bluuebunny/crossref_metadata_2025_split huggingface dataset:
Correlation Between Oil Composition and Paraffin Inhibitors Activity
Authors: Garcia M.C. , Carbognani L. , Urbina A. , Orea M. 
Published: December 2007

Abstract
Highly paraffinic crudes were characterized by means of physico-chemical analysis (pour point, cloud point and API gravity) and hydrocarbon analysis (wax content, paraffin class-type separation, gel permeation chromatography and high temperature simulated distillation). Although all the studied samples were typical light crudes (32 - 43 API), their high paraffin content was responsible for solidification even above room temperature (33 - 48 C). Several commercial paraffin inhibitors were evaluated with these crudes, being pour point depression the selected activity criteria. Some products evidenced good activity when added to three of the crudes under study, while others induced insignificant changes in the pour point under similar dosages. Correlations between crude oil composition and paraffin inhibitors activity were assessed. The normal / cyclo+iso-paraffins ratio of the crudes that were not affected by the paraffin inhibitors was found higher. The molecular weight distribution (GPC) of the crudes sensitive to additives showed a bimodal character. Additionally, the Concentration of components with more than 24 carbon atoms was found lower than 39 % wt, as determined by simulated distillation. On the other hand, the crudes insensitive to the action of inhibitors displayed monomodal molecular weight distributions with larger contributions of heavy components (more than 52 % wt). Doping experiments carried out with Cl 3-C20 and C20-C44 paraffin extracts and using polarized light microscopy for cloud point determinations, supported the previous findings and permitted to assess the inefficiency of commercial paraffin inhibitors for crudes rich in C24+ alkanes.
P. 681
Development of Gas Tight Seal for Tool Joint
Authors: Bailey Edmond I. , Petrella Jim , Smith Jackie E. 
Published: December 2007

Abstract
A tool joint for 4-1/2 inch drill pipe has been developed that will seal 12,500 psi gas pressure. Pipe with this tool joint can be used for the drilling program and for tasks normally done with a work string. This paper includes the description of the applications for which the tool joint was developed, the development process, the results of the finite element analysis of the tool joint and seal, the performance characteristics of tool joint and the testing that was done.
P. 613
Why Internally Coated Piping Is Used for the World's Largest Seawater Injection System
Authors: Chen E.Y. , Ahmed T. 
Published: December 2007

Abstract
Since Saudi Aramco's seawater injection system was commissioned in 1978, it has undergone a series of expansions and modifications. The system is unique, not only in its size (7 million barrels per day capacity), but also in its complicated piping network. While the original piping system was completely made of bare carbon steel, the new system is made of pipe which is internally coated with fusion bonded epoxy (FBE).
Saudi Aramco's field experience in the past ten years with its seawater injection system has demonstrated the benefits of internally coated pipe. This paper explains why Saudi Aramco decided to use internally coated pipe, which is not a standard practice in the oil industry. Saudi Aramco has two objectives: minimizing water quality deterioration and controlling internal corrosion. First, despite the stringent solids and oxygen removal processes at the intake, water quality always deteriorates as it travels through the pipe. This water, upon arrival at some remote injection wells 250 to 300 kilometers away and 36 hours later, could cause excessive injectivity decline of the wells. Second, internal corrosion generally has not been a problem for uncoated lines, if they are regularly scraped and treated with bactericide for control of microbiologically influenced corrosion. However, uncoated lines which are unscrapable and untreatable require extra corrosion protection.
This paper also discusses the technical challenges concerning coating applications, particularly for coating girth-weld areas in the field. It also discusses scraping requirements for internally coated pipelines, which remains a controversial topic.
P. 721
Case Study of Gas BTU Control For Operational Strategy and Inert Gas Injection Planning
Authors: Lebon M. , Nabil R. , Lehuen P. 
Published: December 2007

Abstract
The aquifer gas storage of Gournay-sur-Aronde (France) has been in operation since 1976. There was a few months of low Btu gas injection, followed by ten years with high Btu gas injection. A gas sweeping was achieved in 1986 to convert the reservoir to a low Btu value gas storage. The cushion gas is therefore a mixture of low and high Btu value gases. The average Btu value during withdrawal periods since 1986 is occasionally very close to the maximum allowed value, potentially raising operational difficulties. For the next ten years, additional wells and surface facilities will be gradually added to increase the working gas and the peak flow rate capacities. This paper describes how a history matching of gas Btu content is performed for the first time using a full field in-house reservoir simulator. In fact, a model was matched the conventional way, then the detailed Btu value history was added. The results of the model in terms of energy and nitrogen content during withdrawal periods have accurately reproduced the actual behavior of the gas storage. This confirms as correct the previous history matching of the reservoir pressure and saturation.
By calculating the evolution of Btu values within the storage, the model proves very efficient in assisting the engineer to define the best strategy for injection and withdrawal periods in order to meet the customers required gas Btu value. Therefore emissibility problems can be avoided by choosing the most suitable wells.
It has been possible to optimize inert gas injection planning by evaluating, under various operational scenarios, the influence of gas mixing on the withdrawn gas Btu values.
P. 563
Analysis of Interference and Pulse Tests in Heterogeneous Naturally Fractured Reservoirs
Authors: Araujo Hugo N. , Andina S.A. , Gilman J.R. , Kazemi H. 
Published: December 2007

