Understanding the behavior of the drill bit, bottomhole assembly (BHA), and drillstring in drilling operations is difficult without accurate measurements of tensile load, torque, pressure, and various vibrations both at surface and downhole. A variety of methods have been employed to compress measurements obtained downhole in order to transmit them to the surface with measurement-while-drilling (MWD) mud-pulse telemetry. During the last ten years, some success has been achieved in making these measurements, recording them, and then retrieving the data at surface upon the end of the bit run. Meanwhile, the comparable measurements at surface have limitations in terms of accuracy, calibration, and dampening.An instrumented surface sub (ISS) has been developed that replaces the saver sub at the bottom of the top drive on a rig's traveling assembly. It measures in real time at the top of the drillstring, using accurate and calibrated sensors, tension/compression, torque, rotational speed in revolutions per minute (RPM), and surface pump pressure, among other parameters. These measurements, made at 400 Hz, are not dampened by the drill line and sheaves. A drilling mechanics module (DMM) sub that is part of the BHA has also been developed, which provides downhole measurements including, but not limited to, tension, torque, RPM, internal and annular pressure, at frequencies between 200 and 2,000 Hz. Additionally, along-string vibration measurements are provided using memory only devices.To evaluate both of these downhole and surface drilling data acquisition tools, a test was conducted in June 2010 at the Schlumberger directional drilling test facility near Cameron, Texas. Four different BHAs were run to evaluate downhole behavior and collect data using milled-tooth and PDC bits while directional drilling in surface rotary mode as well as with steerable motors. This paper presents some of the wide-range findings regarding the use and analysis of the data gathered in terms of static drilling mechanics, as well as dynamic drillstring behaviors and downhole vibrations. IntroductionDrilling operations have historically monitored surface drilling data as a tool to make the necessary adjustments in a drilling activity to maximize performance. The basic measurements are torque, tension or hookload, mud pressure, flow rates, and rotational speed (RPMs). The frequencies at which these data sets are gathered range from 1 to 15 Hz. Modern drilling rigs utilize sensor data obtained using technologies that are hydraulic-based, electronic-based, or a combination of both. The data may be displayed on a simple hydraulic gauge, or conversely, viewed on an electronic human-machine interface (HMI) display. The same measurements are made downhole, but the frequency of the data gathered is limited by bandwidth in mudpulse telemetry. Generally, large quantities of higher frequency data can be post-processed only after the BHA has been brought back to the surface. Experience has shown that data of higher accuracy and frequency is needed to dia...

No abstract

This paper presents version-I of SoftLink, a software package based on Simulink and Matlab for the synthesis and analysis of linkage mechanisms. The purpose of the package is to provide teachers/students with a user-friendly, easy to use tool to facilitate teaching/learning of analysis and synthesis of mechanisms using the familiar programming platform provided by Matlab/Simulink which is used to solve a myriad of other engineering problems. SoftLink is organized and structured to facilitate future additions and enhancements. The current version of SoftLink provides for the analysis, synthesis, optimization, and simulation of 4R mechanisms. Precision point synthesis methods and optimimum synthesis techniques are coded to yield a mechanism for a specific task. The code is designed such that kinematic and dynamic analysis and synthesis of other linkage mechanisms, gear drives, and cam-follower mechanisms may be easily included in future versions. The basic structure of SoftLink is described in detail and two application examples on 4R synthesis are presented to demonstrate its usefulness.

This paper presents a new complete CAD-driven rapid prototyping system for polystyrene. ModelAngelo, as it is called, consists of six subsystems featuring hardware and software. The system utilizes a virtual 3D CAD model to produce a set of commands used to control a 5-axis CNC Machine to move a heated-wire tool into a block of polystyrene to form the desired surface. The ultimate goal of ModelAngelo is to reach the stage of “what you see is what you get”. An overview of ModelAngelo system is first presented followed by a detailed discussion of ModelAngeloSoftware. The various mechanical subsystems responsible for realizing the final product are then described. Advantages and disadvantages of several tooltip designs are discussed and the best solution is selected. The main features of the robotic arm, which carry the tooltip is also discussed in detail. Finally ModelAngelo controller that manages the interaction between software and hardware is briefly highlighted and possible applications of ModelAngelo are suggested.