bluuebunny/crossref_metadata_2025_split huggingface dataset:
Production – Log Base Model for Carbonate Permeability Distribution and Steam Flood Optimization
Authors: Ahamed Sayed Fadel , Choudhry M. A. , Abdulbaqi J. B. 
Published: October 2008

Abstract
Shallow shelf carbonate reservoirs like the Eocene heavy oil reservoirs of Kuwait-Saudi Arabian divided zone exhibit a high degree of fluid flow heterogeneity where carbonate admixture with anhydrite. Diagnosing shallow shelf carbonate fluid flow heterogeneity is a very complex problem and represents a big challenge. Moreover, assessment of vertical and lateral permeability variation is a key factor for success of any reservoir development plan. The Eocene heavy oil reservoirs are producing since 1956. limited old well core data, and absence of reliable transient pressure test has added challenges for assessing accurate permeability distribution.
This paper shows how the Eocene wells productivity could be correlated with the common available well logs to develop a log based-permeability model. A series of cross plots for the perforated intervals of highest and lowest productivity wells were constructed. These cross plots show a relationship between the well productivity and location of log parameters on the plots. Based on this observation a relation between rock quality or productivity and conventional log parameters was established. Regression analysis as well as neural net work was used to develop a relationship between permeability and log parameters. The technique was validated by comparison with new wells data; mobility from Modular dynamic tester (MDT), core data and wells productivity.
Based on the developed model, Eocene wells vertical permeability and interwell continuity can be used to optimize new well placement for the horizontal and vertical infill drilling. Also the developed model represents an effective tool to predict the steam injectivity profile and to understand the interesting anomaly related to temperature-depth distribution. Moreover, the developed model will be used to optimize Steam flood process and steam pattern well completion for improving efficiency of formation heating and delaying steam flood break through.
SAGD Gas Lift Completions and Optimization: A Field Case Study at Surmont
Authors: Handfield T. C. , Nations T. , Noonan S. G. 
Published: October 2008

Abstract
Gas lift completions for SAGD1 producers are unique. Conventional gas lift valves and mandrels with a packer completion cannot be used due to the extreme temperatures of the downhole environment. Most lift gas enters the production stream downhole via open-ended tubing or nozzles, which if not properly sized can result in operational issues, such as fluid / gas slugging and pressure instabilities which negatively impact the overall lift efficiency.
In 2006, ConocoPhillips conducted a study to design a gas lift system for the Surmont SAGD development that would allow better control of lift gas into the production string and in late 2007 the wells completed with gas lift were placed on production. This paper will cover the data collection effort and analysis completed to determine the efficiency of the two types of gas lift nozzles used in the completions, the methodology for optimization of SAGD gas lift systems and recommendations for future improvement.
An Integrated Approach to Permeability Modeling Using Micro-Models
Authors: Hosseini A. H. , Leuangthong O. , Deutsch C. V. 
Published: October 2008

Abstract
Spatial distribution of permeability is an important factor in the prediction of performance of Steam Assisted Gravity Drainage (SAGD) well pairs. Presence of short-scale variability in sand/shale sequences, preferential sampling of core data, and uncertainty in upscaling parameters are complications that make the inference of a reliable porosity – permeability relationship impossible. A simple yet effective way of overcoming these complications is micro-modeling. The central idea in micro-modeling is to use an additional source of information, namely digitized core images, to quantify the uncertainty in power-law averaging parameters and construct the porosity-permeability bivariate relationship by Monte Carlo Simulations (MCS). The work-flow in micro-modeling is comprised of a few steps from digitizing the selected core images to building 3D geo-blocks of binary sand/shale mixture, populating them with porosity/permeability values, upscaling the populated binary mixture by flow simulations, determining the uncertainty in power-law parameters and implementing MCS. The porosity-permeability relationships are constructed on a by-facies basis. Results of this research suggest that effective properties of clean sand are changing with the volume fraction of shale; and it has ultimately resulted in the development of an extended version of power-law formalism.
Examination of Oil Sands Projects: Gasification, CO2 Emissions and Supply Costs
Authors: Elliott Katherine 
Published: October 2008

Abstract
Global conventional oil and natural gas reserves are on the decline. As a result, non-conventional resource plays, such as Alberta's oil sands, are experiencing heightened global interest. Bitumen extraction and upgrading is an energy intensive process. This article focuses on gasification as a fuel alternative to natural gas for oil sands operation, reviewing current trends in oil sands reserves, energy requirements, the gasification technology and carbon dioxide (CO2) emissions. A supply cost methodology is employed to analyze the outlook of lower natural gas consumption and higher emission penalties for oil sands projects that integrate gasification.
The results of the supply cost analysis illustrate that an integrated oil sands extraction, upgrading and gasification project is less susceptible to operating cost pressures amidst rising natural gas prices due to its lower natural gas requirements. However, without means to mitigate CO2 emissions, the supply cost approach indicates that federal offset penalties of CAD 60 per tonne erode any benefit associated with the decreased natural gas use.
Practical Considerations of Reservoir Heterogeneities on SAGD Projects
Authors: Baker R. , Fong C. , Li T. , Bowes C. , Toews M. 
Published: October 2008

