bluuebunny/crossref_metadata_2025_split huggingface dataset:
Development of an Ecofriendly Scale Inhibitor for Harsh Scaling Environments
Authors: Fleming N. , Bourne H. M. , Strachan C. J. , Buckley A. S. 
Published: December 2007

Abstract
The recent advances in drilling and completion technology have led to the development of more complex reservoirs including high pressure, high temperature, and high salinity (HP/HT/HS) fields. A combination of high calcium and barium concentrations in the produced water, coupled to high reservoir temperatures presents a particularly harsh scaling environment which dictates the need for high concentrations of exotic scale inhibitor chemistry for effective downhole scale control. These high levels of inhibitor, typically 10–200 ppm, are particularly difficult to sustain over long production periods leading to a relatively short squeeze life and thus, high well intervention frequency and deferred oil costs. In addition, increasing environmental regulations have made the development of green chemistry a high priority.
A number of scale inhibitor chemistries have been shown to be thermally stable and effective at controlling scale deposition under harsh conditions, however, their retention characteristics are less than ideal, leading to short treatment life. In addition, some of these chemistries do not have favourable environmental properties.
To meet the challenges presented by the more severe water chemistries and producing environments a new chemistry was developed. The new chemistry contained vinyl sulphonate monomer species, which were expected to provide the polymer with a high level of thermal stability, calcium tolerance and effective barium inhibition properties. The incorporation of a phosphorus containing monomer was expected to provide good retention properties and relative ease of detection. In addition, the use of the novel phosphorus containing monomer offered the opportunity to increase the biodegradation characteristics of the developed polymer.
Laboratory studies have suggested that the new inhibitor combines significantly improved thermal stability, calcium tolerance, and barium inhibition with superior retention and environmental properties. Nine squeezes with the new inhibitor have been completed in the North Sea, which have already achieved a significant increase in squeeze life1.
Improved Horizontal Well Placement and Performance Using a Bit Inclination Measurement Tool
Authors: Muritala Lateef , Onwuazo C. , Adewumi Femi , Aibangbe Osaretin 
Published: December 2007

Abstract
Accurate geological placement of a lateral in the sweetest portion of the reservoir plays a major role in optimizing production rates and increasing recovery from horizontal wells, particularly for complex reservoirs with heterogeneous features. Horizontal wells have thus been routinely steered both geologically and geometrically using evaluation measurements from conventional bottom hole assemblies with sensor points some 50 feet away from the bit. This implies that correction runs and it's effective response time and footage will be dependent on directional drilling personnel proficiency and tool performance relative to formation type. It is not surprising thus, that a sizeable part of the reservoir is drilled sub-optimally, and in some cases the eventual well bore undulation has caused impossible completions, developed water sumps and have also given birth to speedy breakthroughs of gas and water. All of these have impacted production negatively, and caused unnecessary oil deferment, early work-over and associated cost overrun on budget.
The ideal option would thus be to minimize the undulation while geo-steering the lateral along the sweetest portion of the reservoir in an attempt to minimize attendant production problems and hence allow efficient and early completions.
A tool has been developed which measures well bore inclination 1 foot away from the drilling bit. Shell West Nigeria introduced the At bit Inclination measurement tool to horizontal well drilling on the Opukushi 26 well in March 99. This was to complement multiple depth propagation resistivity and quadrant density-neutron measurements while drilling utilized in horizontal evaluation, to enable full wellbore geologic steering with optimized response time for correcting changes in the desired direction. The result is a significant improvement in the ratio between actual versus predicted production figures as compared to previously drilled wells executed without the combination measurement. It also aided geosteering decision, improved directional performance and enhanced delivery of better quality well.
This paper therefore reviews the SPDC horizontal wells experience in identifying the impact of deviation profiles and lateral placement with respect to production performance, and how the use of the near bit inclination tool along with the formation evaluation measurements has resulted in noticeable improvement.
Integrated Fractured Reservoir Characterization: A Case Study in a North Africa Field
Authors: Gauthier B. D. M. , Zellou A. M. , Toublanc A. , Garcia M. , Daniel J-M. 
Published: December 2007

