bluuebunny/crossref_metadata_2025_split huggingface dataset:
Transfer of pectoralis major for the treatment of irreparable tears of subscapularis
Authors: Elhassan B. , Ozbaydar M. , Massimini D. , Diller D. , Higgins L. , Warner J. J. P. 
Published: July 2008

Transfer of pectoralis major has evolved as the most favoured option for the management of the difficult problem of irreparable tears of subscapularis. We describe our experience with this technique in 30 patients divided into three groups. Group I comprised 11 patients with a failed procedure for instability of the shoulder, group II included eight with a failed shoulder replacement and group III, 11 with a massive tear of the rotator cuff. All underwent transfer of the sternal head of pectoralis major to restore the function of subscapularis. At the latest follow-up pain had improved in seven of the 11 patients in groups I and III, but in only one of eight in group II. The subjective shoulder score improved in seven patients in group I, in one in group II and in six in group III. The mean Constant score improved from 40.9 points (28 to 50) in group I, 32.9 (17 to 47) in group II and 28.7 (20 to 42) in group III pre-operatively to 60.8 (28 to 89), 41.9 (24 to 73) and 52.3 (24 to 78), respectively. Failure of the tendon transfer was highest in group II and was associated with pre-operative anterior subluxation of the humeral head. We conclude that in patients with irreparable rupture of subscapularis after shoulder replacement there is a high risk of failure of transfer of p?ctoralis major, particularly if there is pre-operative anterior subluxation of the humeral head.
Identification of nanometre-sized ultra-high molecular weight polyethylene wear particles in samples retrieved in vivo
Authors: Richards L. , Brown C. , Stone M. H. , Fisher J. , Ingham E. , Tipper J. L. 
Published: July 2008

Nanometre-sized particles of ultra-high molecular weight polyethylene have been identified in the lubricants retrieved from hip simulators. Tissue samples were taken from seven failed Charnley total hip replacements, digested using strong alkali and analysed using high-resolution field emission gun-scanning electron microscopy to determine whether nanometre-sized particles of polyethylene debris were generated in vivo. A randomised method of analysis was used to quantify and characterise all the polyethylene particles isolated. We isolated nanometre-sized particles from the retrieved tissue samples. The smallest identified was 30 nm and the majority were in the 0.1 μm to 0.99 μm size range. Particles in the 1.0 μm to 9.99 μm size range represented the highest proportion of the wear volume of the tissue samples, with 35% to 98% of the total wear volume comprised of particles of this size. The number of nanometre-sized particles isolated from the tissues accounted for only a small proportion of the total wear volume. Further work is required to assess the biological response to nanometre-sized polyethylene particles.
The myofascial compartments of the foot
Authors: Ling Z. X. , Kumar V. P. 
Published: July 2008

Compartment syndrome of the foot requires urgent surgical treatment. Currently, there is still no agreement on the number and location of the myofascial compartments of the foot. The aim of this cadaver study was to provide an anatomical basis for surgical decompression in the event of compartment syndrome. We found that there were three tough vertical fascial septae that extended from the hindfoot to the midfoot on the plantar aspect of the foot. These septae separated the posterior half of the foot into three compartments. The medial compartment containing the abductor hallucis was surrounded medially by skin and subcutaneous fat and laterally by the medial septum. The intermediate compartment, containing the flexor digitorum brevis and the quadratus plantae more deeply, was surrounded by the medial septum medially, the intermediate septum laterally and the main plantar aponeurosis on its plantar aspect. The lateral compartment containing the abductor digiti minimi was surrounded medially by the intermediate septum, laterally by the lateral septum and on its plantar aspect by the lateral band of the main plantar aponeurosis. No distinct myofascial compartments exist in the forefoot. Based on our findings, in theory, fasciotomy of the hindfoot compartments through a modified medial incision would be sufficient to decompress the foot.
A Multi-Purpose Formation Damage Model
Authors: Civan Faruk 
Published: July 2008

AbstractA generalized formation damage model capable of simulating a wide variety of formation damage processes encountered in the field is developed. This model was constructed to simulate the chemical, physicochemical, hydrodynamic, thermal and mechanical damage, rock-fluid and fluid-fluid interactions, and the resulting alterations in the reservoir formation. This model has been developed by combining, improving, and generalizing the features of the various modeling approaches reported in the literature for specific applications into one model. The generalized model takes advantage of the fact that the majority of the models has a common ground in the formulation with some variations in the details specific to certain formation damage processes.
Real-Time Monitoring and Analysis of Matrix Stimulation Operations
Authors: Schiager Bernhard A. , Frick Thomas P. 
Published: July 2008