Abstract
SAGD has been implemented through a variety of different operating schemes. Determining the optimum and cost-effective strategy poses the greatest challenge to any SAGD reservoir. In addition to average rock quality, reservoir heterogeneities have a deep impact in steam chamber development and the overall volumetric sweep. This paper examines two well pairs in the Surmont pilot project. From this analysis and general experience, the following critical factors must be considered when optimizing SAGD operating strategies:
Getting enough heat close to the producer Accounting for areal (lateral) heterogeneity Identifying shale extent and its effect in partially retarding steam chamber height growth Determining the effect of water saturation and assumed irreducible water saturation Understanding that permeability is often higher than air permeability most likely due to dilation effects
This paper also addresses potential geological risk through analogy and the amount of heterogeneity that must be accounted for when developing a representative simulation.
Asphaltene Precipitation and Its Effects on the Vapour Extraction (VAPEX) Heavy Oil Recovery Process
Authors: Luo P. , Wang X. , Gu Y. , Zhang H. , Moghadam S. 
Published: October 2008

Abstract
Asphaltene precipitation is one of the most important physical phenomena during the solvent vapour extraction (VAPEX) heavy oil recovery process. After the asphaltene precipitation occurs, the produced heavy oil is in-situ deasphalted and thus has a lower viscosity and better quality. On the other hand, precipitated asphaltenes may plug some small pores of the reservoir formation and thus reduce its permeability. In this paper, a series of the VAPEX tests is conducted by using a rectangular visual sand-packed high-pressure physical model to study the detailed effects of solvent type, operating pressure, and sand-pack permeability on the asphaltene precipitation and subsequent deposition, which strongly affect heavy oil production and quality. It is found that when the operating pressure is close to the vapour pressure of pure propane or the dew-point pressure of a butane mixture, the occurrence and extent of asphaltene precipitation and deposition strongly depend on the sand-pack permeability. At a considerably high permeability of several hundred Darcies, asphaltene deposition occurs near the injector and solvent-diluted heavy oil drains quickly, which lead to a significant heavy oil viscosity reduction and a high oil production rate, respectively. When the sand-pack permeability is low and close to a typical heavy oil reservoir permeability, however, the residence time of the solvent-diluted heavy oil inside the physical model is long due to its low drainage velocity. A sufficiently high solvent concentration in the heavy oil causes severe asphaltene precipitation in this case. A large number of the precipitated asphaltenes are blocked and deposited at the pore throats so that the porous medium is plugged to some extent.
The Slender Bubble Model for Very Slow Degassing in Porous Media and Cold Production
Authors: Chraibi Mehdi , Zaleski Stéphane , Franco Fabienne 
Published: October 2008

Abstract
Cold production of oil leads to degassing of the light species and the formation of a bubbly phase, sometimes called the "foamy oil" effect. This bubbly phase is particularly observed with heavy oils, combining high viscosity and asphaltenes.
Presence and behavior of a foamy-oil effect appears to be critical to the cold production process. This process is not a well-understood production mechanism because a wide range of different petrophysical parameters and experimental factors interact in a rather complex way. Over the past few years, a number of efforts have been made in many institutions, in order to understand and model the solution gas drive mechanism in primary heavy oil recovery. Conventional simulations are not reliable for prediction forecast purposes. The reason is often that conventional modeling requires relative permeabilities tables that are not universal, but depend at least on the depletion rate and possibly on other parameters.
In this paper we keep the conventional Darcy scale point of view and the Darcy law with relative permeabilities. The key difference however is that relative permeabilities are not fit to experiments but obtained through physically-motivated explicit formulas. These expressions or formulas are based on the analysis of the mechanism of gas phase flow based on the geometry of the bubbles and its consequences on their motion. The theory involves a prediction of the aspect ratio of the bubbles and their velocities. The aspect ratio of the bubbles depends on the characteristics of the porous media in terms of pore size distribution and is obtained based on the Invasion Percolation in Gradient theory.
The resulting model is analyzed and solved in two different ways. First we describe a new type of approximate solution assuming extremely slow degassing. A simple partial differential equation similar to a kinematic wave equation results. This approach is more powerful than the asymptotic expansion described in previous wirk of the authirs, as it allows for the stauration to exhibit gradients and even shocks. Second, we solve the full set of Darcy-scale equations by way of a numerical solution, based on a version of the IMPES method based on previous similar numerical approaches. We show comparisons between the two solutions. We discuss how the formation of strong gradients of the gas phase saturation depends on gravity and viscosity.
The Influence of Diffusion and Dispersion on Heavy Oil Recovery by VAPEX
Authors: Alkindi Abdullah , Muggeridge Ann , Al-Wahaibi Yahya 
Published: October 2008