AbstractIn fractured reservoirs, data directly related to fractures are scarce and uni-dimensional (i.e. cores and image logs). Other types of data are better distributed and have proved to be related to fracturing but only indirectly (e.g. lithology or large scale structure).In such reservoirs, however, one has to understand fracture distribution and behavior at the field scale. A methodology has been developed within TotalFinaElf to define the relationships of all sources of data to fracturing and to integrate them and compared to another independent published method. To that end, a systematic work flow which goes from 1D to 2D and from static to dynamic data has been defined and various technologies tested.A field case in North Africa is taken to illustrate this methodology. In this field, fracture data from image logs have been related to: 1) production data; 2) 3D seismic attributes (coherency, amplitude, structural curvature) and fault interpretation and strain; 3) log data such as porosity, thickness and lithology index. The former type of data is used to understand the contribution of each fracture set to flow. The latter two types of data are used to better map fracture distribution at the field scale. Ultimately, this mapping is calibrated with the production data of the other wells where fracturing data are not available and is then used to validate the specific role of fracturing in this field.A better reservoir simulation and infill well planning can be subsequently achieved.
EOR Screening for Ekofisk
Authors: Jensen T. B. , Harpole K. J. , Østhus A. 
Published: December 2007

Abstract
An investigation of alternative EOR processes having potential application in the giant Ekofisk chalk field is presented. Technical feasibility, process readiness, oil recovery potential, and related uncertainties and risks of five selected EOR processes, namely hydrocarbon (HC) WAG, nitrogen (N2) WAG, carbon dioxide (CO2) WAG, air injection and microbial EOR (MEOR), are assessed for possible application at Ekofisk. The objective of the screening study was to evaluate and rank the EOR alternatives and to select the most attractive process(es) on which to pursue further work toward possible field pilot testing. The focus of the paper is on the technical assessment of the relative oil recovery potential of each process, and on the importance of identifying critical operational and logistical considerations for implementation of an EOR processes in the offshore North Sea operating environment.
Estimates of potential EOR incremental oil recovery for the Ekofisk field can be quite significant. However, key project development and implementation issues and additional cost elements must be weighed equally with oil recovery forecasts in any EOR process ranking. Some of these issues (e.g. injection gas supply, facilities requirements, and the impact of EOR on chalk compaction, subsidence and wellbore integrity) may be significant enough to eliminate a process from further consideration.
In addition, there are significant differences in the quantity and quality of key laboratory and field data supporting the viability of the various EOR processes being considered. Only a limited amount of field-specific data are available to calibrate the performance predictions for some of the processes. There is also a wide variation in the technical readiness of each process to begin field pilot design studies. Table 1 summarizes the state of technical readiness for field implementation of each process and identifies some of the major risk elements and remaining work required to progress these EOR processes at Ekofisk.
Table 1 Technical Readiness of EOR implementation at Ekofisk.
Design Methodology for Selection of Horizontal Open-Hole Sand Control Completions Supported by Field Case Histories
Authors: Bennett C. , Gilchrist J. M. , Pitoni E. , Burton R. C. , Hodge R. M. , Troncoso J. , Ali S. A. , Dickerson R. , Price-Smith C. , Parlar M. 
Published: December 2007

Abstract
Reservoirs requiring sand control pose a major challenge for selection of a suitable completion method. Horizontal open-hole completions have been successfully utilised in such reservoirs to eliminate sand production, while maximising productivity/injectivity and well deliverability throughout the expected life of the completion and minimising risk and complexity.
Although horizontal open hole sand control completions have been applied widely in the last decade, ranging from preperforated/slotted liners to gravel packs, and many case histories have been discussed in the literature, a systematic methodology for selecting these completion methods remains to be documented. It is the objective of this paper to propose such a design methodology by unifying the broad experience and understanding from a global and technically integrated perspective.
The paper first discusses a generalised and unified methodology for determining when to install sand control, what to install for sand control and how to install sand control in horizontal open-hole completions. Specific factors recognised as affecting "when" are in-situ stresses and pore pressure decline (sand prediction), expected well life, production rate, hydrocarbon and well type, gross product value, sand tolerance capacity, environmental limitations and intervention capabilities, whilst the integration of all these factors have an impact on the overall risk analysis. In addition to many of the previous factors, critical drivers affecting "what" are identified as wellbore architecture, reservoir lithology and petrophysical properties, and sandface equipment reliability. Additional parameters impacting "how" are reservoir drilling fluid, displacement and cleanup methodology, screen type, operational implementation/assurance (risk management, operational timing and location logistics), torque and drag analysis, and gravel placement simulations.
Secondly, examples of this methodology are presented in detailed case histories pertaining to different types of horizontal openhole sandface completions including slotted liners, standalone screens (including expandable) and gravel packs as well as various integrated cleanup methods, along with a summary of lessons learnt by each company.
Best Practices and Methods in Hydrocarbon Resource Estimation, Production and Emissions Forecasting, Uncertainty Evaluation and Decision Making
Authors: Jonkman R. M. , Bos C. F. M. , Breunese J. N. , Morgan D. T. K. , Spencer J. A. , Søndenå E. 
Published: December 2007

