bluuebunny/crossref_metadata_2025_split huggingface dataset:
Delivering Performance in Shale Gas Plays: Innovative Technology Solutions
Authors: Baez Franklin , Barton Steve 
Published: March 2011

Abstract
This paper focuses on technology development for improving drilling performance in natural shale gas plays. These wells involve long horizontal laterals with frequent problems in controlling tool face and maintaining ROP. This results from a number of factors including, high tortuosity through the build section, use of high bend settings on directional motor assemblies, sub-optimal hydraulics, and drill bits with compromised aggressivity.
A combination of technologies can be used to dramatically increase performance in these challenging sections by limiting resistive torque, maximizing bit hydraulics, and improving weight transfer. In each example, a separate engineered solution is introduced. These include;
A novel tool that vibrates the drill string with low frequency, low amplitude axial vibrations to reduce drag and dramatically improve weight transfer to the bit. This tool has been used successfully in hundreds of horizontal wells A specific sealed bearing, motor technology that delivers 100% of the mud flow to the bit. Advantages of full flow include increased bit hydraulics (improved ROP in Shale), and no detriment in response when using tools below the motor that rely on pressure or flow to activate. Run data demonstrates a 37% average increase in ROP compared to conventional sealed bearing motors that rely on flow restrictor bypass leakage for seal performance Development of a unique flexible bit design, specifically for directional applications. These bits contain novel features that allow rapid design modifications to be performed locally, significantly reducing response time, and allowing the drilling program to proceed at a much faster pace than previously possible
Case studies are documented where these solutions have proven extremely successful in gas shale plays. The savings produced by the improvement in drilling performance has greatly assisted the economic viability of continued development in these applications.
Effective BHA Design and Vibration Modeling for Improving the Quality of Sonic Measurements
Authors: Chatar Crispin , Blyth Matthew 
Published: March 2011

Abstract
The first logging while drilling (LWD) sonic tool was developed in 1996. For the oil industry, sonic tools have now become a critical part of the existing suite of LWD tools. They allow the determination of formation velocities while drilling, enabling real-time decision making. Compressional and shear velocities obtained can be used for calculating rock mechanical properties, which can then be used for drilling optimization, ensuring hole stability, or as inputs into mechanical earth models. Compressional velocities are also sensitive to pore pressure and can be used to determine pore pressure trends while drilling. This allows the calculation of a safe mud weight window and the ability to update it in real time. LWD sonic tools also allow the calculation of interval transit time, which can be used to update seismic data while drilling. Acoustic tools, therefore, offer a variety of measurements critical for drilling successful wells, so it is imperative to ensure that the best quality data are delivered at all times.
The detrimental physical effects of shock and vibration on drillstring and bottomhole assembly (BHA) components are well known. However, vibrations have also been known to have adverse effects on downhole LWD tool measurements. Measurements of acoustic signals are sensitive to excessive sources of downhole noise, such as shock, vibrations, and poor drilling practices. It is therefore critical to the quality of the sonic log to minimize vibrations while drilling, to design BHAs that minimize tool movement, and to optimize drilling parameters. The effects of shocks and vibration can be clearly seen by comparing acoustic logs over zones with high downhole shocks to those zones in which shocks were minimized. The primary way to reduce the likelihood of these problems is to design a BHA that is less prone to vibrations and is correctly configured to optimize the acoustic measurement. Today, many companies have a range of software available, from simple vibration to finite element analysis software that can create models required for this type of design.
Background information on acoustic measurement and its uses is presented, along with an overview of some current BHA vibration modeling techniques. We review data from projects with poor quality sonic data due to lack of vibration modeling and from projects in which vibration modeling was done so that the results can be compared and analyzed. We look at what is required at the design phase for planning BHAs to minimize vibrations and to optimize the acoustic measurement. Some examples of what is done today are discussed, and a list of general guidelines for BHA design that should be considered when running acoustic tools is included.
Hydrocarbon Reservoirs Where Proactive Geosteering is Most Likely to Succeed
Authors: Seifert Douglas , Aramco Saudi , Chemali Roland , Bittar Michael , Althoff Gary , Lotfy Amr 
Published: March 2011

