bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Complete Three-Dimensional Simulator for Analysis and Design of Hydraulic Fracturing
Authors: Lam K. Y. , Cleary M. P. , Barr D. T. 
Published: December 2007

Summary
The formulation, development, implementation and application of a complete three-dimensional hydraulic fracturing simulator, 3DHFRAC, is described. The simulator consists of two principal components: the first represents the solid deformation, crack opening and propagation, using a surface integral scheme, hybridised with finite-elements as needed, and a condition of critical stress-intensity-factor or energy-release-rate to track the motion of the fracture perimeter; the second captures the fluid flow along the open fracture, and into the reservoir. The simulator has been tested extensively by comparison to analytical results, other simpler models cad laboratory experiments: the latter are most vindictive because they have provided a comprehensive self-consistent data-set showing repeatibility and verifying the basic concept of the model, namely a characteristic time deriving from pressures, material moduli and fluid viscosity. Thus uniquely vindicated, the 3DHFRAC model may be applied to study a variety of field conditions: fracture containment by stress-contrast between reservoir and adjacent strata; the role of earth-stress and hydrostatic head gradients in controlling vertical growth of the fractures; fracture propagation after shut-in and its effect on deductions about fluid leak-off coefficients from minifrac tests; and the evolution of interfaces between different fluids, including the transportation of proppant, in typical complex job schedules. An even more exciting application of the model is proposed, namely that of fracture diagnostics in real-time during the job, or at least as a post-mortem determination of fracture geometry: this employs a concept called "surge analysis", namely the matching of measured transient pressure response to the calculations of pressures caused by changes in flow or rheology. Such a capability would finally bring the effort of modelling to full fruition.
Thixotropy Without Viscosity: A New Approach to Rheology Control of Oil Muds
Authors: Grantham C. K. , McLaurine H. C. 
Published: December 2007

ABSTRACT
A new oil mud additive which imparts thixotropic properties to oil base muds has been developed and field tested. This new product is used in combination with an organophilic clay and imparts gel strength to oil base fluids without the corresponding increase in plastic viscosity. The use of this new amide resin is especially useful in developing thixotropy in oil emulsions drilling fluids using low viscosity mineral oils.
The data presented demonstrates that a new additive has been developed which beneficiates organophilic clays without adding to the viscosity of the fluid. This additive causes organophilic clays to yield at ambient temperatures and low shear to produce fluids with minimum rheology changes over a wide range of temperatures. The use of this additive makes possible thixotropic fluids with reduced yield points and improved gel strengths without a corresponding increase in plastic viscosity. These properties make possible the formulation of fluids with inverted flow properties having low plastic viscosities and desirable gel strengths. Using this new additive, oil continuous fluids can be formulated with water contents ranging from 0 to 30 % with minimal changes in rheology. It is further suggested that the application of the amide resin chemistry creates the opportunity for novel waterless drilling, coring and packer fluids.
Directional Drilling With PDC Bits in the Gulf of Thailand
Authors: Perry C. J. 
Published: December 2007

ABSTRACT
Polycrystalline Diamond Compact (PDC) bits have shown individual directional characteristics in the deviated drilling of the 8-1/2" (216 mm) hole section in Unocal's Gulf of Thailand operations.
The effective and successful use of those directional tendencies and the parameters that can affect them are described and illustrated with detailed examples in this paper.
Five typical 8-1/2" PDC bits (Fig 1) make up a data base of over 200 "Rotary Bit" runs in low-toxic oil base mud through soft and medium soft formations. Bits used in correction runs on Positive Displacement Motors (PDM) and turbines with or without the offset stabilizer are discussed.
Study of Severe Slugging in Real Offshore Pipeline Riser-Pipe System
Authors: Farghaly M. A. 
Published: December 2007

ABSTRACT
Severe slugging has been experienced in most of Upper Zakum pipeline riser-pipe system. It is characterised by generation of slugs ranging in length from one to several riser-pipe heights; occurs at low gas and liquid flow rates in undulated, nearly horizontal, pipeline.
The significance of this study arises from the fact that it is an extensive field application and is not a small scale simulation as the case in most published works. This study has covered wide range of pipe diameters, pipe lengths, and flow rates.
By the merit of data acquiring telesystem, after the grace of God, considerable volume of data were collected so accurately that each variable was monitored every 10 seconds. These data were extracted from computer terminal at company main office in Abu Dhabi.
Screened data were applied to predict severe slugging map. The same data were compared with a hydrodynamic computer model developed to predict the slug behavior.
Methods to alleviate or to eliminate severe slugging are discussed. Riser-pipe choking has been found to be an effective solution.
The Economics of Late-Life Field Production in the North Sea
Authors: Griffith J. O. H. , Cox T. F. 
Published: December 2007

