bluuebunny/crossref_metadata_2025_split huggingface dataset:
Production and Injection Profiling Through Permanent-Downhole-Pressure-Gauge Recording During a Coiled-Tubing-Conveyed Workover Operation
Authors: Ouyang Liang-Biao , Sawiris Ramzy 
Published: May 2006

Summary
Production and injection profiling through permanent-downhole-pressure-gauge (PDG) recording during a coiled-tubing (CT) -conveyed workover operation, a novel and unique application, has been proposed in the present paper. Theoretical development of the new technique is provided first. Example studies are then given to illustrate the application of the technique. Application scenarios, practical issues, and key impacting parameters have also been addressed. Finally, a field case study implementing the new technique for a long horizontal well has been performed to demonstrate how the production profiles calculated from PDG data compare closely to the results from a recent production logging survey, which was expensive and mechanically risky yet turned out to be unsatisfactory.
The technique could be applied to real-time production and injection profiling for different well configurations (vertical, horizontal, deviated, and multilateral) and bring tremendous financial benefits through replacing conventional production-logging surveys that could be cost-extensive for horizontal or multilateral wells offshore.
Optimizing Fracture Stimulation Using Treatment-Well Tiltmeters and Integrated Fracture Modeling
Authors: Mayerhofer Michael J. , Stutz H. Lloyd , Davis Eric J. , Wolhart Stephen L. 
Published: May 2006

Summary
This paper covers the optimization of hydraulic fracture treatments in a new coalbed methane (CBM) reservoir in Wyoming. A mul-tiwell pilot project was conducted in the Copper Ridge (CR) field to assess future development potential. Hydraulic fracture mapping was successfully performed with treatment-well tiltmeters on six wells including the first-ever used on propped treatments. The mapped fracture height was then used to calibrate the fracture model, perform on-site fracture-design changes, and optimize future fracture treatments. This paper shows how early use of fracture diagnostics can assist in the development of a new reservoir.
A New, Improved JSA Process Gets Enthusiastic Approval From Field Personnel
Authors: Veley Carl , Ritchie Norman , Coats E. Alan , Disatell Joel 
Published: May 2006

SummaryMany oilfield companies require field crews to systematically analyze safety aspects of their activities before starting work. Most commonly, this process is called a job safety analysis, or JSA.Recent developments in measuring safety performance have changed the JSA process by better defining its function, as explained in this paper. This change provides major improvements and is rapidly gaining acceptance throughout the Gulf of Mexico petroleum industry.An informal survey of Gulf of Mexico offshore production facilities and drilling rigs showed that JSAs tend to be viewed as a tedious formality that crews comply with only because they are required to do so. For a typical jackup drilling rig, adopting the new JSA process and its standards can reduce the total time spent in JSA meetings from approximately 30 man-hours per day to fewer than 4 man-hours per day. In general, work crews enthusiastically approve of the new style of JSA because of the time savings and because it clarifies key responsibilities. Where conventional JSAs simply identify things that should happen, the new style causes things to happen, and the result is a considerable reduction in the likelihood of accidents.
Measurement and Prediction of Salt Solubility in the Presence of Hydrate Organic Inhibitors
Authors: Masoudi R. , Tohidi B. , Danesh A. , Todd A. C. , Yang J. 
Published: May 2006

Summary
Organic inhibitors (e.g. methanol, ethanol, ethylene glycol, and triethylene glycol) are generally used to reduce the risk of gas hydrate formation in drilling and production operations. The addition of organic inhibitors has a significant adverse effect on the solubility of salts, increasing the risk of salt deposition. A better understanding of salting-out problems is necessary for effective design and implementation of flow assurance strategies in such complex systems.
In this paper, we present an experimental investigation on the effect of methanol, ethanol, and ethylene glycol on the solubility of several salts, including halite, sylvite, and antarcticite. The results show that ethylene glycol has a much lesser adverse impact on salt deposition than methanol and ethanol. The details of an experimental setup used for measuring salt solubility and salting out are described. The setup could also provide valuable information on the effectiveness of various inhibitors used for preventing salt deposition in the presence or absence of gas hydrate organic inhibitors.
In addition, a novel predictive numerical approach is proposed to model salt formation in brine solutions with or without hydrate organic inhibitors. The model is based on the equality of the fugacity of salt in the solid phase and aqueous phase, which are calculated by an equation of state. The validity of the new developed model is demonstrated over a wide temperature range (i.e., −20 to 125°C), salt concentration up to saturation point, and hydrate inhibitor concentration up to 50 mass%.
An Analytical Model of Temperature and Stress Fields During Cold-Water Injection Into an Oil Reservoir
Authors: Kocabas I. 
Published: May 2006

