bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sipuleucel-T: A Vaccine for Metastatic, Asymptomatic, Androgen-Independent Prostate Cancer
Authors: Patel Punam H , Kockler Denise R 
Published: December 2007

Objective: To review the design, efficacy, safety, dosing, therapeutic, and pharmacoeconomic considerations of sipuleucel-T, an investigational, autologous, dendritic, cell-based prostate cancer vaccine. Data Sources: English-language literature searches of MEDLINE (1966–September 2007) and the Cochrane Database (2007, Issue 3) were performed using the terms sipuleucel-T, APC8015, and prostate cancer vaccine. Other data sources were identified from bibliographies of selected articles and from press releases. Study Selection and Data Extraction: All published articles or abstracts on human studies of sipuleucel-T for androgen-independent prostate cancer (AIPC) were reviewed for inclusion. Manufacturer Web sites, Food and Drug Administration (FDA) documents, and the clinical trials registry were used to obtain information regarding ongoing clinical trials. Data Synthesis: AIPC is an incurable disease with a median survival rate of 18–20 months. Docetaxel-based chemotherapy is currently the only FDA-approved treatment for AIPC with a survival benefit (2.4 mo). Sipuleucel-T is a novel active cellular immunotherapy under investigation for the treatment of metastatic, asymptomatic AIPC. In clinical trials, the primary endpoint of time to disease progression was not met; however, an underpowered analysts of data suggests that sipuleucel-T prolongs survival by a median of 4.5 months compared with placebo. Sipuleucel-T has been relatively well tolerated, although a possible increased risk of cerebrovascular events may exist. In May 2007, the FDA did not approve the biologics license application for sipuleucel-T since the primary endpoint of the Phase 3 trials was not met. However, its approval will be reconsidered by the FDA once interim survival results from an ongoing Phase 3 trial, IMPACT, are determined. These data are anticipated to be released in the fourth quarter of 2008. Conclusions: Metastatic AIPC Is an incurable disease that currently has limited treatment options. Approval of sipuleucel-T hinges on results from the IMPACT trial. If improved survival is shown, sipuleucel-T may become the first approved active cellular immunotherapy for treating metastatic, asymptomatic AIPC.
Sensitivity Analysis of Geomechanical Behavior on Time-Lapse Seismic Velocity Modeling
Authors: Vidal-Gilbert S. , Tisseau E. 
Published: December 2007

Abstract
The petroelastic model identifies how the dynamic elastic properties (P and S velocities and density) change during reservoir production. This forms the basis of time-lapse seismic feasibility studies. To provide accurate and meaningful predictions, the model requires appropriate input from reservoir engineering (pore pressure and saturation variations) and geomechanics (stress and strain variations). In stress sensitive reservoirs, a geomechanical simulation coupled with the conventional reservoir simulation provides the updated vertical deformation and the mean effective stress field in and around the reservoir. The key objective of this work is to identify how the combined reservoir and geomechanical effects will influence predictions of the petroelastic model.
A methodology integrating reservoir engineering, geomechanics and rock physics is applied on a 3D synthetic case. The first task of this study consists in modeling deformation and stresses induced by reservoir exploitation in the reservoir and in its surrounding formations. For this, the pore pressure issued from the reservoir simulation is used as a load in the geomechanical simulation. Then, a sensitivity analysis of some mechanical parameters (Young's modulus contrast, Poisson's ratio, initial effective stress ratio, plasticity behavior) is performed with a 3D model including the reservoir and the rocks around. The results of these geomechanical modelings are analyzed considering the compaction effect, the stress arching effect and the mean effective stress value in and above the reservoir. Then, the mean effective stress issued from each geomechanical simulation allows updating seismic velocities and the time shifts associated to seismic horizons, using Hertz-Mindlin's model. Last, this approach, considering the geomechanical aspect, is improved by the contribution of the fluid substitution on the petroelastic model, taking the saturation effects into account. The geomechanical approach is compared with some classical non-geomechanical approaches commonly used.
In this work, it is demonstrated that the geomechanical approach influences the results in and around the reservoir. The time-shift values of the seismic horizons issued from this approach would be detectable on 4D seismic data and in this case study the effect is much stronger than the saturation effect alone.
Method for Conditioning the Reservoir Model on 3D and 4D Elastic Inversion Data Applied to a Fluvial Reservoir in the North Sea
Authors: Andersen T. , Zachariassen E. , Høye T. , Meisingset H. C. , Otterlei C. , van Wijngaarden A. J. , Hatland K. , Mangerøy G. , Liestol F. M. 
Published: December 2007

