bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Use of Risk Adjusted Values in Exploration Portfolio Management
Authors: Moore C. R. K. , Moyes C. P. , Patterson P. D. 
Published: December 2007

Abstract
Maximizing Expected Present Value predicts that firms will seek 100% working interest in attractive ventures. However, firms frequently desire less than the entire working interest, and clearly pay much less than EPV to participate, management behavior often explained as a result of firms’ risk aversion.
Although there is little published evidence that firms routinely calculate Risk Adjusted Values (RAV), they provide a useful way to quantify risk aversion. This is not a new tool, as methods of deriving RAV and an Optimum Working Interest have been available in the literature for some time. Previous studies, which we review, have concentrated on defining a firm's Risk Tolerance, a necessary input in determining RAV.
We have expanded the use of RAV in a number of ways. Firstly, we believe that a firm's RT is not constant, but varies by business unit to match the strategic direction of the firm. Secondly, we use actual and hypothetical examples to illustrate the use of RAV in (a) rationalizing the Fair Market Value of exploration portfolios, (b) defining the relative contributions of firms’ exploration assets in mergers and acquisitions, (c) assessing farm-out values and targeting potential farminees, (d) selecting aligned partners for bidding groups and (e) government use for designing license rounds.
Existing applications of RAV have usually been restricted to a simple lottery in which a single success leg is represented by mean success. This ignores the uncertainty in the success leg, with RAV being independent of the variance of the underlying reserves distribution. Through analysis and simulation, we review the sensitivity of RAV to reserves and value uncertainty.
Assessment of Rock Mechanics Properties Starting From Geophysics Logs With the Garcia-Garcia: A General Model for Calculating Total Compressibility and Formation
Authors: García-Muñoz N. A. , García D. , Ortega-Serrano R. 
Published: December 2007

Abstract
This paper uses the effective media theory to estimate the heterogeneous distribution, the bulk and formation compressibility in the reservoir, in function of rock elastic properties, such as, the volumetric moduli (K) and shear (μ) vs. depth, by means of field available data, such as geophysical logs (density and sonic).
Results from four (4) naturally fractured carbonated reservoir are shown and from one sand reservoir counting on log information for validation.
Potential of Different Polyamino Carboxylic Acids as Barium and Strontium Sulfate Dissolvers
Authors: Lakatos I. , Lakatos-Szabó J. 
Published: December 2007

Abstract
The studies were focused on evaluation of different scale dissolvers for barite sag or barium sulfate scales, while the chemically similar compound, the strontium sulfate obtained much less attention. Therefore, an extensive research programme was launched with the aim at evaluating the potential of seven different polyamino carboxylic acids (NTA, EDTA, DCTA, DTPA, EGETA, HEDTA and TTHA) using both technical and economic aspects to compare the behavior of these two compounds.
Dissolving capacity of each compounds was determined under equilibrium conditions as a function of BaSO4 and SrSO4 concentration in both the presence and absence of reservoir rock. The absolute and relative selectivity of dissolution were precisely analyzed. Dissolution of all components was followed in time and kinetic calculations were made. Results of the measurements provided reliable data for comparison of dissolution capacities under identical chemical conditions.
On the basis of the experimental findings it was concluded that the sequence of dissolution capacity is different if the results were evaluated in technical or economic sense. It was also shown that the preferentially used compounds (e.g. DTPA, and particularly EDTA) are not the best choices when technical considerations are only enforced. Namely, the practice justifies their application at the expense of poor efficiency. Results of that systematic analysis may open new vistas in mitigation of formation damage caused by BaSO4 or SrSO4 and accelerate the search for more effective mixtures of complex-forming dissolvers.
Corrosion Control during Acid Fracturing of Deep Gas Wells: Lab Studies and Field Cases
Authors: Al-Mutairi S. H. , Nasr-El-Din H. A. , Al-Muntasheri G. A. , Al-Driweesh S. M. 
Published: December 2007