Abstract
A geological model of a heterogeneous naturally fractured reservoir was constructed using geostatistical techniques. Single-well, interference and pulse tests were numerically simulated in this reservoir. The purpose was to compare the result obtained from conventional interpretation techniques with the properties of the geologic model in the drainage areas of the wells tested. Relevance of this work is shown by application to an actual field interference test.
The following were concluded in this study:Conventional interpretation of simulated single well tests in heterogeneous naturally fractured reservoirs results in an effective permeability (ke) close to the arithmetic average of the effective permeability distribution in the drainage area of the wells,Conventional pulse and interference test interpretations in naturally fractured reservoirs, in general, yield permeabilities larger than average reservoir permeability in the drainage areas of the wells. These results are consistent with our experience with actual field tests.Single-well test transmissivity (keh/u) can be used in conventional single-porosity pulse and interference interpretation (e.g., PD vs. tD type-curve analysis) to obtain an approximate fracture storativity (ofctfh). Storativity in turn can be used to estimate fracture porosity in the drainage area.
P. 619
Polymeric Damage and a Cost Effective Method for Damage Removal from Wells
Authors: DeVine C. S. , Tjon-Joe-Pin R. M. , Rickards A. R. , Carr M. 
Published: December 2007

AbstractPolymeric damage is due to inconsistent breaks of stimulation fluids as well as to dynamically formed filter cakes. Fluid viscosity reduction is commonly used to gauge polymer degradation, and, although viscosity reduction indicates polymer degradation, reduced viscosity does not necessarily equate to improved fracture conductivity or retained formation permeability. Polymer fragments which contribute to fluid viscosity are not a measure of residual polymer damage.Historically, several methods have been employed to remove polymeric damage and increase well productivity. Prior treatments to remove polymeric damage include bleach (sodium hypochlorite) and acids. In cases of horizontal wells with slotted liners or screens, bleach or acids are not preferred. Additional expensive trips have become mandatory, when coiled tubing or drill-pipe are utilized for spotting the treatment. Additionally, some formations are acid sensitive.Laboratory evaluations of the effects of various gel breakers on linear and crosslinked, guar-based fracturing fluids from room temperature to 210°F, based on the size distribution of generated polymeric fragments, have been previously discussed. Additional studies have demonstrated that a correlation exists between formation rock permeability and the degree of damage resulting from residual polymer fragment deposition - the greater the formation rock permeability, the greater the degree of damage to the formation.The development of a treatment which could effectively reduce polymeric damage in fracture stimulated wells has been a subject of recent research. Core flow and regained conductivity testing have shown that multi-fold improvements can be achieved, even at elevated temperatures exceeding 250°F, and over a wide pH range.Results of extensive core flow and fracture conductivity testing, performed in an effort to correlate cleanup effectiveness to original rock permeability using near neutral and high pH cross-linked frac fluids, have been conducted. In general, a greater percentage of regained permeability was noted for more severely damaged (i.e. permeable) rocks. Rocks tested in this study exhibited permeabilities from 3 md to 2 darcies. Conductivity proppant pack baseline ranges were 250 to 500 darcies. Detailed analyses of the data are provided. Several field case histories of wells which were suffering from polymeric damage are presented.
Monitoring Casing Offset Damage Using Ultrasonic Measurements
Authors: Morris C. W. , Gwinn R. L. , Rambow F. H. K. , Mitzel D. P. 
Published: December 2007

Abstract
Many reservoirs are located in tectonically active areas, experience formation subsidence, or have salt formations which can result in the wellbore casing being mechanically damaged by the relative movement of a formation layer interface. The casing is forcibly ‘offset’ in the horizontal direction through a short vertical depth interval of less than 10 feet. The offset increases with time until there is complete collapse and/or shearing of the casing. Many casing inspection tools can measure the inside radius of a casing joint with various degrees of accuracy and resolution, and some tools can measure the casing thickness. However, casing offset monitoring requires an accurate determination of the casing distortion in the vertical dimension also. Measuring this offset is difficult unless the entire tool position within the wellbore can be defined.
Because of the unique measurement capabilities of the ultrasonic cement evaluation tool, it is now possible to monitor casing offset conditions accurately and to use these results to predict casing failure. The ultrasonic tool can measure the casing offset across a short interval, the inside radius, the thickness, and the external cement conditions in one operation. Thus, all of the information needed to evaluate the potential mechanical failure of a casing joint is known as the situation develops at the formation layer interface.
Ultrasonic imaging data from over ten wells were evaluated using this new monitoring technique. Multiple logging trips over a period of nearly one year showed the progressive casing damage in these wells. The monitoring technique and resulting measurements will be illustrated. Also, the casing was pulled from one well for surface inspection and the actual casing dimension data from the damaged interval was compared with the log results. This well validated the use of the technique for casing monitoring throughout the area. The new casing inspection technique provides for better well and reservoir management information in a difficult production environment.
Planning for Successful Window Milling Operation
Authors: Dewey Charles H. , Childers Ronald D. 
Published: December 2007