Abstract
Since matrix acidizing is a low-budget stimulation operation, there has been little incentive to improve acidizing treatments including real-time technology, despite the wide usage of matrix stimulation. Hence, for matrix acidizing real-time quality control, job monitoring and job optimization is seldom practiced and no sophisticated tools were available. However, the ever increasing length of stimulated segments and the associated technical and economical problems in combination with reports on high stimulation failure rates have created an emphasis on the development of real-time tools, not only for monitoring and analyzing acidizing treatment efficiency but also for evaluating pre- and post-treatment job performance. All the tools available today use the evolution in skin factor as a quantitative measure of the overall treatment. For the calculation of the skin factor three methods, based on measuring the injection rate and pressure, are presented. The methods differ widely, from applying a steady-state approach to the fully transient flow regime accounting for various effects influencing the pressure response. Comparisons are presented, based on detailed analysis of the models' features and matching of field data An obvious conclusion is that the fully transient method is the most promising means of real-time monitoring and analysis of matrix treatments for the future.
Frac-and-Pack Completions of Low-Permeability Formation in West Africa
Authors: Bruggeman J. L. , de Vinck B. , van Domelen M. L. , Boissier J. C. 
Published: July 2008

Abstract
This paper describes the successful application of the frac-and-pack completion technique to a low-permeability oil-bearing formation in coastal Zaire, West Africa. Using various completion methods since initial field development in the early 1970s, operators have recovered less than 1 % of the estimated oil in place from this formation to-date. Encouraging results from a two-well pilot project initiated in late 1994, led to a decision to work over an additional four wells for frac-and-pack completions in 1995 as part of the pilot project.
This work centers around the Turonian formation, which is a soft, low-permeability siltstone formation. The friable nature of this formation combined with a low median sand-grain size (20 to 40 microns) has led to formation sand and fines production in some wells. Past attempts to stimulate the Turonian through matrix acidizing have been unsuccessful, and completions of the reservoir with both open- and cased-hole gravel packs have shown uneconomical production rates.
The first two frac-and-pack treatments of the pilot project, one in cased hole and one in a 15-in. underreamed open hole, were pumped through a short weight-down gravel pack assembly that allows for monitoring a live annulus during the job and accurate measurement of net fracturing pressures. The four additional frac-and-pack completions were performed with a similar downhole assembly.
This paper highlights the main aspects of this project, including the reservoir description, completion equipment, fluid and proppant selection, design and analyses of the fracture treatments, and optimization of the treatments as the project progressed. A summary of well performance following the frac- and-pack completions is also presented.
Formation Damage Due to Fines Stabilized Water-in-Oil Emulsions: A Possible Mechanism of Plugging in the Near Well Bore Area?
Authors: Kotlar H. Kr. , Selle O. M. , Kristensen M. H. 
Published: July 2008

Abstract
The generation of stable emulsions at reservoir temperature was investigated as a possible mechanism of formation damage in the near well-bore area. Typically, emulsions have been considered a top-side process problem. Furthermore, experimentation is often based on a set of single events and a traditional conclusion would be that emulsions are of little concern in plugging mechanisms. However, in nature single event mechanisms are scarce. Under actual reservoir conditions both generation of scale and mobilization of fines together with formation of emulsions might be simultaneous events. Thus, a combination of such mechanisms may lead to the plugging. In the present investigation a set of 11 different well parameters were tested in a factorial screening design for potentials in emulsion formation. The results from this screening design show that combinatorial effects are key events in fines stabilized emulsions. Two different North Sea degassed crudes gave emulsions under various combination of variable settings at reservoir temperature.
The present paper gives a survey on the influence of these variables on the stability and viscosity of the generated emulsions. Generation of emulsions and increase of flow viscosity might have great influence on well productivity.
Application of Fractal Analysis in Characterising and Predicting Critical Conditions for Fines Migration in Petroleum Reservoirs
Authors: Chen H. , Nguyen H. , Rahman’ S. S. 
Published: July 2008

Abstract
Formation damage due to fines migration is a major factor which reduces reservoir productivity. It is, therefore, essential to know the critical condition at which particles migrate in pores and subsequently plug the channels. This paper describes the application of fractal analysis for predicting critical conditions for particles to deposit in pores. The experimental data were obtained by injecting suspensions (bentonite) through a fabricated glass micro capillary (100 μm ID) at a controlled flow rate and at the same time continuously monitoring the pressure build-up across the capillary. Based on the experimental data and theoretical analysis, a criterion for predicting the critical condition for fines migration in pores is proposed.
The Use of Scale Dissolver and Scale Inhibitor Squeeze Treatments to Repair and Prevent Formation Damage in Two Statfjord Field Wells
Authors: Lejon K. , Vikane O. 
Published: July 2008

Abstract
Scale dissolvers have successfully been used to restore well productivity in two Statfjord Field wells suffering from scale induced formation damage. Combined with scale inhibitor treatment further production loss has been avoided. The dissolver efficiency towards BaSO4, and SrSO4, is strongly depending on high pH (pH&gt; 9–10) in the treatment slug. Two different scale dissolvers have been tested, and are found to have equally good performance regarding dissolution capasities and effect on production. Well case histories and details about job design and production data before and after the treatments are documented. Combined scale dissolver and scale inhibitor squeeze treatment is implemented as the current scale treatment strategy for the Statfjord Field.

