bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Case Study of the World's First Maximum-Reservoir-Contact Well With Intelligent Well Systems and MultiPhase Flow Monitoring
Authors: Al-Bani Fahad , Al-Sarrani Hassan , Arnaout Ibrahim , Anderson Adam , Aubed Yaser , Johansen E. S. 
Published: December 2007

Abstract
In today's drive to improve well production, more innovative methods are continually being implmented to enhance well productivity and reservoir management. Remote monitoring and interactive control are two such methods that are more frequently employed to derive more value from wells. In Saudi Arabia, the world's first maximum reservoir contact (MRC) well, using Intelligent Well Systems and fiber-optic monitoring to maximize production performance was implemented.
This paper discusses the implementation of remote monitoring and interactive control systems on Well-194, which was drilled as a tri-lateral MRC well with 4.2 km (2.61 mi) of total reservoir contact. The Intelligent Well System utilized feed-through production packers to isolate each of three laterals in the motherbore. Three remotely operated downhole chokes were installed to independently control flow from each lateral for the purpose of optimizing overall well production. This control extends the production plateau while maximizing reservoir drainage. The fiber-optic monitoring system enables remote monitoring of key production parameters, including pressure, temperature, total flow rate and water cut from each of the laterals, used to determine optimum downhole choke settings. Finally, the well was implemented as "ESP Ready" with 7" tubing and a Deep-Set SCSSV to enable subsequent installation of a thru-tubing ESP to further improve production.
Ultimately, this configuration resulted in a well capable of producing at a very high rate with low drawdown for an extended period of time. This strategy will result in a long-term sustained rate while optimizing the reservoir drainage process. This paper will review the lessons learned and key issues around implementing this type of "Next Generation" well completion system.
Anionic Surfactant Gel Treatment Fluid
Authors: Welton Thomas D. , Bryant Jason , Funkhouser Gary P. 
Published: December 2007

Abstract
Typical viscoelastic surfactant gels used for gravel packing and hydraulic fracturing have relied upon cationic, amphoteric, or zwitterionic surfactants as their primary gelling agent, complicating the stimulation of some wells due to wettability or formation fluid compatibility issues. This paper describes an anionic viscoelastic surfactant developed for fracturing and gravel packing applications. The performance of the gel as a function of temperature, salt type and concentration, and cosurfactant will be presented along with the chemical structure/activity relationship. Rheological measurements demonstrate that fluids made with the new anionic surfactant have effective performance over a range of conditions encountered in treating wells.
Deflation AMG Solvers for Highly Ill-Conditioned Reservoir Simulation Problems
Authors: Klie Hector , Wheeler Mary F. , Clees Tanja , Stüben Klaus 
Published: December 2007

Abstract
In recent years, deflation methods have received increasingly particular attention as a means to improving the convergence of linear iterative solvers. This is due to the fact that deflation operators provide a way to remove the negative effect that extreme (usually small) eigenvalues have on the convergence of Krylov iterative methods for solving general symmetric and non-symmetric systems.
In this work, we use deflation methods to extend the capabilities of algebraic multigrid (AMG) for handling highly non-symmetric and indefinite problems, such as those arising in fully implicit formulations of multiphase flow in porous media. The idea is to ensure that components of the solution that remain unresolved by AMG (due to the coupling of roughness and indefiniteness introduced by different block coefficients) are removed from the problem. This translates to a constraint to the AMG iteration matrix spectrum within the unit circle to achieve convergence. This approach interweaves AMG (V, W or V-W) cycles with deflation steps that are computable either from the underlying Krylov basis produced by the GMRES accelerator (Krylov-based deflation) or from the reservoir decomposition given by high property contrasts (domain-based deflation). This work represents an efficient extension to the Generalized Global Basis (GGB) method that was recently proposed for the solution of the elastic wave equation with geometric multigrid and an out-of-core computation of eigenvalues.
Hence, the present approach offers the possibility of applying AMG to more general large-scale reservoir settings without further modifications to the AMG implementation or algebraic manipulation of the linear system (as suggested by two-stage preconditioning methods). Promising results are supported by a suite of numerical experiments with extreme permeability contrasts.
Algebraic Multigrid Methods (AMG) for the Efficient Solution of Fully Implicit Formulations in Reservoir Simulation
Authors: Stüben Klaus , Clees Tanja , Klie Hector , Lu Bo , Wheeler Mary F. 
Published: December 2007

