bluuebunny/crossref_metadata_2025_split huggingface dataset:
Balanced Pressure Drilling With Continuous Circulation Using Jointed Drillpipe—Case History, Port Fouad Marine Deep 1, Exploration Well Offshore Egypt
Authors: Calderoni A. , Chiura A. , Valente P. , Soliman F. , Squintani E. , Vogel R. E. , Jenner J. W. 
Published: December 2007

Abstract
This paper presents the industry's first application of balanced pressure drilling to drill a difficult well section with continuous circulation using jointed pipe. Previous attempts to drill the section in 2004 failed and balance pressure drilling was identified as the only safe and practical drilling technique to use.
The paper will present the reasons for employing a new drilling technique, together with the associated changes to conventional drilling and well control procedures.
In the Port Fouad Marine Deep–1 (PFMD–1) well below 4000m, there exists a critical pressure gradient zone with pore pressures exceeding 2.0 sg EMW, with the difference between pore and fracture pressure gradients as low as 0.10 sg EMW. The dynamic hydrostatic pressure difference between the Equivalent Circulating Density (ECD) and the mud weight was equivalent to about 0.07 sg during drilling operations. The well was re-entered in June 2005 using the Continuous Circulation System (CCS™) and the problem zone drilled maintaining constant ECD. Drilling difficulties resulting in the earlier suspension were successfully overcome.
Balance Pressure Drilling (BPD) with uninterrupted circulation and revised drilling and well control procedures significantly improved drilling performance and operational safety in the critical gradient zone. This resulted in adding significant new hydrocarbon reserves that could not previously be drilled.
Restoring Injectivity of Wells Drilled in Sour Carbonate Formations
Authors: Nasr-El-Din H. A. , Zabihi M. , Al-Dossary K. , Djelliout M. A. , Kelkar S. K. 
Published: December 2007

Abstract
Saudi Aramco has embarked on developing an oil field located in the Northern area of Saudi Arabia. This field is characterized by the presence of tar-mat zones that are present at the base of oil-column. These zones form a barrier which physically isolates the producing zones and the injection water. This paper addresses the challenges faced in maintaining the injectivity of water in this particular field.
Open-hole water injectors with extended reach (ER) were completed horizontally at the bottom of the producing zones and just-above the tar-mat zones. The typical open-hole lengths in these wells are between 3,000 –7,000 ft. Challenges were faced in drilling these wells in a populated area in the northern area of Saudi Arabia and being stratified, tar-mat was encountered in the open-hole sections of these wells. Tar content varies inconsistently around these injectors. This limits the injection rate of these injectors initially to as low as 600 BWD at 2,400 psig.
The low-injectivity of these water injectors is attributed to the damage induced by the drilling mud (water-based mud) and the presence of tar and asphaltenes in the injection zone. Acid stimulation treatments of these wells were needed to reach the target injection rates. Furthermore, this particular northern field in Saudi Arabia is sour and located inside a highly populated area and as such, environmental regulations prohibit any well flow back post acid treatment and no flaring is allowed.
To overcome these challenges a tailored acid treatment was designed. It included a preflush of an aromatic solvent, then stages of 20 wt% HCl regular and emulsified acids. To achieve better acid diversion in horizontal wells, stages of a surfactant-based acid system were utilized. Along with tailored acid treatments, new methods to place the acid in the zone of interest were also employed. More than 20 extended reach horizontal injectors were successfully stimulated in a sour carbonate oil reservoir. Pre and post treatment injectivity tests were performed using down-hole gauges in order to evaluate the efficiency of the acid treatments. This paper will discuss challenges faced during stimulation of water injectors in this sour heterogeneous reservoir, fluid selection, design criteria, field treatments, lessons learned, and results of the acid treatments.
The Challenges of Accident Response Training and Application in a Middle East Environment
Authors: Williams J. M. , Allan H. 
Published: December 2007

Abstract
This paper describes the development of, and challenges in the implementation of accident response training schemes and their results both for employees and students. Key issues relating compatibility with a Middle Eastern environment are discussed.
It is not believed emergency training issues have been addressed in this way previously. The study demonstrates that successful transfer of health, safety, and environmental (HSE) practices between countries or regions must accommodate local culture and traditions. Recommendations and suggestiuons are made that can be used by other organizations.
Analysis of Time-Dependent Wellbore Stability of Underbalanced Wells Using a Fully Coupled Poroelastic Model
Authors: Hodge M. , Valencia K. L. , Chen Z. , Rahman S. S. 
Published: December 2007

