bluuebunny/crossref_metadata_2025_split huggingface dataset:
Tight Sand Evaluation Applied to the Medina Group of Chautauqua County, NY
Authors: Pekot Lawrence J. , Wozniak David A. , Martin John P. 
Published: December 2007

Abstract
A systematic evaluation of the Medina Group in Chautauqua County, New York was performed in 1998 to identify production and reserve improvement opportunities in this large, continuous, low permeability gas accumulation. Petrophysical analysis, geological mapping and advanced production type curve analysis was performed over a 200 well study area covering 38,000 acres. Net pay, net sand and hydrocarbon pore-feet was determined from the log analysis. Structure, isopach, pay thickness, gas in place, permeability and well drainage areas were mapped.
Several infill/stepout locations were identified based on geologic parameter mapping and four new wells were drilled in the fall of 1998. Medina pay was encountered in agreement with the geologic prognosis for the wells. However, pore pressure was below original conditions indicating partial depletion at the new locations. Weekly production data was collected from the new wells for a six month period and decline curve analysis performed to estimate recovery.
Reducing the Cost of Field-Scale Log Analysis Using Virtual Intelligence Techniques
Authors: Mohaghegh Shahab , Popa Andrei , Koperna George , Hill David 
Published: December 2007

Abstract
One of the costliest parts of field-scale reservoir studies is log analysis. A recent GRI project required a detailed study of a field with hundreds of wells. As part of this study all the well logs were to be analyzed by an engineer in order to identify net pay, porosity, and saturation. It soon became apparent that a considerable amount of time must be devoted to well log analysis in order to obtain consistent and high quality reservoir characteristics throughout the field. This was mainly due to the fact that logs for several wells were missing and many wells did not have the suite of logs that were necessary for analysis.
This paper presents a novel approach to reduce the cost of well log analysis while maintaining the quality of the analysis. The cost reduction is achieved by analyzing only a group of the wells in the field. Using the detailed analysis of this group of the well logs by an expert engineer, an intelligent software tool is built to learn and reproduce the analyzing capabilities of the engineer on the remaining wells.
This approach provides a means to increase the efficiency of the engineering team. It can decrease the time needed to analyze a large number of well logs while considerably reducing the project cost to the operator. It will provide means to attain well log analysis for wells that do not have all the necessary logs needed for the analysis. This is achieved by generating virtual wireline logs for these wells. Virtual intelligence techniques are used in construction of the intelligent software tool presented in this study.
Infill Drilling Recovery Models for Carbonate Reservoirs - A Multiple Statistical, Non-Parametric Regression, and Neural Network Approach
Authors: B. R. Soto , Wu C. H. , Bubela A. M. 
Published: December 2007

Abstract
We used multiple mathematical techniques to develop primary ultimate oil recovery (PRUR), initial waterflooding ultimate oil recovery (IWUR), and infill drilling ultimate oil recovery (IDUR) models for carbonate reservoirs in West Texas. These are (1) non-linear regresion, (2) non-parametric regression (a statistical approach that constructs the functional relationship between dependent and independent variables, without bias towards a particular model), and (3) neural network models. Development of the oil recovery forecast models help understand the relative importance of dominant reservoir characteristics and operational variables, reproduce recoveries for units included in the database, and forecast recoveries for possible new units in similar geological setting.
One of the challenges in this research was to identify the dominant and the optimum number of independent variables. The variables is large including porosity, permeability, water saturation, depth, area, net thickness, gross thicknees, formation volume factor, pressure, viscosity, API gravity, number of wells in initial waterflooding, number of wells for primary recovery, number of infill wells over the initial waterflooding, PRUR, IWUR, and IDUR. The limited number of field data (43 data) points) are inexact and often exhibit uncertain relationships. We used an intelligence software1 that integrates multivariate statistical and neural networks to develop accurate neural network models. Multivariate principal component analysis is used to identify the dominant and the optimum number of independent variables. We compared the results from neural network models with the non-parametric approach. The advantage of the non-parametric regression is easy to use and the disadvantage is retaining a large variance of forecast results for a particular data set.
Develop a neural network model that is an "accurate" representation of data may be and ardous task that require experience with the qualitative effects of the structural parameters of neural network models. The advantage of neural network PRUR, IWUR, and IDUR models are capable of forecasting the oil recovery with less error variance.
The Evaluation of Aerial Surveys for Detection of Natural Gas Pipeline Leaks
Authors: Aminian K. , Chamorro A. , Ameri S. , Bilgesu H. I. 
Published: December 2007

