bluuebunny/crossref_metadata_2025_split huggingface dataset:
In-Fracture Explosive Hydraulic Fracturing Fluid and Its Rheological Study
Authors: Cui Mingyue , Shan Wenwen , Jin Liang , Ding Yansheng , Ding Yunhong , Chen Li , Liu Ping , Xu Zhihe 
Published: December 2007

Abstract
Low permeability reservoirs take a large portion of the newly discovered hydrocarbon reservoirs. Stimulating low and ultra low permeability reservoirs faces more technical challenges.
Unlike other stimulation techniques such as "well shooting", "nuclear explosion", and "high energy fracturing", the concept of in fracture explosion (IFE) is to create a fracture hydraulically, convey solid explosives deep into the fracture and place them in the fracture. Then ignite the explosives in the fracture to generate crushed zones or shear fractures near the main fracture while keeping the well bore intact. In such a way, the well productivity is increased. For complex tight gas reservoirs, especially those that tend to develop multi fractures and shear fractures by conventional hydraulic fracturing making the placement of proppant difficult, this technology has irreplaceable advantage.
Fracturing fluid for in fracture explosion has two functions -to carry solid explosives while create hydraulic fractures, and to propagate ignition. This study has found such a fluid system that can meet both general requirements for hydraulic fracturing fluid and the realization of lighting, transmit fire, ignition, and propagate explosion under simulated reservoir conditions.
The fluid system was tested successfully in a narrow fracture simulator. Expected explosion realized in this simulation. The simulated fracture has a length of 2300 mm with variable width of 0–50 mm. The process of squeezing, igniting, and explosion of 300g TNT equivalent was tested.
This fluid system has the following properties:
Rheology at reservoir temperature can be adjusted according specific requirement. Viscosity ranges from 10 to 50 mPa.s. Wall building leak off coefficient is 3.6×10−4 m/min0.5 and spurt loss is 0.25 ml/cm2. Combined with a regular fracturing fluid as a lead (pad), such properties allow the fluid to satisfy the requirements of generating deep fractures and transport/place explosives in the fractures.
This paper will provide details of the study and discuss the potential applications for tight gas reservoir stimulation.
Electrostatic Demulsification on Crude Oil: A State-of-the-Art Review
Authors: Noïk Christine , Chen Jiaqing , Dalmazzone Christine 
Published: December 2007

Abstract
Electrostatic coalescence is the most efficient water-in-crude-oil demulsifying technology having been adopted in upstream dehydration and downstream desalting operations. Significant improvements in the capacity and performance of existing crude oil dehydrators/desalters have been achieved through continuous improvement in the mechanism research, the electric field development, and the practice of pre-coalescing step.
The first part of this paper presents the current understanding about the electrocoalescence mechanism of water droplet in crude oil emulsions up to now. Besides analyzing various forces acting on the water droplet at a macro-scale, it also discusses the influence of turbulent flow conditions and electric field voltage/frequency.
The second part of this paper presents systematically some typical technologies in electrostatic demulsification process and online electrostatic pre-coalescers up to now. For the electrostatic dehydrator/desalter, the authors pay more attention to the composite plate electrode, PC-based Load Responsive Controller, improved feed-stream distribution and variable voltage/frequency electric field. The variable voltage/frequency technology is the tendency which makes it possible for the customer to adjust the voltage and frequency simultaneously according to the corresponding physical properties of the inlet crude oil stream, thus the dehydration efficiency will definitely be improved. The typical representatives of compact electrostatic pre-coalescer which have achieved successfully field trial results, such as CEC, IEC, VIEC, highlight the moderate turbulent flow in their corresponding proprietary technologies, rather than the power supply.
Finally, some technological tendencies related with electrostatic coalescence of water-in-oil emulsions have been presented, such as integration with centrifugation, combination with flotation, etc.. Considering that heavy oils are becoming increasingly attractive from the stand point of reserves and economic status including China, the authors introduce the challenge and some successful trials on the electrostatic dehydration of heavy oils. Some suggestions are put forward as concluding remarks.
Rotary Steerable Systems Result in Step Change in Drilling Performance – A Case Study
Authors: Malik Mirghani , Tewari Raj Deo , Naganathan Sivaraman 
Published: December 2007