Abstract
A primary challenge for a new generation of reservoir simulators is the accurate description of multiphase flow in highly heterogeneous media and very complex geometries. However, many initiatives in this direction have encountered difficulties in that current solver technology is still insufficient to account for the increasing complexity of coupled linear systems arising in fully implicit formulations. In this respect, a few works have made particular progress in partially exploiting the physics of the problem in the form of two-stage preconditioners.
Two-stage preconditioners are based on the idea that coupled system solutions are mainly determined by the solution of their elliptic components (i.e., pressure). Thus, the procedure consists of extracting and accurately solving pressure subsystems. Residuals associated with this solution are corrected with an additional preconditioning step that recovers part of the global information contained in the original system.
Optimized and highly complex hierarchical methods such as algebraic multigrid (AMG) offer an efficient alternative for solving linear systems that show a "discretely elliptic" nature. When applicable, the major advantage of AMG is its numerical scalability; that is, the numerical work required to solve a given type of matrix problem grows only linearly with the number of variables. Consequently, interest in incorporating AMG methods as basic linear solvers in industrial oil reservoir simulation codes has been steadily increasing for the solution of pressure blocks.
Generally, however, the preconditioner influences the properties of the pressure block to some extent by performing certain algebraic manipulations. Often, the modified pressure blocks are "less favorable" for an efficient treatment by AMG. In this work, we discuss strategies for solving the fully implicit systems that preserve (or generate) the desired ellipticity property required by AMG methods. Additionally, we introduce an iterative coupling scheme as an alternative to fully implicit formulations that is faster and also amenable for AMG implementations. Hence, we demonstrate that our AMG implementation can be applied to efficiently deal with the mixed elliptic-hyperbolic character of these problems. Numerical experiments reveal that the proposed methodology is promising for solving large-scale, complex reservoir problems.
Efficient History Matching and Production Optimization With the Augmented Lagrangian Method
Authors: Doublet D. C. , Aanonsen S. I. , Tai X. -C. 
Published: December 2007

Abstract
A new method for reservoir history matching and dynamic optimization of water flooding with smart wells is presented. For the dynamic optimization of water flooding case, we solve a constrained optimization problem where the net present value is maximized and the reservoir flow equations are considered as constraints. Similarly for the history matching, we recover the permeability field from measurements of pressures and saturations. In both cases the problem is formulated as finding a saddle point of the associated augmented Lagrangian functional. We compare the method with a more traditional optimal control method, based on solving the adjoint system of equations. In the examples tested the new method obtains approximately the same results using the same or less computational effort compared to the adjoint method. An advantage of the new method is that we do not solve the flow equations exactly at each iteration. As the optimization proceeds, the flow equations will be fulfilled at convergence. Thus, each iteration of the new minimization algorithm is cheaper than for the adjoint method.
Conventional Analysis for the Determination of the Horizontal Permeability from the Elliptical Flow of Horizontal Wells
Authors: Escobar Freddy H. , Montelegre-M Matilde 
Published: December 2007

Abstract
Besides the regular four flow regimes normally seen during a pressure test of horizontal wells, it is possible, under special circumstances, to observe such additional flow regimes as spherical, hemi-radial, linear (reservoir channel) and elliptical. The last flow regime is characterized by a slope of 0.36 of the pressure derivative curve and occurs between the early linear flow and the pseudo-radial flow periods. This may have been overlooked in horizontal well test analysis, because it is often masked by the other flow regimes, unless the conditions are just right.
The elliptical flow regime has been previously mentioned by very few researchers5-7. A methodology for its characterization has been also introduced using the pressure derivative concept and TDS technique7. However, conventional analysis for the characterization of this has not yet been reported in the literature. This flow regime is very useful to estimate the horizontal permeability, especially, when the pseudo-radial flow is very short or unclear, or simply, when it is desired to verify this estimation.
In this paper, equations for the estimation of the horizontal permeability and elliptical skin factor are developed for both gas and oil horizontal wells, so that the mentioned parameters can be estimated, respectively, from the slope and intercept of linear plot of pressure versus time to the power 0.36. The equations were successfully tested with two field examples previously worked in the literature.
Special Issues in the Stress Analysis of Casing Strings in Steam-Injection Wells: Mathematical Development and Design
Authors: Garside R. , Pattillo P. D. , Pattillo P. D. II , Sathuvalli U. B. 
Published: December 2007

Abstract
This paper presents a mathematical model of casing strings subjected to thermal loads in steam injection wells. The model includes the effects of temperature on material properties and the effects of wellbore curvature and pre-stress during the heating cycle. Several counter-intuitive aspects of the casing stress state during cooling/unloading are examined. Example calculations are used throughout to illustrate key insights.
Accreditation of an Oil Company Training Scheme for Graduate Engineers
Authors: Saadawi Hisham , Al Sammarrai Wathik 
Published: December 2007

