bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Fully Coupled Model of Nonisothermal Multiphase Flow, Solute Transport and Reactive Chemistry in Porous Media
Authors: Zhang Ronglei , Yin Xiaolong , Wu Yu-Shu , Winterfeld Philip H. 
Published: October 2012

Abstract
Over the past decades, geochemical reaction has been identified through experiments in different processes, e.g. the CO2 EOR process, the CO2 sequestration, the enhanced geothermal system. Research has gradually led to the recognition that chemical reactions between injected fluid and mineral rock have significant impacts on fluid dynamics and rock properties in these processes. However, for the majority of the reactive transport simulators, the sequential calculation processes of fluid flow, solute transport, and reactive geochemistry result in numerical instability and computation efficiency problems. In this paper, we present a fully coupled computational framework to simulate reactive solute transport in porous media for mixtures having an arbitrary number of phases. The framework is designed to keep a unified computational structure for different physical processes. This fully coupled simulator focuses on: (1) the fluid flow, solute transport, and chemical reactions within a three- phase mixture, (2) physically and chemically heterogeneous porous and fractured rocks, (3) the non-isothermal effect on fluid properties and reaction processes, and (4) the kinetics of fluid-rock and gas-rock interactions. In addition, a system of partial differential equations is formed to represent the physical and chemical processes of reactive solute transport. A flexible approach of integral finite difference is employed to to obtain the residuals of the equation system. Jacobin matrix for Newton- Raphson iteration is generated by numerical calculation, which helps the future parallelization of the fully coupled simulator. Finally, the fully coupled model is validated using the TOUGHREACT simulator. Examples with practical interests will be discussed, including CO2 flooding in a reservoir, supercritical CO2 injection into a saline aquifer, and cold water injection into a natural geothermal reservoir. This type of simulation is very important for modeling of physical processes, especially for CO2 EOR and storage, and geothermal resources development.
Paraffin Deposition Analysis for Crude Oils under Turbulent Flow Conditions
Authors: Karami Mirazizi Hamidreza , Shang Wei , Sarica Cem 
Published: October 2012

Abstract
This paper presents the results of a modeling study for paraffin deposition under single-phase turbulent flow conditions. Analysis on flow loop deposition data is presented for various crude oils such as South Pelto crude oil, Garden Banks condensate and Trans Alaska Pipeline System (TAPS) crude oil. A new closure relationship simulating shear effects is proposed.
The experimental data were obtained under single-phase turbulent flow conditions using different types of crude oils on different test facilities at TUPDP (Tulsa University Paraffin Deposition Projects). These data were used to develop a correlation which can be used to predict the relative difference between the estimated wax mass deposition rate and mass diffusion rate from Fick's law as a function of the Nusselt and Sherwood numbers representing the heat and mass transfer characteristics under turbulent flow conditions. Uncertainty analysis was conducted on this correlation and most of the data points fall within the range of ±25%. Model predictions have been compared using a film mass transfer model and equilibrium model. It is observed that the film mass transfer model always over predicts the deposition rate. But the equilibrium model can both under predicts and over predicts the deposition rate. The results presented in this paper can be used to improve the accuracy of paraffin deposition model predictions under turbulent flow conditions.
Gas/Water IFT Measurements Using the Pendant Drop Method at HP/HT Conditions: The Selected Plane vs. Computerized Image Processing Methods
Authors: Shariat A. , Moore R. G. , Mehta S. A. , Van Fraassen K. C. , Rushing J. A. 
Published: October 2012

Abstract
This paper presents a comparative evaluation of gas-water interfacial tensions (IFT) measured using the pendant drop technique and computed using either the Selected Plane (SP) or the Computerized Image Processing (CIP) Methods at high- pressure/high-temperature (HP/HT) conditions. Both the SP and CIP Methods are based on solutions to the Young-Laplace equation. The SP Method, which is derived from an approximate solution originally developed by Bashforth and Adams (1883), is dependent on just two pendant droplet dimensions. Further, the solutions were generated for the air-water system at pressures and temperatures much lower than typically encountered in oil and natural gas reservoirs. However, these solutions are often extrapolated mathematically to HP/HT conditions.
Although it is relatively simple to use, the IFT computational accuracy using the SP Method is questionable since it is dependent on the precision to which the two pendant droplet dimensions are measured. However, improvements in computerized data acquisition and imaging systems have made it possible to digitize droplet shapes completely such that IFTs may be computed using the entire shape. So while the CIP Method is also an approximate solution (numerical solution which discretizes the droplet interface) to the Young-Laplace equation, it utilizes many more points on the pendant droplet and incorporates the actual fluid properties directly into the solution. Therefore, the question addressed in this study is: what is the accuracy of the SP Method for computing gas-water IFTs at HP/HT conditions?
To answer this question, we conducted a two-stage study. First, we used the pendant drop method and measured droplet dimensions for the gas-water system at pressures of 1,000 psia to 20,000 psia and temperatures of 122°F, 212°F, 300°F, and 400°F. We then compared gas-water IFTs computed using both the SP and CIP Methods. The comparative evaluation indicates the gas-water IFTs from the SP Method are generally and consistently lower than IFTs from the CIP Method. Differences between the two methods are dependent on pressure/temperature conditions, gas composition, droplet geometry and size, and the illumination when the droplet shape is photographed. However, the maximum absolute mean error for all evaluations was less than 3.5%, suggesting the SP Method is valid for computing gas-water IFTs at HP/HT conditions.
Well Planning Based On Passive Magnetic Ranging And Magnetized Casing
Authors: Noort Roger van , Abrant William , Towle James 
Published: October 2012