Introduction
The Upper and Lower Brent reservoirs in the Statfjord Field are developed with a row of sea water injectors, completed below the oil/water contact, to displace oil up structure to the east toward a row of oil producers near the crest of the structure. Key information about the Statfjord Field is listed in table 1.
Formation Damage Assessment Around Horizontal Wells During Injection Processes
Authors: Malekzadeh D. , Rahman M. M. , Day J. J. 
Published: July 2008

AbstractFormation damage around horizontal wells can result in poor performance and failure of these wells. The objective of this paper is to present a new solution for transient pressure behavior of horizontal well injectors and/or producers in injection processes. Equations for productivity and injectivity of horizontal wells during injection processes are introduced that are based on the effective horizontal well length contributing to unimpaired injection or production. Effective horizontal well length in steady state reservoirs is the well length with zero skin factor that will yield the same steady state productivity or injectivity index as the one obtained with actual drilled horizontal section length with skin factor. A relationship between mechanical skin factor and effective horizontal well length is derived and explained. Guidelines for analyzing transient testing of horizontal well injectors for determination of reservoir permeability, skin factor, and effective length are presented. It was found that flow efficiency is the ratio of steady state shape factor evaluated at actual length of the horizontal section and the one evaluated at effective length. Furthermore, flow efficiency is always greater than the fraction of horizontal well contributing to unimpaired production or injection, Xf2/Xf1. This indicates that a decrease in effective length is not equal to the loss in injectivity or productivity of the horizontal well, thus implying tolerance for formation damage around these wells to a certain degree.
Performance of Fractured Horizontal Wells in High-Permeability Reservoirs
Authors: Valkó P. , Economides M. J. 
Published: July 2008

Abstract
Two of the most important recent developments in petroleum production are horizontal wells and high-permeability fracturing. This work combines them with potentially considerable incremental production economics. Hydraulic fractures have a distinctly defined azimuth, in almost all cases of interest; they are vertical and normal to the minimum horizontal stress direction. Horizontal wells can thus be drilled either normal or longitudinal to the fracture azimuth. The first configuration has been already considered in the literature and in practice, and is applicable for relatively low-permeability formations. The emergence of high-permeability fracturing, also apparently successful in a number of fields, often results in low dimensionless conductivity hydraulic fractures. The possibility of fracturing horizontal wells longitudinally may have the net effect of installing a high-conductivity streak in an otherwise limited conductivity flow conduit. A rigorous model was constructed to describe this configuration. This paper presents comparative production rates and cumulative productions for longitudinally fractured horizontal wells vis a vis vertical fractured wells and unfractured horizontal wells. The range of attractiveness of the individual options is presented in the framework of discounted revenues.
A Phenomenological Modeling of Critical Condensate Saturation
Authors: Fang Fang , Firoozabadi Abbas , Abbaszadeh Maghsood , Radke Clay 
Published: July 2008

Abstract
We have developed a phenomenological model for critical condensate saturation. This model reveals that critical condensate saturation is a function of surface tension and contact angle hysteresis. On the other hand, residual oil saturation does not have such a dependency. Consequently, the selection of fluids in laboratory measurements for gas condensate systems should be made with care.
Successful Integrated Engineering Service Contract in South China Sea
Authors: Sanders T. K. , Huculak Brian , Dale Dana , Jiang Zhang Ming 
Published: July 2008

Abstract
An Integrated Engineering Service (IES) Contract covering drilling and completion services was formed to develop two sixteen well platforms for Phillips Petroleum International Corporation Asia (PPICA) in the South China Sea. The purpose of the contract was to improve well quality and to reduce the cost and development time to PPICA by taking advantage of existing service company/lead contractor infrastructure in the area. Through a cooperative team environment, a cycle of continuous improvement has resulted in dramatically reduced drilling/ completion times, improved production, and a much lower development cost to the operator.
This paper views the IES relationship from both the per-spective of the operator and the lead contractor and its sub-contractors. It reviews in detail: 1.) the project history and background (including why an IES Contract was the right fit in this case) 2.) the "Team Xijiang" structure, roles and responsibilities, and decision making process 3.) the pricing mecha-nisms and how interests are aligned through incentive pricing 4.) the continuous improvement cycle and 5.) the actual results of the project as compared to anticipated results from previous experience in the area. This new business relationship has laid important groundwork for future opportunities in the industry, for both the operator and lead contractor. An atmosphere of cooperation and trust has removed many of the. barriers that exist in a traditional buyer/supplier relationship (or even in an expanded alliance).
By empowering team members to make decisions at the lowest possible level, personnel from all organizations involved are encouraged to contribute freely to the overall success of the project. The industry is continually faced with the need to improve efficiencies through unique solutions to problems. For any given circumstance, there are numerous alternatives to meet the need. In this case, employing an Integrated approach via one lead contractor, has been a great success.
Application of a Multi-Purpose Compositional Simulator in Designing Steam Injection Projects
Authors: Cicek O. , Ertekin T. 
Published: July 2008

