bluuebunny/crossref_metadata_2025_split huggingface dataset:
Guando Field: Underpressured-Field Development
Authors: Amaris O. H. V. , de Freitas L. C. S. , Gomes H. P. , Pereira J. R. B. 
Published: December 2007

Abstract
The purpose of this paper is to present the main challenges involved in the Guando field development project, how they were addressed, the lessons learned, and in a more general sense, describe how a severely underpressured, partially naturally fractured reservoir was successfully developed using a phased approach to water injection implementation.
The field appraisal and phased development approach utilized resulted in a technically and commercially successful project, despite the high degree of uncertainty that initially existed.
Application of a Fully Viscosified Scale Squeeze for Improved Placement in Horizontal Wells
Authors: James J. S. , Frigo D. M. , Townsend M. M. , Graham G. M. , Wahid F. , Heath S. M. 
Published: December 2007

Abstract
Nelson is a platform development in the Central North Sea approximately 180km east of Aberdeen, producing 38° API oil from a Forties type reservoir with seawater injection pressure support. The high-salinity formation water contains up to 370 mgl-1 of barium, creating a significant scaling risk to the wells upon sea-water breakthrough. The majority of current wells are highly deviated but several horizontal wells with variable permeability exist, which pose a considerable challenge in terms of scale-squeeze placement. N19z is a horizontal well in the North Central region of the reservoir with a 500m cased/perforated producing interval in which breakthrough of sea-water has been confirmed. The well has previously been squeezed, both non-diverted and diverted with wax beads, each with varying success. Earlier reports have examined the effect of applying lightly viscosified fluids on placement of treatment fluids across long intervals to overcome friction and crossflow effects with the potential to assist in treating zones with permeability contrasts1. This approach was pursued to improve the effectiveness of squeeze treatments in long-reach horizontal wells in Nelson, culminating in the successful squeeze of well N19z with a precipitating inhibitor in which all squeeze stages were viscosified. The paper reviews the advantages of the viscosified approach, reports laboratory testing, compares the performance of the squeeze relative with non-diverted and wax-bead-diverted treatments, and highlights some of the pitfalls in applying fully viscosified treatments in both Nelson and other field horizontal or high permeability contrast wells.
Suggested Modifications to the Reporting Requirements for a Company's Oil and Gas Reserves
Authors: Verbeek G. E. H. 
Published: December 2007

Abstract
The recent restatements by several Oil and Gas companies of their petroleum reserves has created a lot of short-term publicity, but not a fundamental and widespread discussion regarding the process that is followed to determine a company's reserves.
To minimize the chance of reserves misstatements in the future, some have called for the certification of the individuals preparing a company's petroleum reserves or even the use of outside auditors to certify the reserves claimed, much like the certification of the financial reports by an independent auditor.
This paper will review both sides of such an approach, but conclude that a solution in line with the thinking behind the Sarbanes-Oxley regulations governing a company's financial reporting is more appropriate.
However, while this approach clearly defines the responsibility for the reserves estimate, the reporting of this estimate has to be expanded to ensure more transparency. This paper will recommend that the reserves statement uses a set of probabilistic numbers rather than a single deterministic number.
Finally, the objective of this paper is not necessarily to answer all questions surrounding the process to be followed by a company for stating its reserves, but rather to ensure that there is a fundamental discussion regarding that process, and that in the end the methodology is improved in a practical manner that provides added transparency and accountability.
Novel CO2-Emulsified Viscoelastic Surfactant Fracturing Fluid System
Authors: Chen Y. , Pope T. L. , Lee J. C. 
Published: December 2007

Abstract
The solid-free viscoelastic surfactant (VES) fluid has good proppant transport and excellent cleanup capabilities. Coupling the benefits of a VES fluid with a carbon dioxide (CO2)-emulsified system will further enhance cleanup in a depleted reservoir, extend the application to water-sensitive formations, and maintain reservoir gas saturation to prevent any potential water blocks. This paper reports on a new multisurfactant VES fluid system developed specifically to provide a robust surfactant-base fracturing fluid with supercritical CO2. The field test results indicate the new system is CO2 compatible and still possesses all the attributes normally associated with VES systems.
A Mechanistic Model for Formation Damage and Fracture Propagation During Water Injection
Authors: Abou-Sayed A. S. , Zaki K. S. , Wang G. G. , Sarfare M. D. 
Published: December 2007