Abstract
Pipeline leaks are of major concern to natural gas industry. They can result in loss of revenue, potential danger to public, and environmental damage. To ensure pipeline safety and reliability, a ground surveillance program to detect leaks is conducted on annual basis. Considering the number of miles of natural gas pipeline, this method is time consuming and expensive. There has been interest in developing other methods for rapid survey of natural gas pipelines. The visual aerial surveys, which rely on the identification of dead vegetation to detect a leak source, have a very limited application. The use of infrared technology to detect a leak based on thermal differences between the leaked pipeline gas and surrounding area has not been developed to the point to be reliable. An effective aerial pipeline leak detection system has been developed recently. The system utilizes an aircraft, which is equipped with flame ionization hydrocarbon detector. The hydrocarbon detector can analyze the samples taken during the flight over the pipeline right-of-way. Presence of natural gas anomalies, that are larger than natural gas background levels, represent a potential leak source. The accuracy and reliability of the aerial surveys however remains questionable. This paper reports the results of the both modeling studies and field tests conducted to evaluate the accuracy and reliability of the aerial surveys.
Buoyant plume rise and dispersion has been studied extensively because it is the primary mechanism for dispersing stack gases to the environment. A jet plume model that predicts the trajectory and dilution of vertically oriented gas jet was considered for this study. The model was then modified to develop user-friendly (Windows-based) input and output interfaces. The plume rise model was then utilized for sensitivity analysis in order to design a field test. The modeling results were utilized to determine the optimum flight plan. A pipeline leak was simulated by release of the natural gas during the field test. The model predictions were compared to the measured gas concentration to evaluate the predictability of the model. The measured gas concentrations were generally found to be in agreement with the predicted values. The results indicated that model can be used for the design of the flight plan and the analysis of the field data.
Viscosity and Thermal Conductivity Prediction for Hydrocarbon Systems
Authors: Erdogmus M. , Adewumi M. A. 
Published: December 2007

Abstract
Accurate prediction of thermophysical properties of gas- condensate systems is very important for optimum design and operation of most equipment involved in production, transportation, and processing of gas-condensate systems. The need for accurate prediction methods for these properties is inevitable because it is almost impossible to obtain thermophysical property data for every fluid that would be encountered. In addition, obtaining all of these properties via experimental procedures is not only time-consuming but also extremely expensive. Viscosity and thermal conductivity are such properties. In this study, a new technique using Enskog dense-gas theory coupled with an equation of state is developed to predict viscosity and thermal conductivity of gas-condensate systems. Ten different equations of state are used and extensive comparisons with experimental data are made over wide temperature and pressure ranges both for pure components and mixtures. The comparison with experimental data is good for both viscosity and thermal conductivity.
Developing Competence-Based Learning in Oman's Drilling and Well Services Sector
Authors: Davidson Ian A , Ali Al-Hashmi Khamis Bin , Al Zadjali Isam 
Published: December 2007

Abstract
To fully benefit from their natural resources Gulf states need to develop the skills of their indigenous populations and employ them at all levels in industry. Competence based learning is a means to effectively develop a competent workforce comprised of individuals who can consistently perform work activities to the standards required of the industry. The drilling and well service sector, through the efforts of the International Association of Drilling Contractors (IADC) and the Offshore Petroleum Industry Training Organization (OPITO), amongst others, is developing standards that are appropriate to the Gulf region.
This paper discusses some of the hurdles facing the implementation of competence-based learning and the optimum development of the national workforce. It concludes with recommendations for the way forward and highlights the potential benefits, to Governments, National Oil Companies and drilling and well service sector companies, of initiating competence based learning both at the workplace and in their training programmes.
Spectral Gamma Ray Measurement on Cuttings: An Alternative to MWD
Authors: Alixant JL , Collie D. A. L. 
Published: December 2007

