bluuebunny/crossref_metadata_2025_split huggingface dataset:
Two-Phase Flow Rock-Typing: Another Perspective
Authors: Hamon G. 
Published: December 2007

Abstract
Petrophysical units, also called rock-types, are usually defined to help the reservoir engineers to assign petrophysical characteristics to different zones of a detailed description of a reservoir. Estimate of initial hydrocarbons in place accounts for such petrophysical units which are usually generated, using both single-phase data, i.e. porosity, permeability, and two-phase drainage data (i.e capillary pressure curve) and coupled with sedimentological descriptions. It is then frequently assumed that these rock-types are valid to assign two-phase flow characteristics, such as relative permeability curves, to a reservoir, whatever the recovery process. This paper shows that this assumption is often not correct, using several field examples, including sandstone and carbonate reservoirs. Based on a large number of core flood results, it is shown that the usual rock-typing methods may not capture the actual variability of relative permeability curves, and particularly:
Porosity, permeability or pore size distribution might be poor indicators of actual controls for two-phase flow, whatever the technique used to combine them into a rock-type representation There is no systematic correspondence between rock-types used to estimate hydrocarbons in place and those required to describe production behaviour, There is no systematic correspondence between sedimentological facies and rock-types required to describe production behaviour,
It is also shown that:
Multivariate descriptions, including petrophysical characteristics, mineralogical data and wettability indicators, succeed in capturing the actual variability of relative permeability curves and should be the basis for the generation of multiphase flow rock-types. Two-phase flow rock-types should be dependent on the recovery process.
Consequences on sampling for coreflood programmes, as well as inputs of simulation models are pointed out.
Experimental Relationships between Residual Gas Saturation and Initial Gas Saturation in Heterogeneous Sandstone Reservoirs
Authors: Suzanne K. , Hamon G. , Billiotte J. , Trocmé V. 
Published: December 2007

Abstract
Residual gas saturation is considered to be a key factor in evaluating gas recovery from a lean gas reservoir invaded by water. Residual gas saturation is known to be dependent on both pore network characteristics and initial gas saturation. In this paper, sixty experimental relationships between initial gas saturation (Sgi) and residual gas saturation (Sgr) are presented for a large set of sandstone samples and checked against former empirical Sgr-Sgi laws. Previously, no more than two authors have presented more than twenty full experimental Sgr-Sgi relationships.
The core plugs are selected from two different sandstone gas reservoirs and from Fontainebleau sandstone outcrop. Porosity and permeability plugs, respectively range from 0.06 to 0.25 and from 0.1 to 2000 mD, with Sgrm values ranging from 0.04 to 0.65.
Two-phase Sgr is achieved by controlled evaporation - spontaneous imbibition methods. The main results are:
Two-phase Sgr-Sgi experimental relationships have piecewise linear form, characterized by two parameters: the maximum residual gas saturation, Sgrm, and the saturation corresponding to the intersection of the two segments, Sgo. Sgo was found to be dependent on the amount of microporosity and different from Swir. The constant Sgr region confirms that the microporosity does not trap gas. The linear Sgr/Sgi region corresponds to gas trapped in the macroporosity. None of the hyperbolic laws is able to describe correctly the observed experimental behavior. Jerauld's and the simplified version of Land's relationships are the poorest estimates of Sgr as a function of Sgi. The best relationship to describe Sgr-Sgi curves is the piecewise linear Aissaoui's law. It results in a significantly better agreement with experimental data than Land's original formulation. Both forms rely on two fitting parameters. Our experimental results show that porosity (or permeability) and the amount of microporosity along with the initial gas saturation control Sgr values.
Flow of Hydrates Dispersed in Production Lines
Authors: Peysson Yannick , Nuland Sven , Maurel Philippe , Vilagines Régis 
Published: December 2007