Abstract
Coupled poroelastic response of formation around wellbore is expected to differ from the classic linear elastic theory when subject to changes in the state of stress. This may lead to redistribution of stress and pore pressure around the wellbore and consequent time-dependant wellbore deformation. These effects could cause delayed wellbore failure, loss of circulation and even the total loss of the well, especially in the case of underbalanced drilling. This paper presents a fully coupled poroelastic model developed for wellbore stability analysis with particular emphasis on fluid flow induced stress changes around wellbore. By using finite element methods, the model is able to simultaneously compute the geomechanical and hydraulic variables.
In analogy with the common approach of wellbore stability analysis through initial and infinite time stresses calculation, the model can evaluate transient stress and pressure profiles to demonstrate the behavior of a wellbore throughout its history. This allows us to widen the safety mud weight window which leads to reduced drilling time and costs. The time of failure can be predicted by using modified Mohr-Coulomb criteria for breakout failure and tensile failure criteria for fracture. Thus, the coupled poroelastic approach can examine the factors influencing the wellbore stability more accurately than linear elastic method.
The model was used to analyse wellbore stability in different formation types, stress conditions and drilling situations. Time-dependent shear stress distributions are presented so that they can be compared with shear strength of these rocks at different depths to select appropriate mud weights for underbalanced drilling.
The Timing of Investment in Deepwater Heavy-Oil Opportunities With Uncertainty in Oil Price and Production Technology
Authors: de Abreu C. A. Camargo , Lima G. A. Costa , Suslick S. B. 
Published: December 2007

Abstract
Many offshore heavy oil discoveries in deep waters can be considered valuable assets if new technologies are available to transform geological successes into economic successes through projects of development and production. But, there are some latent questions: i) how to forecast future technology advances in order to produce this heavy hydrocarbon?; ii) how companies can estimate development cost for the next five to ten years?; iii) with which degree of certainty will new technologies be available to reduce present production costs for these oil types? This paper proposes the application of the theory of option pricing for valuation and decision-making in opportunities to invest in projects to produce heavy oil in a deep water environment. The first uncertain variable is oil price, which evolves over time as a Geometric Brownian Motion. The second uncertain variable is the impact of advances of production technology on production cost that evolves as a Poisson process. The assumptions in oil price modeling are based on continuous fluctuations over time. In case of production technology, we assume that advances take place in a discrete way through jumps that can represent gains, which may enable the firm to produce with greater efficiency reducing costs. This timing model is applied for valuation and decision-making of a typical heavy-oil project located in Campos basin in Brazil (15 °API, 2900 m water-depth). This production includes 7 production and 7 injection wells. Preliminary results show that the investment-rule is far from that of traditional NPV (that is, invest as long as NPV&gt;0), especially in case of increasing oil pricing volatility and size and arrival of technological innovations.
Meeting the Environmental Challange: A New Acid Corrosion Inhibitor for the Norwegian Sector of the North Sea
Authors: Vorderbruggen M. , Kaarigstad H. 
Published: December 2007

Abstract
The rigorous environmental regulations of the North Sea oil and gas fields have required fundamental changes in the way service companies acidize wells. Traditionally, acid corrosion inhibitors have been some of the most toxic chemicals routinely pumped downhole. This paper describes a new acid corrosion inhibitor (NSACI) that meets the Norwegian environmental "Yellow" specifications for chemicals. This inhibitor functions in both mineral and organic acids and has been successfully used in the larger fields on the Norwegian Continental Shelf. Laboratory data is presented in detail along with field references to explain both the strengths and limitations of this new, environmentally-friendly acid corrosion inhibitor.
Robust Waterflooding Optimization of Multiple Geological Scenarios
Authors: van Essen G. M. , Zandvliet M. J. , Van den Hof P. M. J. , Bosgra O. H. , Jansen J. D. 
Published: December 2007

Abstract
Dynamic optimization of waterflooding using optimal control theory has a significant potential to increase ultimate recovery, as has been shown in various studies. However, optimal control strategies often lack robustness to geological uncertainties. We present an approach to reduce the impact of geological uncertainties in the field development phase known as a robust optimization (RO). RO uses a set of realizations that reflect the range of possible geological structures honoring the statistics of the geological uncertainties.
In our study we used 100 realizations of a 3-dimensional reservoir in a fluvial depositional environment with known main flow direction. We optimized the rates of the 8 injection and 4 production wells over the life of the reservoir, with the objective to maximize the average net present value (NPV). We used a gradient-based optimization method where the gradients are obtained with an adjoint formulation.
We compared the results of the RO procedure to two alternative approaches: a nominal optimization and a reactive control approach. The nominal optimization is based on a single realization, while in the reactive approach each production well is shut in when production is no longer profitable. The three control strategies were applied to each realization, from which the average NPV's and three cumulative distribution functions were determined. The RO results displayed a much smaller variance than the alternatives, indicating the increased robustness to geological uncertainty. Moreover, the RO procedure significantly improved the average NPV, compared to the alternative methods: on average 9% higher than using reactive control and 3% higher than for the nominal case.
Interfacial Tension Data and Correlations of Brine/CO2 Systems Under Reservoir Conditions
Authors: Chalbaud C. , Robin M. , Egermann P. 
Published: December 2007

