bluuebunny/crossref_metadata_2025_split huggingface dataset:
Laboratory Evaluation of Water Swellable Materials for Fracture Shutoff
Authors: Abbasy Imran , Vasquez Julio , Eoff Larry , Dalrymple Dwyann 
Published: March 2008

AbstractThe existence of high permeability features such as fissures, fractures, and eroded out permeability zones, diminishes the sweep efficiency of any water, gas, or polymer flooding. This paper presents the laboratory evaluation of three water swellable materials that can be bullheaded into the well to shut off fractures. The water swellable materials would be mixed on the fly, entering fissures and fracture systems as they swell without invading the matrix of the rock. The rate of absorption can be controlled based on the particle size, carrier fluid, and formation fluid. This conformance technology is also applicable to address loss circulation problems in production and injection wells.The following materials were evaluated: (a) a polyacrylamide polymer, (b) a chloroprene rubber, and (c) a nitrile rubber. The polyacrylamide polymer is capable of absorbing 30 to 400 times its own weight in water while the two rubbers swell approximately 5 to 10 times their original weight. The water swellable materials were evaluated for effectiveness to: (1) provide controllable swelling rates at different conditions, (2) shut off the flow of water in synthetic cores with simulated fractures at 135°F, and (3) provide long-term thermal stability in H2S and CO2 environments.Discussed are: (1) the methodology used for measurement of swelling properties for each material at different conditions including carrier fluid, particle size, and temperature, and (2) core flow tests with simulated fractures. These materials are nontoxic and do not contain heavy metal crosslinkers. Based on this study, these materials present an innovative technology for fracture shutoff and to control loss circulation problems. In addition, these materials are resistant to acid contamination in CO2 and H2S environments.
Challenging Chemical Gas Shut off in a Fractured Carbonate Reservoir—Case Studies
Authors: Al-Sharji Hamed , Ali Ehtesham , Kosztin Bela , Edwards Clement , Neyaei Fardin Ali , Shaheen Tarek 
Published: March 2008

Abstract
This paper discusses the gas shut-off treatments carried out in a fractured carbonate field in north Oman and also describes the good practices and lessons learnt from a number of jobs. In addition to the technical analysis, the paper also addresses the economic value of the campaign.
Oil production from this field with complex geology and reservoir mechanism was negatively affected by gas breakthroughs in several wells. The constraints on gas handling capacity resulted in shutting-in a number of high GOR wells. These wells were required to be treated to shut-off source of the gas breakthrough in order to restore oil production. Challenges faced in shutting off these gas zones included: 1) Poor cement bond behind the liner shoe. 2) Massive fractures resulting in loss circulation. 3) Uncertainty with fractures volume estimation. 4) Fracture shut-off in open-hole sections. 5) Treatment execution under sub-hydrostatic conditions.
To overcome these challenges a robust chemical shut off methodology had to be innovated. This methodology consisted of the following main pillars: a) Utilize various reservoir diagnostics tools to identify fractures and sources of high GOR. b) Use of flowing cross-linked polymer gel combined with a ringing type of cross-linked polymer gel as a capping fluid. c) Utilize an on-fly mixing system that enables volume and concentration adjustment as plugging progression dictates. d) Utilize matrix diagnostics plot along with modified hall plot in real-time to continually estimate flowing gel volume. e) Deploy a fit-for-purpose gel placement assembly for treatment under Sub-hydrostatic conditions.
Integration of Resistivity Imaging and Enhanced Vertical Resolution Nuclear Magnetic Resonance Data for Improved Quantification of Reserves in Thinly Bedded Reservoirs
Authors: Hashem Abdel Hakim , Reda Ahmed 
Published: March 2008

Abstract
There is little that is more important to an operating company than the accurate assessment of its oil and gas reserves. In thick, clean formations that are relatively homogeneous laterally and vertically, reserves calculations are usually straightforward. The level of uncertainty in these calculations can increase substantially, however, with increasing reservoir complexity.
One such source of complexity is the challenge presented by thinly laminated formations. The challenge is that thinly bedded formations are, by definition, below the resolution of the most commonly used logging tools. As such, many thin bed formations may not even be detected, let alone properly evaluated and accounted for in reserves estimates.
Two wireline formation evaluation technologies are available that, when used in concert with conventional macro wireline logs, can substantially reduce reserves uncertainty in thin bed formations.
One of these is a resistivity imager tool such as the X-tended Range Micro Imager (XRMI). With vertical resolution down to 0.10 inches, resistivity imager tools provide a reliable means of thin bed detection. The other technology is nuclear magnetic resonance (NMR). NMR tools such as the MRIL Prime can provide estimates of formation porosity, permeability and hydrocarbon properties in thin bed formations, albeit with relatively coarse vertical resolution which can be enhanced by post-processing technique.
This paper explores a new method for enhancing the vertical resolution of the MRIL data that leads to integrates the best attributes of both NMR and resistivity imaging tools to bring about improved reserves estimates. A case study is presented from the Nile delta in which a field - comprised of a thick, clean, high porosity deltaic sedimentary layer overlain by a thinly laminated sand-shale sequence – is quantitatively evaluated for fluid saturation and productivity with a new post-processing technique. Recommendations for future data integration methods and applications are also proposed.
Modeling and Simulation of Instabilities in Gas-lifted Oil Wells
Authors: Jahanshahi E. , Salahshoor K. , Kharrat R. , Rahnema H. 
Published: March 2008