Abstract
The majority of injectors are likely to be fractured (intentionally or unintentionally) during their life cycles. Assessment of facture conductivity damage and associated surrounding formation damage is an essential step for maximizing and maintaining injector performance during produced water injection for water flooding. Fractured injectors experience less injectivity decline over time in comparison to matrix injectors.
The current paper will present a mechanistic model for the plugged fracture behavior and discuss its applications to field cases. In addition, implications, recommendations and best practices for optimized produced water injection will be addressed within this context.
The well undergoes two distinct processes that alternate over its life to create the sustained injectivity behavior associated with this scheme. Injectivity damage can occur particularly in pseudo-matrix conditions, where a stationary fracture progressively plugs (in addition to permeability impairment of the surrounding reservoir rock), resulting in pressure buildup and injectivity decline. As solids are deposited in the fracture, the "effective" exposed surface area is gradually reduced, at least partially, as a function of the injected amount of solids. Furthermore, fracture face damage (external filter cake build-up) and accumulated surrounding formation damage (internal filter cake build-up) progress as the volume of injected water increases. This plugging process continues until the injection pressure required for the designated injection rate reaches a critical value, which is greater than the pressure required to re-fracture the formation and/or to extend or propagate the plugged fracture. At such pressure a sudden fracture propagation or further breakdown of the formation is evidenced by a sudden increase in the Injectivity Index or similarly, a sudden drop in the Reciprocal Injectivity Index – RII - (unit injection pressure per unit constant injection rate). Thereafter, the required pumping pressure drops and/or the injection rate increases with the newly created surface area that has been caused by fracture propagation or initiation. The process then repeats itself. As the pressure rises it approaches and finally exceeds the fracture pressure required for further propagation, resulting in a saw-toothed shape pressure-time (or rate-time) behavior. The slopes of the bounding lines are controlled by the damaged formation and fracture characteristics, as well as the injected water quality. The slopes can be made to diverge, converge or remain almost parallel. The third option indicates a well optimized injection scheme.
The final section of this paper will imply lessons learned, mitigation strategies, conclusions and recommendations based on analyses of field data from a number of produced water injectors. Pressure transient analysis and results from pressure fall-off test will be presented to verify the study results.
Maximizing Inflow Performance in Soft Sand Completions Using New One-Trip Sand Control Liner Completion Technology
Authors: McElfresh P. , Williams C. , Garfield G. 
Published: December 2007

Abstract
Maximizing inflow performance for any completion involves balancing the natural forces of the reservoir with the operational limitations of the well or field. In the case of soft or unconsolidated sand, completion procedures often dictate equipment or procedures that can potentially limit the inflow area by way of various forms of formation damage. There are three major types of formation damage: the filter cake and fluid loss damage associated with drilling; the skin increase due to compaction and debris associated with perforating; and, the skin added to the completion by the gravel or frac pack. While there are treatments that can remove or reduce the effects of damage, all of them involve subsequent intervention into the well, which elevates risk and as increases rig time. This paper discusses a recently developed one-trip completion system that has been successfully used to eliminate or reduce these causes of formation damage and improve inflow area and performance.
This new system provides a means of deploying a production liner, perforating, primary cementing, removing filter cake, and controlling sand production in a single trip. The one trip system is especially beneficial in wells needing sand control. The procedure utilizes a telescoping conduit that can be expanded hydraulically, mechanically, or both, to seal onto the formation face. The conduit is then cemented into place. The sand control media is inside the telescoping conduit in the form of appropriately sized stainless steel beads. The damage typically associated with the perforating phase is eliminated because there is no explosive discharge during the deployment of the system, and the well is brought on production normally. Studies have shown that decreasing initial perforation damage results in a more productive well over its lifetime. This new completion method also eliminates gravel packing, minimizes the amount of intervention into the well completion, and saves substantial rig time due to its one trip operation. Additionally, the authors will illustrate how the new completion simplifies operational logistics, especially in remote or offshore environments, because it is not dependent on large fluid pumping treatments nor does it require excessive pumping horsepower.
Simple Thermal Efficiency Parameter as an Economic Indicator for SAGD Performance
Authors: Shin H. , Polikar M. 
Published: December 2007

Abstract
A new economic indicator, called simple thermal efficiency parameter (STEP), was developed to evaluate the performance of a SAGD project. STEP is based on CSOR, CDOR and RF for the time corresponding to SOR = 4. STEP was found to be a useful quantitative economic criterion, with a value of 1 for an economic case (CSOR of 3, CDOR of 0.111 m3/d/m of horizontal well length and RF of 0.5).
To validate this new economic indicator, STEP was calculated based on data from two published studies in which SAGD related simulations were performed. The first study, which provides no economic parameters, shows that most of the optimal cases always have the highest STEP values. The second study, which provides economic parameters (ROR and NPV), shows a good linear relationship between ROR and STEP. STEP is greater than 2 in the case of the economic SAGD scenarios.
This study has validated the usefulness of STEP as an economic indicator. STEP can be used as a financial metric quantitatively as well as qualitatively for this type of thermal project.
External Filter Cake Erosion: Mathematical Model and Experimental Study
Authors: Al-Abduwani F. A. H. , Bedrikovetsky P. , Farajzadeh R. , van den Broek W. M. G. T. , Currie P. K. 
Published: December 2007