Abstract
In the design of an optimum enhanced oil recovery operation an accurate areal and vertical mapping and analysis of the simulation results plays a fundamental role. In this type of analysis not only should the finer details of the reservoir be considered, but also the grid system superimposed over the domain of interest should exhibit compatibility and consistency with the actual physics of the problem. This will help in accurate characterization of the reservoir and the ongoing physical processes within the domain of interest.
The implications of the aforementioned statements are investigated with the aid of developing a 3-D fieldscale steam injection simulator. The multi-phase mass and energy transport equations are based on compositional balances. In the model the gravitational and capillary forces are accounted together with the viscous flow phenomenon. A fully implicit treatment is used at the multi-block production and injection wells to couple the wellbore to the reservoir. A fully implicit technique is utilized in the solution of the nonlinear system of equations. The model is capable to solve (nh+5) primary variables simultaneously where "n. c" represents the number of hydrocarbon components that can be considered.
A systematic analysis of the areal and vertical distribution of parameters such as pressure, temperature, phase saturations and composition is conducted. Through this detailed analysis the ever-changing relative effects of the various dominant forces on the establishment of production mechanisms and ultimately on the oil recovery are studied.
The fully implicit formulation, which assumes all the reservoir parameters and operational parameters to be functions of all primary variables identified, makes it possible to focus on any parameter and investigate its effects on oil production. Both qualitative and quantitative implications of capillary pressure on the oil production are observed to be strong functions of the size and uniform nature of the grid constructed over the computational domain.
The proposed model provides some significant insight into the displacement mechanisms and aids us in developing a comprehensive understanding of the nature and magnitude of die forces and controlling parameters. Such an understanding will help in the design of specifics of a recovery operation.
Well Testing and Evaluation of Tubing-Conveyed Extreme Overbalanced Perforating
Authors: Azari Mehdi , Burleson John , Soliman Mohamed , Mason Justin , Gazi Naz 
Published: July 2008

Abstract
Traditionally, underbalance perforating has been the preferred perforation technique. Recently, however, a new extreme overbalance perforating (EOBP) that has the potential to improve the completion efficiency of a well without additional stimulation has been introduced. With this method a well with a fluid column is pressurized with nitrogen to above fracturing pressure of the formation before the gun is fired. Gas is then injected, with or without acid or proppants, to create short fractures that extend from the perforation tunnels. The presence of gas lowers the amount of liquid that contacts with the formation, facilitates the well's coming into production after perforation, and results in less formation damage.
This new EOBP method creates highly conductive short fractures, the benefits of which outweigh any restriction that may be caused by perforating debris. The debris that exits the gun when it detonates will be pushed away from the wellbore during the pumping stage, and this will greatly diminish any adverse effects on productivity that overbalanced perforating could cause. This can be considered as a near-wellbore stimulation method that also improves the completion efficiency of a well by allowing perforating and stimulation to be accomplished in one operation. By performing two or more completion procedures during a single trip into the wellbore, service operators have been able to generate economical advantages.
There are numerous ways in which EOBP may be performed. This paper will cover the design, planning techniques, and equipment that can be used to perform tubing-conveyed overbalance perforating. Examples and field cases will show scenarios in which wells with a variety of wellbore conditions such as open perforations and packerless and tubingless installations can be perforated in an extremely overbalanced condition.
An analysis technique that can be applied to a short falloff test immediately following the perforation treatment as well as the standard well testing is also described in this paper. The method of analysis can be used to calculate skin damage, formation permeability, reservoir pressure, and if applicable, fracture parameters such as fracture half-length and conductivity. Several field cases are included to illustrate application of this method.
The Problems Facing the Doha Development Agenda
Authors: Christy David S. 
Published: July 2008

The prospects of successfully concluding the Doha Development Agenda negotiations in 2008 are poor. Even a basic agreement on major issues with details to be filled in later is unlikely. Possibly, there may be an agreement this year on modalities. Deep divisions remain in all major negotiating areas—agriculture, non-agricultural market access (NAMA), services and rules. Moreover, in some respects, the Members do not even agree on the form the negotiations should take, e.g., the level of importance to be accorded to services.