bluuebunny/crossref_metadata_2025_split huggingface dataset:
How an Improved Depth Measurement and Smart Processing Can Help the Driller Improve Efficiency
Authors: Unsworth M. I. , Burgess T. M. , Kerbart Y. J. 
Published: December 2007

ABSTRACT
Drilling monitoring systems have been available for many years yet none have ever fully considered the most important active link to drilling safety and performance; The Driller. With this in mind the first computerized drilling monitoring system specified by drillers has been designed and installed by a drilling contractor.
A significantly improved depth measurement has been included in the system. This paper describes how the measurement is made and its applications. The measurement and associated processing have led to automated pipe tally listings; penetration rate resolution of 8" (20 cm) for correlation purposes; and safety improvements due to better drilling break definition and permanent monitoring of the bit or shoe position when tripping pipe or casing. Field experience, examples and case studies from offshore installations are presented to highlight the effectiveness of this driller-controlled system.
Estimating Tooth Wear From Roller Cone Bit Vibration
Authors: Jardine S. I. , Lesage M. L. , McCann D. P. 
Published: December 2007

Abstract
This paper describes the development of processing techniques to extract roller cone bit wear information from near-bit force and acceleration measurements. Laboratory data have been col-lected for bits in a variety of wear states operating in a small atmospheric drilling machine and under the simulated downhole conditions provided by a fullscale drilling test station. This has given information on how bit cone speed increases as the wear process progressively reduces the cone radius. Recent studies are reported and the detailed dynamic features of force mea-surements made on laboratory drilling machines are described. The improved understanding of the nature of the bit signature has led to the development of novel processing techniques for the detection of bit wear from near-bit measurements. A com-parison with results obtained from bit modelling work is also presented.
Air-Drilling, Electromagnetic, MWD System Development
Authors: Harrison W. H. , Mazza R. L. , Rubin L. A. , Yost A. B. 
Published: December 2007

ABSTRACT
Two-way communications, between sensors and other devices at the bottom of, or along, boreholes and the surface, have traditionally been performed by wirelines and stored-data technology. Telemetry (up-link) and command (down-link) func-tions have more recently been performed by use of real-time, mud-based methods.
As more and more horizontal, slant-hori-zontal, arc, and other high-angle bore-holes are drilled (some with air), the need for non-wireline and non-mud-based communications becomes more important because of the difficulty of inserting tools and logs in the absence of a large gravitational force component, and the inability of mud-based systems to operate in air or for that matter in the absence of flow. The oilfield logging industry has developed tubing-conveyed-logging tools, but these too lack the flexibility required, because they still require a wireline. Even with side-entry subs, these tools are too costly or difficult to use in some cases. Air-drilling of directional wellbores is on the rise for a number of reasons, and wireline stee-ring tools and mud-based MWD tools are proving to be less than effective.
In recent years new wireless electromag-netic-based real-time borehole communica-tions techniques have been developed with capabilities for supporting relatively-low data rates (compared with wireline) adequate for some applications. These are in commercial use for Measurement-While-Drilling (MWD) systems. Others are find-ing their way into non-drilling use in connection with oil and gas reservoir evaluation and completion work. While most of the work has been done in larger boreholes, some systems are being built into drill-strings as small as 2.5 inches (6.35 cm) OD. Wireless electromagnetic borehole communications technology holds out hope for providing reliable, two-way, high-data-rate data and command links in wellbores; regardless of hole size and angle, mud or air, flow and no-flow, cased or open-hole.
This paper traces the development of wireless electromagnetic borehole commu-nications technology, and describes the state-of-the-art in oilfield and non-oilfield applications. Development of, and field results from, a recently-com-pleted air-drilling model are presented.
Analysis of Gas Influxes in Oil-Based Muds in the Gullfaks Field
Authors: Rommetveit R. , Olsen T. L. , Sorheim J. O. 
Published: December 2007

ABSTRACT
Several gas-influx events have occurred during drilling with oil-based mud on the Gullfaks field. These have usually started when hard chalk stringers were penetrated, and abnormal pressurized gas bearing zones were drilled into. These zones are often of low productivity and volume.
Based on all available data from the influxes in wells I and II, the events have been analyzed. The analysis has helped to explain the development of the influx events, and also the control phases have been evaluated.
A Computer Model for Kicks in Water- and Oil-Based Muds
Authors: White D. B. , Walton I. C. 
Published: December 2007