Abstract
A work flow to improve the modeling of a fluvial reservoir is presented. Modeling of fluvial reservoirs can be very uncertain when only conditioned to well data. By utilising 3D and 4D seismic inversion data to condition the geological model, the uncertainty in the facies distribution is reduced. Cross plot of 3D elastic inversion data predicts facies better than acoustic impedance data or Vp/Vs data individually. By including 4D elastic inversion data, the correlation between the classified facies from seismic and the facies zonation in the wells, is further improved. A sand probability cube is computed from 3D and 4D elastic inversion data, and used to condition the geological model of the fluvial reservoir. Upscaling and flow simulation are carried out on a set of realisations. This results in a range of simulated production profiles. The dynamic information in the 4D seismic is then used to rank the realisations by comparing the real 4D data with forward modelled elastic parameters from the flow simulation model.
The described work flow is a new way of integrating different types of data in the modeling process in order to reduce uncertainties. The method is applied to the fluvial Ness reservoir in the Oseberg field in the North Sea.
Air-Injection EOR in Highly Water-Saturated Light-Oil Reservoir
Authors: Teramoto T. , Uematsu H. , Takabayashi K. , Onishi T. 
Published: December 2007

Abstract
Since 1950s In-Situ Combustion (ISC) has been applied to mainly heavy-oil reservoirs. In recent years, High Pressure Air Injection (HPAI) which is a displacement process categorized as ISC, is applied to light-oil reservoirs. And it has proven to be a valuable Enhanced Oil Recovery (EOR).
Reduction of oil viscosity is very important for ISC process. In contrast, it is not so essential for HPAI because original viscosity of light-oil is not as high as that of heavy oil. HPAI is considered as flue gas injection, since a flue gas sweep is one of the most important recovery factors of HPAI. However a flue gas sweep recovery factor is not effective for highly water saturated light-oil reservoirs, while thermal effects become an important recovery mechanism.
This paper discribed the feasibility study of HPAI for watered out light-oil reservoirs, oil recovery mechanism and several simulation studies to establish maximum oil recovery factor.
For the feasibility study, Combustion Tube tests (CT tests) and simulation studies were conducted. The oil recovery was observed in the CT test with crushed core which was flooded out by water. This result suggests that HPAI can be applied to highly water saturated light-oil reservoir. The results of simulation studies also indicate its feasibility. They also made clear that distillation process that was one of thermal effects of HPAI was a main recovery factor for a HPAI in this case.
In order to maximize the oil recovery, controlling a channeling of injected air is important because early breakthrough of the air reduces oil production period significantly. The results of our studies show that not only a design of well completion but also an adjustment of air injection rate enable to increase vertical sweep efficiency and that line drive injection is effective to increase areal sweep efficiency.
Theoretical and Practical Aspects of Tertiary Hydrocarbon Migration
Authors: Minescu F. , Popa C. , Grecu D. 
Published: December 2007