ABSTRACT
The major North Sea oilfields, discovered during the 1970's, will be well into their decline within the next ten years. During this period operators will be faced with a number of decisions concerning workover, infill drilling, artificial lift, EOR and, ultimately, abandonment.
This paper places a number of factors against an economic background and highlights problems that may be encountered in justification of various actions proposed to recover additional reserves. The work also addresses the problems of field abandonment.
Results show that, in the U.K. sector, the form of the PRT allowances, together with the scale of abandonment cost to both government and operator, will encourage the delay of abandonment for as long as possible. This, together with the awareness that net income over the final years will be dedicated solely to abandonment, must strongly colour companies approach to the last years of production.
Experiences with Exploration and Appraisal Well Tests Offshore Norway
Authors: Lansink Herbert 
Published: December 2007

Abstract
Norske Shell's testing experience over the last few years centres on 12 wells tested in 340 m (1120 ft) water depth in the Troll field, drilled during 1980 – 1984, and on 6 wells tested in 240 m (790 ft) water depth in the Draugen field, drilled during 1984 – 1986. This paper outlines developments in gravel packing techniques, equipment and procedures, the use of tubing conveyed perforating guns, the selection and application of tools included in the production test string to provide downhole shut-in and a circulation path, and finally, summarises the experience gained with downhole pressure gauges.
Rationality in Completion Design and Equipment Selection in the North Sea
Authors: Peden J. M. , Leadbetter A. 
Published: December 2007

Abstract
The design of completions which are effective and reliable is of increasing significance to the viability of both existing and new fields. With greater emphasis being placed on the input of advanced engineering techniques to oilfield developments, the improvement of the completion design process is an important area for investigation. This paper presents results, based on information supplied by North Sea operators, of an attempt to rationalize how design decisions are reached and what factors influence the selection or specification of completion equipment and completion procedures. The paper discusses the process of constructing design logic flow charts with the completion knowledge acquired in the study.
Computer Monitoring of Surface Parameters While Tripping
Authors: Peltier B. 
Published: December 2007

Abstract
The digital acquisition and processing of surface data while tripping brings a new type of information for the monitoring of rig activities and well condition. The measurement of the hook load and the travelling block altitude can be used to generate a log versus bit position which helps in decision making at the well-site. The high resolution obtained on the drill-string position makes new interpretations possible. Several field examples are presented.
Operational Experiences With Automated Mud Mixing Systems
Authors: Førde R. , O’Hara T. 
Published: December 2007

ABSTRACT
The main objectives in introducing automated chemical handling system were:
To provide more effective product mixing. To minimize chemical losses through inefficient sack cutting operations or broken sacks during transport and storage. To improve the working environment.
The three rigs that Norsk Hydro equipped with automated mud mixing reduced chemical losses to almost zero. This is because the sack cutting operation was totally mechanised. In addition, the arriving sacks were inspected before being processed. Broken sacks or obviously old material was returned to the supplier.
The mixing operation offshore has been computerised and this ensures that accurate and even dosing of additives occurs.
The working environment has been vastly improved both onshore and offshore. The sack-opening operation and mixing process are totally enclosed. Even the empty sacks are automatically compressed into plastic " sausage skins" that allow no exposure to the atmosphere.
Manhandling of sacks is eliminated. The only exception is mixing of lost-circulation or stuck-pipe pills. Due to the relatively smaller quantities of chemical used, these are mixed manually.
Ball-Type Storm Valve System Improves Safety and Saves Rig Time
Authors: Caskey K. D. , Breaux M. J. 
Published: December 2007

ABSTRACT
Safety and economy of offshore operations have been improved by application of a ball-type storm valve system (SVS) that can be installed without left hand rotation, thus eliminating the danger of unscrewing drill pipe joints. The new valve system is latched by setting an overshot down over a stinger and applying weight; releasing is accomplished by right hand rotation and lifting. A retrievable test, treat, and squeeze packer is installed below the valve.
Design of the ball-type SVS offers these advantages :
Ease of operation. When the system is set down, the ball valve automatically closes to shut the well in. Latching onto the system is accomplished without opening the ball. Since the ball valve is not opened by latching on for removal, it can be closed by setting back down in the event high pressure is detected below the SVS. Wireline equipment can be run through the SVS. High volumes of drilling fluid may be circulated through the SVS to condition the mud system prior to removing the SVS from the hole.
Present paper discusses design of the valve, with operational schematics illustrating its operation. Field results are presented describing use of the SVS in stress situations and for some maintenance functions, and resumption of operations. Rig time savings are discussed.
Training Rig Hands in the People's Republic of China
Authors: Turner L. A. , O’Brien W. E. 
Published: December 2007