Abstract
Acid fracturing treatments are used to enhance gas production from tight, deep carbonate reservoirs in Saudi Arabia. The produced gas has a regional variation between 0 and 10 mol% H2S. This variation in H2S content has impacted the metallurgy of well tubulars used in these areas. Gas wells in the high H2S area are completed with low-carbon steel (L-80 and C-95); those in the low H2S area are completed with super Cr-13 tubulars.
Acid systems used to fracture these wells included: regular, emulsified, and in-situ gelled acids, all based on 28 wt% HCl. However, 15 wt% HCl – 9 wt% formic acid was used to stimulate wells completed with super Cr-13 tubing. High temperatures (275°F) encountered in deep wells, the presence of high H2S content and the use of large volumes of concentrated acids render corrosion control of tubulars a very difficult task.
Experiments were performed to develop a cost-effective acid system to enhance the productivity of deep gas wells, while maintaining the integrity of well tubulars. Acid fracturing treatments were monitored in the field and well flow back samples were collected following these treatments. The concentrations of key ions were measured in these samples including iron and manganese for completions with low-carbon steel tubulars and chrome, molybdenum, and nickel for completions with super Cr-13.
Analysis of flow back samples following the initial acid fracturing treatments showed that the return samples contained high concentrations of acid (up to 16 wt% HCl) and total iron (up to 20,000 mg/l). The presence of iron was a major concern during acid fracturing treatments. Modifications of the corrosion inhibitors package, increasing soaking time and over flush volume resulted in better results. Most importantly, the integrity of well tubulars was maintained. This paper discusses lab studies and application of these modifications in the field.
A General Approach to Well Evaluation
Authors: Diyashev I. R. , Economides M. J. 
Published: December 2007

Abstract
Petroleum well performance and its evaluation are clearly some of the most important functions of modern production engineering. We present a general approach to the issue by employing the field-derived, dimensionless productivity index (JD) which we calculate from measured information including the production rate, reservoir and flowing pressures and well and reservoir data.
The dimensionless JD is independent of well completion, i.e., it transcends the geometry, whether the well is under radial flow, hydraulically fractured or whether it is vertical or horizontal. The determined JD's are then compared against benchmarks we have developed for optimized production such as the concept of Unified Fracture Design (UFD) or maximized horizontal well performance. We have developed deterministic methods for this analysis and new means to graphically depict the results.
Such evaluations are important in concluding whether the well is underperforming or whether the past engineering could have been improved and by how much. Decisions such as refracturing, the redesign and improvement of future treatments and whether to fracture vertical or drill horizontal wells can be readily made.
Introduction of a Dual-Cell Depurator for FPSO Application-Theory to Practice
Authors: Rivet C. , Movafaghian S. , Chen J. 
Published: December 2007

Abstract
This paper is intended as part of the continuous development of Wemco® Dual-Cell Cylindrical Depurator® and adaptation of Induced Gas Floatation technology to meet the demands of today's offshore production practices as the best-available-technology (BAT). The focus of this paper is relating theory to practice for this new and proven technology and the real life example of one of its applications. This paper is presenting the problem solving and selection process adopted by ChevronTexaco North America's Operations Team at Typhoon Production Facility, located in deep water Gulf of Mexico. The paper compares alternative solutions and economical advantages and disadvantages of each alternative. It also provides an in-depth analysis of the performance achieved after installation of the Dual-Cell, based on the theoretical model developed for this equipment.
Sustaining Fracture Conductivity
Authors: Weaver J. D. , Nguyen P. D. , Parker M. A. , van Batenburg D. 
Published: December 2007