Abstract
Historically, the applications of window milling tools and methods were limited to remedial operations. The main bore would be sidetracked only in the event of irretrievable fish, collapsed casing, depleted reservoir, etc. In recent years however, the re-entry drilling has become an increasingly popular option for production optimization as a result of advanced developments in the milling, drilling and measurement tools and technology.
One of the important aspects of re-entry drilling is to mill a window in the existing casing and sidetrack the well bore. Past experience shows that inadequate planning for a window milling project has resulted in either an aborted attempt or premature failure in the hole.
In order to achieve a successful window milling operation, the following ten (10) points must be addressed and situations resolved prior to commencing with the casing exit operation; (1) Selection of best place to set and to orient the whip-stock, (2) Hole angle, (3) Radius of curvature (build, drop, left or right tum) in the vicinity of casing exit, (4) Whip face orientation methods (MWD, gyros), (5) Flexure characteristics of the bottom hole assembly and resulting dogleg severity, (6) Length of sidetracking assembly, (7) Depth of rat hole to facilitate drilling objective (short, medium or long radius) after milling window, (8) Casing conditions, (9) Formation types, and (10) Retrievability of whip-stock assembly.
This paper will discuss the above points in detail using data from actual field runs. The field runs will be selected from a large database of window milling jobs maintained over the last 10 years. Additionally, the paper will present recommendations and guidelines for planning a successful window-milling project.
On The Choice of Current Profiles for Deep-Water Riser Design
Authors: Adams A.J. , Thorogood J.L. 
Published: December 2007

Abstract
The paper describes the present state-of-the-art in fatigue analysis for vortex-induced vibration (VIV) of ultra-deep water unfaired drilling risers (1000 m water depth and above) in steady currents. It complements an earlier work on the broader issues of deep-water riser design and management.
To date, strength and VIV fatigue life analyses have always been based on the enveloping current profile, i.e., the locus of predicted extreme speeds for the various current meter depths. For most offshore structures, this is a conservative approach, and it was believed that this was also true of deepwater risers. However, recent work for BP Norway has shown that this is not the case, and that analysis for the mean concurrent profile (i.e., the current at any given instant in time) gives predicted fatigue lives an order of magnitude lower. It is thought that this was not previously known to the industry.
Techniques are presented for the selection of concurrent design profiles, and the analysis methods and assumptions for VIV response prediction and fatigue damage calculation are described. Fatigue life results are presented for five deep-water wells, all in the Atlantic Margin area (West of Shetland, the Rockall Trough and the Voring Plateau). Riser safety management via monitoring of predicted damage is discussed, and cumulative damage results are given for a recent well.
P. 781
Miscibility Variation in Compositionally Grading Reservoirs
Authors: Høier Lars , Whitson Curtis H. 
Published: December 2007

Abstract
Minimimum miscibility conditions of pressure and enrichment (MMP/MME) have been computed using an equation of state (EOS) for a number of reservoir fluid systems exhibiting a compositional gradient with depth due to gravity/chemical equilibrium. MMP/MME conditions are calculated using a multicell algorithm developed by Aaron Zick, where the condensing/vaporizing (C/V) mechanism of developed miscibility is used as the true measure of minimum miscibility conditions, when it exists. The Zick algorithm is verified by detailed 1D "slimtube" simulations with elimination of numerical dispersion. The miscibility conditions based on the traditional vaporizing gas drive (VGD) mechanism are also given for the sake of comparison, where it is typically found that this mechanism overpredicts conditions of miscibility.
Significant variations in MMP and MME with depth exist for reservoirs with typical compositional gradients, and particularly for near-critical oil reservoirs and gas condensate reservoirs where the C/V mechanism exists. An important practical implication of these results is that miscibile displacement in gas condensate reservoirs can be achieved far below the initial dewpoint pressure. The requirement is that the injection gas (slug) be enriched somewhat beyond a typical separator gas composition and that the C/V miscibility mechanism exist. This behavior results in many more gas condensate reservoirs being viable candidates for miscible gas cycling than previously assumed, and at cycling conditions with lower cost requirements (i.e. lower pressures) and greater operational flexibility (e.g. cycling only during summer months).
A Novel Approach to Characterize Dynamic Interaction Between Super Permeability Layers with Vertical - Faults and Their Affect on Flood Front Movement
Authors: Al-Shahri Ali M. , Al-Muraikhi Ahmed 
Published: December 2007

