rotation method. Besides all of its advantages, the rotation approach induced some problems like pipe sticking and downhole cleaning to the drilling procedure. Hole cleaning and reduction of torque and drag seems to be vital in incl...

Bone drilling is an essential part of many orthopaedic surgery procedures, including those for internal fixation and for attaching prosthetics. Estimation and control of bone drilling forces are critical to prevent drill breakthrough, excessive heat generation, and mechanical damage to the bone. This paper presents a 3D finite element (FE) model for prediction of thrust forces experienced durin...

Executive summary This thesis proposes and evaluates a concept for downhole depth estimation by matching subsurface measurements from two sensors in a bottom hole assembly. The application of a downhole depth estimate in automated subsurface navigation has also been demonstrated. One of the key hurdles in achieving real time subsurface navigation lies in communication bottom neck between surfac...

the drilling is well known as one of the most common hole making processes in the industry.due to close tolerance requirement for drilled holes in the most of work pieces, onlinecontrolling of the diameter of drilled holes seems to be necessary. in the current work, an onlinedimensional controlling system was developed for drilling process. doing this, drilling processwas executed in different ...

This paper presents an integrated adaptive estimator-controller scheme for a class of systems with only partially measured states. To estimate the non-measured states, a fast adaptive estimator is applied. The estimation is used in the L1 adaptive controller, which adapts to time-varying unknown parameters and time-varying bounded disturbances in the system without restricting their rate of var...

numerous parameters influence bit selection process, which considering all them is not normally feasible. existing methods use limited number of these parameters to choose a suitable bit for a specific drilling condition. one of the widely used methods is cost per foot. specific energy and drilling strength are another methods currently used for bit selection. different methods of bit selection...

We give a detailed view of estimation and control problems raised by the drilling process where the distributed nature of the system cannot be ignored. In particular, we focus on the transport phenomena in Managed Pressure Drilling (MPD) and UnderBalanced Operations (UBO), as well as the time-delay mechanisms of the mechanical stick-slip vibrations. These industrial challenges raise increasingl...

The problem of slow drilling in deep shale formations occurs worldwide causing significant expenses to the oil industry. Bit balling which is widely considered as the main cause of poor bit performance in shales, especially deep shales, is being drilled with water-based mud. Therefore, efforts have been made to develop a model to diagnose drilling effectivity. Hence, we arrived at graphical cor...

The rheological regulation of the “three high” (high temperature, high density and high salinity) water-based drilling fluid is a worldwide problem due to the combined influence of temperature, solid content and salinity. This paper investigates the factors and regulation methods about rheological property of “three high” water based drilling fluid, and the effects of clay, salinity and weighti...