Abstract
Exploration and development of Heavy oil fields with high water cut and sand production in Muglad basin in Nothern Africa started with vertical wells and as time progressed matured into drilling Horizontal wells.
Typically drilling challenges in this area include drilling very reactive shales, shallow kick off depths and high build rates, unconsolidated sand stones interbedded with shales which are sensitive to mud weight and are prone to lost circulation.
First few horizontal wells were drilled with conventional technology of positive displacement motor with silicate mud. Many of these wells faced hole cleaning issues leading to pack off, excessive back reaming and stuck pipe incidences. Uneven build rates via sliding in interbedded formation leading to high borehole tortuosity. It is significant to note that due to these difficulties one of the planned horizontal wells was side tracked three times after stuck pipe incidences and finally completed as a 30 degree deviated well with a total cost over run of 300% above AFE.
Since then Rotary steerable system has been deployed to drill these challenging wells with significant improvement in drilling performance, saving days and cost and eliminating stuck pipe incidences. This paper compares the performances of drilling with PDM Vs RSS in the same reservoir and presents the lessons learnt. A cost benefit analysis has also been performed and it clearly shows that RSS is both technically and economically a sound approach to drilling horizontal wells in Muglad basin.
History Matching with Combustion-Tube Tests for Light-Oil Air-Injection Project
Authors: Onishi T. , Okatsu K. , Teramoto T. 
Published: December 2007

Abstract
A series of experiments is essential in light oil air injection (LOAI) study. Accelerating Rate Calorimeter (ARC) test, Thermo Gravimetric Pressurized Differential Scanning Calorimeter (TG/PDSC) test and Combustion Tube (CT) test are generally conducted to evaluate a potential of air injection in fields. ARC test is used to determine the extent and continuity of reactions in the low and high temperature range. TG/PDSC test also helps to identify the temperature ranges over which oil reacts with the oxygen. The purposes of the CT test are (1) to assess the overall burning characteristics of oil, (2) to measure incremental oil production, air and fuel requirements and other parameters and (3) to measure produced gas compositions and oil and water production to provide benchmarks for monitoring future field operations. On this series of experimental work, using domestic oilfield sample, two CT tests were conducted, in low water saturation case and high water saturation case after waterflooding, to estimate the applicability of LOAI including on tertiary mode. Both tests showed stable combustion performance in terms of temperature, pressure response, produced gas compositions and incremental oil production.
On the other hand, numerical simulation is important to predict field production performance. The appropriate reaction kinetics on the combustion has to be used in the numerical simulation. History matching with CT tests were conducted to obtain the kinetics, and two kinds of reactions, "oxidation reaction" and "combustion reaction" were used in the study. In the former reaction, oxygen is consumed by the oil to form oxidation compounds. In the latter one, oxygen reacts with the compounds to form carbon dioxide and water. Reaction parameters were used as matching parameters. Results of history matching with both CT tests using same reaction kinetics were obtained.
This paper presents the results of the CT tests and the history matching studies with these tests and also some discussion of the air injection process.
An Integrated Approach to Risk and Hydraulic Simulations in a Well Control Planning Perspective
Authors: Arild Øystein , Kåre Fjelde Kjell , Løberg Tove 
Published: December 2007