Abstract
A computer model of kicks in oil- and water-based muds has been developed as part of a contract from the UK Department of Energy. This work followed a study by the safety directorate of gas kicks taken while drilling deep, high pressure wells. The study highlighted the need for comprehensive mathematical modelling of kicks in oil-based muds incorporating the effects of gas solubility.
A ‘research’ model developed jointly by Schlumberger Cambridge (SCR) and BP International, includes both oil- and water-based muds, pressure transient effects, the density and dispersion of gas-cut mud and new models for the migration of free gas. This paper describes the philosophy behind the code structure, the solution techniques and modes of operation.The capabilities of the simulator are summarised, the coding considerations discussed and com-parisons between kicks in oil- and water-based muds are illustrated. Some details of the validation of the code against field and experimental data are given.
The code structure is designed for maximum portability and is highly modular, allowing ease of maintenance and upgrade. The full mass and momentum equations are solved in a core algorithm using an implicit finite difference scheme. An equation of state developed by BP is used to describe the density of gas-cut drilling mud at conditions of up to 15,000 psi and 350 deg F. The temperature dependence of the drilling mud rheology and the rise velocity of gas bubbles in non-Newtonian fluids are described by new experimental work from SCR.
The Design, Fabrication, and Utilization of a Leg Support Structure for Drydocking and Repairing the Spud Cans on a 300-ft Water Depth Jackup
Authors: Graham D. J. 
Published: December 2007

ABSTRACT
The "Diamond M Nugget", a Levingston Class 111 jack-up, had been operating for the past 12 years in the Straits of Magellan off the coast of Chile. Bottom soil conditions in this area were found to be very hard with numerous large rocks or boulders just beneath the surface. Underwater in Lieu Of Drydocking examinations which were carried out to meet the U.S. Coast Guard and the American Bureau of Shipping requirements revealed that the hard sea floor had caused indentations and cracking in the bottom shell plating of the rig's footings. After monitoring the progression of the can damage for the past ten (10) years, the regulatory agencies and Diamond M's Engineering staff recommended that provisions for drydocking the rig and repairing the damaged spud cans be made.
Many alternatives were investigated for drydocking the rig. Facilities that could lift the rig out of the water were not geographically close enough to be considered economically feasible. Transportation of barges or other equipment to the Straits of Magellan also would have been too costly. With these limitations in mind it was decided to design and fabricate a LEG SUPPORT STRUCTURE which could be floated out to a predetermined location and positioned underneath the jacked up rig. The rig would then jack down, pushing the structure to the sea floor. The structure would then be wedged between the sea floor and the rig's bottom, providing the support necessary to raise one leg out of the water until its spud can had sufficient clearance to effect repairs.
The 327 ton LEG SUPPORT STRUCTURE was successfully designed, fabricated, and utilized in repairing all three damaged spud cans on the "NUGGET". This project proved to be a practical and economical solution to drydocking and repairing a large jack up drilling rig in a remote location where conventional facilities are not available.
Performance Testing of Jars
Authors: Kyllingstad A. , Halsey G. W. 
Published: December 2007

ABSTRACT
This paper presents results from a test programme on jars and jar accelerators. More than twenty jars in the range of 6.25" OD to 8" OD have been tested in a horizontal jarring rig built especially for this investigation. The test program comprises both single tool tests and full jarring tests where the jars are tested together with accelerators. In the single tool tests, the jars are extended and closed slowly to provide data on release forces, friction forces, jar strokes and delay times for hydraulic jars. In the full jarring tests the jars have been tested dynamically under realistic conditions. In these tests the dynamic friction is measured at realistic telescopic speeds and the strength of the jar is checked. The tests have revealed significant differences in the performance of various jars. In particular, dynamic friction forces vary widely between tools. The test results and their applications to downhole jarring are discussed.
Gravel-Sizing Criteria for Sand Control and Productivity Optimization
Authors: Leone J. A. , Mana M. L. , Parmley J. B. 
Published: December 2007

ABSTRACT
Field experience has demonstrated that gravel sized at 5-6 times the mean formation grain size usually results in adequate sand control. However, the use of larger gravels could provide greater well productivity since the pressure drop through gravel-filled perforations is often significant. Larger gravels are especially attractive in those cases where both fracture stimulation and gravel packing are required. This study was undertaken to determine an optimum proppant/gravel that will provide maximum proppant permeability and effective sand control in a friable sandstone reservoir.
Conventional gravel sizing procedures are based on laboratory studies performed with clean river sands substituted for actual formation materials. In this study, experiments were performed in flow cells using formation core plugs and carcass material. Brine, oil, and gaseous carbon dioxide were injected through the formation material at rates representative of the maximum expected in the nearwellbore region. Gravel permeability and the movement of formation material into and through the gravel pack were then evaluated as a function of gravel size and size distribution, formation mineralogy, degree of formation consolidation, type of flow (single- or multi-phase, steady or pulsed), and experiment duration.
The results indicate that effective sand control is obtained in this formation with larger than expected gravels (ratio of mean gravel diameter to mean formation diameter = 16:1.) Much higher well productivity can be obtained with the experimentally determined optimum proppant/gravel as compared to that attainable with a gravel/proppant sized using a conventional 5 to 1 gravel to formation ratio. The mechanisms which give rise to effective sand control with such large gravels were determined and are discussed. The method of experimentally determining the optimum gravel size for any formation is described and shown to be simple and fast to perform. The approach can be used with any formation requiring sand control. In many cases the optimum gravel size obtained by this method will be consistent with that predicted by conventional procedures; however, much greater well productivity is possible when the laboratory method indicates that larger gravels can be used.
Phase Behavior Properties of CO2/Heavy Oil Mixtures for EOR Applications
Authors: Sayegh S. G. , Sarbar M. 
Published: December 2007

