bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evaluating Intelligent-Well System Requirement for an Offshore Field Development
Authors: Ajayi A. , Konopczynski M. 
Published: December 2007

Abstract
The paper describes the study conducted to evaluate the number of wells (producers and injectors) required to develop a small segment of an offshore field. The development plan consisted of both conventional and intelligent well completions. The main objective was to identify the best application of intelligent well technology in the field and quantify the gains from such applications. The technical performances of these cases are compared using the same base reservoir simulation model. Binary and multiple position downhole flow control valves are considered to determine the right level of "smartness" required for the field.
The study has shown that application of intelligent well completion (IWC) technology in selected wells will add value through control of produced water after breakthrough and manage subsurface uncertainty by mitigating unexpected well performance. We estimated incremental oil gain of 2.5% to 26% within the first two years after water breakthrough.
The results also demonstrated the capability of the IWC system to maximize asset productivity in cases where breakthrough occurred early and when it occurred somewhat later. In the former case, the non-offending intervals are able to easily complement the effect of choking back the offending zone resulting in significant gain.
Well Control Aspects Regarding Slender Well Drilling With Surface and Subsea BOP
Authors: Avelar C. S. , Santos O. L. A. , Ribeiro P. R. 
Published: December 2007

Abstract
The 2003 Brazilian deepwater drilling record (4th in the world) was achieved with a slender well in a 2887-meter water depth in Campos Basin (block BMC-10), Rio de Janeiro. Uncommon to the drilling practices throughout the world and, particularly, in the Brazilian coast, the well was safely drilled with a surface blowout preventer system (SBOP). Beyond the importance of a world record class, the result points out to an important paradigm shift in the current technical culture throughout the country, considering safety (human, environmental and material), economical and regulatory issues which surrounds such decision taking task. This work presents two discussions: the first one concerns the technical issues considering well control operations performed on the drilled well and on a hypothetical conventional well that could also be drilled under the same conditions. This discussion involves the calculation of pressures at the choke, at the casing and liner shoes, pit gain and produced gas rates at the surface using the driller's method. The results were obtained with an existing well control simulator for deep and ultradeep water drilling. The second discussion concerns important aspects of the surface BOP technology mainly related to well control. Thus, the main objective of the present work is to bring to light a broad discussion regarding the potential application of the SBOP concept to explore and develop deep and ultradeep-water reserves in Brazil, with emphasis on well control.
Integrated Downhole Fluid-Identification Applications for Complex Reservoir Development
Authors: Ferraris P. , Carnegie A. J. 
Published: December 2007

Abstract
A UAE offshore operator drilled a pilot well in a complex layered Middle Jurassic formation to confirm where to land a high inclination production drain.(fig. 1)
The reservoir underwent gas injection EOR. Reservoir simulation (fig. 2 & fig. 3) predicted possible gas fingering that required further confirmation before committing to drill the production drain. The objective was to positively identify all the intervals where liquid hydrocarbons could be produced avoiding the dry gas zones.
The petrophysical analysis was complicated by rock heterogeneities and fluid mixture including gas, heavy and light oils plus water.
A traditional approach based on standard logs was not conclusive.
The addition of NMR data versus depth allowed carbonate texture differentiation and a derivation of a simultaneous multi-fluid solution that highlighted the zones with possible oil production.
This initial information was used to select suitable intervals where to perform nuclear magnetic resonance stations with diffusion editing sequences designed for maximum sensitivity in the gas to light-hydrocarbon region.
Several stations were acquired with success and processed in pseudo real time making use of a VSAT link to share data with wellsite and predict the most likely downhole fluid composition.
With integrated depth and stationary information available, a few sets of sampling stations with real time downhole fluid identification were chosen to verify dynamically which formation fluid would finally flow.
Sampling was achieved using either a single probe or dual packer, depending on rock permeability. The fluid was analyzed in-situ using an innovative downhole fluid separation technique and some samples were taken to surface for a final PVT confirmation.
The combined information proved to be very consistent and provided a detailed reservoir description inclusive of fluid types.(fig. 31, fig. 32 & fig. 36)
The immediate impact was the change of the target drain location to a deeper zone in the reservoir structure. In fact, the zone a priori selected would have produced dry gas, due to the poor miscibility of injected gas and relatively viscous hydrocarbons in place.
The methodology used was well communicated to the various operator departments and had a broad acceptance, opening the way for a systematic similar approach in the future.
Reservoir Study Considering a TLP and Dry-Completion Development for a Deep Offshore Heavy Oil Field
Authors: Branco C. M. , Santos R. L. A. , Peres A. M. M. , Prais F. , Pinto L. A. 
Published: December 2007