Abstract
It has been long recognized that interfacial interactions (interfacial tension, wettability, capillarity and interfacial mass transfer) govern fluid distribution and behavior in porous media. Therefore the interfacial interactions between CO2, brine and reservoir oil and/or gas should have an important influence on the effectiveness of any CO2 storage operation. As a model, the interfacial tension of the pure water-CO2 system has been studied intensively. Nevertheless, to our knowledge, no interfacial tension (IFT) equilibrium data for brine-CO2systems are available at reservoir conditions for different salinities, temperatures and pressures.
In this paper, we present experimental IFT brine-CO2data obtained at high pressures (45 to 255 bar), high temperatures (27 to 100°C) and different salt concentrations (5,000 to 150,000 ppm of NaCl) using the axi-symmetric drop shape analysis technique (ADSA) for a rising drop case. Special attention was paid in developing a procedure to achieve true thermodynamic equilibrium. The themodynamic conditions were selected in order to cover the most practical CO2 storage cases of interest, liquid and supercritical CO2. A correlation was developped on the basis of the Parachor model, the salt effect and a regression fit of more than a hundred IFT experimental values obtained in this study. This correlation yields a Brine-CO2IFT prediction at reservoir conditions with a mean absolute deviation of 2.5%. We also present correlations to determine the IFT increase due to salt concentration. The existence of a plateau in the brine-CO2IFT values, independent of the temperature and the pressure and only dependent on the salt concentration, has been demonstrated from the experimental data for temperatures between 27 to 71°C and pressures above 150 bar. These pressure and temperature values can be easily found in many geological sites considered as prospects for CO2storage. The linear dependency of the IFT increase with molal NaCl concentration has also been demonstrated.
Solid Expandable Tubulars Facilitate Intelligent-Well Technology Application in Existing Multilateral Wells
Authors: Rivenbark M. , Abouelnaaj K. 
Published: December 2007

Abstract
A major Middle Eastern operator has been exploiting long reach, openhole, multi-lateral technology to maximize oil recovery from a large field producing from a limestone reservoir. Significant production increases have been attained, but the recovery efforts have been hampered by an inability to re-enter openhole sidetracks for remedial purposes. The operator has also encountered water production problems with no real way to identify the source of the water or to remediate it if the source is found.
These problems have been overcome with the introduction of solid expandable tubulars in combination with intelligent well technology. An openhole multi-lateral involves sidetracking out of the main bore while in the open hole. In wells where the technology has been applied, production rates have generally been higher and recovery has improved. A lower unit development/operating cost is also a key driver in this type of well. The new adaptation of using solid expandable tubulars and intelligent well technology allows for re-entry into the lateral for remedial work and real-time pressure, temperature and flow data without the need for well intervention. Intelligent well components allow for quick identification of any water-producing zones and provide a means for shutting off the water production, again without the need for well intervention.
This paper describes the deployment and operation of the new combined-technology application and presents field examples of its use. The paper also discusses applications under development that will push solid expandable tubular technology even further.
Startup of an ESP Well Producing Heavy Crude Oil
Authors: Guerrero-Sarabia I. , Fairuzov Y. V. 
Published: December 2007

Abstract
Numerical simulations of the pump start-up in an ESP were performed A comparison of the model predictions with field data is shown. Results of numerical simulations of the ESP start-up in a well producing heavy (13 °API) crude oil are presented. Liquid level variations in the casing annulus observed during the well start-up are explained. A parametric study was carried out to investigate the effects of reservoir characteristics and oil viscosity on the pressure and flow rate variations, as well as on the system response time. The results obtained can be used for the development of operational strategies for artificial lift systems with ESP.
Coulomb Na Kika: Deepest Water-Depth Completion with Internal Plastic Coating Tubing Application
Authors: Ituah I. A. , Stockwell L. , Stair C. D. , Kumar R. , Neeld S. , Lauer R. 
Published: December 2007