AbstractPrimary and secondary migrations are well defined terms in hydrocarbon reservoir genesis. Both of them designate spontaneous displacement of the hydrocarbon, from the source rock to the final trap, i.e. to the reservoir rock.Producing the reservoir implies a forced movement of hydrocarbons towards the wells, consuming the energy accumulated over the ages.Mainly due to the gravitational forces and water influx, a new kind of fluid movement is taking place into the reservoir towards its production final stage. The main feature of the fluids displacements into the reservoir is their spontaneous character. This kind of fluid movement that occur after reservoir abandonment, defines the tertiary migration process.As a consequence of tertiary migration, the reservoir fluids, water, oil and gas, tend to place themselves to a normal-gravitational position. Additionally, the dynamic pressure distribution at the end of the production history tends to relax, amplifying the migration process towards normal stationary pressure gradients. The result of the tertiary migration is a new saturation distribution into the reservoir and it is expected that in the most favorable cases, the production potential of some parts of the reservoir should be restored.From this point of view, an enormous interest for Romania concerns the old oil reservoirs, abandoned over 7080 years ago with a final recovery factor sometimes less then 20%.The present paper examines the principles and factors involved in the tertiary migration process. A special attention is paid to pressure redistribution and gravitational segregation during such a process. To demonstrate the concept, this study discusses two successful production restarting projects in Romania. If today the world is not very proud about production restarting projects, tomorrow will be for sure.
Integration of Volumetric and Material Balance Analyses Using a Bayesian Framework To Estimate OHIP and Quantify Uncertainty
Authors: Ogele C. , Daoud A. M. , McVay D. A. , Lee W. J. 
Published: December 2007

ABSTRACT
Estimating original hydrocarbons in place (OHIP) in a reservoir is fundamentally important in estimating reserves and potential profitability. Two traditional methods for estimating OHIP are volumetric and material balance methods. Probabilistic estimates of OHIP are commonly generated prior to significant production from a reservoir by combining volumetric analysis with Monte Carlo methods. Material balance is routinely used to analyze reservoir performance and estimate OHIP. Although material balance has uncertainties due to errors in pressure and other parameters, probabilistic estimates are seldom generated.
In this paper we use a Bayesian formulation to integrate volumetric and material balance analyses and to quantify uncertainty in the combined OHIP estimates. Specifically, we apply Bayes’ rule to the Havlena and Odeh material balance equation to estimate original oil in place, N, and relative gas-cap size, m, for a gas-cap drive oil reservoir. We consider uncertainty and correlation in the volumetric estimates of N and m (reflected in the prior probability distribution), as well as uncertainty in the pressure data (reflected in the likelihood distribution). Approximation of the covariance of the posterior distribution allows quantification of uncertainty in the estimates of N and m resulting from the combined volumetric and material balance analyses.
Our investigations show that material balance data reduce the uncertainty in the volumetric estimate, and the volumetric data reduce the considerable non-uniqueness of the material balance solution, resulting in more accurate OHIP estimates than from the separate analyses. One of the advantages over reservoir simulation is that, with the smaller number of parameters in this approach, we can easily sample the entire posterior distribution, resulting in more complete quantification of uncertainty.
Comparison and Investigation of Recovery Factor From Simulation of Water and Gas Injection in One of the Fractured Reservoirs in the South of Iran
Authors: Sobhi G. , Kiani M. , Alizadeh N. 
Published: December 2007

Abstract
Most of the oil production in the Middle East comes from carbonate reservoirs, the majority of which are fractured. These reservoirs tend to produce at high rates in their early production period followed by low rates later on, leading to low overall recovery. The challenge is to manage the field and arrest the production decline for a long time.
A reservoir simulation study was performed on a fractured Middle Eastern carbonate field to determine the optimal production strategy. Three possible scenarios – natural depletion, gas injection and water injection were compared. Results indicated that water injection yields better recoveries than gas injection and natural depletion; this is expected since the rock is intermediate to oil-wet, meaning that there was high recovery from imbibition in water flooding. The presence of connected fractures led to early breakthrough and low recoveries in gas injection scenarios. The different physical mechanisms affecting oil recovery are discussed and recommendations are made for other fields with the same fracture properties and wettability
Innovative Approach for Automatic Real-Time Monitoring of the Fluid Level in Wells Without Returns to Surface During Workover Operations—A Successful Field Test
Authors: Pattay P. W. von , Strasser R. , Seitzjef A. 
Published: December 2007