Summary
A new transient analytical model has been developed to study the temperature and stress distribution induced by nonisothermal fluid injection, particularly conventional waterflooding. In the model, the transient pressure, temperature, and stress fields are computed consecutively. The pressure field has been computed by using either the exponential integral solution for a unit mobility ratio displacement or Ramey's composite reservoir model for a nonunit mobility ratio pistonlike displacement. The transient temperature field has been computed by using a model that can account for both the overburden heat losses and transversal heat dispersion within the reservoir. The stress distribution has been calculated with a method presented for a plane strain in a hollow cylinder.
The results implied that the thermoelastic changes in the cooled zone could affect the surrounding stress fields in a profound manner. For instance, for a porous medium with stiff material (such as carbonate reservoirs) owing to cooling by the injected cold water, large-scale tensile stresses arise and may induce new fractures (or propagate existing ones) far into the reservoir. In addition, a major tangential stress concentration develops just in front of the cooled zone; hence, shear yield is highly likely to occur ahead of the thermal front.
The 2D treatment of the temperature field makes the new method superior to the previous analytical models where only a 1D field has been used.
Development and First Field Application of a Gel/Cement Water-Shutoff System
Authors: van Eijden Jip , Arkesteijn Fred , Akil Ihab , van Vliet Jacques , van Batenburg Diederik , McGinn Paul 
Published: May 2006

Summary
Water production in northeast Syria has increased significantly in recent years. As a result, costs per barrel of oil have increased and the field's production is currently constrained by the facilities capacity.
Production logging tool (PLT) surveys, combined with a reservoir study, showed that good-quality sands were not properly swept by the water, probably because of poor connectivity in the reservoir. It was anticipated that these unswept sands could contribute to production if the watered-out sands were shut off.
A newly developed gel/cement has been used to shut off the watered-out sands in a cost-effective manner. The gel/cement system combines the properties of two shutoff techniques:
Cement for mechanically strong perforation shutoff. Gel for excellent matrix shutoff.
The gel, used as "mix water" of the cement, will be squeezed into the matrix, creating a shallow matrix shutoff. The cement will remain in the perforation tunnel as a rigid seal. This system showed superior shutoff performance in the laboratory compared to normal cement squeeze techniques. Selective perforation of the hydrocarbon zones will re-establish the oil production. The shutoff zones can be reopened later in the well's life when artificial lift has been installed.
The system was tested in the field in two wells. In the first field trial, 84 m of perforations (gross) was squeezed off with the gel/cement in a single attempt. After reperforation of the top and the middle zone, the well produced at a strongly reduced water cut (i.e., 25 to 33% compared with 60 to 62% before the treatment) and an increased oil production (i.e., 3,000 BOPD compared with 1,000 BOPD before the treatment). The oil production declined to 2,000 BOPD over a year; the water cut gradually increased over that period to 56%. In the second well, full shutoff was achieved but oil production could not be resumed for reasons that are not fully understood.
Flow in Perforated Pipes: A Comparison of Models and Experiments
Authors: Clemo Tom 
Published: May 2006

Summary
A model of pressure losses in perforated pipes that includes the influence of inflow through the pipe walls compares favorably with past and recent experimental studies. The single-phase model was developed in 1987, but it is not generally known in the petroleum industry. This model is compared to three experiments: one using air and two using water. The model must be manipulated to conform with the way individual experimenters report their findings. In general, there is good agreement. Where there is poor agreement, the cause may be experimental artifacts. A second model fails to match experimental results when the pipe geometry changes significantly.
Flow Profiling by Distributed Temperature Sensor (DTS) System—Expectation and Reality
Authors: Ouyang Liang-Biao , Belanger Dave 
Published: May 2006