Abstract
Proactive geosteering is the fastest-growing form of geosteering. It enables reservoir exits to be anticipated before they occur and well paths to be altered to navigate within the best portion of the reservoir. This paper demonstrates that proactive geosteering when utilizing resistivity tools is most likely to succeed when drilling in a high resistivity reservoir surrounded by low resistivity formations. The likelihood of success is further improved when the different media are separated by sharp boundaries, whereas gradational transitions prove to be challenging.
These observations are substantiated and quantified with models and actual case histories. The key enabling geosteering technology considered in this study is the newly deployed azimuthal deep resistivity family of logging-while-drilling (LWD) sensors. These sensors can detect and locate an approaching boundary from several feet. The geosteering personnel track oil/water contacts and shale/sand interfaces. The earlier these boundaries are identified, the better the chances for successful geosteering. The resistivities of the formations are important because the lateral reach of the sensor is most favorable when navigating in a high resistivity reservoir adjacent to low resistivity formations. Similarly, the least favorable situations occur when navigating in a low resistivity interval and seeking a high resistivity formation. Series of modeling results help to quantify and visualize the expected geosteering performance for various resistivity values in the reservoir and approaching formations.
The paper includes case studies from actual geosteered wells to illustrate the performance predicted by the theoretical models. It also provides guidelines for planning and interpreting a proactive geosteering operation.
Understanding and Managing Bottom Hole Circulating Temperature Behavior in Horizontal HT Wells - A Case Study Based on Haynesville Horizontal Wells
Authors: Trichel Keith , Fabian John 
Published: March 2011

Abstract
While HT wells have always presented drilling challenges, the recent activity increase in the Haynesville shale located across the border between Texas and Louisiana presents a unique and extreme environment for drilling equipment. Not only is there a high frequency of temperature related MWD/LWD failures, the profile and architecture of Haynesville wells has provided an opportunity to study and better understand the thermal behavior of horizontal HT wells in general. Through improved understanding, well specific operational guidelines and planning considerations can be implemented to ultimately reduce the risk of downhole temperature related failures.
This paper discusses a Haynesville horizontal well case study where temperature simulations were compared and calibrated to actual downhole temperature measurements taken while drilling. After calibration of the model was established, a series of simulations were conducted to investigate the sensitivity of bottom hole circulating temperature to choices of drilling systems, fluids systems, mud cooling systems and well design.
The simulation results indicate:
The bottom hole circulating temperature profiles of HT horizontal wells are significantly different than those of vertical wells and can even exceed the bottom hole static temperature. The simple every day choices made with regards to the drilling program including fluids selection, hole size, bottom hole assembly type, bit hydraulics, and flowrate all influence bottom hole circulating temperature and can either increase it or decrease it. Optimization in the traditional sense (focused on ROP) does not apply and can result in even higher bottom hole circulating temperatures. The correct procedures are often counter intuitive.
This paper will detail the above mentioned effects on bottom hole circulating temperature and will present optimization guidelines and planning considerations for managing circulating temperatures. At the time of this writing, the implementation of these guidelines and procedures discussed in this paper is just beginning. The overall trends for MWD/LWD performance for the Haynesville, while improving over time still indicate significant room for improvement in planning and operating practices (Appendix - Figure A1). Guidelines and planning considerations, and operating practices for horizontal Haynesville wells are presented along with the reasoning behind them.
How to Accelerate Drilling Learning Curves
Authors: van Oort Eric , Griffith James , Schneider Barry 
Published: March 2011

Abstract
Given the current economic climate and continued volatility in oil and natural gas prices, extracting maximum benefit from drilling performance optimization is key to the economical exploitation of many resource plays around the world. Shell Upstream Americas is employing a highly effective performance improvement team to help drive performance optimization and the delivery of top quartile performance on its wells in North America and beyond. Central to this group is a dedicated team of optimization engineers that deliver drilling efficiency optimization techniques, the innovative use of real-time optimization centers, and value-adding root-cause failure investigations to various land and offshore well delivery teams in a fit-for-purpose way. Using the optimization approaches taken, it has been possible to help accelerate well delivery times and associated learning curves by as much as a factor of three, often in a minimum amount of time. A main conclusion is therefore that this approach is a highly effective way to bring performance optimization focus to field operations.
This paper highlights the modus operandi of these optimization engineers, the techniques and tools they employ, and the remarkable results achieved. The workflow and organizational structure was applied to well delivery optimization with projects ranging from shale gas drilling in the Continental US and Canada as well as hard rock drilling in the Middle East.
Testing the Combination of High Frequency Surface and Downhole Drilling Mechanics and Dynamics Data under a Variety of Drilling Conditions
Authors: Lesso Bill , Ignova Maja , Zeineddine Firas , Burks James , Welch Brent 
Published: March 2011