Abstract
Being an environmentally sensitive area, wells drilled in the Barents Sea are subject to comprehensive well planning, particularly with respect to well control issues. On the Obelix field, which is a limestone prospect in the Barents Sea, an extensive quantitative risk-based well control study was undertaken in order to establish robust operational routines for facing major risks and uncertainties.
An advanced dynamic computer model was used to evaluate potential well control scenarios which could occur. Drilling into caves can lead to severe mud losses and introduce large influx volumes in the well. An important part of the study was therefore to include a discussion of possible scenarios, e.g. mud loss and influx detection critiera and evaluate procedures for mitigating severe losses. The advanced well control model was then used to evaluate the consequences of large influx volumes. Since the well was relatively shallow with a potential for large influx volumes, gas migration issues and consequences related to that was evaluated thoroughly. It was important to stress the need for rapid well control response in case of such events.
The model was also used to evaluate maximum casing shoe pressure for various kick volumes, and the typical dynamics to be seen when applying a given well control method for safely bringing up the kick. Special focus was on evaluating the dynamics of large influx volumes e.g. with respect to separator capacity.
The paper aims at presenting a way of working, where the initial work focus on obtaining an overall quantitative risk assessment with respect to well control. Critical factors are then identified in order to direct more detailed studies.
The paper also demonstrates that advanced models are necessary in order to support operational choices and procedures. The holistic approach which combines modelling and practical insight is regarded as a valuable improvement to better well control planning.
Using Laboratory Flow Experiments and Reactive Chemical Transport Modeling for Designing Waterflooding of the Agua Fría Reservoir, Poza Rica-Altamira Field, Mexico
Authors: Birkle P. , Pruess K. , Xu T. , Figueroa R. A. H. , López M. Díaz 
Published: December 2007

Abstract
Waterflooding for enhanced oil recovery requires that injected waters be chemically compatible with connate reservoir waters, in order to avoid mineral dissolution-and-precipitation cycles that could seriously degrade formation permeability and injectivity. Formation plugging is a concern especially in reservoirs with a large content of carbonates, such as calcite and dolomite, as such minerals typically react rapidly with an aqueous phase, and have strongly temperature-dependent solubility. Clay swelling can also pose problems. During a preliminary waterflooding pilot project, the Poza Rica-Altamira oil field, bordering the Gulf coast in the eastern part of Mexico, experienced injectivity loss after five months of reinjection of formation waters into well AF-847 in 1999. Acidizing with HCl restored injectivity. We report on laboratory experiments and reactive chemistry modeling studies that were undertaken in preparation for long-term waterflooding at Agua Fría. Using core plugs obtained from the field, laboratory flow experiments were conducted to examine sensitivity of mineral dissolution and precipitation effects to water composition. Native reservoir water, chemically altered waters, and distilled water were used, and temporal changes in core permeability, mineral abundances and aqueous concentrations of solutes were monitored. The experiments were simulated with the multi-phase, non-isothermal reactive transport code TOUGHREACT, and good to excellent agreement was obtained for changes in solute concentrations. TOUGHREACT was then used for reservoir-scale simulation of injecting ambient-temperature water (30°C, 86°F) into a reservoir with initial temperature of 80°C (176°F). Untreated native reservoir water was found to cause serious porosity and permeability reduction due to calcite precipitation, which is promoted by the retrograde solubility of this mineral. Using treated water that performed well in the laboratory flow experiments was found to be able to avoid excessive precipitation, and allowed injection to proceed.
Synergy Between Engineered Fibers and Lightweight Cement Slurries to Cement Depleted Formations
Authors: Zepeda Garduño Rafael , Martinez José Antonio , Maldonado Reinaldo 
Published: December 2007