Summary
Permanent downhole monitoring can provide valuable information for production decisions in real time without the need to perform an intervention to collect data. One of the commercial permanent monitoring technologies is the fiber-optic DTS, which can record the wellbore temperature profile in real time with decent accuracy and resolution. A key potential application for DTS data is to profile injection or production for wells, which is the primary motivation and focus of this project.
In the present paper, a thermal model recently developed for single-phase-and multiphase-fluid flow along a vertical, deviated, or horizontal well will first be briefly described. The model can be applied for both wellbore temperature prediction (forward modeling) and for flow profiling using a measured temperature profile (inverse problem).
The model has successfully been applied for investigating key thermal characteristics of single-phase- and multiphase-fluid flow along a wellbore. In particular, the dependence of wellbore temperature upon phases, flow profile, fluid type, fluid properties, well deviation, and Joule-Thomson effect will be demonstrated in the paper. The model has further been adapted for directly predicting production and injection profiles (i.e., flow profiling) based on a given wellbore temperature profile. The potential impact of noise in the DTS measurement on flow profiling has been explored.
It is found that the wellbore temperature does not change significantly along horizontal or near-horizontal sections because of the small variation in geothermal temperature. Therefore, based only on steady-state DTS data, the amount and the location of each fluid entry would be difficult to identify. The current study shows that a maximum wellbore deviation of 75° should be honored to appropriately estimate flow profile directly through steady-state DTS data. The study has also led to an observation that under certain circumstances such as multiphase flow, a production profile may be determined through DTS temperature measurement with extra data or information provided. The types of the extra measurements and the appropriate approaches will be recommended.
Compressed Natural Gas (CNG): An Alternative to Liquefied Natural Gas (LNG)
Authors: Economides Michael J. , Sun Kai , Subero Gloria 
Published: May 2006

SummaryNatural gas is rapidly becoming an even more important resource of energy, with its share in the world consumption expected to increase dramatically over the next two decades. Currently, natural gas is transported to the markets by pipelines as LNG. Transporting the natural gas by pipelines is convenient and economically attractive onshore. For the offshore transport of natural gas, pipelines become challenging as the water depth and transporting distance increase. LNG, an effective means of transporting gas for long distances across the seas, constitutes 25% of the world gas movement. But LNG projects require large investments, along with substantial natural-gas reserves, and are economically viable for distances of 2,500 miles and beyond.CNG provides an effective way for shorter-distance transport. The technology is aimed at monetizing offshore reserves that cannot be produced because of the unavailability of a pipeline or because the LNG option is very costly. Technically, CNG is easy to deploy, with lower requirements for facilities and infrastructure. "Coselle" and "Votrans" are two would-be commercial, high-pressure gas-storage and -transport technologies for CNG. Technical and economic analyses of these two technologies were done in this study, and a comparison is provided. The results show that for distances up to 2,500 miles, natural gas can be transported as CNG at prices ranging from U.S. $0.93 to $2.23 per MMBtu compared to LNG, which can cost anywhere from $1.5 to $2.5 per MMBTU depending on the actual distance. At distances beyond 2,500 miles, the cost of delivering gas as CNG becomes higher than the cost for LNG because of the disparity in the volumes of gas transported with the two technologies.
Cleanup of Oil Zones After a Gel Treatment
Authors: Seright R. S. 
Published: May 2006

SummaryA simple mobility-ratio model was used to predict cleanup times for both fractured and unfractured production wells after a gel treatment. The time to restore productivity to a gel-treated oil zone (1) was similar for radial vs. linear flow, (2) varied approximately with the cube of distance of gel penetration, (3) varied inversely with pressure drawdown, (4) varied inversely with the kw at Sor in the gel-treated region, and (5) was not sensitive to the final ko at Swr. Although ko at Swr (after gel placement) had no effect on the cleanup time, it strongly affected how much of the original oil productivity was ultimately regained.
Deep Downhole Chemical Injection on BP-Operated Miller: Experience and Learning
Authors: Wylde J. J. , Williams G. D. M. , Careil F. , Webb P. , Morris A. 
Published: May 2006