Abstract
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.
Cutting Carbonates — New Technology Delivers Step Changes in Bit Performance
Authors: Weeden R. W. , Williams S. , Lugo F. , Gaduan P. 
Published: March 2011

Abstract
Carbonate formations are renowned for their propensity to quickly turn a great interval into a set of costly challenges. These formations can quickly damage the cutting structure of drill bits which can result in a short/slow run. Consequently, bit aggressivity is often sacrificed for longevity to guarantee a minimal amount of trips to complete the section.
Historically, these formations were drilled with rolling cutter technology. However, after decades of development, rolling cutter bit designs could not provide the versatility and efficiency required by operators. Subsequently, fixed cutter technology was trialed through PDC and diamond impregnated drill bits. While providing abundant leaps in drilling efficiency, PDC suffered from diamond table loss which resulted in multiple trips. Conversely, diamond impregnated technology was able to provide improvements in longevity and reduce trips, but these improvements were offset by reduced drilling efficiency.
The reliability and durability of diamond impregnated bits has offered the industry a good option to reduce the number of trips required to drill a carbonate interval when tripping costs outweigh the operational costs of low penetration rates. While there are still improvements to be made with this technology, the next step change in performance will come from a bit which has the longevity of diamond impregnated bits and the efficiency of PDC bits.
This manuscript details a project aimed at delivering the next generation of drill bit technology for carbonate formations. In this project, key performance challenges associated with carbonate intervals were identified and concepts developed to overcome these challenges. After evaluation of these concepts, products were developed for field testing. Following a series of tests, the advantage of these concepts became apparent when performance illustrated abundant increases in efficiency while maintaining the longevity of diamond impregnated technology.
Natural Gas as a Fuel in Drilling Operations-Analysis, Testing and Implementation
Authors: Hill David G. , Johnson Jeff , Bell John , Mayer Nathan , Giberson Hugh , Hessler Ryan , Matthews Will 
Published: March 2011

Abstract
Utilizing natural gas as fuel to power large engines is not a new technology; however the application of dedicated natural gas powered engines to power drilling rigs can be considered a new approach to environmentally and socially responsible operations in the oil and gas industry.
The use of dedicated natural gas engines on drilling rigs provides the opportunity to capture the following advantages:
reduced emissions reduced cost improved maintenance characteristics, and improved for domestic energy security.
Barriers to adoption of this technology application for drilling operations included low cost of diesel, certainty around diesel handling and performance, uncertainty on natural gas engine performance under variable load conditions, impact of variations in gas composition on engine performance and operational challenges related to bringing natural gas to the rig in remote operations.
This paper describes the process used to evaluate, test, implement and measure the application of dedicated natural gas drilling systems in the Jonah Tight Sands drilling operations in Wyoming and in the Haynesville Shale Gas operations in northern Louisiana. Key learnings from deployment of natural gas engines in the field will be shared.
As part of the technology application process, dedicated and dual fuel engines were tested and different forms of natural gas fuel sources were utilized based on maturity of the field, proximity to natural gas infrastructure and natural gas quality. This included utilization of lease/field gas, treated gas (tailgate of gas plant) and liquefied natural gas. The evaluation process included the following: engine performance, engine emissions, natural gas quality, cost differential when compared to dieselburning engines, planned maintenance costs versus diesel and life cycle analysis. Evaluation results will be summarized along with economic analysis.
A decision tree model was developed to assist in evaluating when to consider natural gas as a fuel in drilling operations and what adaptations to the application would be required to respond to various forms of natural gas available for use. The model will be applied to an emerging natural gas field in Europe or Asia.
Enabling Technology Optimizes Dynamic Mud Weight Management and Reduces Well Cost Associated with Drilling Operations
Authors: Barbato Thomas L. , Cenberlitas A. Serkan , Gala Deepak M. 
Published: March 2011

Abstract

Description of the Material:
The drilling industry's new Micro-Flux Control (MFC) System technology has enabled safer and cost effective processes and practices in defining uncertain down-hole limitations in wells ranging from wildcat to mature fields. MFC is a closed loop system that evaluates available drilling data in real time.
The standard application of MFC technology optimizes drilling practices by its ability to ascertain actual downhole pressure environment limitations in real time. Knowing these limitations allows continuous conventional drilling operations while retaining the benefits of the Managed Pressure Drilling (MPD) through dynamic mud weight management. This paper presents a description and features of the MFC system, benefits of standard application, and case studies with real field data.