Abstract
In this article a system of equation to describe the steady state external filter cake thickness profile along the cuboid crossflow filtration setup geometry as well as the well bore geometry are introduced. The first equation is obtained from the analysis of forces acting on a deposited particle at the outermost limit of the external cake. The second equation is obtained from the volume conversation of the transporting fluid in the given geometry. Coupling the two equations yields an implicit solution of the cake profile. Boundary conditions are required as well as the quantification of an empirical factor that can be quantified experimentally.
Experiments conducted were analysed and the empirical friction coefficient was quantified and presented. Simulations based on the developed solution are also presented.
Analysis of the Performance of Hydraulic Fracturing Treatments and Quantum Design Improvements
Authors: Demarchos A. S. , Economides M. J. , Diyashev I. , Svaykin V. A. 
Published: December 2007

Abstract
Hydraulic fracturing has emerged as the compelling completion and stimulation procedure in Russian petroleum production credited to a large extent for the impressive production enhancement experienced in the last several years. We present in this paper approximately one thousand hydraulic fracturing jobs from Western Siberia and their performance is analyzed and compared with design and execution variables.
The well performance is measured through, among other things, the actual, field-derived, dimensionless productivity index (JD) and is compared against our concept of Unified Fracture Design (UFD) which has been used to physically optimize and maximize the productivity index from a hydraulic fracture treatment. We have demonstrated in the past that for a given mass of proppant there is a specific dimensionless fracture conductivity, which we called the optimum, at which the JD becomes maximum. The Proppant Number is a seminal quantity unifying the propped fracture and the drainage volumes and the two permeabilities, those of the proppant pack and the reservoir.
One of the important observations of our analysis is that the distributions of the achieved JD follow the theoretical curves, however there is a gap between the theoretically achievable and actually achieved JD. We evaluated the gap and identified measures to improve our fracture designs.
Conventional fracture designs can be extended considerably by injecting large proppant masses with far better proppant-pack permeabilities within reasonable field and logistical constraints. It is against these two concepts, the desired optimum fracture conductivity for the injected fracture size, and the would-be "pushing the limits," design that we compare the already executed treatments. We provide critique and offer suggestions for design improvements.
Investigation of a Novel Chemical for Bullhead Water Shutoff Treatments
Authors: Elewaut K. , Stavland A. , Zaitoun A. , Krilov Z. , Zitha P. L. J. 
Published: December 2007

Abstract
Traditionally bullhead water control consists of the placement of water-soluble chemicals without mechanically isolating oil layers. In order to be successful, bullhead treatments should block water-bearing layers without affecting the permeability of the oil-bearing layers too much. This paper reports an experimental investigation of an innovative water shutoff chemical deemed suitable to accomplish this task. The chemical is soluble in oil without any reaction, and is transferred into and reacts with water to form a stable gel. Core flow experiments consisting mostly of the injection of either oil or water in cores containing the chemical dissolved in oil were performed to investigate the ability of the gel to reduce water permeability while maintaining oil permeability. To ensure that the results are relevant for designing field applications, the experiments were performed under conditions encountered in various sandstone reservoirs in the North Sea, Croatia and other regions. Permeabilities and temperature ranging from 100 to 300 mD and 70-900C were therefore considered in this study. The influence of the other physical parameters, such as viscosity, concentration of active chemical in oil chemical, injection rate, etc., was also investigated.
Impact of Intelligent Well Systems on Total Economics of Field Development
Authors: Sakowski S. A. , Anderson A. , Furui K. 
Published: December 2007

Abstract
Intelligent well technology, referring to the implementation of fundamental process control downhole, has advanced rapidly over the last decade in the upstream oil and gas industry. Application of this technology has continued to expand since recent installation results have demonstrated the value of these completions with a high success rate that operators find attractive.
In this paper, we present an economic evaluation procedure to quantify the benefit of Intelligent Well Systems based on net present value (NPV) calculations. Reducing well count and eliminating or reducing interventions by using Intelligent Well Systems has the potential to add many millions of dollars to well NPV, since drilling rig and workover costs may be very expensive, especially in offshore deepwater environments. Delayed revenue associated with production shut-in also must be considered and reduced by discount rate at the same time that intervention and well operating costs increase by inflation rate.
The use of Intelligent Well Systems not only reduces or eliminates some capital and operating costs, but also allows operators to accelerate oil production, increase the ultimate recovery and reduce water handling cost, which result in significant benefits in NPV of a project. Thus, Intelligent Well Systems are becoming economically attractive for modest-cost onshore operations as well as for the high-cost offshore environments for which they were initially deemed applicable.
Visualization and Interactive Filtering of Strategy Driven Portfolios as an Alternative to LP Optimization
Authors: Rasey S. M. 
Published: December 2007