Abstract
The industry has developed standard methods to effectively evaluate the propping agents used in hydraulic fracturing operations. The understanding gained from the consistant application of the methods has greatly helped to optimize productivity.of hydraulicly fractured wells.
This paper presents two mechanisms that may significantly increase the understanding of how to optimize fracture conductivity to sustain productivity. The standard methods use well "aged" (passive) proppant and simulated formation materials; whereas, in practice, formation faces are highly activated as an immediate result of mechanical fracturing, as is a significant portion of the pumped proppant.
The chemistry that occurs at freshly exposed mineral surfaces is different than that of the aged surfaces used in the laboratory. For example, condensation of polymers on freshly generated surfaces may result in polymer chains becoming anchored to the surface. This anchoring prevents some polymer from being removed by normal gel-breaking mechanisms and forms points of attraction for the collection of broken polymer and fines debris, leading to significant permeability damage and reduced fluid recovery.
After a treatment when pressure is relieved and well clean-up begins, temperature and stress gradients are high; significant crushing of proppant and formation material may occur as a packed fracture moves toward an equilibrium condition. The presence of hHigh-ionic-strength fracturing fluids, particularly at high pH, may promote a rapid mineral diagenesis-type reaction that leads to proppant compaction, embedment, and crystalline overgrowth permeability damage.
This paper provides laboratory and field data supporting the conclusion that the application of a thin, highly dielectric, polymer film to coat proppant can result in a long-term reduction in mineral dissolution rate, compaction, embedment, and polymer anchoring sites. Field data shows this effect has a dramatic improvement in fracturing fluid recovery and well productivity.
Experimental Analysis of Swirl Tubes as Downhole Desander Device
Authors: Martins J. A. , Rosa E. S. , de Oliveira Souza R. 
Published: December 2007

Abstract
This work analyses the impact of the viscosity increase on the separation efficiency of swirl tubes based on experimental data. The data is reduced using dimensionless analysis. A functional relationship between the separation efficiency and the dimensionless groups is obtained. It discloses how the separation efficiency depends on the liquid viscosity, flow rate, solid size, and other geometrical parameters of the separator.It helps to push the design of these desander devices to new scenarios with heavy crudes or to oil-water mixtures with low water cuts prone to evolve to oil-water emulsions.
Reliability and Uncertainty in Reserves: How the Industry Fails, and a Vision for Improvement
Authors: Demirmen Ferruh 
Published: December 2007

Abstract
Review of field reserves from different parts of the world reveals that reliability of reserves estimates is rather poor. Many fields show wide fluctuations in reserves estimates through time, both at pre- and post-production stage, with a tendency toward underestimation. Accompanying this trend, uncertainty attached to the "best" reserve estimate does not shrink with additional data, defying intuition. Reasons for such phenomena are varied, but one fundamental reason is the approach the industry generally takes toward reserves estimation. Reserves variations, whether in upward or downward direction, adversely affect project economics.
Factors that affect reserves evaluation include reservoir aspects, development scheme, operations and technology, economic and regulatory aspects, and "intangibles" that relate directly to human input and conduct. In the last-named category, proclivity to ignore statistical rules leads to distortion in reserves and associated uncertainty estimates.
The vision toward improving reserves reliability involves a multi-prong approach that tackles all these root causes. An optimal appraisal strategy that addresses the key subsurface uncertainty, due regard to statistical rules, and use of volumetric methods that consider different scenarios and put the evaluator in contact with "real" data, are viewed, among others, as providing tangible improvements.
TNK-BP Wellwork Performance Management
Authors: Postnikov M. 
Published: December 2007