Abstract
Today, mature fields are a major interest for many oil companies since their un-recovered potentials are expected to help satisfy the worlds growing oil demand. However, while operating in such fields companies face new challenges.
As such, many mature fields show under-hydrostatic reservoir pressure due to depletion, which might lead to no returns to surface during workover operations. No returns to surface make it impossible to recognize any losses as an indicator for potential formation damages or gains as an indicator for a potential kick.
The crucial question is therefore how to recognize losses or gains in real time without returns to surface during workover operations?
Knowing the depth of the fluid level in the well at any point in time would allow recognizing losses and gains, simply by monitoring all the changes of the fluid level in the well.
This paper presents a newly developed measurement approach using a specially designed echometer that allows monitoring the fluid level in the well without returns to surface during workover operations automatically in real time, which is a fundamentally new application for an echometer.
All the technical requirements that were identified to be critical for this measurement approach are highlighted in the paper. Further the paper lines out all the associated technical challenges that were faced while implementing this measurement approach. Finally, reliability and functionality of the measurement approach were proven in a series of field tests under various operational conditions.
Permeability Determination of the PL19-3 Field for Geologic Model Input
Authors: Fetkovich M. D. , Gerard M. G. , Chin L. Y. , Shuxing D. 
Published: December 2007

Abstract
The overall structure of the PL19-3 field, which is located in Bohai Bay, is an asymmetrical wrench anticline that formed by a combination of differential subsidence, strike-slip faulting, and normal faulting. Faults form the main trapping components for the individual hydrocarbon-bearing fault blocks. The reservoir sands of the deeper Guantao formation are dominantly braided fluvial sandstones, while the shallower Minghuazhen formations are dominantly meandering fluvial sands. Fault blocks penetrated by appraisal or development wells tested oil with viscosities ranging from 10 to 380 cp. Multiple vertically separate pressure systems exist in each fault block.
The purpose of this paper is to present a case history that demonstrates multiple methods used to calculate permeability for input into a fine grid geologic model and ultimately a flow simulation model. Special core analysis and facies description was used to generate facies-based permeability versus porosity relationships that can be used with log-calculated variables. Permeability log curves were calculated for each well in the field, and then input them into a geologic flow model. Pressure transient analysis was used to condition the facies based porosity versus permeability relationships to ensure that they matched actual well performance.
The permeability logs for all of the producing and injection wells were input into a flow simulation model. Comparisons of model predicted versus actual performance show close agreement. A good permeability estimate ultimately results in reasonable values of transmissibility, original oil in place, and sand connectivity. Advanced decline curve analysis was used as an additional method for calculation of kh, skin, and original oil in place (OOIP) and to validate model predicted performance matched actual transient, depletion, and waterflood performance behavior. In addition because this field contains reservoirs with unconsolidated sands the effect of stress dependent permeability was studied.
Multiscale Pore-Structure Characterization by Combining Image Analysis and Mercury Porosimetry
Authors: Han H. , Ioannidis M. , Dusseault M. B. , Xu B. 
Published: December 2007

AbstractThis article introduces a multiscale pore structure characterization method using a combination of mercury porosimetry and image analysis. The method was used to determine the distribution of pore volume by pore size and to estimate the pore-to-throat size aspect ratio. The key idea of the method is that pore size distribution obeys a fractal scaling law over a range of pore size. On this basis, scattering intensity data computed from the measured two-point correlation function and those measured from mercury porosimetry are extrapolated in the size range 0.01 μm &lt; r &lt; 1000 μm, using the known fractal scaling law.A set of siltstone samples taken from Daqing Oilfield was analyzed through this method. Distribution of pore volume by pore size over the entire range of pore length scales was determined. The results demonstrated significant similarities in the pore structure of all samples. The image analysis results were in qualitative agreement with the results of mercury intrusion/extrusion tests.The results were also compared with some other samples (including siltstone, sandstone, and dolomite) that had been analyzed using similar methods. It is shown that the surface fractal dimension obtained by analysis of MIP data is consistent with the value obtained by image analysis for different samples with different porosity and permeability.Novel information on the pore-to-throat aspect ratio is obtained by comparing the complete pore volume distribution (PVD) to the MIP data.
The Valuation of the Multistage Investment in an E&P Project Using a Four-Fold Compound Option
Authors: Liu J. , Chen H. , Yang S. 
Published: December 2007

