bluuebunny/crossref_metadata_2025_split huggingface dataset:
Hydrate Monitoring and Warning System: A New Approach for Reducing Gas Hydrate Risks
Authors: Zain Z. M. , Yang J. , Tohidi B. , Cripps A. , Hunt A. 
Published: December 2007

Abstract
The current industry practice for hydrate prevention is injecting hydrate inhibitors at the upstream end of pipelines based on the calculated/measured hydrate phase boundary, water cut, worst pressure and temperature conditions, and the amount of inhibitor lost to non-aqueous phases. In general, systematic ways of controlling and monitoring along the pipeline and/or downstream to examine the degree of inhibition are very limited.
It is also known that hydrate formation would result in some changes in the aqueous phase. Therefore, it should be possible to detect initial hydrate formation by detecting these changes. The focus of our work is to develop a warning system against initial hydrate formation either by detecting minute hydrate particles and/or any changes in the water structure. The aim is to give the operator adequate time to initiate remedial steps prior to massive hydrate formation/build up which could result in pipeline blockage.
In this paper, we present a new approach for hydrate monitoring and warning system using physical property measurements such as dielectric properties and ultrasonic wave signal. The results demonstrate that dielectric properties at microwave frequencies has potential to be used as a downstream analysis and online analysis for detecting the initial hydrate formation and/or presence of hydrate particles and/or change in water structure due to hydrate formation. The ultrasonic signals (e.g., FFT and amplitude) could detect the presence of minute hydrate crystals and even nuclei, while there is no sign of hydrate formation from monitoring system pressure. The results are very encouraging and could potentially change the industrial approach to gas hydrate control strategy.
This work is part of a comprehensive project which covers monitoring the degree of inhibition against hydrate formation to further improve the safety of offshore/deepwater operations, as well as optimizing inhibitor injection rate to minimize their environmental impact and improve the economical aspects of the development. Some of the methods developed in this work are equally applicable to reducing the risks associated with wax and/or salt depositions, further improving the flow assurance aspects of deepwater developments.
Case History Evaluation of RPMs on Conform Fracturing Applications
Authors: Dos Santos J. A. C. M. , De Melo R. C. B. , Di Lullo G. 
Published: December 2007

AbstractActual worldwide oil production averages some 75 million barrels per day and, while estimates vary, this is associated with the production of 300 - 400 million barrels of water per day. These values of approximately 5 - 6 barrels of water for every barrel of oil are quite conservative. In some areas around the world, fields remain on production when the ratio is as high as 50 to 1.Water production causes several problems to oil wells such as scaling, fines migration or sandface failure, corrosion of tubular, and kills wells by hydrostatic loading, amongst other things. Thus, while water production is an inevitable consequence of oil production, it is usually desirable to defer its onset, or its rise, for as long as possible.Numerous strategies, both mechanical and chemical, have been employed over the years in attempts to achieve this. Simple shut-off techniques using cement, mechanical plugs and cross-linked gels have been widely used. Exotic materials such as DPR (disproportionate permeability reducers) and the new generation of relative permeability modifiers (RPM) have been applied in matrix treatments with varying degrees of success. Most recently, Conformance Fracturing operations have increased substantially in mature fields as the synergistic effect obtained by adding a RPM to a fracturing fluid have produced increased oil production with reduced water cut in one step, consequently eliminating the cost of additional water shut off treatment later on.This paper is an evaluation of various RPM materials commonly used on Conformance Fracturing treatments performed in the northeast of Brazil and other South American countries, rather than the usual laboratory testing methods and theoretical estimations. The paper also describes the technical design and operational methodology to treat single zone to laminated reservoirs with different mobility ratios. We believe conformance fracture techniques could significantly impact the development strategies of many fields worldwide.
Multilateral/High-Pressure Jet Wash Tool System Successfully Employed in Multilateral Wells
Authors: Lesinszki A. , Stewart C. , Ortiz A. , Heap D. , Pipchuk D. , Zemlak K. 
Published: December 2007

Abstract
Multilateral wells provide optimal recovery of reservoir pay and can become more prolific with stimulation or cleanout treatments. Downhole tools exist that index and allow the coiled tubing string to find and enter additional legs; however, they function using flow rate modulation. Any additional tool component beneath the multilateral tool that requires high pressure will suffer in performance because of the indexing multilateral tool. This technical paper addresses the performance of a new system that allows the indexing tool to find the lateral and then effectively treat the reservoir through the stimulation tool at the end. The entire cycle can be repeated for all laterals in the wellbore.
The results of field tests using this multilateral jetting system were similar to what was seen in yard tests perform at test facilities in Rosharon TX. Field tests showed that operating parameters produced clear indications that the system was operating correctly. All legs were efficiently and effectively treated to improve well production. Additionally, this system reduced the number of trips into the well from three to one, resulting in a 50 % reduction of time at the client's well site.
Economics of GTL Plants
Authors: Al-Saadoon F. T. 
Published: December 2007