Abstract
On behalf of a group of sponsors consisting of the Norwegian Petroleum Directorate (NPD) and most E&P companies active in Norway, a workgroup was set up to author a report on the Best Practices and Methods in Hydrocarbon Resource Estimation, Production and Emissions Forecasting, Uncertainty Evaluation and Decision Making. The workgroup is part of Norway's forum for Forecasting and UNcertainty (FUN).
Following a detailed data acquisition and interviewing phase to make an inventory of the current practice of all sponsors involved, the workgroup postulated a relationship between a company's practices and its economic performance. A key distinguishing factor between companies is the degree to which probabilistic methods are adopted in integrated multidisciplinary processes, aimed at supporting the decision making process throughout the asset life cycle and portfolio of assets.
Companies have been ranked in terms of this degree of integration and best practices are recommended. In many companies a gap seems to exist between available and applied technology. Data and (aggregated) information exchange between Governments and companies is also discussed. A best practice based on their respective decision making processes is recommended.
Successful Field Application of Chemical Flow Improvers in Pipeline Transportation of Highly Paraffinic Crude Oil in Kazakhstan
Authors: Zettlitzer Michael 
Published: December 2007

Abstract
In autumn 1998, an international consortium started the continuous production of highly paraffinic crude oil in a newly developed field in Central Kazakhstan. Due to the crude´s high pour point and the related high viscosity at low temperatures, intensive laboratory investigations had to be carried out before production start-up to find an effective method for flow improvement in winter conditions. Duly considering technical and economic aspects, it was decided to use chemical flow improvers for transportation through the 60 km pipeline to the neighbouring oil field and from there to the refinery 700 km away.
Out of 18 flow improvers tested in the laboratory, only a handful proved to be suitable for this specific crude. The pour point was lowered from +17 to −5°C and viscosity at 10°C was reduced from several thousand mPa*s to about 14mPa*s. In spite of the significant flow improvement, yield stress remained high (≍60Pa), even for properly inhibited oil whenever the crude was cooled down statically, whereas, after dynamic cooling, yield stress was nearly negligible. Thus, special precautions had to be developed for potential phases of export stops.
Field application of the selected flow improver fully confirmed the encouraging lab results: the measured pressure drop across the pipeline – under laminar as well as turbulent flow conditions -very closely coincided with the values derived from calculations based on lab viscosity (and yield stress) measurements. Furthermore, pour point could be permanently kept far below zero. Regular pipeline pigging provided, uninterrupted production could be achieved without major technical problems even at surface temperatures of well below −20°C.
A special task not yet fully mastered is the adaption of flow improver implementation to the standards and test procedures of the Kazakh authorities and pipeline organizations. This is especially true of pour point and viscosity measurements.
Trends in the Development of Environmentally Acceptable Additives for Zonal Isolation Applications
Authors: Reddy B. R. , Vijn Pieter , Chatterji Jiten , Dao Bach , Wilson J. Michael , Caveny William J. 
Published: December 2007

Abstract
For the past 20 years, there has been increasing global emphasis on development of environmentally acceptable materials to replace chemicals that are considered to be either toxic to flora and fauna or otherwise to pose a long-term hazard to the natural environment. However, globally accepted definitions for unacceptable toxicity or environmental hazard do not exist. Likewise globally accepted protocols for testing methods to evaluate these hazards do not exist.
The Oslo-Paris Commission (OSPARCOM) was inaugurated in 1992 for the protection of the marine environment of the Northeast Atlantic. In 1998, OSPAR Conventions were ratified by Belgium, Denmark, the Commission of European Communities, Finland, France, Germany, Iceland, Ireland, Norway, Portugal, Spain, Sweden, the United Kingdom of Great Britain and Northern Ireland, Luxembourg, and Switzerland.
The goals of the OSPARCOM are to prevent and eliminate pollution from land-based sources, dumping or incineration, and offshore sources, and to assess the quality of the marine environment.
To this end, the OPSARCOM has initiated a series of stringent testing protocols that are used to evaluate chemicals that may be detrimental to the marine environment. Additionally, the Harmonised Offshore Chemical Notification Format (HOCNF), which must be completed on all chemicals to be registered for offshore use, has unified the reporting format.
Elsewhere around the globe, the regulations on use of chemicals in the offshore environment are not as highly structured, and, generally, are less strict. For example, chemical discharges offshore in the Gulf of Mexico are based on oil- and grease-extraction tests and static sheen. Aquatic toxicity testing is usually required before discharge is allowed in the Gulf waters. However, these restrictions are rapidly changing and may become much more structured in the near future.
This paper summarizes Halliburton's research efforts over the past several years to comply with, and preferably exceed, the diverse global regulations and guidelines in the areas of environmentally acceptable cement dispersants, retarders, viscosifiers, foamers, defoamers, fluid-loss additives, and spacer-blend additives.
Applications of Singular Value Decomposition to Determine Streamline Distribution for Sectionally Homogeneous Reservoirs
Authors: Guevara-Jordan J. M. , Rodriguez-Hernandez F. 
Published: December 2007