Abstract
Conventional mud logging techniques cannot reliably distinguish the organic-rich, micro-porous Athel silicilyte reservoir cuttings from shale. Yet, a simple gamma ray log resolves most uncertainties in this respect. Spectral Gamma Ray logging on cuttings was introduced in South Oman in 1995 as a practical and cost effective means to optimise operational decisions on Athel wells. Target applications included picking casing setting depth, selecting coring points, and confirming TD. Equipment was designed and constructed, procedures were created, and personnel were trained. The "Cuttings Spectral Gamma Ray" has since become an integral component of the mud logging suite on many exploration wells in South Oman. In this environment, the technique proves technically and economically more attractive than alternative solutions involving wireline or MWD logging.
The original objectives were met, and new applications evolved as experience and confidence in the system grew. They include: depth-matching mud logs to wireline logs; correcting driller's depth; logging to the deepest point in the well; data assurance in case of hole problems; logging after completion or abandonment (where cuttings have been stored); and, in hindsight, a qualitative hole cleaning efficiency indicator. The paper reviews design considerations, operating procedures, and aspects of data processing. Using field data and comparisons with wireline logs, the discussion then focuses on current capabilities and inherent limitations of the system, to conclude with a brief assessment of the potential for a cuttings-based wellsite formation evaluation package.
Core Data Acquisition – An Alternative Approach
Authors: McKay A. M. , Moore T. A. 
Published: December 2007

Abstract
An ongoing requirement exists in the hydrocarbon industry to reduce the cost of wells and improve results when obtaining core samples. To achieve this objective in an already competitive market requires radical thinking. The result is a new and novel method of core acquisition, the SCORE system, which takes a continuous 7.62m (25ft) 36.5mm (1.44") diameter core from the sidewall of a well at an angle of 2° to the well trajectory. The tool comprises an inner coring assembly and an outer whipstock assembly run on standard API drill pipe. The whipstock section can be run as the bit for a wiper trip, thus technically eliminating all requirements for conventional tripping to acquire core samples. Additionally, the ability to log a well prior to any decision to cut core can produce significant savings in time and resources utilised in coring dry wells.
Downtime Reduction With Updated Maintenance System
Authors: Khelifi Mahmoud 
Published: December 2007

Abstract
The company is involved in drilling and workover activities and has currently 28 rigs operating in both Onshore & Offshore locations. Due to the large number and variety of equipment, formulation of a maintenance strategy to cater for the maintenance needs of all the above has become very complex. Initially jobs were done on a monthly basis & involved a lot of paper work and clerical time. There was no reliable means of automatically or manually updating the job completion hence a need was felt to have a computerised Preventive maintenance system.
With the formulation of the Maintenance Strategy in 1994, it was decided to go in for an optimum mix of Preventive, Predictive and Breakdown maintenance aiming to achieve equilibrium between them. As part of the Preventive maintenance exercise the company installed a computerised maintenance program designed to cover most of the equipment on the rigs. The same was installed on all the rigs in August 1996. As part of the Predictive maintenance exercise, procedures for overhaul/inspection of equipment were developed. Condition monitoring tools were introduced and some already in force were extended to cover more equipment. To minimise breakdown time standard repair workscope, overhaul procedures & spare parts lists were developed. To ensure that the workforce was geared to meet any eventuality, in-house training programs have been designed and personnel have been sent on specialised training programs so as to enhance the skill and know-how of latest maintenance techniques.
These measures have resulted in significant improvement in equipment availability and decreases in mean time between overhauls. Downtime for engines has reduced by 35.5% and in the case of Hoisting & Rotating equipment it has reduced by 33.97% as compared to the year 1994. In the case of Electrical, BOP & Controls & Mud system the downtime has reduced by 83.9%, 84.9% & 70.7 % resp. as compared to the average downtime in the year 1994.
Optimizing High-Temperature Kill Pills: The Åsgard Experience
Authors: Svoboda Charlie 
Published: December 2007