AbstractHeavy oil recovery by VAPEX appears to be a promising IOR technique as it uses less energy than SAGD and, if CO2 is injected, can also provide a means of disposing of excess CO2 in the subsurface. Nonetheless field application of this process has been limited due to concerns that favourable laboratory recoveries may not scale up to the field. In particular previous laboratory studies of VAPEX in porous media have obtained significantly higher production rates than predicted either by analytic models derived from Hele-Shaw experiments or numerical simulations. The discrepancy between experiment and models has been explained by assuming greater mixing between vapour and oil than would be expected from molecular diffusion. Justifications for this increase include convective dispersion, an increased surface area due to the formation of oil films on sand grains, imbibition of oil into those films and a greater dependence on drainage height. Convective dispersion seems to be the most plausible mechanism.This paper investigates the role of convective dispersion on oil recovery by VAPEX using a combination of well characterized laboratory experiments and numerical simulation. A first contact miscible fluid system was used so that all mechanisms contributing to increased-mixing apart from convective dispersion were eliminated. Longitudinal and transverse dispersion coefficients were measured experimentally as a function of flow-rate and viscosity ratio. Vapex drainage experiments were then performed over a range of injection rates.The laboratory measurements of oil drainage rate were compared with those predicted by the Butler-Mokrys analytical model and numerical simulation using either molecular diffusion or convective dispersion. Using measured convective dispersion improved prediction of oil drainage rate by 50%.The numerical model was then used to investigate the impact of rate (through viscous to gravity ratio and Peclet number), well separation and reservoir geometry on recovery.
A New Water Treatment Scheme for Thermal Development: The SIBE Process
Authors: Pedenaud Pierre , Dang Fabrice 
Published: October 2008

Abstract
The production of extra heavy oil or bitumen through Thermal methods (e.g. SAGD - Steam Assisted Gravity Drainage) requires the generation and injection into the reservoir of significant quantities of steam which is finally recirculed with the produced bitumen. Considering the need to minimize fresh water consumption and the possibility of increasingly stringent environmental regulations, it is likely that maximization of the recycling of the produced water into steam will be mandatory.
The SAGD water treatment scheme is complex because it depends on the water characteristics, the steam generator type selected (OTSG or conventional boiler) and the decision to completely eliminate waste water disposal (zero liquid reject) or use other waste handling and disposal methods. SAGD water treatment also faces some additional specific challenges compared with oil fields worldwide, such as the high silica content in the produced water.
An overview of the current water treatment process options for SAGD will be presented, followed by a new patented process called SIBE (ie Silica Inhibition and Blowdown Evaporation). The principle of this new process is based on TOTAL's research in the area of silica inhibition and an optimized application of conventional water treatment equipment with Zero Liquid Discharge process (e.g. evaporators and Crystalliazer). An estimate of the economic benefit of the new SIBE process relative to conventional process schemes will be presented.
Methodology of Calibration for Nucleonic Multiphase Meter Technology for SAGD Extra Heavy Oil
Authors: Pinguet Bruno , Pechard Philippe , Guerra Elsie , Arendo Vincent , Shaffer Mark , Contreras Jose 
Published: October 2008

Abstract
Metering of bitumen produced by Steam-Assisted Gravity Drainage (SAGD) induces many issues arising from high operating temperatures (150-200 C), steam presence in the gas phase, foaming, emulsion and small density differences between bitumen and produced water. Nucleonic technology could be well-suited for this environment especially if the temperature issue can be properly handled. A multiphase meter (MFM) utilizing a multi-energy gamma ray (nuclear fraction) meter associated with a Venturi can potentially handle these operating constraints and replace separation devices for permanent or periodic well testing, providing accurate monitoring and optimization of oil, water, gas and steam production.
Following a 2008 field trial planned at a Canadian SAGD site, this paper will present specific strengths of the MFM with emphasis on its ability to meter correctly the liquid/gas phases depending of the calibration method and operating measurement range. Indeed, the overall methodology is a key element of the utilization of the MFM to ensure consistency with metering figures from well tests performed with a test separator equipped with accurate liquid and gas measurements and this field trial explores variations in process conditions to identify strengths and weaknesses of this MFM technology versus the operating envelope in standard operation (Non SAGD).
An entire study of the main parameters which could influence the measurement associated with this technology will be provided based on practical and simulated data and the impact of changes in each parameter will be evaluated. This paper will be a guideline for future users in the oil industry of this technology by providing an understanding of how to apply it to bitumen metering.
Combined Reservoir Simulation and Seismic Technology, A New Approach for Modeling CHOPS
Authors: Aghabarati Hossein , Dumitrescu Carmen , Lines Larry , Settari Antonin 
Published: October 2008