Abstract
A unique approach for assessing the economic viability of gas to liquid (GTL) plants is utilized. The capital expenditures ("CAPEX") are based on the production of one barrel of hydrocarbon liquid per day (BLPD) whereas the annual operating expenditures ("OPEX") are expressed as percentages of CAPEX. Both expenditures cover the range of costs envisioned by various venders/investigators. It is assumed the overall thermal efficiency of GTL plants is about 60% and the plant operates 330 days per annum. The capital expenditures utilized in this study are 20,000, 25,000, 30,000, 35,000, and 40,000 USD/BLPD. The annual operating expenditures utilized are 5%, 6%, and 7% of CAPEX. Thus, the range of operating expenditures utilized is 3.03 to 8.48 USD per barrel of liquid hydrocarbon produced.
Two measures of profitability are utilized in assessing the economic viability of GTL plants, namely, rate of return ("ROR") and undiscounted pay-out time ("POT"). Rates of return used in this study are 10%, 15%, and 20% whereas payout times used are 4, 5, 6, 7, and 8 years. Construction periods of 3 and 4 years are considered in the analysis. It is determined, for a 3-year construction period, that when crude oil prices are in the range of 10.27 USD/Bbl (for 20,000 USD/BLPD in CAPEX, 3.03 USD/Bbl in OPEX, and 10% for ROR) and 37.76 USD/Bbl (for 40,000 USD/BLPD in CAPEX, 8.48 USD/Bbl in OPEX and 20% for ROR), GTL plants are profitable. Likewise, it is concluded that when crude oil prices are in the range of 10.48 USD/Bbl (for 20,000 USD/BLPD in CAPEX, 3.03 USD/Bbl in OPEX, and 8 years for POT) and 38.32 USD/Bbl (for 40,000 USD/BLPD in CAPEX, 8.48 USD/Bbl in OPEX, and 4 years for POT), GTL plants are profitable. For a 4-year construction period, crude oil prices range between 10.64 and 40.87 USD/Bbl rather than 10.27 and 37.76 USD/Bbl, respectively. Crude oil prices as function of undiscounted pay-out times, however, remain unaffected by the change in the construction period. It should be noted that it is assumed the premium on GTL products offsets the cost of feed stock gas. A general survey of GTL processes is also included.
Quantifying Environmental Benefits of Improved Oil and Gas Exploration and Production Technology
Authors: Godec M. L. , Johnson N. 
Published: December 2007

Abstract
This paper summarizes work that documents the technological progress made by the oil and gas exploration and production (E&P) industry and the environmental benefits realized from this progress. The paper provides quantitative evidence of the improvements in environmental performance made by the E&P industry, examines industry and societal trends, and highlights some of the specific technological improvements contributing to this improved environmental performance. This paper examines and quantifies how specific technological advances in the areas of oil and gas exploration, drilling, well completion and stimulation, and production operations -- primarily focused on improved efficiency, lower costs, and increased recovery -- have resulted in reduced environmental impacts. The paper demonstrates how these technological advances are allowing greater access and better development economics in environmentally challenging settings. Finally, the paper offers some perspectives on the role of research and development to support continued technology improvements in the future.
Energy Policy and Conservation Act (EPCA) Inventory: Good Data and Sound Science to Address the Issue of Federal Lands Access
Authors: Eppink J. F. , Johnson R. 
Published: December 2007

Abstract
The EPCA Inventory represents a first-time compilation of disparate datasets to assess the issue of access to federal lands and resources. Comprehensive datasets for the inventory comprise federal lands status, leasing stipulations, and oil and gas resource data. This paper examines the EPCA Inventory methodology, geographic information systems (GIS) analysis, categorization, and strengths and weaknesses.
Minimizing Environmental Impact: Exploration and Production on an Urban University Campus
Authors: Grey J. E. , Spady D. W. 
Published: December 2007