Abstract
For an oilfield service company to survive in the important markets of the developing countries, it must replace expatriate personnel with qualified local nationals. This is necessary to cut costs and meet the nationalization and technology transfer requirements of host nations. An effective training program is essential to meet these requirements while at the same time maintaining international standards of service quality and safety.
This paper explores the lessons learned by one such training effort — the China Nanhai-Oxy-Sedco Drilling Corporation (CNOSDC) Training Center, located in the Shekou Industrial Zone in mainland China just north of Hong Kong. It discusses some of the problems encountered by our program, and analyses a set of factors which we have found to be significant in making our recruitment and training of Chinese workers more effective. We believe these factors can be used by other service companies and operators to better select their Chinese personnel and expedite their training.
We examine the results of three years of training of seventy-two Chinese employees considering the impact of home province, age, language abilities, educational background and previous work experience upon each man's success or failure. We go on to address questions beneficial to all oil companies and service contractors working in China and other developing nations:
Chinese from some geographic areas or provinces tend to fail while those from other areas do quite well. Why is this the case? How can you identify these areas in your company's recruitment efforts? Some technical schools produce students with a markedly higher chance of failure in our training program, while other schools have produced trainees who do consistently well. Why? College graduates have a high rate of success and a high rate of promotion, but also one of the highest rates of failure. Why is there such a high rate of failure among trainees with college degrees? What kind of Chinese colleges produce trainees most likely to succeed in the oilfield? Motivation, or the lack of it, is decisive in training success and failure. How can key motivational factors be identified and utilized? Are these motivational factors different in China than in the West ?
An Analysis of the Performance of PDC Hybrid Drill Bits
Authors: Williams J. L. , Thompson A. I. 
Published: December 2007

ABSTRACT
This paper details the results of a project to extend the range of PDC bit applications to harder non-uniform formations. These formations had previously proved difficult to drill with PDC.
The resulting design concept is outlined and the targeted formations, field operating parameters and performances are illustrated with emphasis on North Sea bit runs.
The success of the project is shown in the economic analysis.
The result is a new range of bits which have exceeded their design specifications and significantly increased drilling efficiency.
Relationship between Cement Bond Log Output and Borehole Geometrical Parameters
Authors: Jutten J. J. , Parcevaux P. 
Published: December 2007

ABSTRACT
This paper describes and quantifies the importance of some geometrical parameters on the main output of the cement bond log, i.e. the attenuation of a sonic wave propagating along a casing to cement interface. These geometrical parameters are the cement thickness, the casing stand-off, the percentage of cemented area and the shape of the noncemented channels. Also the nature of the fluid in the noncemented channel has been investigated.
These experiments were performed with a laboratory cement bond tool of variable spacing between 0.5 and 3.0 feet, coupled to an oscilloscope and a data acquisition unit.
It is observed that cement sheath thickness is an important parameter that can significantly affect the output of the tool up to a thickness of more than 2 inches. As a first approximation, the percentage of cemented area is confirmed to be in linear relationship with the attenuation rate. Casing stand-off can also change the log output by a factor of up to 30%. Conversely the shape of the channel is found to have no significant influence on the result provided the percentage of cemented area is the same. The nature, from gas to liquids, density and gel strength of the fluid in non cemented channels have surprisingly been found to be negligible factors.
Some of the conclusions are illustrated through the interpretation of several field logs of cased hole or of open hole sections where both the cement and the caliper logs were available.
Recommendation for Standardization of Log Format, Correction Charts, and Definitions of Measurement-While-Drilling-Tools
Authors: Power M. T. , Huchital J. , Ramsey M. , Weeks K. , Rubin B. 
Published: December 2007

ABSTRACT
The IADC-RIM Downhole Telemetry Subcommittee is composed of members representing eight major oil companies, nine service companies, and one drilling contractor. The group has been meeting since January, 1985, in an attempt to bring a degree of standardization to the Measurement While Drilling industry in the areas of log format, correction charts, definitions of pertinent terms, and to present interim standards for specifying MWD – Communication – Channel – Performance as affected by variables such as depth, temperature, mud properties, noise, etc. The final objective is to provide information to the end users (drilling engineers, geologists, petrophysicists, etc.) that will enhance an objective understanding of MWD performance for evaluation and comparison of the products offered by the various MWD companies. The Subcommittee is presently divided into four groups: 1) Log Presentation Standards, 2) Drilling Parameter Influences on MWD Tools, 3) Standardized Tool Reliability Statistics, and 4) Specifications of Telemetry Systems. This paper is presented in four segments that reflect the findings and/or the recommendation of the four work groups, respectively.
Selection of Bits and Mud Types to Drill 12,500 ft Underthrust Herrera Wells in Trinidad
Authors: Jokhoo K. 
Published: December 2007