Abstract
This paper presents a model for valuing and the multi-stage investment in E&P project using N-fold continuous compound option formula. This model resolves the multi-stage investment decision problem, and extends the notion of a compound option to the n-fold compound option with time- dependent volatility and interest rate. It indeed presents additional insights into the creation of shareholder value of petroleum production and should therefore be used next to more traditional approaches such as Black-Scholes-Merton simulations, especially when tailored to the characteristics of real-life cases of E&P project development processes.
Failure Analysis of String Corrosion and Its Protection during Constructing and Operating Gas Storage Facility in Bedded Salt Deposit
Authors: Guangjie Yuan , Qinghua Wang , Ruichen Shen , Jinping Yuan , Lijun Lu , Chunmao Wang 
Published: December 2007

Abstract
With more and more salt cavern gas storage under construction, the corrosion problems of leaching string, production string, and production casing require more attention by experts o gas storage. This paper introduces several corrosion phenomena which are encountered during the operation of leaching salt caverns, and natural gas injection and withdrawal. The main corrosion factors are discussed such as brine, air, microbes, components of natural gas, gas injection velocity, operating status and others. The corrosion mechanisms are also analyzed. Inorder to prevent the corrosion effects a series of measures are applied successfully during different construction phases of the gas storage facility in the Yangtze River Delta, such as oxygen scavenger and biocide, coating protection, annulus protection liquid, cathodic protection.
Hydrate-Inhibited Scale Inhibitor for Use on Subsea Templates
Authors: Hills E. , Hase A. , Turner K. , Brice S. , Ross A. , Auflem I. H. , Saeten J. O. 
Published: December 2007

Abstract
An offshore Mid-Norway oil field includes wells on sub-sea templates at a depth of 350m. The formation waters contain up to 300 mgl−1 of barium, giving a sulphate scaling potential on seawater breakthrough. Scale protection on the template and down-hole is provided by squeeze treatments. Deployment possibilities include bull-heading down the methanol injection line (a distance of 10km) and bull-heading directly to the sub-sea template from a boat. In the event of a produced gas leak into the system, the conditions dictate that a water-based squeeze inhibitor will be in the region for hydrate formation. In such an event hydrates would be formed in minutes, blocking the service line before it could be re-flooded with the thermodynamic hydrate inhibitor methanol.
Current scale inhibitors (SI) are hydrate-inhibited by formulation in MEG. This paper describes an innovative SI protected from hydrate formation by formulating with kinetic gas hydrate inhibitors (KHI).
The field scale squeeze inhibitor was modelled and shown to have the potential for hydrate formation under sub-sea conditions. The concentration of MEG required to avoid this region was also modelled as &gt;50% based on water. This was followed by laboratory autoclave tests when gas hydrates formed as predicted by the model. Using the same SI formulated with a small addition of a KHI the hydrate induction time was extended beyond the SI residence time in the injection line. Further testing of SI efficiency demonstrated an improved efficiency over an equivalent scale inhibitor formulated in MEG.
Due to the spiralling costs of installing new oil production facilities the use of sub-sea templates is increasing. Any scale squeeze treatments must be protected against potential gas hydrate formation. This paper describes such a protection by adding a KHI to a water-based product rather than formulating in MEG thereby allowing formulation at higher SI actives, potential lower costs and a lower viscosity product at low temperature.