Abstract
The Appalachian Basin is one of the oldest hydrocarbon producing regions of the United States. After over 100 years of drilling and production, the industry was very comfortable drilling behind hills, in isolated areas, and generally away from population. To demonstrate modern oil and gas exploration industry practices and the ability to operate responsibly in a challenging environment, a well was proposed on the football field of the University of Charleston. Located in the heart of the city, the well was within sight of the West Virginia State Capitol, on a mineral lease owned by the University. In order to accomplish this project, a successful well required a tenuous journey through geological identification, regulatory hurdles, resident opposition, logistical restrictions, location stability concerns, drilling surprises and reclamation procedures.
This paper will detail the planning and process that resulted in a successful drilling project in an environmentally sensitive location. In addition to being on the banks of a major waterway, within sight of a State Capitol, and adjacent to an office building, the real hurdle was cooperating with a neighborhood that was as close as 501 feet from the wellbore. The project drew a significant amount of local media attention, as each aspect of the operation was cross-examined in various public forums.
The project brought together an E&P company and six of its major vendor partners, each donating their products or services to a project that earned strong community support. Working under intense public scrutiny, each part of the drilling and completion process was pre-planned, including noise generation, dust control, spill response, and evacuation procedures. In fact, an observation tent was erected on-site for the purpose of public viewing, an action that proved to be very much accepted by the residents.
As a result, the local University has their own source of energy, but more importantly, the industry has a greatly enhanced reputation in the community of operating in a clean, efficient and professional manner. This paper will journal the steps of the process, effectively outlining a template for future projects in sensitive urban environments.
Treating Disease Prevention Like Safety: Educating Managers and Employees to Think of Anti-Malarial Medications as PPE (Personal Protective Equipment)
Authors: Shallenberger L. G. , Buford D. L. 
Published: December 2007

Proposal
As oil and gas industry employees are located in sub-Sahara African countries and other areas where malaria is endemic, non-immune workers need to adopt multiple strategies to prevent contracting this potentially fatal disease. Awareness training, personal protection against mosquito bites and vector control measures are all important in reducing Anopheles mosquito bites.
In addition, the prevention of malaria in non-immune individuals relies heavily on the proper use of effective anti-malarial medications, i.e., chemoprophylactic agents. In spite of implementing a comprehensive Malaria Control Program (MCP) and contractually requiring its contractors to implement similarly effective programs for their employees, ExxonMobil affiliates and projects (ExxonMobil) continued to experience Falciparum malaria cases among contractors' non-immune employees assigned to ExxonMobil, including two fatalities.
A multidisciplinary team was formed to identify opportunities to enhance the effectiveness of the MCP. One of the team's key recommendations was to develop and implement a Malaria Chemoprophylaxis Compliance Program (MCCP) to address identified malaria chemoprophylaxis use shortcomings.
At the heart of the MCCP is the random, unannounced acquisition of urine specimens from non-immune individuals for laboratory verification of the presence of an effective anti-malaria medication. Novel laboratory analytical methods were developed and validated, and forensic-type chain of custody specimen handling procedures were adopted. Individuals producing non-conforming specimens are subjected to a confidential medical review process to determine their ongoing fitness-for-duty in malarial areas. The MCCP was implemented in Chad and Cameroon, then in Angola, Equatorial Guinea and Nigeria. As other countries with ExxonMobil employees and contractors working in upstream and downstream operations are added to the MCCP, it is becoming clear that malaria prevention should be treated like other safety initiatives.
Traditionally, employees are issued properly fitted respirators and hard hats to prevent injuries and diseases from hazardous exposures. To be effective, employees need to be educated in the proper use of these PPEs and self-motivated to use them. Likewise, managers must ensure that employees traveling to malarial areas are issued appropriate chemoprophylactic agents and educated in their proper use. Employees need to be motivated and willing to use the medications as prescribed for optimal program results.
Northern Sahara Aquifers Protection: Casing Corrosion Problems and Defining New Well Construction Performance Objectives—Case Study: Hassi Messaoud Oilfield in Algeria
Authors: Dhina O. , Aissat M. S. , Belkheir K. 
Published: December 2007

Abstract
Well construction reliability is always of great importance especially when it is about drilling in an arid region that contains strategic groundwater reserves. This is the case of Hassi Messaoud and satellite oilfields (HMDs) in Algeria where aquifers of the Northern Sahara System (NSAS) Spread out. Problems closely related to well construction such as casing corrosion, cementing lack and also those of post- abandonment are encountered by Sonatrach and partners there.
The main environmental concern becomes, then, how to ensure a reliable and highly safe well design and structure by improving drilling practices and introducing innovative architecture technologies aiming at significantly reducing aquifers contamination risks.
This paper describes how Sonatrach has been able to deal with such problems. Besides, it points out how risks are assessed according to an appropriate method that was fitted for purpose. On the other hand, field data are used to analyze the occurring phenomena and lessons learned from what is considered as the most tragic disaster related to well construction in Algeria - that occurred in Berkaoui satellite field in 1986 -are stressed.
Furthermore, the paper summarizes the steps and the approach taken along the way in stating new drilling performance objectives for HMDs to meet world-class standards and fulfil NSAS protection commitment.
Time-Lapse Production Logging and the Concept of Flowing Units
Authors: Cortez O. D. , Corbett P. W. M. 
Published: December 2007