Abstract
The production of hydrocarbons from pressure-depleted zones is becoming a common practice around the world and drives the constant development and improvement of cementing technology. This paper addresses the evolution of lightweight cement slurries to ensure zonal isolation and mechanical stability of casing in highly permeable and depleted formations.
To prevent lost circulation while cementing depleted formations, a new technique has been developed based on adding inert fibers to ultralightweight slurries. During the cementing operation, the fibers create a network across the loss zone, to enable the cement to bridge off these zones and regain circulation. Also, these fibers enhance the mechanical properties of the cement as the created net provides additional stability to resist tensile stresses.
This paper discusses the challenges and solutions of developing ultralightweight slurries (without foaming) that control rheology and cement properties by the interaction of fibers and cement particle size distribution.
The paper addresses the synergies that cement slurries and inert fibers, with specific gravity values between 1.0 sg and 0.88 sg, bring to cement production casings in the Cantarell field of Mexico. The pay zone of the Cantarell field is a highly fractured, highly permeable, vuggy, and depleted Cretaceous formation that is typically drilled under total loss of circulation. The ability to reduce and prevent losses of slurry by adding this engineered fiber helps to ensure that the cement slurry is placed according to design to provide good zonal isolation and to permit completion of the new well.
A Holistic Approach to Production Assurance
Authors: Gonzalez D. , Jamaluddin A. 
Published: December 2007

Abstract
Due to the large potential reserves, increased global demand for oil and high oil price, exploration & development in deepwater and more challenging areas around the world have become a key target for the majority of oil and gas Exploration and Production Companies. Development activities in the deepwater face significant challenges. Of particular concern are the effects of produced fluid hydrocarbon solids (i.e. asphaltene, wax, and hydrates) precipitation and their potential to disrupt production due to deposition in the near-wellbore regions and production tubulars. Besides hydrocarbon solids, other production hindrance elements include wellbore fluid loading, fluid slugging, inorganics, corrosion, erosion and emulsions. All these elements adversely affect production assurance in deepwater systems and are key risk factors in assessing deepwater developments. The production assurance risk factor can create game-changing impact on field development planning, especially, when dealing with marginal deposits having variable fluid characteristics.
In this paper, we will review and provide a synopsis of some of these production hindrance elements. Consequently, we will discuss how some of these elements can affect the field development planning by utilizing a field example.
Enhanced Oil Recovery by Utilization of Multilateral Wells on the Troll West Field
Authors: Berge F. , Ruyter E. , Grønås T. , Vasicek A. 
Published: December 2007

Abstract
Norsk Hydro has been installing multilateral wells for 10 years. By the end of March 2006, a total of 64 multilateral junctions were installed. The vast majority have been sealed TAML level 5 junctions constructed from floating vessels, primarily on the Troll West field. Hydro identified early multilateral wells as a key technology to enhance the oil recovery from the Troll West field. In 1995, a multilateral technology vendor was selected as supplier of multilateral systems. The close cooperation between Hydro and the multilateral technology vendor has been the key to the development of new multilateral systems and system variants to meet new requirements for the implementation of this emerging technology.
This paper will briefly describe the development of the FlexRite® system and the subsequent variants like FlexRite® Intelligent Completion Interface and ReFlexRite®. Field operations involving these systems will be discussed, and the use of multilateral wells on Troll West will be presented in some detail with respect to; statistics for junctions installed by March 2006, presentation of example wells and economic effects from the use of multilateral wells.
Integrating Geology and Velocity Data To Constrain Pressure Prediction in Foldbelts
Authors: Couzens-Schultz B. A. , Hedlund C. A. , Guzman C. E. 
Published: December 2007

