bluuebunny/crossref_metadata_2025_split huggingface dataset:
Taking the Forties Field to 2010
Authors: Thomson R. L. , Howden A. B. , Neill T. H. , Lindsay S. T. 
Published: December 2007

ABSTRACT
The continued success of BP's Forties Field, is crucially dependant upon fundamental changes in working practices and the development of world class operating and maintenance techniques. For the past two years, the Forties Team have taken the concept of an empowered work force from its infancy through to adolescence. At the same time, one of the five platform teams has tackled the issue of developing excellent standards of Total Productive Maintenance (TPM) in the offshore environment. TPM is an application of operator autonomous maintenance, developed in the West and perfected by the Japanese. We believe that this is the first ever application of TPM offshore and the first "whole team" approach to empowerment. The visionary aim is to be the role model in the operation of a declining oil field.
This paper describes the way in which empowered teams have been put in place in Forties. Examples of how organisational and cultural challenges have been successfully addressed, are illustrated. The application of TPM offshore is described, from initiation, introduction, development and onwards to the goal of self sustaining improvement from within the teams. Through the efforts of the empowered teams and implementation of world class systems, the aim of extending the Field life of Forties from 2003 to 2010 and beyond, is now seen to be a reality.
A Three-Dimensional Hydraulic Propagation Theory Simulating Fracture Growth Simultaneously from Two Sets of Perforation
Authors: Lee W. S. 
Published: December 2007

ABSTRACT
When planning a fracture treatment where more than one set of pay zones will be perforated, a designer must consider that multiple fractures will initiate simultaneously and later merge into a lesser number of fractures. Unfortunately, almost all published three-dimensional fracture simulation papers assume that there is only one fracture made during the entire fracturing process. Consequently, if more than one set of perforations exists, some averaging techniques must be used that reduce the accuracy of the simulation. This simplifying assumption is often made due to the mathematical complexity of dealing with multiple fractures with or without merging.
This paper represents the first effort to solve this complex problem. In this paper, we discuss a simple case with only two sets of perforation zones; in the future, it is planned to extend the problem to more sets of perforations.
Practical Applications of EPT Measurements in Gas, Condensate, and Oil-Bearing Reservoirs in the North Sea
Authors: Harrison Bob , Jeffs Paul , Skelt C. H. 
Published: December 2007

ABSTRACT
The Electromagnetic Propagation Tool (EPT) remains unloved by many in the North Sea oil industry due to concerns over tool performance, log interpretation and value for money. While acknowledging its limitations, this paper sets out to show that, given the right circumstances, the EPT can provide information unavailable from any other electric logging device, especially in wells drilled with OBM. Examples of EPT applications are given for several reservoirs in the North Sea, each bearing different hydrocarbon phases.
The Use of a New Technique To Determine Permeability Anisotropy
Authors: Wannell M. J. , Colley N. M. , Halford F. R. 
Published: December 2007

Abstract
Vertical permeability is an important input to coning and water influx studies and also choice of perforation policy. For British Gas Exploration and Production knowledge of this parameter is important for a number of small gas fields underlain by very large aquifers where water influx could significantly reduce reserves.
Conventional ways of measuring Kh/Kv (anisotropy) at reservoir scales have either proved unsuccessful or can only be undertaken once differential depletion effects become apparent.
A new openhole testing technique is described. It uses a dual inflatable packer run with a wireline formation tester as part of the logging program. The measurement scale is greater than that for core measurements and offers both versatility and precision to measure anisotropy within and between selected reservoir units at in-situ conditions.
The technique and analysis are briefly described, and results compared with other sources of permeability data. The paper concludes that this type of interference test can provide valuable and timely data that reduces the risk involved in a development decision and the cost of using conventional testing equipment.
The Environmental, Reservoir, and Operational Advantages of Cable Tool Drilling Natural Gas Storage Wells
Authors: Hayes J. P. , Fisher Peter 
Published: December 2007

ABSTRACT
The first oil well in North America was drilled in 1858 near Oil Springs, Ontario, Canada. Today, over 135 years later, Union Gas Limited is using cable tool rigs to drill natural gas storage wells within a 30 kilometer radius of that first well.
Union's storage pools are located in Lambton County, Southwestern Ontario, Canada (Figure 1). Lambton County is approximately 5,600 hectares (560,000 acres) of which 88% is actively farmed. There are over 3000 farms located in this area, and it is Union's priority to minimize environmental damage to these agricultural lands during well drilling activities.
This paper discusses cable tool drilling as an alternative to rotary drilling, and examines the environmental, reservoir, and operational advantages of cable tool drilling natural gas storage wells.
New Direct-Control Gas Storage Safety Valve
Authors: Gano J. C. , Revay J. R. 
Published: December 2007