Abstract
Abu Dhabi Company for Onshore Oil Operations (ADCO) is the major oil and gas producer in the United Arab Emirates (UAE). For the past ten years, ADCO has implemented a Graduate Development Program (GDP) to train and develop the young UAE national engineers who join the ADCO every year.
With the increasing development activities in the Company and shortage of experienced personnel in the oil industry, there is a pressing need to accelerate the training and development of the young UAE national engineers. In order to ensure that quality is maintained and to benchmark the Graduate Development Program, ADCO applied to the various engineering institutions in the UK to accredit the program. The training scheme was successfully accredited by four major engineering institutions in the UK.
This paper outlines ADCO Graduate Development Program and the need for accrediting the Program. The differences between certification and registration of engineers versus accreditation of the training program are discussed.
The paper also describes how an organization can accredit its training program and the benefits of such accreditation.
Designing Cement Slurries for Preventing Formation Fluid Influx After Placement
Authors: Santra Ashok , Reddy B. R. , Antia Mfon 
Published: December 2007

Abstract
Formation fluid influx into cement slurries immediately after placement presents not only a short-term problem, for example losing the slurry due to shallow water flows, but also presents a long-term problem, for example gas flow and pressure buildup behind the casing. It is critical that cement slurries be designed carefully when such problems are anticipated. Cement slurries that often offer the best solution to resist the formation influx are those that do not gel while being pumped then gel/set and gain strength rapidly once placed. These are sometimes referred to as "right-angle set" cements and should possess the following attributes in laboratory design testing:Maintains a low rheological profile while pumping for lower ECDs.Predictable thickening and set times.Retains the ability to transmit hydrostatic pressure under static conditions until the cement is ready to gel/set.Short gel to set time under static conditions, often termed "transition time."Short waiting on cement (WOC) time.
This paper shows that although a cement slurry having a "right-angle set" may ensure the first two benefits, it does not always guarantee the latter two when present behind a casing. For example, some slurries might reach thickening time and become unpumpable rapidly, but strength development may not occur until long afterward, due to a time lag between thickening and hydration time (set time) of cement. In such cases, slurry should be designed such that the thickening time and hydration time are essentially identical. Novel slurries that maintain low rheological profiles while the slurry is being placed, then set and gain strength quickly due to cement hydration afterward, have been developed for a variety of densities and downhole temperatures. Results from laboratory and related field case histories will be presented.
Scalability and Load-Balancing Problems in Parallel Reservoir Simulation
Authors: Gratien J. M. , Guignon T. , Magras J. F. , Quandalle P. , Ricois O. 
Published: December 2007

Abstract
New parallel reservoir simulator software designed for Linux clusters enable to overcome hardware limitation and to simulate models with large amount of data. Reservoir engineering industry is very interested in using ever growing dataset with more and more complex physics and detailed models. The key issue still remains running simulations in an acceptable CPU time. As, the trend in hardware technologies is not to improve drastically the performance of individual CPUs but to facilitate the aggregation of computation facilities (with high bandwidth network, multi-core architectures …), the challenge is to improve the efficiency of reservoir simulation software on a large number of processors.
New numerical difficulties and performance problems appear when the number of cells and the number of processors are growing. As a matter of fact, the architecture of Linux clusters is very sensible to memory distribution and load balancing: the cost of parallel solver algorithm is usually sensible to the size of the reservoir model (lack of scalability) and the consequences on CPU performance can no more be neglected;the domain decomposition algorithms used to distribute data between processors have a great influence on the computing load balancing between processors;using adaptive numerical schemes with dynamic space criteria (AIM schemes, flash algorithms based on the thermodynamic state of each cell) is a source of unbalance that cannot statically be resolved;simulation result storages on irregular data structures, such as unstructured grids, multilateral smart wells and perforated cells, lead to store an important amount of information during the simulation. With the variety of IO subsystems found on Linux clusters the simulator must be able to adapt its IO strategy to the underlying IO library/file system and hardware.
In this paper, we present different approaches to overcome these kinds of problems. We discuss technical choices such like: advanced scalable linear solver algorithm;load balancing issue with different domain decomposition strategies;dynamic space criteria, mesh partitioner strategy and parallel solver performance management;flexible IO strategy from simple file system to more complex parallel file system or database.
We have developed and benchmarked these different solutions on published reference large scale problems and actual case studies with several tens millions of cells. We analyze the results and discuss the efficiency of each solution to overcome the scalability difficulties and performance limitations due to load unbalance.
Efficient Parallel Simulation of CO2 Geologic Sequestration in Saline Aquifers
Authors: Zhang Keni , Doughty Christine , Wu Yu-Shu , Pruess Karsten 
Published: December 2007