Abstract
The objective of this study is to measure the phase behavior and physical properties of a Canadian heavy crude oil (11°API) saturated with carbon dioxide as a function of pressure and temperature. These data are used to evaluate the feasibility of using carbon dioxide as a pretreatment for steam floods or as a steam additive.
Experimental measurements were carried out at 69.8°F (21°C), the reservoir temperature, and at 284°F (140°C). The saturation pressures were between 400 psi (2.8 MPa) and 1,500 psi (10.3 MPa). At each pressure level the solubility of CO2 in the oil, the density, and the viscosity of the saturated mixture were measured.
The results showed an increase in the solubility of CO2 in the oil with increasing pressure and decreasing temperature, while the densities of the mixtures did not change to a large extent with changing compositions. The most dramatic effect observed was the decrease in viscosity with CO2 dissolution in the oil: A 53–fold reduction occured at 69.8°F (21°C) and a 2–fold reduction at 284°F (140°C).
SARA analyses of various samples were carried out. It was found that at 69.8°F (21°C) some redistribution of asphaltenes and resins occurred at pressures above the liquifaction pressure of CO2 (850 psi or 5.9 MPa).
These results indicate that, from a phase behavior point of view, enhanced oil recovery by CO2 injection in the heavy oil reservoir is feasible, and that viscosity reduction would play a major role in improving productivity at lower temperatures. The asphaltenes/resins balance should be taken into account when selecting the injection pressure.
Injection Profile Control in a Multizone Los Angeles Basin Waterflood
Authors: Dayvault G. P. 
Published: December 2007

Abstract
Following is a review of 51 waterflood injection well workovers designed to improve vertical sweep efficiency in the Inglewood field, California, from 1984 through 1988. A cost comparison is made for five types of workovers based on improvement in injection profile for two years after the workover. Damage mechanisms known to occur in these injection wells are: 1) bacterial slime; 2) iron sulfides; 3) calcium carbonate scale; 4) migrating clays and formation fines; 4) drilling fluid damage; and 5) formation crushing during jet perforating.
An index was developed to characterize a well's injection profile with a single value, allowing objective comparison of injection profiles before and after workovers and comparing profiles between different wells. The index was developed after reviewing actual data from about 200 temperature-spinner-tracer (TST) surveys. The index is equal to the total feet of perforated sandstone taking water injection, modified to account for uniform or nonuniform vertical distribution. The index is independent of total completion interval, allowing comparison of wells with differing net pay.
The index is used to evaluate cost effectiveness of the workovers and to estimate vertical sweep efficiency of the waterflood.
Long-Term Production Response of Sequential HF Acid and Conventional HF Acid in the NCL Field
Authors: Marino A. W. , Underwood P. J. 
Published: December 2007

ABSTRACT
Long-term production response to matrix acidizing has been analyzed in the Stevens Sand in the North Coles Levee field in the San Joaquin Valley. Twenty-nine acid jobs on production wells, using either sequential hydrofluoric acid (SHF) or regular hydrofluoric acid (HF), have been performed over the last 15 years. SHF treatments were considerably more effective than regular HF treatments over the entire period of response to the stimulations.
An Innovative Method To Determine Low- and High-Pressure Steam Properties
Authors: Alcocer C. F. , Onuba L. 
Published: December 2007

Abstract
Oil recovery by the use of steam injection techniques involves the evaluation of steam properties at varying temperature, pressure properties at varying temperature, pressure and volume. This evaluation is necessary in order to determine heat losses and the varying nature of steam quality at the surface lines, wellbore and within the reservoir during the steam Injection process. process. Several authors have developed correlations for pressures below 500 psi and yet others in most recent publication have developed in some instances, several sets of correlations for the steam properties as a function of pressures between 500 psi to 2500 psi. pressures between 500 psi to 2500 psi. This work presents an innovative mathematical model that predicts the properties of the steam as a function of pressure from as low as 1 psi to as high as 3200 psi as obtainable in revised steam tables (laboratory data).
The computer model presented here is about 99.98% accurate and was developed based on numerical analysis techniques, in combination with the use of an advanced statistical package available at USL Computer System. package available at USL Computer System. The powers to which the pressure was raised was obtained and suitable designed for this task. The model uses an equation developed especially for this computer program written in Fortran 77.
It Is now possible to determine the value of steam properties as a function of pressure for any practical range of pressures. The values obtained from the correlation closely match the experimental values given in professional steam tables. professional steam tables. In general the results generated by this new correlation are far better than any other correlations that have been published at present. present. P. 602
Application of Saturation Pressure Profiles to Detect Oil Vaporization in CO2-Oil Systems
Authors: Beladi M. K. , Ghalambor A. , Alcocer C. F. 
Published: December 2007