Abstract
The Coulomb field is the 6th field of the ultra deepwater GoM Na Kika subsea development. The two subsea tie-back wells in the Coulomb development (the C–2 and the C–3) were completed in April and May of 2004, in 7,570' of water depth. When completed, the Coulomb wells held the industry record for the deepest water depth subsea completions in the world. The subsea trees and the surface-controlled subsurface safety valves also represented the deepest set to date.
The development planning included selection of the optimum completion design to address a wild-cat in the northern block, which had not previously been penetrated. While the conceptual sand control design was based on data from the previously appraised southern block.
The execution phase was performed on a Generation 5 Moored Mobile Offshore Drilling Unit (MODU) with no prior experience in deepwater completions. Value creation activities were employed to raise the awareness and competence of the rig team to transform improvement opportunities into high performance goals. The Heave-Compensated Landing System (HCLS)1 was used to install the subsea tree, tubing head spool and well jumpers from anchor handling vessels, hence expanding the scope of activities performed off the critical path of the rig and contributed significantly to the record-breaking pace.
Completion fluid, workstring and treatment fluid were carefully selected and tested for well-specific conditions. Specific challenges included the quick turn around completion design and execution on a wild cat, optimizing the drill/complete sequence to complete in uncertain mineralogies, high day rate leading to a desire to be "quick but good", cooling effects due to huge riser volume and long riser trip times. Through extensive preparation and the use of several innovative concepts, record performance was achieved.
This paper also gives an overview of the application of internal plastic coating of the production string in the Coulomb wells. Through nodal analysis with a match to the well performance data, it is demonstrated that the reduced tubing friction associated with the use of internal plastic coating in the tubing has been estimated to yield a 15% increase in daily production in these wells. Success in this application further proves the effectiveness of today's new and novel coating system.
Study on Cement Displacement by Lattice-Boltzmann Method
Authors: Li X. , Novotny R. 
Published: December 2007

Abstract
Cement displacement plays a key role in the well construction and completion. The displacement of drilling fluids with cement to support, protect casing and seal reservoir formation has been a required process in oil industry for years. Also plug cementing has been applied in the abandoned wells for the environmental concerns. In all these cases, poor cement displacements such as cement channeling and bad zonal isolation will result in a subsequent remedial squeeze cementing, which is both expensive and time consuming. Currently, the cement displacement process relies very often on field engineer's experience. So far, in the literature, cement displacement phenomenon has been qualitatively described by lubrication theory on the basis of the macro-scale consideration.
In order to understand the fluid transport behavior, we propose a new approach to simulate the cement displacement process in this paper. From the micro-scale viewpoints, this new approach is using a Lattice-Boltzmann method to describe quantitatively the fluid flow's behavior in the tubular and annulus during the displacement operation. The traditional approaches such as finite-difference, finite-element or finite volume methods of computational fluid dynamics have serious problems: like long computational times, poor convergence and numerical instabilities. However, the Lattice-Boltzmann method is another computational approach that is more efficient and it is based on a more rigorous description of the transport phenomena, the Boltzmann equation.
The velocity distribution profiles with mud and slurry in the annuli will be obtained from the fluid dynamics computation. The effects of slurry properties, inlet flow rate on the displacement's velocity profiles are investigated. The chances of cement channeling also are discussed with the Lattice-Boltzmann's simulation results. This study will provide insight in the mechanism of miscible fluid transport properties and a guidance of cement displacement's job design.
Tahiti: Assessment of Uncertainty in a Deepwater Reservoir Using Design of Experiments
Authors: Carreras P. E. , Johnson S. G. , Turner S. E. 
Published: December 2007

Abstract
Tahiti prospect in deepwater Gulf of Mexico is a three-way anticlinal structure trapped against salt, with primary pay sands ranging from 24,000 to 27,000 ft TVD. The field contains several hydrocarbon-bearing turbidite sands. The discovery well was drilled in 2002, and two appraisal wells were drilled soon afterwards. Due to significant uncertainties remaining after appraisal, probabilistic methods were used to assess development plan alternatives and reserves. The primary purpose of this paper is to show the integrated earth modeling and reservoir simulation workflow, which incorporates uncertainty analysis and experimental design.
The first step of the reservoir simulation workflow was the identification of the uncontrollable parameters that might influence performance predictions. These uncontrollable parameters included the earth model, water-oil contact location, faulting and compartmentalization, reservoir anisotropy, aquifer support, relative permeability curves, pore volume compressibility, rock compaction and dilation, fluid characterization, skin factor and well pressure drawdown. The analysis of available information from Tahiti field and analog fields with simple statistical techniques allowed the unbiased estimation of low, medium and high values of each uncontrollable parameter. The second step was the application of design of experiments to evaluate the impact of each uncertainty on reservoir performance. Monte Carlo simulation was used to estimate P10, P50 and P90 oil recovery and discounted oil recovery for each reservoir. Finally, we developed reasonable P10, P50 and P90 reservoir simulation models that incorporate the full range of each significant reservoir uncertainty.
Probabilistic production forecasts for primary depletion and waterflood strategies supported project decisions like number of pre-drills, total well count, bottom-hole locations, waterflood strategies and facility capacity. Reservoir simulation results also supported proved reserves estimation and economic evaluation of the project.