Abstract
No one wants or expects to have to drill a relief well; however, it is a fact that a number of relief wells are required each year. Recent events have drawn attention to the need for, and the benefit of, comprehensive contingency relief well planning. On a deepwater Gulf of Mexico (GOM) well, it was noted that "Active Electro Magnetic Ranging" technology would not work at the planned intercept depth due to the presence of a large salt body. Furthermore, the planned survey program would result in a relatively large Ellipse of Uncertainty (EOU) at the desired intercept depth, which would make a relief well intercept on a first pass unlikely to succeed. A combination of "Passive Magnetic Ranging" and a modified survey program was identified as the solution to demonstrate the ability to intercept the target well on the first attempt.
Due to the inherent problems associated with "active" ranging technologies in salts (De Lange, J.I., Darling, Toby J., 1990), "passive" MWD Ranging was identified as the likely ranging technique due to the fact that it is not impacted by formation type (salt). Based upon the modified survey program, it was determined that a reliable range of detection of eighty feet (80’) would be required to qualify passive magnetic MWD Ranging technology as the primary ranging technique should a relief well be required. This detection range would allow a "no flyby" intercept (also referred to as a direct intercept) by the theoretical relief well. To confirm this capability, a qualifying demonstration protocol was established and executed using casing joints that would ultimately be run into the well. The proving tests were conducted first with only remnant magnetization of the casing joints and then again after the casing joints had been magnetized with a coil.
New Logging-While-Drilling Ranging Technique for SAGD: Theory and Experiment
Authors: Bittar Michael , Wu Hsu-Hsiang , Li Shanjun 
Published: October 2012

Abstract
In a heavy oil production steam-assisted gravity drainage (SAGD) project, two horizontal wells were separated by only a few meters. The separation had to be kept parallel to enable steam to be injected from one well and oil to be produced from the other twin well located below. In general, the currently practiced techniques rely on wireline technology to position the wells; in many cases, the technique requires access to the existing well in SAGD operations.
This paper presents a novel technique for locating the relative position of one well with respect to another by using a rotating azimuthal logging-while-drilling (LWD) electromagnetic tool. With this technique, the relative position between a well with a rotating LWD electromagnetic tool and casing in an adjacent existing second well can be determined in real time. Consequently, the relative position and the relative distance between the two wells provide the field engineer with calculated inter-well spacing and direction to maintain the two wells parallel and spaced within a certain distance apart.
This paper discusses and explains the fundamentals of the new LWD ranging technique. Several cases were modeled and compared with experimental data collected in a water tank with a conductive casing. The experiments successfully validated the computed responses. The casing position and distance to the LWD tool were successfully determined. This new LWD technique presents a ranging method alternative to the existing wireline technique and can be successfully used in a SAGD application.
Organizational Success Integrating Safety and Training with Operations: An Engineered Approach
Authors: McNeil Michael , Howard Myke 
Published: October 2012

Abstract
Success for any company in today's highly competitive global market is dependent on ensuring company-wide safety and efficiency are always at peak performance.
At the core of this success is the philosophy that Safety and Training are not about attaining compliance; but rather, about engineering a cultural improvement that holds an organization's primary assets—its employees—as a top priority. To achieve this end, Safety and Training must overcome the traditional roadblocks such as time, cost and attitude. By expanding the emotional and intellectual capacity of the organization's employees through a consistent demonstration of value, Safety and Training become integral to the culture and lifestyle of an organization.
This paper will demonstrate statistically how successful integration of Safety and Training improves the overall culture and performance of an organization and how such an investment can lead to greater efficiency and ultimately greater profitability.
It illustrates how, through the acceptance of improved integration and awareness processes, one organization experienced 380% growth over a three-year period with a 329% reduction in Total Recordable Injury Frequency (TRIF). Additionally, the organization's employee retention rate improved 31% resulting in a more experienced workforce, improved efficiency, increased service quality and stronger customer relationships.
The main objective of Safety and Training is to satisfy the needs of the end-users—employees—while propelling the organization forward. The reciprocal relationship between Safety, Training and Operations stimulates personnel to challenge Safety and Training to provide continued improvement. The upshot of this is greater profits stemming from a more motivated and efficient workforce, which sustains fewer injuries, related downtime and cost.
An Approach to Model CHOPS (Cold Heavy Oil Production with Sand) and Post-CHOPS Applications
Authors: Rangriz Shokri A. , Babadagli T. 
Published: October 2012