ABSTRACT
Subsurface safety valves for large-completion, gas-cavern storage systems must comply with the economic, safety, and regulatory restraints required by industry standards in addition to satisfying the demanding environmental restraints imposed by gas wells with significantly high flow potentials. In addition, location of the valve and all protected systems must also be given careful consideration in completion design since this type of well is prohibitively expensive to kill if workover is required.
A direct-control subsurface safety valve has now been developed to meet these stringent requirements. The valve, which can be installed in the tailpipe below the packer, can be expended into the cavern, if necessary, and has the capability to provide efficient operation with minimal pressure loss at anticipated high flow rates.
This paper will discuss the history and field testing of the earlier prototypes of this valve and how the unique design criteria of the new design address the problems of valve mechanism damage that are generally attributed to high-flow-rate closures. An actual case history from a storage facility in Germany will demonstrate the advantages that the newly-designed valve can provide.
At present, two valves have been installed, with one being used to conduct long-term evaluations. All closures have been as predicted with no subsequent leakage or damage to the valve or lock. The new valve design has demonstrated excellent reliability in a demanding, high-flow-rate environment and maintains structural integrity during high-energy valve closures. Elimination of a hydraulic control system also allows unrestricted setting depths. Design analyses, surface testing, field testing, and wireline applications all indicate that a poppet-closure mechanism can be combined with "up-to-set" and "down-to-set" lock mandrels to successfully to address the problems previously associated with high-flow-rate closures in applications of this type.
Design Appproach Accounts for Condensate in Gas Pipelines
Authors: Adewumi M. A. , Nor-Azlan N. , Tian Shifeng 
Published: December 2007

ABSTRACT
With more than 1.2 million miles of gas pipelines crisscrossing the entire landmass of the United States, there is little doubt that the capital investment on these pipelines is tremendous. Optimal use of these pipelines is a must, both for operational reasons and cost-effectiveness. One of the prevalent problems in these pipelines is condensation. The existence of the condensate, in addition to reducing deliverability, creates several operational problems. Pigging and drips are two of the methods used to alleviate this problem. Since condensates are not uniformly distributed along the pipeline, either of these two solution strategies will be rendered ineffective unless the distribution of condensate in the pipeline is known. During the past several years, a compositional hydrodynamic model has been developed at Penn State University. This couples a phase behavior model with a fundamental multiphase hydrodynamic model. This model has since been tested and validated. Several design strategies and operational options that may be encountered in the field are defined and modelled. The results of these are reported in this paper. The results clearly demonstrate that in spite of the complex nature of this problem, condensation in pipelines can be modelled by using the approach presented here.
The Effect of Pressure Pulsation and Pilot Setting on the Performance of Pressure Relief Valves
Authors: Foy C. E. , Kiel Darwin , Jungowski Wiktor 
Published: December 2007

ABSTRACT
Pressure relief valves are essential components of natural gas pipelines. To ensure safe operation of the pipeline it is imperative that these valves function properly and reliably. Improper installation or setup can lead to potentially catastrophic problems in the field. In this study the performance of a commonly used pilot operated safety relief valve was examined under both normal and abnormal circumstances. The fundamental operating principles of the valve are reviewed, followed by presentation of experimental data illustrating the blowdown performance of the valve. The experimental techniques employed in the laboratory to simulate pipeline conditions are also described. While the performance of the relief valve was consistent with the manufacturer's specifications under normal setup and operation, significant problems were found to exist when the pilot was incorrectly adjusted, or when pressure pulsations were present. Examples of both cyclic venting and premature relief are shown in the paper. To assist in determining when a pulsation suppressor is required a semi-emperical relationship between pulsation strength, and premature opening pressure, is proposed.
Complexities in the Analysis of Pressure-Transient Response for Non-Newtonian Power-Law Fluid Flow in Fractal Reservoirs
Authors: Chakrabarty Chayan , Tortike W. S. , Farouq Ali S. M. 
Published: December 2007

ABSTRACT
This study presentient model for transient flow of a non-Newtonian power-law fluid in a fractal reservoir. The pressure, pressure derivative, pressure-derivative-to-pressure-ratio and rate behaviour of such a flow system are examined. The model is shown to be useful in the identification and modeling of power-law fluid flow in a fractal reservoir. The model also demonstrates the importance of analyzing both transient pressure and rate data for a single-well situation in such flow systems.
A Comparison of Two Devonian Shale Wells: Why Is One Well Better Than the Other?
Authors: Hopkins C. W. , Jochen J. E. , Fink K. J. 
Published: December 2007