ABSTRACT
Five different formations are penetrated and three casing strings run and cemented before encountering the hydrocarbon bearing Underthrust Herrera sands. Success depends on drilling 6500 feet (1981 m) of water sensitive and abnormally pressured fractured shales from 4000 to 10,500 feet (1219m-3200m).
Clay mineralogy analyses were obtained on the shale samples and the physical and chemical properties of the active clays determined. Pore pressure profiles of the different formations were approximated from electric logs, "d" exponents and shale densities.
Five different mud systems have been used and in conclusion an inhibitive water base system has been found to be most cost effective. However, an overbalance of 2 to 3 ppg is necessary to keep the long shales sections open while drilling. Bit types were selected based on rock hardness, degree of compaction and mode of deposition. Steel tooth bits were best suited down to 8000 feet and journal bearing tungsten carbide inserts for the deeper formations.
Drilling times and costs have been reduced by ten to fifteen percent. However, there is scope for operational improvement.
Natural Gas Drilling Methods and Practice: San Juan Basin, New Mexico
Authors: Cummings S. G. 
Published: December 2007

ABSTRACT
The majority of published literature on air/gas drilling methods is concentrated on empirical relationships which yield little information on field performance, successes, and failures. This paper, however, concentrates on the field application and results of drilling with natural gas in the San Juan Basin of northwestern New Mexico where natural gas has routinely been used as a circulating media for thirty years.
This paper encompasses gas drilling programs, equipment, volumetric requirements, bit performance, special drilling considerations, safety, and economic evaluation of gas drilling versus mud drilling in a lost circulation area of the San Juan Basin. Results indicate that natural gas is a safe, efficient method for development drilling operations in the San Juan Basin, especially in areas of lost circulation.
Polymerization in Supercritical CO2 To Improve CO2/Oil Mobility Ratios
Authors: Terry R. E. , Zaid A. , Angelos C. , Whitman D. L. 
Published: December 2007

ABSTRACT
The efficiency of carbon dioxide flooding is hindered by mobility problems resulting from the unfavorable mobility ratio, λCO2/λoil. Several approaches were tested in the past to improve CO2 flooding efficiency (1–6). One approach attempted direct thickening of CO2 by dissolving a commercially available polymer in the CO2. In this paper a novel idea to increase the CO2 viscosity is presented. The increasing of CO2 viscosity is attempted by insitu polymerization of monomers miscible with CO2. The polymerization is done while the monomer (solute) is in the CO2 supercritical phase (solvent). CO? viscosity changes are evaluated by direct measurement using a high pressure Ruska rolling ball viscometer.
Several runs have been made and polymerization has been successfully achieved – in the presence of CO2 supercritical phase – as evidenced by NMR and infrared spectrophotometry. Both gas and liquid phase monomers, measured at standard conditions, were tried and both were polymerized. Polymerization initiators that were used consist of commercially available peroxides with a weak O-O bond. Polymerization was carried out at approximately 160°F and 1800 psi. The values of temperature and pressure are typical for oil reservoirs in which CO2 is applied as a miscible fluid. Further evaluation of viscosity changes are done by flowing the mixture of CO2 and polymer in a high pressure sandpack.
Continuous Steam Quality Measurement in a Steam Distribution System Quality Measurement
Authors: Strome R. K. , McStravick D. M. 
Published: December 2007

ABSTRACT
In an effort to provide accurate, reliable data on steam distribution, 67 continuous steam injection wells on Santa Fe Energy Company's steam flood project in the Kern River Field were equipped with steam quality meters using vibrating densitometer principles combined with flowmeters and microprocessors for continuous monitoring of temperature, quality, mass flow rate and energy content.
Although equipment limitations were encountered, techniques for validating steam quality measurements and flow rates by overall system mass balance were developed.
Instrumentation of the type employed in the project combined with the centralized processing of the data from each individual injection well is a new tool for optimizing steam distribution and injection documentation for reservoir modeling.
Evaluation of Gas Flows in Cement
Authors: Rang C. L. 
Published: December 2007

ABSTRACT
Cementing of casing in California can be characterized as having two major concerns, cement "fallback" and gas contamination. The cement fallback problem is widely known. Gas flows into the cements have been recognized for some time, but only recently have they been measurable. Improvements in cement bond logging tools and interpretation techniques have enabled engineers to correctly identify several distinct regimes behind casing. Among them are cement, gas, fluid, or gas-cut cements. Identification and measurement help the drilling and production engineer to design slurries that overcome the cementing concerns.
Fracture Identification in Openhole From a Cement Evaluation Tool
Authors: Westermark R. V. , Scholes P. 
Published: December 2007

ABSTRACT
This paper addresses the use of the cement evaluation tool for open hole fracture identification and orientation by the analysis of acoustic caliper data in granodiorite.
The high acoustic reflectivity of the granodiorite is similar to casing; therefore, the tool's acoustic caliper data required no special processing to determine wellbore diameters. The presence of highly irregular borehole diameter information was interpreted to be the effect of fracturing. By merging the caliper information with directional survey data, a fracture orientation log was prepared.