ABSTRACT
Due to its lower cost, the cold heavy oil production with sands (CHOPS) method is becoming more popular, not only in Canada where it originated, but also in many other countries including Venezuela, Kuwait, Russia and China. However, this method has several practical limitations. It continuously changes the geo-mechanical and petro-physical properties of the reservoir due to the sand produced, resulting in high permeability channels known as wormholes. Moreover, the method has a low oil recovery factor of 5 to 15 % and this entails further recovery techniques.
Thermal methods after CHOPS are not usually favorable due to heterogeneity and reservoir instability. In addition, the CHOPS method is typically applied in thin formations in which heating by injected steam is characteristically inefficient. Solvent injection possesses similar problems caused by heterogeneity and cost. An option could be the hybrid application of steam/solvent. Assessment of this technique first requires a realistic modeling of the CHOPS application. Due to dynamic changes in reservoir properties, no valid model is yet available to accurately simulate CHOPS production.
Our main focus in this paper is to investigate efficient EOR/IOR methods after CHOPS. To achieve this, we first propose a partial-dual porosity approach coupled with algorithms for wormhole generation to create a realistic static reservoir model. After generating fractal wormhole patterns of different kinds using a diffusion limited aggregation (DLA) algorithm, they were introduced into a reservoir model with extremely fine grids. It is assumed that wormhole's properties are a function of its radius and can be controlled along its length and pattern, which facilitates the history matching process. After validation of the model using data obtained from a field in Alberta, several post-CHOPS scenarios including thermal, solvent and thermal/solvent hybrid applications were simulated.
The new modeling workflow, proposed and validated to model the CHOPS process with realistic wormholes representations along with a simple mathematical wormhole network growth model, are the primary contributions of this paper. Secondarily, hybrid steam/solvent applications were evaluated using this validated static model and compared with the sole application of steam and solvent.
Reservoir Parameter Estimation with Improved Particle Swarm Optimization
Authors: Awotunde Abeeb A. 
Published: October 2012

Abstract
Effective reservoir management relies heavily on the accurate prediction of reservoir flow performance over the entire life of the reservoir. Accurate prediction of flow performance is possible only if reservoir flow parameters are known with reasonable accuracy. Consequently, a major challenge in reservoir management is the estimation of reservoir parameters that affect the flow and distribution of reservoir fluids the most.
Estimation of distributed reservoir parameters has been done using mainly gradient-based optimization algorithms because these algorithms are relatively faster than global (stochastic) optimization algorithms. However, the gradient-based algorithms are local in nature and thus limited in their search ability. In this paper, we present a local-global optimization method that generates multiple realizations of reservoir parameters at coarse scale. The method involves the use of a local search optimization algorithm to parameterize the model space at a coarse scale followed by a stochastic search for better estimates in the vicinity of the local estimate. At the end of the search, the method produces a distribution of estimates that can be used for uncertainty quantification. To test the effectiveness of the method, the local-global optimization algorithm was applied to a sample reservoir with a known distributed permeability field. Results obtained indicate that the method is able to produce multiple history-matched realizations of the permeability field, some of which are closer to the true reservoir permeability distribution than the estimate obtained from an exhaustive local search.
First Highly Deviated Openhole Gravel Pack Jobs in the Mediterranean with Alternate Path Technology
Authors: Bessada Ashraf M. , El-Shafaie Ibrahim , Nashaat Mohamed , Roy Alistair , Russell Wood W. , El-Attar Hesham Bahaa 
Published: October 2012