ABSTRACT
This paper summarizes the detailed analysis of geological, geophysical, geochemical, and well test data from three Devonian Shale and Berea sand wells located in Pike County, Kentucky. These three wells were part of a Gas Research Institute (GRI) project designed to gain a better understanding of the producing mechanisms of the Shales and Berea and the impact of stimulation on well performance.1 All three wells were completed in both the Shales and Berea, which is typical for the area. Detailed data were collected in both the Shales and the Berea on two of the three wells which were used to develop layered, naturally fractured reservoir descriptions for each producing horizon. Each formation was stimulated with nitrogen foam and sand fracture treatments, and in general, the pre- and post-stimulation well performance was similar to predictions made using the layered, naturally-fractured reservoir descriptions. This paper compares these reservoir descriptions and provides a technical basis for the widely varying production often observed with Shale and Berea wells in this region.
The Evaluation of Proppant Transport and Cleanup of Foamed Fluids Used in Hydraulic Fracturing of Shallow, Water-Sensitive Reservoirs
Authors: Penny G. S. , Conway M. W. , Schraufnagel R. A. 
Published: December 2007

ABSTRACT
The use of foamed fluids has become popular in coal and shale reservoirs due to their inherent non-damaging properties. Foam is generally considered to be a perfect transport fluid. However, the proppant transport properties have not been fully measured in the laboratory. This paper discusses the design and construction of equipment to generate stabile foams in the laboratory and in the field, as well as the measurement of proppant transport and cleanup of foams commonly pumped into shallow, water sensitive reservoirs.
The equipment assembled for measuring proppant transport of foamed fluids includes a high pressure slurry pumping system, a choke system to generate field quality foams, a pipe rheometer to obtain in-line pipe rheology, a high pressure, see-through slot with remote video to observe proppant transport and a pressure control and exhaust system. Other equipment used includes a conventional sand column generator and core flow equipment to look at the impact of foam on coal permeability.
Several tests have been completed including the optimization of mixing tube diameter and velocity to achieve a stabile foam in the laboratory and in the field.
The impact of gel concentration and surfactant concentration on foam stability is measured to achieve minimum stability and maximum cleanup. Various surfactants are evaluated for cleanup. Their ability to avoid foam regeneration or blockage during flowback is also evaluated. Finally, the rheology, transport properties and half-lives of foams with and without sand are examined.
Improving Hydraulic Fracturing Results in the Clinton Sandstone of Ohio: A Case History
Authors: Jacot R. H. , Hopkins C. W. , Gonzalez D. W. , Meyer B. R. 
Published: December 2007

ABSTRACT
This paper describes a hydraulic fracturing study undertaken on the Clinton Sandstone in southern Ohio. The purpose of this study was to improve the effectiveness of the fracturing treatments being pumped to increase well production. The methodology employed in this study used a hydraulic fracturing simulator and production data analysis to evaluate the effectiveness of the treatments.
Historical fracture treatments were analyzed with a 2dimensional fracture design model1 to estimate propped fracture half-lengths. These treatments, typical of Clinton fracture treatments in Ohio, consisted of a gel pad followed by gel and slick water carrying 20/40 Ottawa sand at low concentrations. Results showed that most of the fracturing sand was falling out of the pay zone due to the low fluid viscosity. Over a period of one year, the treatments were modified using the fracture simulator as a design tool. Some of these changes included increasing sand concentration and pumping the sand with a higher viscosity fluid.
This simple methodology presented in this paper is applicable to Clinton wells in Ohio and other tight gas formations throughout the Appalachian Basin to improve production by modifying fracturing practices without increasing fracturing costs substantially. The methodology does not require large data collection and thus is cost effective to apply.
CO2/Sand Fracturing in Devonian Shales
Authors: Yost A. B. , Mazza R. L. , Gehr J. B. 
Published: December 2007

ABSTRACT
A total of five carbon dioxide (CO2) /sand well stimulations were successfully executed with two Devonian shale operators in Perry and Pike Counties, Kentucky. This new stimulation method offers a minimum formation damage proppant stimulation approach for natural gas producers in the United States.
Some operators have been concerned about the frac fluid formation damage associated with the water and chemicals used in conventional foam stimulations, whereas other operators have been concerned about the lack of proppant in straight nitrogen fracs used by service companies today. Two carefully screened geological areas of established Devonian shale production were selected based on active ongoing drilling and completion operations. One selected control area contained an existing set of wells with established production histories.
More specifically, one operator furnished three offset wells which were stimulated with the carbon dioxide/sand frac method. The quantity of proppant and fluids pumped during each well stimulation ranged from 23,000 to 43,000 pounds of proppant and from 120 to 160 tons of liquid carbon dioxide. Another operator furnished two offset wells which were each stimulated with approximately 47,000 pounds of proppant and 120 tons of carbon dioxide.
The logistics and field layout of a typical carbon dioxide/sand frac treatment has been described and highlighted. The importance and unique aspects of the closed system blender that is required for job execution is discussed. Five stimulation treatments have been reviewed, and stimulation and preliminary production data compared to offset wells stimulated with nitrogen, and explosives. Initial production results indicate more than a 50 percent increase in production rate compared to nitrogen fraced wells in the Pike County area. In addition, production is also 4.8 times better than conventional shot wells in the same area. These results are encouraging enough to formally combine existing pumping equipment, a closed system blender, and liquid carbon dioxide supplies to develop a new fracturing service in the eastern U.S. A total of 22 additional jobs are planned in the eastern U.S. in low permeability gas formations over the next year.
Using a Three-Dimensional Concept in a Two-Dimensional Model To Predict Accurate Hydraulic Fracture Dimensions
Authors: Rahim Zillur , Holditch S. A. 
Published: December 2007