Abstract
The continuous search for new oil resources is driving the major companies to start considering the development of offshore heavy oils (OHO) fields. Although not as heavy as inland heavy oil fields, where thermal methods are usually employed, development of these fields imposes extra technical difficulties as waterflooding might be the only feasible economical alternative for increasing recoveries. The process is used in association with long horizontal production and injection wells carefully placed in order to take advantage of the geological setting. OHO projects may face several production related problems during their lifetime, such as early water breakthrough and increasingly fast water rates. Other problems may also arise: strong water-oil emulsions, flow assurance problems related to hydrates, poor gas lift efficiency opposed to a less reliable satellite wells electrical submersible pumps (ESP) technology. Moreover, most offshore developments are based on FPSO production systems and satellite wells where one has limited (and highly expensive) well access.
The reservoir study described in this paper quantifies the worth of reservoir management actions that would be feasible in a TLP production system equipped with drilling and workover capabilities. This work focuses on the optimization of a development plan using different technologies such as side tracking existing wells, multilateral wells, ESPs, etc. A thorough discussion on the impact of operational efficiency factors (downtime factors) is also offered. The methodology described in this paper is applied to a full scale reservoir flow model that was continually history matched with oil/gas/water flow rates and measured downhole pressure data, gathered by a one well pilot production system for over a year period.
The results of the study are interpreted in terms of the scenarios more suitable for TLP developments. The benefits are directly related to the complexity of the reservoir geology which, in turn, governs the possibility of field development by phases. Other aspects such as the existence of pipeline infrastructure nearby the field and use of innovative artificial lift systems may either help or impair the use of dry completion wells concept. Although the present study reveals the FPSO option as the best economical alternative, for the particular field investigated, this work sets a standard for future OHO development studies.
Development and Application of Methodology for Assisted History Matching
Authors: Maschio C. , Schiozer D. J. 
Published: December 2007

Proposal
History matching is a difficult task due to a high level of complexity caused by factors such as nonlinearities and a large amount of variables present in the process. Besides the complexity intrinsic to the process, there are other difficulties in manual procedure, such as managing a large amount of data, many simulation runs, comparison between observed and simulation data, manual modifications in the data file, etc. Therefore, the manual process is more susceptible to errors and usually requires more human resources. Assisted history matching allows the automation of part of the process, keeping the main decisions to be taken by the professionals involved in the process.
In this paper, three main topics related to assisted history matching are developed and applied: (1) use of independent objective function, separating the problem in several sub-domains where a minimum value of the objective function is searched, through an optimization process for each of sub-domains, started and performed simultaneously and independently; (2) use of heuristics to start the search with a higher probability to find the better solution using less simulation; and (3) development of a new direct search method of the optimization algorithm.
In order to validate the methodology, a synthetic field is used. Afterwards, it is applied to a real field. Results showing the benefits, limitations and effort reduction are presented and discussed.
Evaluation of Polymer Injection Projects in Brazil
Authors: De Melo M. A. , de Holleben C. R. C. , da Silva I. P. G. , de Barros Correia A. , da Silva G. A. , Rosa A. J. , Lins A. G. , de Lima J. C. 
Published: December 2007

Abstract
Petrobras has implemented three polymer injection pilot projects during the last two decades, in the onshore fields of Canto do Amaro (Rio Grande do Norte state), Carmópolis (Sergipe state) and Buracica (Bahia state), all of them in Northeast of Brazil. The first one is in the middle of the operation and the last two are already finished.
Polymer flood in oil reservoirs has been performed for several decades around the world. The polymers act basically increasing the viscosity of the injected water and reducing the porous media permeability, allowing for an increase in the vertical and areal sweep efficiency of the water injection, and, consequently, increasing the oil recovery.
The main drive for the pilot projects in Petrobras was to gain practical knowledge of the process, for a possible future expansion for other reservoirs and even for offshore fields.
This paper describes the experience of Petrobras in implementing and managing those polymer flood pilot projects. The laboratory tests, the designing and programming of the field operation, as well as the analysis and interpretation of the results, were all carried out by Petrobras personnel and are covered in this paper. The tracer injection for reservoir characterization purposes, which preceded the polymer floods, is also described.
In this work we performed a technical evaluation of the whole polymer injection process, investigating the reservoir response in terms of oil recovery and time. The economical study will be made hereafter in another work.
Reduction of Water-Environment Hydrocarbon Pollutions with the Use Of Porous Glass
Authors: Macuda Pawel , Zawisza Ludwik , Macuda Jan , Rogowska-Kwas Renata 
Published: December 2007