ABSTRACT
Crude oil vaporization using carbon dioxide (CO2) is known to have application in oil recovery for highly fractured formations and heterogeneous reservoirs where the major oil content is contained in the non-fractured porosity or isolated oil patches with little associated permeability. Oil vaporization is also the triggering element for formation of miscible front which displaces the oil in CO2 enhanced oil recovery process.
The objective of this experiment was to establish a saturation profile and examine the Pressure-Volume relationship of crude oil in the presence of different CO2 concentrations. The saturation pressure with its Carbon Dioxide concentration is believed to be the required condition necessary for initiating the oil vaporization.
To achieve the above objective a series of experiments were performed to show the oil swelling behavior and obtain the saturation pressure profile and pressure at which vaporization takes place.
The pressure-volume profile of the swelling tests showed that an increase in CO2 concentrations will increase the saturation pressure and cause a dampening on the pressure-volume curve. It also showed that the saturation pressure of the mixture increases according to exponential increase in CO2 concentration.
This study in swelling of crude oil by CO2 will provide an insight into the oil property and behavior as the vaporization takes place, and will provide the explanation on how the misibility is triggered. It will also provide the minimum CO2 requirement to achieve vaporization.
A Regulatory Approach to Horizontal Drainholes
Authors: Richter T. H. , Bright B. R. 
Published: December 2007

ABSTRACT
In response to the increasing number of horizontal drainholes being drilled in Texas, the Railroad Commission of Texas developed guidelines for issuing drilling permits for these wells. While these guidelines do serve the purpose of outlining permitting procedures, they do not address such issues as between well spacing requirements, acreage and allocation assignments and the definition of a horizontal drainhole for regulatory purposes. A general statewide rule is being formulated by the Commission to address these issues. The proposed rule should offer some flexibility to encourage the use of this relatively costly and complex technology while honoring the Commission's legislative mandate to prevent waste and protect correlative rights.
Electricity Cost Reductions in the Oil Field
Authors: Balch G. R. 
Published: December 2007

ABSTRACT
Oil producers must reduce electrical costs in order to remain competitive. Established reservoirs are maturing, and new fields are becoming more remote. As a result, oil production is increasingly more expensive to obtain; however, higher operation and maintenance costs are not being supported by higher product prices. The challenge faced by today's oil producers is to reduce production costs while at the same time they are also being called upon to produce oil from maturing and remote fields.
This paper outlines a successful electrical cost reduction program developed by Exxon Company, U.S.A. Electrical cost reduction is an obvious goal of any cost control program since it typically is the largest single operating cost component of a particular field. In large fields, even minor reductions can result in significant savings.
Substantial savings can be obtained in the utility company costs. This paper explains why utilities charge the way they do, and it shows what to look for when evaluating electric bill reduction possibilities.
The Development of a Marginal Clearfork Waterflood Prospect
Authors: Hunter C. D. , Kilgo W. M. , Hickman T. S. 
Published: December 2007

ABSTRACT
The effect of depressed oil and gas prices on investors' confidence has been reflected by the low activity levels in the Permian Basin as elsewhere. Yet, even during the 1986-87 period viable projects were available to the industrious and imaginative.One example is the Wentz (Clearfork) Field where a small independent operator recognized potential in what appeared to be a very marginal waterflood prospect. Through data gathering and engineering, the potential was documented to the point that investor funding became available.A cooperative waterflood plan was agreed to with the field's other operator. The project was installed with an emphasis on practicality, cost savings and attention to details. After a year of injection, production response is exceeding expectations.
Mixing System for Fracturing Slurries
Authors: Reidenbach V. G. , Phillippi M. L. 
Published: December 2007

ABSTRACT
Fracturing operations in Texas and other locations have been improved by (1) mixing fracturing slurries under microprocessor control, (2) applying new baffle and agitator design concepts, and (3) using new methods for achieving rapid material wetting. With these new methods, high sand concentration slurries can be mixed in high-viscosity gels, at low or high rates. A ramped pumping schedule can be used to help achieve greater fracture length since pumping stoppage caused by "sandout" can be delayed or prevented.
This paper presents the design and description of the mixing system that makes possible the above-mentioned improvements. and presents case histories of field applications. Proppant schedules and job data are also presented.