Summary
The BP-operated Miller field poses a unique chemical challenge because it has arguably the harshest oilfield scaling regime in the North Sea, if not the world. An average of three to four squeeze treatments per week are performed across the online wells, creating tremendous operational, chemical, and logistical challenges. This produces the ideal environment in which to evaluate new technologies and engineering solutions in an attempt to increase the wells’ overall efficiency.
Deep downhole chemical injection (DDHCI) was installed on Well A26/08 and brought on line in July 2003. The Miller DDHCI is unique to the industry because it allows the injection of a scale inhibitor at the perforations by means of a tail pipe, essentially protecting the whole of the tubing from scale deposition. This approach has the potential to reduce the need for additional scale control through squeeze treatments.
Much emphasis has been placed on the efficiency of scale protection that DDHCI offers. A year of flowing the well under the protection of the continuous-injection chemical has yielded much information about the nature of the chemical delivery and inhibitor efficiency. Much also has been learned about the pumping hardware required to ensure continued performance. Further information has been provided by two intensive sampling exercises that have allowed independent analysis of the squeeze chemicals and the injected chemical.
This paper details the design criteria of the DDHCI completion as well as the philosophy of installing such a device. It then gives details on the management strategy of using DDHCI in a proactive manner to maximize the time between squeeze treatments.
Stabilization of Gas-Distribution Instability in Single-Point Dual Gas Lift Wells
Authors: Eikrem Gisle Otto , Aamo Ole Morten , Foss Bjarne A. 
Published: May 2006

SummaryWhile casing-heading instability in single gas lift wells has attracted a lot of attention, gas-distribution instability in dual gas lift wells has not. In this paper, we present a simple, nonlinear dynamic model that is shown to capture the essential dynamics of the gas-distribution instability despite the complex nature of two-phase flow. Using the model, stability maps are generated showing regions of stable and unstable settings for the production valves governing the produced flows from the two tubings. Optimal steady-state production is shown to lie well within the unstable region, corresponding to a gas distribution between the production tubings that cannot be sustained without automatic control. A simple control structure is suggested that successfully stabilizes the gas-distribution instability in simulations and, more importantly, in laboratory experiments.
Geochemical characterisation and erosion stability of fine‐grained groyne field sediments of the Middle Elbe River
Authors: Schwartz René 
Published: May 2006

AbstractBecause of the significant reduction of flow velocity relative to the main current there is an accumulation of sediment material in the centre of the groyne fields over time (years to decades) up to a maximum of 1.5 m. Based on the element‐ and compound‐specific depth functions of this fine‐grained material with high organic matter content the sedimentation history of the Elbe River sediments concerning the environmentally relevant nutrients and pollutants can be reconstructed. It could be shown that the fresh sediments are less polluted than the deeper older ones. During the extreme flood of the river Elbe in August 2002 the critical erosion shear stress in the groyne fields was high enough to remobilise a considerable portion of the sediment depot. The hazard to the environment is high due to the fact that a significant part of the remobilised polluted sediments was distributed over the recent floodplain which is normally used as pasture. Thus these groyne field sediments represent a temporary danger for the water quality of the river Elbe. But the hazard of the solids sedimented in the recent floodplain of the river can be viewed as long‐lasting.
The effects of mining in Northern Romania on the heavy metal distribution in sediments of the rivers Szamos and Tisza (Hungary)
Authors: Kraft Claudia , von Tümpling Wolf , Zachmann Dieter W. 
Published: May 2006