Abstract
An efficient parallel simulator for large-scale, long-term CO2 geologic sequestration in saline aquifers has been developed. The parallel simulator is a three-dimensional, fully implicit model that solves large, sparse linear systems arising from discretization of the partial differential equations for mass and energy balance in porous and fractured media. The simulator is based on the ECO2N module of the TOUGH2 code and inherits all the process capabilities of the single-CPU TOUGH2 code, including a comprehensive description of the thermodynamics and thermophysical properties of H2O-NaCl-CO2 mixtures, modeling single and/or two-phase isothermal or non-isothermal flow processes, two-phase mixtures, fluid phases appearing or disappearing, as well as salt precipitation or dissolution. The new parallel simulator uses MPI for parallel implementation, the METIS software package for simulation domain partitioning, and the iterative parallel linear solver package Aztec for solving linear equations by multiple processors. In addition, the parallel simulator has been implemented with an efficient communication scheme. Test examples show that a linear or super-linear speedup can be obtained on Linux clusters as well as on supercomputers. Because of the significant improvement in both simulation time and memory requirement, the new simulator provides a powerful tool for tackling larger scale and more complex problems than can be solved by single-CPU codes. A high-resolution simulation example is presented that models buoyant convection, induced by a small increase in brine density caused by dissolution of CO2.
Engineering Rhamnolipid Biosurfactants as Agents for Microbial Enhanced Oil Recovery
Authors: Fang Xiangdong , Wang Qinhong , Bai Baojun , Liu Cai Xi , Tang Yongchun , Shuler Patrick J , Goddard Willliam A. 
Published: December 2007

Abstract
This investigation considered engineered rhamnolipid biosurfactants as EOR agents that potentially could be manufactured at low cost from renewable resources, and have lower toxicity than synthetic EOR surfactants. This particular biosurfactant comes mainly from the microbe Pseudomonas aeruginosa. Disadvantages of working with this strain include that the chemical structures of the produced rhamnolipids are not easily controlled, plus there is a preference to use instead a completely non-pathogenic microbe. Towards that end, the study took the approach to clone the genetic information from a P. aeruginosa strain into E. coli to manipulate systematically the structure of the created rhamnolipids and evaluate their EOR performance by themselves (no co-surfactant or viscosity chemical added).
Six E.coli strains (ETRA, ETRAB, ERAC, ETRABC, ETRhl, ETRhl-RC) that carry different combinations of the genes involoved in rhamnolipid bio-synthesis were successfully engineered and tested for their rhamnolipid production. Sand-pack core flooding tests were run to evaluate and compare the effectiveness of these products as agents for enhanced oil recovery. The brine with optimized pH and salt concentration in which a given biosurfactant product has its lowest IFT was used to saturate the core, perform a waterflood, and prepare the surfactant solution. Injection of 6 PV of only a 250 ppm rhamnolipid biosurfactant solution and 4 PV of a brine chaser could recover as much as half of the waterflood residual hydrocarbon (n-octane). The engineered E. coli strains that include more of the implanted genetic code had the better performance in these oil displacement tests. The IFT, biosurfactant concentration and pH of effluents from core flooding were monitored to address EOR mechanisms and quantify the adsorption of each product in the sand pack.
Horizontal Fracture Stimulation Success in the Alpine Formation, North Slope, Alaska
Authors: Schneider Tim S. , Uldrich David O. , Hodge Richard , Barree Bob , Martin Michael W. 
Published: December 2007

Abstract
The Alpine field located on the North Slope of Alaska was developed using open-hole horizontal completions drilled along the maximum principle stress and dominant fault orientation (northwest/southeast). Open-hole completions were considered the best completion option based on rock mechanics, improved profile surveillance and cost. The original Alpine field development plan did not include hydraulic fracture stimulation based on the reservoir characterization. Well performance had proven to be economic in this Jurassic, marine sandstone without hydraulic fracturing, until drilling the CD2-37 well in 2003. The poor reservoir quality found in the southwestern edge of the field required stimulation to produce at economic rates. A hydraulic fracture treatment was performed resulting in a 200% production increase. Over the past three years, a stimulation program has evolved with improvements in candidate selection, performance and predictability. Future plans include continuing to stimulate candidate wells by incorporating horizontal completion technologies that are more conducive to multiple fracture technology.
This paper presents the evolution of the candidate selection process and a review of reservoir characterization as a result of the significant production improvements gained from hydraulic fracturing. We will also present how the Alpine full field model predictions have impacted the candidate selection process and discuss the stimulation design history that includes fracture fluid changes resulting from core analyses.