Abstract
This paper presents some results obtained in a Research project managed by IFP (Institut Français du Pétrole) and IFE (Institute for Energy Technology), where the objective is to study the transport of hydrates in production lines.
A number of research projects are devoted to the study of thermodynamic equilibrium in the presence of hydrates, and the kinetics of hydrate formation, in order to develop prevention tools like hydrates inhibitors, insulation.... But with the development of deep water and ultra deep water production schemes where these technologies become expensive and some times limited, a fair prediction of hydrate formation and transport conditions becomes necessary for anticipating the design of the production facilities and could help the production engineers to make the appropriate decisions. In the literature, however little efforts have been directed towards the hydrodynamic modeling of hydrate transport. This project aims at the study of hydrate slurries in flowing conditions and particularly in multiphase flow lines. Experimental data in flow loop are presented. Comparisons have been made with flow models. In presence of hydrate crystals, the production fluid resembles a slurry with effective transport properties. This study indicates that the presence of particles in the flow tends to increase the wall drag and, consequently, influences the production capacity of the line. Moreover the settling trends of these solid particles can complicate the problem. Discussions about these issues have been done.
Reliable Sub-Sea Umbilical and Down-Hole Injection Systems are an Integral Component of Successful Flow Assurance Programs
Authors: Shirah A. D. , Place M. C. , Edwards M. A. 
Published: December 2007

Abstract
Sub-sea and down-hole chemical injection systems are necessary components in most successful flow assurance programs. Specially formulated inhibitors and dispersants used in these systems provide solutions to a variety of deepwater and subsurface problems. The prevention or alleviation of wax deposits, asphaltene deposits, hydrate plugs, scale deposits and corrosion depends on an integrated chemical system. This system includes chemical formulation, capillary/umbilical design and proper operation and maintenance.
This paper will review these necessary elements of a successful chemical system: chemical formulation, capillary/umbilical design and proper operation and maintenance. Formulation will take account of the requirements for quality, cleanliness and performance, physical properties targets, and compatibilities with well fluids, other treatment fluids, and system components. Design considerations will include compatibilities with the treatment fluids and the external environments as well as mechanical properties. Operation and maintenance will assure continued functionality by providing for cleanliness, redundancy and unexpected problems in every step of the transportation and delivery system.
The chemical delivery system must be effective, reliable, forgiving and redundant. Replacement or repair of the system as well as loss of production due to failure can be very costly. In the paper's review of the sub-sea and sub-surface chemical injection systems, laboratory data in conjunction with successful and unsuccessful field results will be used to provide lessons learned and best practices.
Water Injection Optimized with Statistical Methods
Authors: Palsson B. , Davies D. R. , Todd A. C. , Somerville J. M. 
Published: December 2007

Abstract
The complexity of the water injection process is often underestimated and asset managers often focus on controlling the water injection costs rather than maximising the injection water, value creation. This paper discusses a several methods to evaluate the techno-economic issues surrounding water injection, ranging from discounted cash flow analysis to portfolio analysis. It is shown how quantitative technical and economic analysis of the available options allows optimum decisions for process management. Advance planning ensures that changes in water injection performance do not surprise managers since they are prepared for such possible events, appreciate the likelihood of their occurrence and are able to quickly identify the optimal response.
In many situations, statistical methods are the most appropriate toos to identify these optimal responses. The industry has experience with these methods and the required input data is often available. Monte Carlo methodology is shown to be a powerful alternative to Portfolio Analysis when the input data for the latter is incomplete or there are insufficient alternatives available.
Portfolio Analysis emphasises the value of diversity. This can be important as the presumption of the simpler methods that all events are independent is often not true. E.g. the chance of a success of a stimulation treatment is not neccessarily independent of the chance of success in next well.
A decision tree analysis of a water injection case study is used to quantify the "Value of Information" and to show how spending significant resources on extended technical studies can be justified. This extra data might lead to a more "advanced" project design, ensuring that operations staff are better prepared for upsets later in field life. Monte Carlo Analysis shows that, although this "advanced" option is likely to create significantly more value, there is still a small possibility that the "low cost" option is more profitable.
Expandable Tubular Casing Repairs: Four Case Histories
Authors: Wright Jon C. , Moore Melvin J. , Winters Warren J. 
Published: December 2007