The Application:
An increasing proportion of wells are drilled in challenging environments; uncertainties and unforeseen events associated while drilling are costly and unsafe. Utilizing MFC methods allows operators to mitigate these drilling events through real time event identification with accurate measurement in mass flow/density and pressures. Furthermore, the MFC system provides an accurate response, and determination, of actual wellbore pressure limitations. Armed with this understanding, wells can be progressively drilled in conventional practice with optimized dynamic mud weight management via drilling parameter adjustments. Common practices of the applications in recent wells are pore/fracture pressure determination through dynamic pore pressure test and LOT/FIT's, identification and mitigation of ballooning, quick identification of kicks and losses in miniscule order of magnitude with or without automatic control, safe and rapid depletion of gas zones, and so forth.
The results, observations and conclusions:
This paper includes actual field cases from recent wells drilled in the United States, North Sea, North Africa, and Asia Pacific. Also, screenshots are presented showing each of the aforementioned events and the mitigation techniques implemented to maintain drilling conditions within the downhole pressure limitations.

The significance of the subject matter:
Micro-Flux Control technology is the only enabling method that closely adheres to the definition of MPD by IADC without changing conventional drilling practices. Eliminating uncertainty during the drilling process enhances overall safety, improves the real-time decision making process, and reduces non productive time and well costs.
Experimental and numerical study of friction and .giffness characteristics of small rolling tires
Authors: van der Steen R. , Lopez I. , Nijmeijer H. 
Published: March 2011

Abstract
Virtual testing is nowadays the standard in the design process of new tires. Besides modeling the static response of the tire itself, the dynamics of a rolling tire in contact with the road needs to be incorporated. Due to the uncontrollable environmental conditions and the complex structure of the tires, it is advantageous to use small-scale testing under more controlled conditions. Experimental characterization of frictional properties of rubber compounds is, however, limited due to the necessity of complex measurement systems. In this paper a commercially available laboratory abrasion and skid tester is used to ide.gify both friction and .giffness characteristics of the same rubber compound. The obtained friction properties are implemented in a finite element model of the setup, and different validation steps are presented. Finally, a steady-state transport approach is used to efficiently compute a steady-state solution, which is compared with the experimental results. The numerical results show a good qualitative agreement with the experimental results.
Avian Diversity of Bhoj Wetland: A Ramsar Site of Central India
Authors: Vyas V. , Vishwakarma M. , Dhar N. 
Published: March 2011

Wetlands provide habitats for various types of birds in different seasons. The present paper discusses the diversity of water birds in Bhoj Wetland of Bhopal which is a Ramsar site and a thousand year old wetland constructed by Raja Bhoj. The wetland provides variety of habitats to the waterbirds and they occupy these habitats according to their niches. Anatidae was the most dominant family recorded during the study period in the peak winter period whereas the population started declining as the temperature rises in the subsequent months. This indicates that most of the migratory species belong to the family Anatidae comprising ducks. They prefer deep water habitats with submerged vegetation. Looking to the importance of the wetland a study was conducted in the winter season in Bhoj Wetland of Bhopal (Central India) which is a Ramsar site. DOI: 10.3126/on.v8i1.4310
Aquatic Oxygen Uptake of the Freshwater Dual Breathing Featherback, <i>Notopterus notopterus</i> (Pallas) in Relation to Body Weight
Authors: Kumari R. , Roy P.K. , Ghosh T.K. 
Published: March 2011

Oxygen uptake (VO2) through the gills in relation to body weight has been studied in Notopterus notopterus at 24.0±1.0ºC under continuous water flow system. With gradual increase in body weight from 5.10 to 122.33 g, the oxygen uptake increased from 1.164-3.975 mlO2.h–1. The log-log plot between the oxygen uptake per unit time and body weight gave a straight line with the slope ‘b’ value of 0.421. The relationship between the two variables was found to be highly significant (r= 0.986; p<0.001). However, the weight specific oxygen uptake decreased from 228.36 to 32.49 with increase in body weight from 5.10 to 122.33 g. A straight line with slope ‘b’ value of -0.629 was obtained when plotted on log-log coordinates, showing a highly significant negative correlation (r= 0.985; p<0.001).DOI: 10.3126/on.v8i1.4320