Abstract
Owing to their properties, oil-products are environmentally noxious, especially for the ground-water environment. In the case of a break-down with an uncontrolled leakage to the environment, only part of hydrocarbons can be removed; a predominant amount of them infiltrate the soil, polluting ground- and surface waters. This results in organoleptic changes in water quality. Besides such leakages have a negative impact on flora and fauna. They accumulate in tissues of the living organisms and hardly undergo treatment.
The physicochemical properties of modified porous glasses Na2O-B2O3-SiO2 are presented in the paper along with the results of experiments on their application to removing hydrocarbons from the environment. It follows from the obtained reduction of pollutions in laboratory samples, that porous glasses can be used as adsorbents for liquidating hydrocarbon pollutions from ground- and surface waters.
A Methodology to Evaluate the Gas Migration in Cement Slurries
Authors: Gonzalo V. , Aiskely B. , Alicia C. 
Published: December 2007

Abstract
Gas migration represents 25% of the primary cement jobs failures.For this reason, studies have been done in order to evaluate several properties of cement slurry like fluid loss, permeability, static gel strength, and others. However, the study of these variables has not shown separately a method to prevent the gas migration and which of these properties of cement slurry have to be controlled to avoid such problem.This paper describes a methodology to control the gas migration.The results of this study were validated with field experiences.
The methodology consists of the next three steps: the first one is the evaluation of the Flow Potential Factor (FPF) which predicts severity of the problem.Then, the static gel strength is measured as a function of time, obtaining the transition time of the cement slurry.Finally, pressure reduction due to static gel strength versus time is simulated with the Fluid Migration Analyzer (FMA), validating gas migration through cement slurry.
Three wells were study in Santa Barbara and San Joaquín fields located in Eastern Venezuela. In each well, pore pressure of the gas zone, temperature, gas zone depth and the annular space across the gas zone were used to determine the FPF.
The results of this study agree with field experiences, based on quantitative measurements like transition time and FPF.This methodology allows selecting the optimum cement slurry design in a way that prevents industrial accidents and assuring the well life.
Key High-Quality Technologies as Pivots for Hydrocarbon-Reserves Expansion
Authors: Navarro J. B. 
Published: December 2007

Abstract
The digital technology trends to transform the hydrocarbons production dynamic and can potentially increase world oil reserves. Several inherents systems and techniques are right now commercially availables, although the support of specialized hardware is required for completing truly integrated projects.
Five key and high quality technologies-remote sensing, visualization, intelligent drilling and completions, automation and data integration- are a set of tremendous new tools that will enable energy companies see reserves more clearly, plan optimal drilling and production strategies, and manage operations more efficiently.
TheInter-well seismic imaging, 4D optimized seismic and other key technologies in coherence cubes are the most recent advances speciality with great value for reservoir management.
Crosswell seismic imaging is the first technology that fills the information gap between surface seismic and well logs and enhances the profitable management of subsurface hydrocarbon resources.
Reservoir dynamic simulation models, running in conjunction with real time sensors and automated controls, provide high importance information, and the operators can visualizate efficiently subsurface conditions to maximize production and manage efficiently field development.
Scalable 3D visualization technology combined with massive data management capabilities and high-speed networks are drastically reducing cycle times for prospect generation, field development planning, well design, drilling and completion.
This paper shows examples of high resolution crosswell seismic visualization, downhole sensors systems, massive data capture with integral systems, and other technologies supported with digital resources as intelligent drilling and completions, which are generating an increase in the productivity in many scenarios and reservoirs in Mexico and worldwide.
Value of Information for a 4D-Seismic Acquisition Project
Authors: Ballin P. R. , Ward G. S. , Whorlow C. V. , Khan T. 
Published: December 2007

Abstract
The decision of any data acquisition should always involve a cost - benefit analysis. While cost identification is usually easy, the value gained with new data is specialy difficult when there are mostly indirect benefits. This is the case of 4D seismic projects where the main contribution is to reservoir production management. Recently, the interest on 4D seismic and the number of such projects have increased significantly. Despite of the high cost, there is a lack of robust and systematic process to evaluate their value.
Bp TT faced this challenge when analyzing a Life of Complex Seismic (LoCS) project for multiple gas reservoirs in the Greater Cassia Complex, located in the Columbus Basin, Trinidad and Tobago. This Complex comprises many producing and future development fields including Amherstia, Immortelle Parang, Kapok, Cannonball and Cassia.A significant fraction of present and future potential reserves of several Tcf is under shallow gas, which has detrimental impact on seismic image quality. Such condition required consideration of expensive 4C OBC (Ocean Bottom Cable) seismic acquisition options. Additional benefits from 4D seismic for monitoring dynamic reservoir performance could be foreseen with a permanent installation. A robust and systematic value of information study was developed as part of the LoCS project in order to support the decision about the 4D acquisition options.
This work describes the Decision Tree process used in the LoCS value of information study as well as discusses the main results used by bpTT to make a based decision about the acquisition program.
Economic Evaluation of Oil-Production Project With EOR: CO2 Sequestration in Depleted Oil Field
Authors: Gaspar A. T. F. S. , Suslick S. B. , Ferreira D. F. , Lima G. A. C. 
Published: December 2007