Abstract
Historically, the survival rate for conventional non-damaging polymer/carbonate kill pills under elevated temperatures was limited. Accordingly, a development program was instituted to develop a new high-temperature kill pill that would possess superb bridging characteristics on a high permeability proppant while remaining thermally stable at temperatures exceeding 165ºC.
This paper describes the development of a sodium formate kill pill geared specifically for the demanding Åsgard Development in the Norwegian North Sea. The pill was engineered and successfully applied in a high-temperature application to seal a high permeability (400-500 Darcys) frac pack sand in the Smørbukk field. In the field, the newly engineered formate-base pill proved to be thermally stable, while providing sufficient leak-off control. Furthermore, the development reinforced the critical role of proper particle size distribution in minimizing fluid invasion and formation damage.
With emphasis on particle size distribution, the authors will review the formation damage testing procedure of the new formulation on simulated frac packs. In the laboratory, the fluids demonstrated excellent thermal stability after long-term exposure to temperatures exceeding 150°C. After the pills were aged for 16 and 72 hours, leak-off tests were performed on 16/30 proppant at 165ºC, resulting in minimal filtration. The authors also will examine the unusually demanding conditions at Åsgard relative to other Norwegian fields and will detail the application and performance of the new kill pill in this hostile downhole environment.
The Galileo Experience
Authors: Koper M. G. M. 
Published: December 2007

Abstract
This paper describes the Underbalanced Coiled Tubing Side tracks executed with a Hybrid Drilling system.
The project was executed from August 1997 to January 1999. During this time a steep learning curve was built on Hybrid drilling Unit technology.
The project comprised three sour gas wells with increasing complexity starting with a through tubing deepening, a world first through tubing double casing exit, through 5" and 7" casing, and finally a short radius side track with a 500 mtr. horizontal section. All three wells are targeted in the Zechstein Carbonate at 3000 mtr. TVD.
The learning curve on the Hybrid Drilling unit and underbalanced surface equipment is described, along with the methods used to manage the risks involved in the introduction of new technology.
The well objectives, drilling for fractures or equivalent matrix production and underbalanced design are discussed.
The different operational stages on the three wells are discussed.
Underbalanced Drilling With Coiled Tubing in Oman
Authors: van Venrooy J , van Beelen N , Hoekstra T , Fleck A , Bell G , Weihe A 
Published: December 2007

Abstract
This paper describes the first few months of operation of a new, purpose built, underbalanced (UB) coiled tubing drilling unit (CTDU).
The unit is designed to drill sidetracks and extensions to existing wells to improve reservoir drainage. The package is fully self-contained, and native crude is used as the primary drilling fluid. Natural gas injection through parasite strings or conventional gas lift mandrels is used to maintain underbalanced conditions.
The paper outlines the drilling and production challenges faced by the operator, including brief overviews of current conventional operations and a trial campaign of wells drilled with coiled tubing. With this background, the expected benefits of underbalanced drilling with coiled tubing (CT) are outlined.
The unit was built during 1998 and mobilised from the USA to Oman at the end of November 1998. Following final construction work and commissioning, the first two wells were drilled during February and March 1999. As part of the commissioning and shake-down process, these wells were drilled overbalanced using a conventional fluids package. The underbalanced drilling process system was integrated into the unit during April 1999 and commissioned in the field prior to initial underbalanced operations on the third well. Details of subsequent operations are included with an overview of drilling performance for the first 5 wells.
The paper concludes that underbalanced drilling technology can be applied safely and successfully. Although the paper deals solely with operations up to the end of June 1999, initial performance indicates that the predicted gains are achievable.
Optimizing Drilling Performance By Wellbore Stability Evaluation And Directional Drilling Practices
Authors: Hassan S. , Klimentos T. , Badri M. , Sengul M. , Zeid A. 
Published: December 2007

Abstract
In this paper we present data from several offshore wells, which have experienced wellbore stability related problems, especially over intervals with higher angles of deviation. We performed a wellbore stability evaluation for several angles of deviation using log, core and drilling data from all the existing wells, in order to predict the optimum drilling parameters to be used in the next wells to be drilled in this area. The answers provided by this study included properties such as, recommended mud-weights (minimum & maximum) as a function of angle of deviation, rock strength, and pore pressure. The determination of the rock strength along with the optimum mud-weight windows improved overall the drilling performance by minimizing washouts, loss of circulation, and optimizing casing design by elimination of unnecessary casing strings. Moreover, improvement of bit performance was achieved by using the predicted rock-strength values. As a result, drilling time and well construction costs were reduced significantly.
A New Hydraulics Model for Slim Hole Drilling Applications
Authors: Hansen Svein A. , Rommetveit Rolv , Sterri Njål , Aas Bjarne , Merlo Antonino 
Published: December 2007

Abstract
A model to predict the pressure loss for slim hole drilling has been constructed. The model, which is constructed by theoretical and numerical analysis and experimental measurements, incorporates the effect of eccentricity, drillstring rotation and rheology.