Abstract
TNK-BP operates 250 fields (the majority of those are mature water-flooded) with 2003 annualized average liquids production of 1.28 mln BPD and August 2004 record liquid hydrocarbons of 1.5 mln BPD. The Company's investment portfolio is dominated by wellwork program which compensates production decline and serves the purpose of maximising production and allows reaching planed growth targets. The wellwork program in 2003 included more than 4300 jobs and more than 5000 in 2004 on 15000 active producers with annualized average incremental oil rate of 189,000 BPD in 2003 and 224,000 BPD in 2004. This year program is of the same and even greater scale. All of the Company's wellwork activity is tracked in the WETS™ wellwork evaluation tracking process, a BP heritage tool. This process was implemented in Sidanco assets in December 2002 – February 2003 and in TNK assets in November 2003 – April 2004. The WETS™ wellwork evaluation database includes results of the following TNK-BP activity - drilling operations, rate addition wellwork on producers, and injector wellwork. This database has more than 9900 jobs as of January 2005. The results of less than a year of full implementation of the tool in TNK-BP are shown in this paper. This paper will illustrate how TNK-BP manages large scale upstream investment activities using the WETS™ wellwork evaluation tracking process. Examples of intra-company benchmarking will be explored to illustrate how major projects in the company are assessed and compared. This paper will also illustrate how historical performance is analyzed to underpin confidence in forward planning and ranking of projects.
The Impact of Injection with Fracture Propagation During Waterflooding Process
Authors: Souza A. L. S. , Fernandes P. D. , Mendes R. A. , Rosa A. J. , Furtado C. J. A. 
Published: December 2007

Abstract
Waterflooding is still the most common method used worldwide for improving oil recovery, either after production by primary mechanisms or at early stages of the field lifetime.
During the waterflooding process, injectivity decline can occur due to rock and fluids characteristics, well geometry, and formation damage caused by fines migration, salt precipitation and by solids and oil particles present in water entrainment. One of the best ways to avoid injectivity decline is the Injection with Fracture Propagation Pressure (IFPP).
In this work a methodology for modeling fracture propagation is presented, as well as the sweep efficiency effects due to IFPP, using an in-house geo-mechanical simulator combined with a commercial reservoir simulator.
The simulations show that the impact on oil recovery due to IFPP can be high, depending on injection pressure, fracture propagation velocity and direction, type of well (vertical or horizontal), well pattern, distance injector-producer and starting time of IFPP. By the other hand, the impact of injectivity loss on the Net Present Value may be high, so that the benefits of injection rate maintenance with IFPP can overcome a possible negative impact on sweep efficiency.
The conclusions point out to the importance of knowing the geo-mechanic reservoir characteristics in order to choose well type, injection pattern and well spacing, so that the benefits of IFPP can be completely achieved.
Produced Water Reinjection in Petrobras Fields: Challenges and Perspectives
Authors: Furtado C. J. A. , Siqueira A. G. , de Souza A. L. S. , Correa A. C. F. , Mendes R. A. 
Published: December 2007

AbstractPetroleum industry has been more and more concerned about the effects of produced water disposal in the environment, particularly in offshore fields. Increasing amounts of produced water have being processed by companies and the search to alternatives for the produced water destination has become a priority for the major operators.As oilfields reach their maturity, the water cut increases, and Produced Water Re-Injection (PWRI) in the producing formation seems to be a convenient way for its destination. Disposal in adjacent, non-oil bearing formations is also an attractive option to be considered.This paper presents an overview of the main PWRI projects in Petrobras. Petrobras has been re-injecting water in their mature onshore fields for many years, and it is starting re-injection projects in offshore Campos Basin.Technical, economical and environmental aspects of PWRI are presented. Related topics, like injectivity loss due to PWRI, injection above the fracture propagation pressure, PWRI effects on oil recovery and reservoir souring potential are discussed.
Making Sense of Return Permeability Data Measured in the Laboratory
Authors: Han L. , Lohne A. , Stevenson B. , Stavland A. 
Published: December 2007