AbstractUnstable production behavior affects many offshore fields, particularly at their decline stages. "Casing heading" and "density wave" are two types of instability that have been identified and both can result in production loss. These instabilities have influence on each other, but the interaction has not been fully addressed yet. One contribution of this paper is to study the interplay of these two phenomena. For this purpose, key variable of density wave phenomenon; pressure at injection point in tubing that is governed by an integral equation; is considered as a fourth state variable added to 3-D dynamical model of casing heading. Another contribution is some modifications on the casing heading and density wave dynamic models. Finally, the proposed model is simulated in MATLAB® and OLGA®, and the results are compared with well operation facts and data from field.
Meeting the Flow Assurance Challenges of Deepwater Developments: From Capex Development to Field Start Up
Authors: Jordan M. M. , Feasey N. D. 
Published: March 2008

AbstractAs oil accumulations in easily accessible locations around the world become less available developments in deeper water locations become a more common target for field development. Deepwater projects, particularly subsea development, present a host of challenges in terms of flow assurance and integrity. In this paper the focus will be on the chemical control of flow assurance challenges in hydrate control, scale control and wax/asphaltene control within deepwater (&gt;750 meter) developments. The opportunities for kinetic hydrate control vs. conventional thermodynamic hydrate control will be outlined with examples of where these technologies have been applied and the limitations that still exist. The development of scale control chemical formulations specifically for subsea application and the challenges of monitoring such control programs will be highlighted with developments in real time and near real time monitoring. Organic deposit control (wax/asphaltene) will focus on the development of new chemicals that have higher activity but lower viscosity than currently used chemicals hence allowing deployments at colder temperatures and over longer distances.The factors that need to be taken into account when selecting chemicals for deepwater application will be highlighted. Fluid viscosity, impact of hydrostatic head on injectivity, product stability at low temperature and interaction with other production chemicals will be reviewed as they pertain to effective flow assurance.This paper brings learning from other deepwater basins with examples from the Gulf of Mexico, West Africa and Brazil, which will be used to highlight these challenges and some of the solutions currently available along with the technology gaps that exist.
Seismically Driven Characterization, Simulation and Underbalanced Drilling of Multiple Horizontal Boreholes in a Tight Fractured Quartzite Reservoir: Application to Sabria Field, Tunisia
Authors: Ouenes A. , Robinson G. , Balogh D. , Zellou A. , Umbsaar D. , Jarraya H. , Boufares T. , Ayadi L. , Kacem R. 
Published: March 2008

Abstract
This paper describes the application of the Continuous Fracture Modeling (CFM) workflow to the Sabria field in Tunisia. This workflow consists of four steps. The first step in the workflow is to interpret key seismic horizons and use them in high resolution inversion and spectral imaging to create impedance and frequency-dependent seismic attributes. The second step consists of building seismically constrained geologic models of lithology and other petrophysical properties. The third step consists of using the derived geologic models along with all the post-stack seismic attributes and additional geomechanical models to derive high resolution 3D fracture models. The fourth step is to use the derived fracture models in a reservoir simulator to verify the validity of the models by their ability to match past individual well performances and to design optimal well trajectories that intercept a large number of fractures and produce economical oil rates. This workflow was applied to the Sabria field in Tunisia and was followed by actual drilling. The seismic attributes and the appropriate geologic and geomechanical models were used as input in REFRACT, a fracture modeling software, to create accurate 3D fracture models. The resulting fracture porosity and permeability were input in a reservoir simulator. All the past individual well performances were matched, confirming the reliability and accuracy of the derived fracture models. The resulting simulation and fracture models were used to plan multiple horizontal boreholes, drilled underbalanced from a single platform. The resulting oil production from the boreholes and the recorded logs confirm the validity of both the fracture and simulation models.
CO2 Geological Storage Field Development: Initial Experiences in an Emerging Industry
Authors: Jenvey N. J. , Moen R. S. , Muller N. , Buehler J. , Costello M. S. , Schwander M. M. 
Published: March 2008