Abstract
Linear Programming approaches to Portfolio Optimization require much effort to "teach the computer" the Petroleum Business. We must described to the optimization program the costs, potential rewards, and uncertainties of every investment opportunity. For an optimizer to generate realistic, executable, investment programs, we must also encode constraints that define the strategic and geologic dependencies between investments, the timing flexibility that exists within and between each opportunity, the working interests that exist or can be negotiated, and their competition for scarce resources such as rigs, people, and partners’ approvals. Strategy gets encoded as portfolio goals to be met.
Perhaps we can employ this effort more effectively. We ought not search for one magical optimum portfolio dependent upon one strategy masquerading as thousands of LP constraints.
This paper describes a portfolio analysis process that quickly creates near optimum executable portfolios on each of thousands of strategies and portfolio value criteria. Each portfolio and its measures, including confidence curves, accumulate in a database. We use laptop-capable visualization software to display and compare the portfolios on dozens of performance measures. Using interactive filtering we can apply portfolio goals and resource constraints to the cloud of portfolios quickly narrowing down to a few portfolios that meet all our criteria. Finally, from these best portfolios we learn which opportunities are funded in all, most, some, or none of the final portfolios. In the end, this is the information we seek: what are the smart investment decisions to make, not which one portfolio we should execute.
Businesses who adopt this process benefit several ways: 1. Using interactive filtering to apply constraints means you can change resource levels very late in the process. 2. You can better set goals and negotiate resources after seeing beneficial potential trade-offs between portfolio measures. 3. You define your constraints using the measures of total portfolio performance you save to the database, including nonlinear measures from uncertainty distributions. This way is easy to apply constraints such as "P90 of NPV &gt;= 500" or "Number of Funded Projects &lt;= 30"; constraints which are impossible with linear programming.
A New Process for Securing Partners for International Farm-outs
Authors: Bagge M. , Finalle L. 
Published: December 2007

Abstract
Companies have difficulty securing partners to farm in to international exploration and development projects. The objective of this paper is to describe a better process to accomplish international farm-outs. Companies of all sizes now pursue business internationally, including many emerging international companies based outside the United States. The time for farm-outs is traditionally short. This factor and the need for global participation amplify the difficulty of finding the right companies for an opportunity and supplying them with the right information to do the requisite analyses and get approvals in time.
The solution developed includes three fundamental elements: 1) an ability to quickly connect with the right people at the right companies, based on relatively real-time intelligence, 2) generation of an improved technical or commercial story, including use of an appropriate economic model for the fiscal regime, and 3) capability to provide the relevant information, including workstation projects whenever pertinent or possible, in a timely, convenient manner. A detailed description of the process will explain the key elements, why they are necessary, and what advantages result.
A new process is required to improve farm-out success, which will lead to the pursuit of more exploration and development projects worldwide. Traditional relationships remain a key component but must be combined with ever-evolving intelligence on companies’ organizations and their preferences. Better technical and commercial analyses to describe opportunities are imperative. Key information must be identified and distributed for maximum effect. Finally, the use of technology can make access to and use of all the key information easy and convenient. Online data rooms (ODRs) can provide quick, convenient access to the right information, including information memorandums (IMs), supporting documents, workstation projects, and economic models.
The process or parts thereof can be employed for most companies seeking to farm-out some level of participation in international opportunities. The process is most important when opportunities have global appeal and yet are associated with a less-known geologic setting, particular engineering challenges, or an unfamiliar fiscal regime.
Accurate and Credible Reserves Requires more than Best Engineering Practices
Authors: Douglas J. , Nguyen T. 
Published: December 2007

Abstract

Proposal
For many years, reserve determination has focused on engineering best practices. As various regulatory agencies increase their scrutiny of how oil and gas companies are determining their reserves and assigning value to those reserves, relying only on engineering best practices is no longer adequate. Reserve determination and subsequent public disclosure of those reserves needs to have a collaborative effort with emphasis on:
Process Security, and Technology
This paper will look at each of these 3 areas, and explain the importance of each area as they pertain to reserve determination and disclosure. It is not enough to have each of these items individually addressed. A solution that addresses these areas must be tightly interwoven and utilized in a seemless architecture. This paper will propose such a solution.