Abstract
Cold Heavy Oil Production with Sand (CHOPS) has become one of the main recovery schemes for developing heavy oil reservoirs in Canada. This became possible with the introduction of progressive cavity pumps, therefore much higher sand cut in viscous heavy oil could be expected from unconsolidated/weakly consolidated formations as opposed to conventional pumps with limited capacity.
In this study, combined reservoir simulation and seismic technology are applied for a heavy oil reservoir situated in Saskatchewan, Canada, for better understanding of the reservoir properties and recovery mechanism. The numerical model was built based on the well log data and several seismic attributes. The integration of seismic attributes improved modeling reservoir heterogeneity, which is a main challenge in modeling sand production.
Firstly, we used geostatistical methods to estimate the initial reservoir porosity, using a seismic survey acquired in 1989. Secondly, sand production was modeled using erosional velocity approach and the model was run based on the oil production. Finally, results of the true porosity derived from simulation were compared against the porosity estimated from the second seismic survey acquired in 2001. This flow provides new tools that validate the simulation model results against the seismic data.
Following this approach the extent and the shape of the enhanced permeability region (wormhole region) for estimated porosity distribution are modeled. The performance of the CHOPS wells is highly dependent on the rate of creation of the high permeability zone around the wells. This method can be used for evaluating future developments of the field such as infill drilling and post CHOPS recovery methods (VAPEX).
The Integrated CO2 Pilot in the SW of France (Oxycombustion and Geological Storage): A Potential Answer to CO2 Mitigation in Bitumen Production
Authors: Aimard Nicolas , Prébendé Claude , Cieutat Denis , Tsiava Rémi 
Published: October 2008

Abstract
In Alberta, Oil & Gas operators are developping Extra Heavy Oils (EHO) production fields requiring much more processes and energy than conventional oil. Consequently, the associated GHG emissions could be potentially huge and operators are seeking options to reduce them. Among the possible options, Carbon Capture and geological Storage (CCS) appears to be the most promising option in addition to power efficiency increase and use of renewable or alternatives energies.
For EHO thermal production, a huge quantity of steam is required; therefore a large quantity of CO2 per produced barrel could be emitted. The existing and future boilers will have to capture these emissions efficiently, either with post-combustion like amine unit, or oxycombustion. New boilers have to be designed to integrate the most appropriate "capture ready" solutions.
TOTAL launched at the end of 2006 an integrated CCS project at Lacq, in the South-West of France. It entails the conversion of a steam boiler into an oxy-fuel combustion unit. The pilot plant, which will produce some 40 t/h of steam, will emit up to 120,000 tons of CO2 over a 2-year period. The CO2 rich flue gas will be cleaned up and compressed. The resulting CO2 will be conveyed via pipeline to a depleted gas field, 30 kilometers away, where it will be injected into a deep carbonate reservoir. CO2 injection start-up is scheduled beginning 2009.
This paper demonstrates that oxycombustion could have some adavantages compared to post-combustion for CO2 capture in term of energy efficiency for steam generation. Secondly, it presents the characteristics of the 30MWth oxy-gas boiler, one of the first world industrial oxy-combustion units. Then, it focuses on the new equipment to retrofit the drum boiler to oxy-combustion: the Air Separation Unit, the Oxy-combustion System developed by Air Liquide, the Flue Gas Recycle set up, the CO2 cooling, compression and drying before transportation.
Enhanced Heavy Oil Recovery on Depleted Long Core System by CH4 and CO2
Authors: Shi R. , Kantzas A. 
Published: October 2008

AbstractThis paper describes a laboratory study of potential post-cold production strategies for heavy oil reservoirs. The tests were conducted on two primarily depleted long core systems (glassbeads core and sandpack core). The glassbeads core is 18.2 m in length with higher permeability (11.8 Darcy) and the sandpack core is 18.5 m long with lower permeability (1.9 Darcy). Both core systems were recharged by CH4 injection followed by a depletion step similar to the cold production experiment. Both cores were then exposed to a single cycle of CO2 injection, soaking and production. This work aims at further understanding the heavy oil solution gas drive mechanism. Furthermore, the study aims at assessing methane and carbon dioxide recharging as a potential recovery method for heavy oil reservoirs, and at establishing a base line for comparison against each other. Results of this study indicate that CH4 and CO2 recharge processes give an additional 8% and 9% OOIP recovery for the glassbeads core and the sandpack core, respectively. Since the cold production for the glassbeads core (22.2% OOIP) was high, the low recharge recoveries may be pessimistic. However, for the sandpack core, the recharge recovery appears more optimistic with almost similar recovery to that of cold production (about 10.2% OOIP).