Abstract
This paper presents an original extension of a new numerical method, recently developed by Marathe et al.1, to determine the streamline distribution in a sectionally homogeneous reservoir with an arbitrary shape and well configurations. It combines the singular valued decomposition algorithm2 and the classical method of images3 into an efficient numerical scheme which computes semianalytical solutions for pressure and Darcy's velocity. These solutions are used to obtain the streamline configuration in two dimensional reservoirs for single phase incompressible flow. Very general test problems and numerical examples show that the new method has, in some cases, substantial reduction in CPU times in comparison with the finite5 and boundary4 element techniques.
Single-well Sonic Imaging: High-Definition Reservoir Cross-sections from Horizontal Wells
Authors: Coates R. , Kane M. , Chang C. , Esmersoy C. , Fukuhara M. , Yamamoto H. 
Published: December 2007

Abstract
The limited resolution of conventional seismic surveys often results in challenges to successful reservoir development. Reservoir structure and thickness may not be determined from the seismic to the level of detail necessary, affecting the placement of the horizontal well. We describe a new sonic imaging technique that resolves these features. In addition the position of the well in relation to the reservoir perimeter can be determined with great accuracy
Single-well sonic imaging places the acoustic transmitter and receivers in the same well, analogous to recording a micro-scale seismic reflection survey downhole. Using modified sonic logging technology, sound is broadcast into the formation and reflections are converted into a two- or three-dimensional spatial image of the zone around the borehole. Acoustic reflectors such as the top of the reservoir, calcite stringers, or fractures are mapped at distances of 10-15 meters from the well with resolution on the order of one-half meter. We show several examples of surveys conducted in horizontal wells to illustrate applications of the technique.
Using Real-Time Fibre Optic Distributed Temperature Data for Optimising Reservoir Performance
Authors: Laurence O. S. , Brown G. A. 
Published: December 2007

Abstract
A new approach to reservoir monitoring using permanent sensors is outlined which employs the use of optical fibre preinstalled on the completion across the intervals of interest. Using optical fibre it is possible to obtain an accurate measurement of well temperature every metre along the producing interval at regular, sub-hourly, time intervals over the producing life of the well. Although temperature is not, in itself, a direct measurement of flow, well performance, water cut or gas breakthrough all do produce quantifiable thermal responses. These responses, combined with continuous monitoring allow identification of producing zones and rapid evaluation of production variations without the need for well intervention.
The paper will outline how optical fibre can be installed into a range of completions and well types. Real well examples are used to illustrate how distributed temperature monitoring can be used to for reservoir monitoring. These illustartions include monitoring gas lift mandrels, cross flow on shut-in, water breakthrough and monitoring flood rates in watered out intervals using the temperature of injected water as a thermal tracer.
The results demonstrate that pre-installed optical fibre is an effective real time method for monitoring wells and thus facilitates the optimisation of reservoir performance.
Horizontal Drill-in Fluid Reclamation for Re-use or Waste Minimization Field Trial
Authors: Bernardi Tony , Ives H. Russell , Lanier Gary , Cole Terry 
Published: December 2007

Abstract
Horizontal Drill-in Fluid Reclamation for Re-use or Waste Minimization Field Trial for Shell Auger Project
Due to the high cost and logistical concerns of drilling open holes in the geopressured arena, Shell began looking at ways facilitate this option. Most horizontal drill-in fluids, regardless of density, are discharged if they meet environmental regulations. In the geopressure fluid densities, these fluids have a lot of value residing in the base brine which can be comparable to, or even more valuable than the base for synthetic fluids. This practice is not only costly, but in the heavier fluids, they have environmental implications as well. Working closely with Reclamation Solutions and MI Drilling Fluids we came up with a process that would both reduce environmental impact give us back a fluid that could be reused. The new process has been developed that incorporates both conventional and new technologies to reclaim these types of fluids back to original specifications which have value to both Shell and MI. This process is known as CENTRIFLUX. Depending upon the solids content and/or characteristics of the waste fluid, a mechanical pretreatment phase involves both decanting and high speed disc centrifuges that jointly remove solids above 1-5 micron. The ultrafiltration phase removes the remaining suspended solids above 0.1 micron by circulating the fluid through a SCEPTER stainless steel membrane module. This ultrafiltration removes both polymer and starch residue which have been a problem in the past. The solids removed by the CENTRIFLUX process are transferred for disposal and the quality of the reclaimed base fluid meets or exceeds original specifications and can be used again.