Abstract
This paper presents an economic feasibility study for CO2 coupled with EOR in a small mature Brazilian oilfield. The present study considers two important and complementary reasons: (1) EOR improvement - CO2 displaces residual oil left in place after primary production and secondary water flooding and has been successfully injected in mature fields for forty years, in order to extend the oilfield life; (2) storing this gas in the oil reservoir and, hence, a contribution to reduce its emissions. The physical aspects of this project are described, and a breakdown cost methodology is proposed in order to estimate the main financial determinants of the integrated EOR with CO2 sequestration (cost of capture, compression, transportation and storage). Project evaluation is derived from a cash flow model, regarding reservoir production profile, price and costs, capital expenditures (CAPEX), operating expenditures (OPEX), carbon credits, depreciation time, fiscal assumptions, etc. A sensitivity analysis study was carried out in order to identify the most critical variables. Results indicate that project NPV is around US$ 3.2 million, what is significant for a small mature field. Additionally, it contributes by removing Green House Gases (GHG) from the atmosphere by storing 0.73 million tons of CO2 over a period of 20 years. Project feasibility, as expected, was found to be very sensitive to oil price, oil production, and CAPEX.
Compositional Simulation of Fluid Flow Coupled Stress-Sensitive Reservoirs
Authors: Benavides Y. , Maya G. A. , Gallego J. G. O. 
Published: December 2007

Abstract
Because of the every time higher complexity of the petroleum and gas reservoirs, their analysis have become into an intensive job that, to get a real behavior, most of then consider numerical modeling of the different phenomena inside the reservoir.Two aspects that have shown transcendental importance in reservoir fluid flow are the compositional characteristic of the fluid and the rock stress sensitive.Several authors have analyzed independently every characteristic, remarking every time more their importance.
A fully implicit model to study this problem is developed on a cylindrical finite difference, point distributed grid. Compositional modeling is performed by means of a 12- pseudocomponent Peng-Robinson equation of state with volume translation, tuned to actual PVT and field data of a gas condensate fluid.Michelsen's phase stability test is also considered in the VLE calculation procedure.Because of the proper multiphase flow-effective stress law is unknown, and the capillary pressure for the fluid-rock system under consideration is negligible, it is approached to zero in this research.The geomechanical rock deformation calculation is based on the non-linear elastic model.
To comprehend the involved phenomena, this model must guarantee numerical stability.It has to be taken into account that in order to obtain numerical stability the time step (?t) used in the models should be long (opposite to the requirements of non coupled models).It was realized that the influence of geomechanical properties at the bottom hole pressure is evidenced by long production time simulations.The major contribution of this research is that it helps to determine the pressure sensitivity to important factors such as boundary and initial conditions, and compositional fluid presence in the reservoir.
This study identifies the necessary ?t values to ensure numerical stability.The model shows that when c[bc] get values closed to the rock compressibility, c[r], the pore pressure fall is every time higher.Some other studied parameters emphasize both, the complexity of the phenomenon and the strong influence of some variables on it.
Impact of Simplifications in Risk Assessment and Decision Making Process
Authors: Costa A. P. A. , Schiozer D. J. 
Published: December 2007

Abstract
Decision analysis applied to the development of petroleum fields must take into account the risk associated to several types of uncertainties. In this phase, the importance of risk associated to the recovery factor may increase significantly and numerical simulation is usually required to model the reservoir yielding high computation effort. The process is complex due to (1) high investments (2) large number of uncertain variables (3) strong dependence of the results with the production strategy definition. Therefore, simplifications are usually required to quantify the impact of uncertainties. In previous works, it was shown the impact of several simplifications in the process to be used in the decision making process after the risk assessment. The risk due to geological uncertainty is then separated from the selection of production strategy and other types of uncertainties. In this work, some results are presented and a discussion is made to show the impact of some simplifications in the selection criteria of the geological representative models before and after the integration of the production strategy optimization. The process is applied in an offshore field in Brazil and the results shows that it is possible to improve the performance and reliability of the risk analysis process with less computational effort.