Abstract
Sand control, particularly gravel packing, is a common practice in the Mediterranean Sea due to the presence of poorly consolidated sandstone reservoirs. Open Hole Gravel Packs (OHGP) in highly deviated wells present an additional challenge due to the risk of sand bridging during the alpha wave propagation. The risk of bridging is escalated further in low fracture gradient environments where the pumping rate is reduced to avoid inducing losses. A major operator in Egypt has performed the first highly deviated OHGP jobs in the Mediterranean using Alternate Path screens. A series of qualification work was performed by the service provider during the planning phase for the 2 wells. Planning work included fluid rheology tests, flow loop testing, modeling full scale tests to achieve desired accuracy with gravel transport equations, pretreatment numerical simulations and post-treatment comparison of simulated data to actual data. Moreover, a lightweight proppant (LWP) product was qualified and successfully pumped on the second well where the fracture gradient was particularly low due to reservoir depletion. This paper discusses the planning, execution and post-job review work that was performed for these wells to produce two successful sand control jobs. Recommendations and lessons learnt for the future wells are also included.
With the Industry and specifically the Mediterranean Basin moving towards more challenging wells requiring sand control in ever higher deviations and significantly depleted sands these highly deviated gravel packs with high overbalances are becoming increasingly important to unlock resources and maintain field plateau.
The paper will detail the simulated results based on flow loop testing and how they compare with the actual job data. Successful sand control integrity was achieved with amount of gravel pumped exceeding 100% of the theoretical volume and sand free production achieved on both wells. Individual well performance with estimated skin values will also be shared.
Fluid Characterization Using an EOS for Compositional Simulation of Enhanced Heavy-Oil Recovery
Authors: Kumar Ashutosh , Okuno Ryosuke 
Published: October 2012

Abstract
Reliable design of solvent injection for enhanced heavy-oil recovery requires accurate representation of multiphase behavior for heavy-oil/solvent mixtures in a wide range of pressure-temperature-composition conditions. Characterization of a heavy oil is more difficult than that of a conventional oil because the former is conducted under more uncertainties in composition and PVT data. Volume-shift parameters are often required to improve density predictions, separately from compositional behavior predictions, in conventional fluid characterization methods (CM). Thermodynamically, however, volumetric behavior predictions (e.g., densities) are consequences of compositional behavior predictions.
In this paper, we develop a new fluid characterization method (NM) that gives accurate multiphase behavior representation for heavy-oil/solvent mixtures without using volume-shift parameters. The Peng-Robinson (PR) EOS is used with the van der Waals mixing rules. In the NM, pseudo components are initially assigned critical temperature (TC), critical pressure (PC), and acentric factor (ω) values that are optimized for the PR EOS for accurate phase behavior predictions for n-alkanes from C7 to C100. The subsequent regression process searches for an optimum set of TC, PC, and ω in physically justified directions. The regression algorithm developed does not require user's experience of thermodynamic modeling for robust convergence. The NM also satisfies Pitzer's definition of ω for each component.
The NM is compared with the CM in terms of various types of phase diagrams, minimum miscibility pressure calculations, and 1-D oil displacement simulations. Twenty two different reservoir oils are used in the comparisons. Results show that the NM with 11 components gives phase behavior predictions that are nearly identical to those using the CM with 30 components. A 1-D simulation case study presents that the NM can robustly reduce dimensionality of composition space while keeping accurate multiphase behavior predictions along composition paths at different dispersion levels tested. We show that the CM with volume shift can give erroneous phase behavior and oil recovery predictions in compositional simulation. The NM does not require volume shift to achieve accurate predictions of compositional and volumetric phase behaviors. The two types of phase behaviors are properly coupled in the NM.
Artificial Intelligence for Heavy Oil Assets: The Evolution of Solutions and Organization Capability
Authors: Popa Andrei S. , Cassidy Steve 
Published: October 2012

Abstract
Artificial Intelligence (AI) techniques have been successfully applied in the petroleum industry since the early 1990s initially attempting to solve simple tasks and more recently evolving into hybrid systems taking on complex optimization and modeling problems. Artificial Intelligence has become an integral part of our business in the last 10 years with applications ranging from reservoir characterization, production optimization to surrogate models used in reservoir simulation. Chevron's San Joaquin Valley Business Unit has been implementing AI technologies through Chevron's i-field™ program since 2003. With the majority of the production coming from heavy oil assets, most of the intelligent applications developed using AI target the optimization of thermal operations.
The paper describes the operator's experience and continuing efforts towards integration of Artificial Intelligence technologies in the Business Unit. The manuscript covers two topics: a review of several successful Artificial Intelligence applications implemented in the heavy oil assets while focusing on solutions and value creation, and an internal training program aimed at developing the company's organizational capability in this domain.
The first part discusses the successful implementation of AI techniques, neural networks, genetic algorithms, fuzzy logic, case- based reasoning and hybrid systems to solve complex projects. Case studies covering well candidate selection, optimization of cyclic steam scheduling, increased production opportunities identification, well failure diagnostic and job planning are presented. The review concludes with lessons learned, challenges and business value creation (increased production, NPV, time savings, etc). The second part highlights the efforts of initiating and implementing a training program aimed at building awareness and organizational capability. In 2009, a few AI enthusiasts and practitioners formed an Interest Group with the mission of enhancing reservoir management workflows by developing innovative solutions using Data Mining and AI technologies. The section describes the target audience, training material, workshops structure, brainstorming exercises and lessons learned from the sessions completed so far.
Ultimately, the review is intended to demonstrate the value of applying AI, and how to grow AI organizational capability. A brief overview of future plans concludes the paper.