Abstract
This paper focuses on the first drilled prospect in the Perdido fold belt, deepwater Gulf of Mexico. The original test well, AC600-001, did not reach its objective, but encountered shallow hard geopressures and the well was lost. That result was unexpected. The seismic velocity trend and data from previous deepwater wells suggested near hydrostatic pressures. To drill a second well, the problem of finding an optimal well location that avoided low drilling margins was addressed. The work involved re-picking of seismic velocity, trend analysis, and developing end-member rock models for pore pressure prediction using constraints from a mechanical seal failure analysis.
Areas of higher velocity, and hence lower predicted overpressure were identified in the same stratigraphic interval that the first well was lost. The second well was drilled successfully through one of these areas. The velocity results, combined with constraints from top seal failure were used to construct drilling margin maps. These indicated that beneath the stratigraphy where the first well was lost, drilling margin would increase. Once a path was found through the shallow hard pressures, the well would be drillable to objective. Results from the second well show that pressure prediction using seal failure arguments is a good first approach. The re-picked seismic velocity data at the well location was fast as compared to the checkshot data, but within error. The methodology is limited by assumptions on sand continuity from top seal failure locations and by velocity fidelity.
Hard overpressures and top seal failure are common aspects of deepwater fold belts. These prospects can be difficult to drill and can be under-filled. Deepwater foldbelts often have little well control to constrain predictions within them. The techniques presented here can be adapted to other foldbelts, and were used to evaluate and rank other Perdido prospects.
H2S Associated With Heavy Oils in Reservoirs Under Primary Production: Cases of Grimbeek and El Alba Fields in Gulf of San Jorge Basin, Argentina
Authors: Cavallaro A. N. , Cerroni M. , Alberdi M. I. , Ostera H. 
Published: December 2007

Abstract
Reservoir souring is a well-documented problem that appears normally when seawater is injected into sweet reservoirs during secondary recovery programs In these cases, microbiologic souring by the growth of sulphate-reducing bacteria (SRB) is the most accepted mechanism.
In some cases, H2S production is reported from the earliest stages of reservoir development. This phenomenon has been named "geologic souring"(2) because the H2S source is generated in the geological past and it is related to some element within the petroleum basin, but not-related to modern microbiological or geochemical processes.
Recently, H2S production has been recorded in El Alba-1 and Grimbeek-1 reservoirs (Manantiales Behr area, San Jorge Basin) where there are no previous reports of sources of H2S. Furthermore, water flooding has not been implemented before the H2S measurement campaing in the field. Thus, the H2S generation mechanism is the main target of this study.
Correlations of isotopic chemical analyses and isotopic measurements from gas, waters and oil samples were developed and integrated into the geological and enginnering information. After the interpretation stage, a monitoring plan and some mitigation options were suggested.
The H2S measurements, geological data and isotopic signatures do not allow locating the H2S source by thermo-chemical decomposition of sedimentary rocks (e.g. anhydrite), kerogen cracking or petroleum decomposition. Chemical data indicate that the sulphate, soluble in connate water, is the most plausible source of sulphur. Moreover microbiological activity is most likely the mechanism of biochemical reduction, even the reservoir show stressing conditions to bacterial development. According to the results, some biocides combined with H2S-scavenging are recommended to mitigate this production inconvient.
Internal Corrosion Direct Assessment for Multiphase Flow Pipeline Systems
Authors: Puente P. G. , Collado C. 
Published: December 2007

Abstract
Owners, operators, regulatory entities and non-governmental agencies focus their attention on pipeline Integrity Management Plans (IMP) to address the safety and reliability of hydrocarbon pipelines as they cross environmentally sensitive areas as well as densely populated areas. IMP includes a base line assessment prioritizing the inspection and remediation of expected sensitive areas. Direct Assessment (DA) along with internal inspection, hydro-test and other equivalent methods to ascertain the condition of the pipeline are used as IMP assessment methodologies.
The topic to be covered in this article is Internal Direct Assessment which includes Erosional Velocity (EV) in addition to Internal Corrosion Direct Assessment (ICDA). This article utilizes the analysis of an onshore gas pipeline in the Gulf of Mexico to identify possible areas susceptible to corrosion.
Multiphase flow analysis simulates the characteristics and specific fluid behavior to determine erosional velocity and internal corrosion in pipelines. A multiphase flow simulator will be used to obtain the specific flow characteristics to evaluate EV and ICDA for the above mentioned pipeline system. Internal corrosion is analyzed both as top of the line corrosion and corrosion at the bottom of the line. In addition multiphase flow simulation provides accurate information related to fluids velocity and residence time.
The internal corrosion rate can be related to residence time of water and other electrolytes to formulate effective mitigation processes. This could serve as the basis for a mitigation program and significantly increase the useful life of a pipeline system.