AbstractThe breach in the dam of a tailing pond in the processing plant of a gold mine in Baia Mare (NW Romania) in January 2000 lead to an ecological disaster in the rivers Szamos and Tisza. It was mainly caused by the released slurries containing cyanides and heavy metals. The investigation of surface sediment samples and depth profiles of the years 2000 and 2001 documented the pollution of the rivers Szamos and Tisza on Hungarian territory. In the Szamos and large areas of the Tisza floodplains a significant enrichment with the heavy metals Pb, Cd, Cu, and Zn is existent. The identification of the binding forms with sequential extraction showed that Cd and Zn exist in an easily available form. Therefore the remobilization is possible and an environmental hazard in the downstream areas must be considered. The anthropogenically caused portions of heavy metal concentrations decrease considerably with increasing distance to the mining region. The comparison of the concentrations of heavy metals in both years shows that the pollution is not only caused by the accident in January 2000. The increase of concentrations is based on the permanent input of pollutants into the rivers. The pollution is mainly caused by the erosion of exposed tailing dumps and the poor maintenance of the treatment plants.
Spatial distribution and bonding forms of heavy metals in sediments along the middle course of the River Elbe (km 287ċ390)
Authors: van der Veen Andrea , Ahlers Corinna , Zachmann Dieter W. , Friese Kurt 
Published: May 2006

AbstractSediments of eight groyne fields along the middle course of the River Elbe (river km 287ċ390) were geochemically studied. The 78 sediment samples were analysed for pH and grain size distribution. The grain size fraction < 2 μm was used for mineralogical and chemical analysis: semiquantitative clay mineral analysis; total element content (Al, Ca, Fe, K, Mn, Cd, Cr, Cu, Ni, Pb, Zn), total inorganic and organic C, and bonding form fractionation with a six‐step sequential chemical extraction. The latter was performed on selected samples (n = 32). The sediments along the Elbe's course are still contaminated with heavy metals far above the local geogenic background level. An enrichment factor of more than 15 was calculated for zinc. Cr and Ni are the elements with the lowest enrichment. The bonding form analysis of selected heavy metals shows a dominance of relatively immobile bonding forms, e. g. the moderately reducible and the residual fraction, which implies a relative low mobility potential. Only Zn poses a higher potential threat to the environment, since it has a higher percentage of the first three extracted phases: adsorbed, carbonate, and easily reducible fraction.
Synthetic, spectral, thermal and antimicrobial studies of bis(N,N‐dialkyldithiocarbamato)arsenic(III) and antimony(III) complexes with diphenyldithiophos‐phate and diphenyldithiophosphinate
Authors: Chauhan H. P. S. , Singh U. P. 
Published: May 2006

AbstractBis(N,N‐dialkyldithiocarbamato)arsenic(III)/antimony(III) diphenyldithiophosphate/diphenyldi‐thiophosphinate complexes of the type [R2NCS2]2MS(S)PX2 [where M = As and Sb; NR2 = N(CH3)2, N(C2H5)2 and N(CH2)4; X = OC6H5 and C6H5] have been synthesized and characterized by physico‐chemical, spectral [UV, IR and NMR (1H, 13C and 31P)] and thermal (TG, DTA and DSC) analysis. The TG analysis shows single‐step decomposition of the complex to Sb2S3. These complexes have been screened for antibacterial and antifungal activity using the disc diffusion method. All the complexes have shown good activity as antibacterial and antifungal agents, which increased on increasing the concentration. Chloroamphenicol and terbinafin were used as standards for the comparison. Copyright © 2006 John Wiley & Sons, Ltd.
Synthesis and structures of cycloalkylidene‐bridged mixed cyclopentadienyl‐indenyl tetracarbonyl diruthenium complexes
Authors: Lin Jin , Luo Shuang , Cheng Bin , Wang Baiquan , Xu Shansheng , Song Haibin 
Published: May 2006

AbstractA series of cycloalkylidene‐bridged mixed cyclopentadienyl‐indenyl tetracarbonyl diruthenium complexes (η5:η5‐RC5H3CR′2C9H6)Ru2(CO)2(µ‐CO)2 [R = H, R′, R′ = Me2 (1), (CH2)4 (2), (CH2)5 (3), (CH2)6 (4); R = tBu, R′, R′ = Me2 (5), (CH2)4 (6), (CH2)5 (7)] have been synthesized by reactions of the corresponding ligands RC5H4CR′2C9H7 with Ru3(CO)12 in refluxing xylene. The molecular structures of 2, 6 and 7 have been determined by X‐ray diffraction. Copyright © 2006 John Wiley & Sons, Ltd.