Abstract
Proper selection of reservoir drilling fluids (RDF) or drill-in fluids can minimize formation damage and maximise well productivity or injectivity. Typically, fluid selection involves pre-screening of fluid candidates followed by laboratory return permeability testing of a selected few. However, as the fluids often have different fluid loss and return permeability properties, the final decision as to which fluid to use is often arbitrary. These difficulties stem from the fact that there is no recognised method for comparing formation damage potential of fluids with different fluid loss and return permeability profiles and the lack of valid models for upscaling laboratory data to field skin factors.
In a recently finished EU project, a methodology was developed to bridge the gap between the laboratory measured data and field skin factors, so laboratory fluid loss and return permeability data can be interpreted in field skin terms. This will help the fluid engineers to select the least damaging fluid for their application. The methodology makes it possible to compare laboratory results obtained under different test conditions, and to estimate skin factors for different reservoir sections from a single return permeability test. This functionality is very useful for calculating the productivity of complex reservoirs with anisotropy and heterogeneity.
For correct upscaling of return permeability to field skin, both the fluid loss and return permeability profiles are required. This paper recommends dynamic fluid loss for return permeability testing. This paper also recommends a slight change to routine formation damage test procedures to obtain the return permeability profile necessary for upscaling. Detailed laboratory data analysis techniques to generate input parameters for the developed models are also reported.
The above mentioned methodology has been built into a simulator in Microsoft Excel with a user friendly interface.
Alternative Material-Balance and 1D- Flux Simulation Applied To Expedite Analysis of Mature Fields
Authors: da Costa Peron J. R. 
Published: December 2007

Abstract
Estimate the remaining potential of mature fields with multiples reservoirs can sometimes be an uncertain time consuming task. As a help in such cases, this paper deals with the concepts of a "modified" one-dimensional flux simulator, able to handle gravitational segregation, phase dispersion, conning, fingering, etc.
Reservoir Representation for Flow Simulation
Authors: Romeu R. K. , Paraizo P. L. B. , Moraes M. A. S. , Lima C. C. , Lopes M. R. F. , Silva A. T. , Rodrigues J. R. P. , Pacheco F. P. T. , Cardoso M. A. , Damiani M. C. 
Published: December 2007

Abstract
Reservoir flow modeling involves two aspects: a functional model (flow equations and numerical methods) and a representation model (related to the reservoir description) - and this last aspect is usually the critical one. Reservoir representation is different from reservoir characterization. It is not a question of describing the reservoir in a more or less exhaustive or realistic way, but a question of incorporating relevant information into the flow simulation model, considering the syntax of the flow simulators and the relative impact of information on the simulation results. Reservoir representation makes the bridge between reservoir characterization and flow simulation.
This paper presents selected results from a cluster of applied research projects in reservoir representation for flow simulation. It includes: (1) gridding issues in the context of integrated reservoir studies (discussion of terminology, grid specification, generic format reading, etc.);(2) identification and representation of critical heterogeneities of turbidite reservoirs; (3) assigning transmissibility multipliers across partially sealing faults in a field case; (4) incorporation of production data in reservoir flow models with an example of application; (5) hyperdocumention for reservoir simulation files (making use of HTML tags to get a much richer documentation of the flow simulation model).
Successful Application of a Unique and Low Friction Frac-Pack Fluid in Gulf of Mexico Deep Wells
Authors: Gadiyar B. R. , Morales R. H. , Nelson E. , Barton K. , Fischer D. , Sorrells D. 
Published: December 2007

Abstract
In recent years, there has been an increase in exploration and drilling activity in deepwater and deep-shelf gas and oil fields in the Gulf of Mexico. The economic feasibility is dependent on completion efficiency, with the goal to optimize the production rate. In addition, most of these formations require sand control to prevent completion failure. To achieve optimum hydrocarbon production and prevent sand failure, frac-pack is considered the best completion option. However, performing frac-packs in deep reservoirs (&gt;15,000 ft) with high reservoir pressures (&gt;10,000 psi), and temperature variations pose many challenges such as pump rate limitations due to high friction pressure and fluid-stability problems due to temperature changes.
To address these challenges and overcome the limitations of conventional fluids, a unique borate crosslinked that employs an encapsulated borate crosslinker with various base-fluid compositions was developed. The fluid has a broad temperature stability range: 40°– 350°F.The crosslink-delay can be varied between 1-20 minutes without affecting fluid stability.The proppant-transport ability is excellent.
These attributes allow fluid injection at optimum rates with minimum friction pressure. This paper presents Gulf of Mexico, deepwater case histories that demonstrate the successful application of this fluid. The fluid design, fluid properties, and job execution, are discussed in the paper context.