Abstract
Managing the Ghawar Field with super permeability layers and vertical faults, with a mission of maximizing oil recovery with the lowest cost, is a challenging task. Super permeability layers are associated with high productivity where the flow is confined to 10-20 feet layer in a 250 feet thick reservoir. After producing part of the reserves, 3-D seismic and horizontal drilling clearly indicate the existence of fault systems. Vertical faults can be connected to the super permeability layers in certain locations of the field.
Pressure testing happens to be a powerful reservoir characterization tool when integrated with geological and geophysical data as well as specially designed horizontal wells. This paper describes the planning, execution and results of series of extensive field testing which were performed to understand reservoir large-scale flow features (faults or joints).
Data integration has resulted in characterizing fluid movement to be governed primarily by systematic large scale flow features which are almost parallel to both flood- front movement and to the maximum horizontal stress direction. The horizontal isolated super permeability layers are a secondary source of water movement, since it is dynamically supported by the faulting system. Diagnostic tools were developed and implemented to address the issue of when can the super permeability be produced to advantage and when it should be avoided, by considering the dynamic interaction between the two systems.
P. 737
New Fast, Stochastic, Boolean Simulation of Fluvial Deposits.
Authors: Viseur Sophie , Shtuka Arben , Mallet Jean-Laurent 
Published: December 2007

Summary
It is now a fairly common practice to characterize fluvial reservoirs via stochastic simulations of fluvial deposits. Three criteria are used to evaluate various simulation processes. They are:honoring input data (usually well data);defining fluvial heterogeneity boundaries; andspeed.
There are two major branches in 3D stochastic simulations: pixel-based and object-based. The pixel-based method distributes property values rather than the heterogeneities. It is fast but the boundaries between heterogeneities are often blurred and do not reveal geological features. The object-based (or boolean) method distributes the heterogeneities directly and can therefore produce well-defined feature boundaries. However, object-based methods often involve a simulated annealing process which converges slowly.
In this paper, we will present a new, straightforward object-based conditional simulation process that honors the input data, produces well-defined heterogeneites and works reasonably fast.
The revolutionary step that makes this possible is a well data segmentation process and a channel generating process that we have developed. This processing enables us to rethink and redesign the entire object-based simulation process. As a result, we are able to, in a reasonable amount of time, produce multiple realistic realizations of a fluvial environment that honor well data and other geological information.
P. 697
A New Method for Saturation Measurements in Core Flooding Experiments
Authors: Bruining Johannes , Nguyen Buu-Long , Slob Evert 
Published: December 2007

Abstract
In this paper we present an application of Frequency Domain Reflectometry (FDR) – an electromagnetic technique that measures the dielectric response of a transmission line. Such a response is related to the electric permittivity and conductivity distribution along the transmission line. In our experimental set-up the sample core replaces the dielectric material of a coaxial transmission line sample holder.
We use a recursive relation to derive the multiple reflection coefficient which is a function of the electric properties of the porous medium and thus a function of the water saturation.
We present an inverse modeling procedure which allows reconstruction of water saturation profiles from the measured multiple reflection coefficients. For the inverse modeling we use the Polak-Ribière conjugent gradient algorithm to extract the saturation distribution.
We show numerically and experimentally that the simulation profiles inclusive the position of the Buckley-Leverett shock front can be followed by a single measurement of the multiple reflection coefficient.
The results of our numerical experiments validate the inverse modeling procedure introduced in this paper.
Predicting Sand Erosion in Chokes for High Pressure Wells
Authors: McLaury B.S. , Shirazi S.A. 
Published: December 2007

Abstract
Sand from reservoirs is carried along with oil and gas in producing wells. This sand can cause severe erosion resulting in failure. A variety of fittings are especially susceptible to erosion damage. For example, geometries that redirect the flow such as elbows experience erosion. In these cases, the particle momentum resulting from the mean flow drives the sand into the wall resulting in erosion. Several researchers have investigated this form of erosion. However, only a few studies have investigated the erosion in chokes where the erosion can even be more severe. In fact, chokes can experience failure due to erosion in a matter of a few days in high pressure gas wells. The present work uses computer simulations to examine the erosion in chokes. The simulation consists of three parts: solve the flow field (velocities, pressure, turbulent kinetic energy), determine sand trajectories, predict erosion resulting from sand impingement information. This paper presents the results obtained during each of these parts for three cases that examine the effect of pressure drop and shape on the severity of erosion. The results obtained from the model are in good agreement with field observations.
P. 769