Abstract
Hydraulic fracture treatments can be used to increase oil and gas flow rates, and ultimate recovery. A fracture treatment should be designed to optimize profit from the well. To design and optimize the fracture treatment, the engineer must use 1) a fracture propagation model, 2) a reservoir fluid flow model, and 3) an economics model.
To properly simulate the fracture and the reservoir, the engineer should use three-dimensional (3D) models.13 Hydraulic fractures grow up, out, and down from the perforated interval. Oil and gas reservoirs are layered and the flow of reservoir fluids occurs both horizontally and vertically within the reservoir and the fracture. Even though 3D models should be used for most reservoirs, a majority of the fracture treatments are designed using two-dimensional (2D) fracture propagation models. The most common models used by industry are the Perkins-Kern-Nordgren (PKN)4 and the Geertsma-deKlerk-Daneshy (GDK)4 models.
Two-dimensional fracture propagation models are used most often because they are easy to program and run fast on a personal computer. Fortran code for both the PKN and GDK models can be found in Appendix G of SPE Monograph 12.5 We have found that 2D models can be successfully used to design a hydraulic fracture treatment when (1) there are barriers that eventually suppress or restrict vertical growth, and (2) the engineer chooses the correct input value for created fracture height. When these two criteria are met (and all other data are reasonable), a 2D model will provide reasonable estimates of created fracture length and created fracture width.
Comparison of Fracture Stimulation of the Berea Sandstone in the Haysi Field
Authors: Norton Jerry , Hyde P. V. , Rothman E. M. 
Published: December 2007

ABSTRACT:
The Berea Sandstone has long been and continues to be a favorite drilling target in many producing areas of the Appalachian Basin. However, its low permeability makes it necessary to fracture stimulate the Berea to obtain economic production rates. The Haysi Field located in western Virginia has responded well to various hydraulic fracture stimulations using a wide range of frac fluids and proppant densities. The initial fracture systems pumped utilized fresh water with linear gels as the fracturing fluid, these were followed by foams, and several massive fracture treatments.
The foam treatments afforded quicker cleanup due to the nitrogen present. However, higher initial production rates with lower decline rates are the direct result of increased proppant densities in the fracture. This concept is supported by the production histories of the individual wells.
Twenty-five (25) years of production data from twenty (20) wells has been analyzed and used as a basis for comparing the different types of fluids pumped and the various proppant densities achieved. Propped fracture lengths were also calculated to compare production results (Figure 5).
A Simple Method for Evaluating Pore Surface Mineralogy
Authors: Mohaghegh Shahab , Ameri Samuel , Aminian Khashayar 
Published: December 2007

ABSTRACT
Majority of mineralogical studies directed at hydrocarbon producing formations are conventional studies that treat the formation as a bulk entity. Focusing on pore surface mineralogy, which is the identification of the elemental composition of the pore surface, seems to be a more realistic approach, since fluids in the formation come into direct contact with these elements on the surface. Rock-fluid properties such as relative permeability, wettability, capillary pressure and certain rock properties, are influenced by pore surface mineralogy. Hence, characterization of pore surface mineralogy will enhance understanding of the interaction between fluid and the porous medium.
This paper discusses Multiple Voltage Scanning Electron Microscopy as a novel method for characterization of pore surface mineralogy. Multiple Voltage Scanning Electron Microscopy, a new method that has successfully been used to study the surface of particles, has been implemented to identify the elemental composition of pore surface.
Results of the investigations of pore surface mineralogy for a reservoir in West Virginia is presented. This reservoir has experienced high injection pressures during a waterflooding project. The concentration of clays on the pore surface can be a possible explanation for high injection pressure.
This paper will try to direct the attention of scientists and researchers to this issue and emphasize the importance of pore surface mineralogy and its effects on rock-fluid properties.