Abstract
Global climate change induced by the release of greenhouse gases (notably carbon dioxide) into the atmosphere is a topic of considerable discussion around the world. Shell believes that this debate is over, and instead has entered into a debate about what we can do about it. Therefore as part of Shell's integrated carbon management plan (which includes renewable energy sources and fossil fuel efficiency improvements) we are currently investigating several sites and geologic formations across the globe for their suitability in the long-term storage of CO2 using technology and experience from over 30 years of safely transporting and injecting CO2 in oil and gas operations.
This talk will illustrate some of the technical challenges that can be expected during the implementation lifecycle (from site exploration to closure) of such projects, and is based upon our learning both in recent CO2 sequestration projects and the industrial analogue of CO2 Enhanced Oil Recovery. These include: establishing initial screening criteria; developing appraisal and piloting techniques; building appropriate reservoir models; designing fit-for-purpose injection wells; assessing containment risks; and determining monitoring requirements. These projects are particularly challenging in today's society where information is easily accessible by the public, yet policy and regulations are still evolving. Based on our own experience, we suggest that an integrated technical evaluation is critical for the accurate long-term fate assessment of CO2 geological storage sites.
Case Study: The Application of Sand Management Solution for the Sarir Field in Libya
Authors: Qiu K. , Gherryo Y. , Shatwan M. , Marsden R. , Alexander J. , Retnanto A. 
Published: March 2008

Abstract
Sand production from the Sarir field became a major concern for AGOCO at the end of the 1980s when ESPs were introduced to the field. The sanding severely impaired the performance of field, and consequently led to significant economic loss.
AGOCO recognized that it was facing a major challenge in terms of understanding potential sanding risk for Sarir, and that it was necessary to design and implement a sandface completion and sand management strategy for more than 400 wells in the field. It was decided to apply a particular systematical approach, termed as Sand Management Solution (SMS), to properly address the sanding issues it was facing, which involved prediction, prevention, monitoring, and, if required, remediation activities. The first step in the SMS was to obtain a clear understanding of the cause and the mechanism for the sand production. This knowledge was required because attempts to run new completion designs without knowing the cause of the sand and understanding the risks had been proved costly, and would be likely to fail.
To this end, a SMS was implemented in Sarir field. The work started from geomechanical reservoir characterization including geomechanics core laboratory test and mechanical earth model building, sanding prediction and evaluation, and a detailed review of sanding history to understand the severity of the sanding risk and sanding mechanism. Based on this knowledge, sanding management and remedial completion measures were devised that would minimize economic loss caused by sanding and optimize hydrocarbon production.
This paper provides details of implementation of this SMS in the Sarir field, and demonstrates that a systematical approach is required when addressing sanding issues in giant mature fields such as Sarir.
Integrated Fluid Characterization: Maximising the Value of Fluid Information From Exploration to Production
Authors: McKinney Daniel , Clarke Ed , Elshahawi Hani , Flannery Mattew , Hashem Mohamed , Stankiewicz Artur 
Published: March 2008

Abstract
Fluid characterisation is critically important to effective reservoir management. Misinterpreting reservoir properties, for instance, can result in non-optimal well placement, completion strategy, and facilities design as well as large errors in reserves, drainage volume and production rate predictions. Characterisation of reservoir fluids based on a single technique or technology such as mud-gas logging, wireline logging, PVT, or wellsite chemistry is standard in most E&P operations. Integrated approaches involving multiple tools and technologies are still relatively new to the industry, but Shell, through its FEAST (Fluid Evaluation and Sampling Technology) global centre of expertise, is routinely implementing such integrated approaches for fluid characterisation. For example, advanced mud-gas logging data can be used for fluid facies prediction and picking sampling points for formation testing; PVT data can be calibrated against mud logging data; and downhole fluid analysis can provide fluid property measurements real time, during sampling. Integration ensures that the evaluation objectives are addressed using the most optimal technologies and workflows, maximises the value of information, and improves operational decision-making.
The interpretative workflow also involves integrating advanced mud-gas logging technology data with formation testing, Geochemical, and PVT data to predict fluid properties in unsampled wells. Understanding reservoir fluid properties ahead of the actual sampling operation enables smart decisions while drilling and logging, which can save millions of dollars in operational costs. The sampling process can be optimized in terms of where and when to sample, and how many samples to collect; and the quality of the fluids collected can be substantially improved. Because each technique has its strengths and limitations, integration is far more valuable than relying on any single source for interpretation. Ultimately, no technique is used in isolation, and no interpretation is worked in a vacuum without adequately understanding the geological setting and the fluid sourcing, migration, and trapping mechanisms.
Deepwater Gulf of Mexico Development Challenges Overview
Authors: Close Frank , McCavitt Bob , Smith Brian 
Published: March 2008