Abstract
Permeability heterogeneity is a well known feature that is present in most if not all reservoirs. Initially when the reservoir is in hydrostatic equilibrium the differences in permeability within the same reservoir unit do not manifest. However as soon as production starts and a pressure drawdown is introduced to the system fluids will start moving towards the wellbore following the easiest paths within the rock. Therefore a system of "flowing units" develops with time allowing the zones with relative high permeability to produce faster than the relatively low permeability zones.
When a well is completed and perforated it is good practice to evaluate reservoir properties and well performance by carrying out transient well testing and multirate tests. Well test interpretation gives a good estimation of kh, skin and boundary effects. Multirate tests, particularly important in gas wells and high flowrate oil wells, allow evaluation of well deliverability and non-Darcy effects. It is therefore important to define the correct thickness that is actively contributing to flow. The effective thickness will be the sum of all the high permeability flowing units. In fact, and depending on the permeability contrast, the few most permeable units are responsible for most of production. Production Logging can verify and quantify flow contribution from these intervals.
Differential depletion within this interbedded layered system occurs by stages. Initially the zones with the highest permeabilities will produce faster and drain their connected volume until a differential pressure threshold is reached and crossflow from the surrounding poorer-quality reservoir facies starts. A production logging survey is a snapshot of the flowing profile across the producing intervals at that particular point in time. In order to monitor this dynamic behaviour running production logging surveys at different times during the field's life is highly recommended especially in mature fields that produce from layered systems or interbedded units within the same formation. Time-lapse production logging provides a realistic visualization of flowing behaviour and helps pre-development of a production optimisation strategy focused in maximizing reserve recovery.
The previous statements are supported by field examples where this pattern of permeability zonation has been observed over time.
Aluminum-Based HPWBM Successfully Replaces Oil-Based Mud To Drill Exploratory Wells in an Environmentally Sensitive Area
Authors: Ramirez M. A. , Clapper D. K. , Sanchez G. , Luna E. , Preciado O. , Santamaria J. 
Published: December 2007

Abstract
Oil-based muds traditionally have been used by Petrobras to drill wells in the Upper Magdalena Valley of Colombia to address wellbore instability problems associated with the Villeta shale. Recently the operator faced additional challenges while drilling an exploratory well due to 1) environmental concerns in a highly sensitive area, and 2) formation evaluation problems associated with oil-based fluids.
Significant advances in mud design in the last few years have allowed water-based mud performance to approach the performance of oil-based mud. Therefore, the operator and fluids company created a task force to evaluate the application of water-based mud for this well.The planning stage included laboratory tests, past history review and an evaluation of the service company's experiences when drilling similar shales in the area.A high performance water-based mud (HPWBM) containing clay and shale stabilizers, a ROP enhancer, and sealing agents was selected to drill the well.
This paper presents the laboratory and field data generated during this project. The well was drilled through the troublesome shale section and to the top of the production reservoir without experiencing wellbore stability problems. The system was resistant to carbon dioxide and anhydrite contamination.Gas kicks were controlled without difficulty and the fluid exhibited excellent rheological properties when higher densities were required to control formation pressures.The operator's expectations were met in this difficult well although areas for improvement were identified for future applications.These include enhanced resistance to anhydrite contamination, increased control of bit balling, reduced hole enlargement and improved ROP through hydraulics optimization.Additional testing to address these issues is planned using shale samples collected from the well. The operator and service company concluded that a properly designed water-based mud is a viable alternative to an oil-based mud in areas where environmental restrictions and formation evaluation problems are a concern.
Cost-Effective Treatment of Barium from Coalbed Natural Gas Produced Water
Authors: Cline J. T. 
Published: December 2007

Abstract
Produced water is generated during the production of coal bed natural gas (CBNG) from the Big George coal at Anadarko Petroleum Company’s (APC) County Line field, near Gillette, Wyoming. The produced water contains dissolved solids that typically meet drinking water standards. But, the total barium limit of 1.8 mg/L, established by the Wyoming Department of Environmental Quality (WDEQ) for discharge to draws leading to the Powder River, was often exceeded for produced water discharging into multiple tire tanks, draws and ultimately into the Powder River. Originally, gypsum was used in the field to reduce the barium levels, but the monthly monitoring results were sporadic. This study was performed to (a) investigate reliable methods for reduction/removal of total barium from the discharge water, in order to meet the limit, and (b) design and construct cost effective treatment systems. The removal mechanisms tested were; (a) precipitation as an insoluble sulfate, or (b) adsorption on zeolite. Precipitation chemicals tested were: sulfuric acid, magnesium sulfate solution, and magnesium sulfate crystals. Even though soluble barium was decreased as a result of sulfate addition, the precipitation mechanisms were not successful in reliably reducing/removing total barium. However, total barium was dramatically and reliably removed by adsorption/filtration in direct, flow-through beds of zeolite, with flow rates of over 500 bbl/day/ton of zeolite. The designed zeolite beds (tinhorn tanks), at each outfall will maintain total barium in the discharge water below the established limit for four to eight weeks before renewal or burial as a non-hazardous waste.