Abstract
Chevron's role as a major player in the global energy arena is due in large part to the Company’s extensive oil and gas exploration and production operations. A large proportion of the Company’s extensive reserves are located in deepwater locations throughout the world. The Company is one of the largest producers of crude oil and natural gas on the Gulf of Mexico (GoM) shelf and among the top acreage holders in the Gulf's deepwater1 and ultra deepwater2. Following on from the successes of an aggressive deepwater exploration campaign in the Gulf of Mexico, a series of major discoveries were rapidly appraised and moved to development (Fig. 1).Fig. 1Chevron GoM appraisal and development activities
This paper will give a high level review of some of the recent development challenges for the deepwater and ultra deepwater fields in the GoM and will explain how these challenges were addressed and how the Company plans to address even more demanding challenges in the future.
Controlled Drug Delivery: Pharmacokinetic Considerations, Methods and Systems
Authors: Zuo Zhong , Lee Vincent H. L. 
Published: March 2008

AbstractControlled drug delivery applies interdisciplinary approaches to engineer systems that improve the therapeutic value of drugs. This review addresses the biological basis of drug delivery, the pharmacokinetic/pharmacodynamic considerations important to the design of controlled release delivery systems, and the methods to fabricate them. The focus of this review will principally be on oral and transdermal applications. Systems at various stages of development for the delivery of more complex molecules, such as proteins, oligonucleotides, genes, and sRNA's will also be discussed.
Molecular Recognition: Computational Analysis and Modelling
Authors: Feldman‐Salit Anna , Wade Rebecca C. 
Published: March 2008

AbstractMolecular recognition is critical to many fundamental processes in biology, including enzymatic reactions, signal transduction, genetic information processing, as well as molecular and cellular transport. The question of how proteins selectively recognize and correctly associate with their partners is an active research problem. For many proteins, experimental information about the structures of their molecular complexes and the details of their interactions are lacking. Macromolecular, structure‐based computational techniques provide a means to predict the interactions of proteins and to investigate their recognition mechanisms. Here, we first discuss the general mechanism of molecular recognition as a multistep process from diffusion of one molecule toward the second to tight complex formation. We then describe the main forces and the physical properties that govern biomolecular interactions and introduce the principles of modeling them. Finally, simulation methods and computational approaches for molecular docking are briefly presented.
Inositol Phospholipids: Biosynthesis and Biological Functions
Authors: Bruzik Karol S. 
Published: March 2008

AbstractPhosphatidylinositol phosphates are cellular signaling molecules that came to prominence in the mid‐1980s, after inositol trisphosphate was discovered as a key intracellular second messenger generated from phosphatidylinositol 4,5‐bisphosphate in response to stimulation of a wide range of extra‐cellular receptors. Since then, many novel inositol phosphates and phospholipids have been discovered, and their cellular functions have been studied. The roles of these molecules encompass regulation of many processes indispensable to organism homeostasis. On the cellular level, the processes include regulation of cell growth and differentiation, cell motility and invasiveness, vesicular trafficking, protein targeting to specific cell compartments. This review focuses on biosynthesis and biological roles of phosphatidylinositol phospholipids.
Systems Approach to Studying Disease
Authors: Foltz Gregory D. , Hood Leroy 
Published: March 2008

Abstract
The emerging field of systems biology promises to transform our understanding of the molecular basis of human disease. Recent technological advances allow for multiparameter measurements to be integrated across global genomic and proteomic platforms to inform predictive and probabilistic gene and protein regulatory networks. A systems approach to disease is based on the idea that disease‐perturbed gene and protein regulatory networks differ from their normal counterparts, and that these differences are predictive of the disease course and response to therapy. The ability to detect disease‐related perturbations in individual patients will transform health care over the next decade from our current reactive medicine to a new medical practice that is predictive, personalized, preventive, and participatory (P4 medicine).
Practical Synthesis of (E)‐α,β‐Unsaturated Carboxylic Acids Using a One‐Pot Hydroformylation/Decarboxylative Knoevenagel Reaction Sequence
Authors: Kemme Susanne T. , Šmejkal Tomáš , Breit Bernhard 
Published: March 2008

AbstractCombining the regioselective room temperature/ambient pressure hydroformylation and a modification of the Doebner–Knoevenagel reaction allowed for the development of an efficient, one‐pot procedure for the synthesis of (E)‐α,β‐unsaturated carboxylic acids. The reaction proceeds under mild conditions, tolerates a variety of functional groups and gives (E)‐α,β‐unsaturated carboxylic acids in good yields and with excellent regio‐ and stereocontrol. The practicability of this process has been demonstrated by a short protecting group‐free synthesis of the queen honeybee pheromones 9‐ODA [(E)‐9‐oxodec‐2‐enoic acid] and 9‐HDA [(E)‐9‐hydroxydec‐2‐enoic acid].