AbstractIn November 2002 BP America installed four expandable tubular casing patches, totaling 5,000 feet in length, in three Texas Panhandle gas wells that had been shut-in due to corrosion leaks. The casing repairs were successful and the wells were restored to production. The jobs were completed consecutively in rapid sequence. This contributed to improved workover economics and quick implementation of lessons learned. This paper details project objectives, job design and implementation, plus problems encountered, unique solutions and best practices established as the result of this work. Successful application of this new technology has given the producing asset a cost-effective alternative to the standard practice of squeeze cementing to fix casing leaks.
Integrated Geostatistical Reservoir Characterization of Turbidite Sandstone Deposits in Chicontepec Basin, Gulf of Mexico
Authors: Abbaszadeh Maghsood , Takano Osamu , Yamamto Hiroshi , Shimamoto Tatsuo , Yazawa Nintoku , Sandria Francisco Murguia , Zamora Guerrero David H. , de la Garza Fernando Rodriguez 
Published: December 2007

Abstract
This paper presents a pixel-based hierarchical geostatistical modeling of submarine fan turbidite sandstone deposits in Tajin and Agua Fria fields of Chicontepec basin in the Gulf of Mexico. Methods are discussed for identifying and dividing the stack of heterogeneous siliciclastic sediments in these fields, using sequence stratigraphy, petrophysical well log characteristics, geological facies model and 3D seismic data.
An integrated multidisciplinary geostatistical reservoir characterization is conducted in two main steps. First, a large-scale reservoir framework of multiple sequence and subsequence surfaces is constructed based on the integration of data sources of geologic well markers, petrophysics, and seismic horizons. Second, high-resolution 3D distributions of reservoir properties are generated, accounting for inherent inter-relationship among reservoir property data and the three main data scales of log, sub-sequence layer and sequence interval.
At onset, shale volume content in Tajin field and total porosity in Agua Fria field are modeled. Block kriging, trend model, and conditional thickness-weighted Bayesian scheme are presented for the integration of data types and data scales. Facies distributions in Tajin are modeled by indicator kriging conditioned to Vsh content, and hence to seismic. Porosity distributions are by sGsim collocated with Vsh for each facies group, and water saturation distributions are collocated with porosity. Permeability distributions are function of porosity, water saturation, facies and sub-sequences. In Agua Fria, effective porosity and facies are by p-field related methods. Patterns of sand continuity and pay sand connectivity are derived and uncertainty in their prediction is evaluated.
Modeling Facies Bodies and Petrophysical Trends in Turbidite Reservoirs
Authors: Hauge R. , Syversveen A. R. , MacDonald A. C. 
Published: December 2007

Abstract
A two-stage approach for modeling turbidite reservoirs is presented. The first stage is to model the distribution and geometry of turbidite sandbodies using an object model that can be constrained to local vector directions. The facies objects are individual turbidite sandbodies that are locally aligned to a vector parameter to model the effect of local seafloor topography on sandbody geometry and orientation.
The second stage involves modeling petrophysical variation within each turbidite body. This is done by using a variety of intrabody trends, which describe vertical and lateral variation in the petrophysical properties. These variations are the result of grain-size and sorting trends within each turbidite sandbody.
Developing a Risk Assessment and Situation Response Program for Crisis Events
Authors: Butler Rindos Vickie L. 
Published: December 2007

Abstract
Many organizations believe the type of crises appearing in the daily press will never happen to them. They rarely appreciate the impact a crisis can have upon the lives of employees, the company, or its products/services. Moreover, they fail to see just how vulnerable they are - even when risk is staring them in the face. ‘Crisis’ costs seldom appear on the bottom line of the budget - until the enormous recovery costs must be added to the balance sheet as an expensive post-script. The early hours of any incident are critical to its outcome and timely, preventive actions pay dividends that can make the difference for financial recovery. The prepared organization recognizes potential enemies, knows possible strike areas, and is proactive in defense. This paper will address a risk assessment, the development of a flexible Situation Response Program (SRP) for various crisis events, and after-crisis activities for companies that provide services to the petrol-chemical industry. It will include crisis events not generally identified in Health and Safety Procedures that deal with fires, injuries, weather, etc.
Leadership for Safety Excellence: The "Passion" and "Relentless Follow-Up" Needed for Continuous Improvement
Authors: King William (Bill) T. , Artym John 
Published: December 2007

Abstract
Arguably, the ultimate objective of safety is injury prevention. But historically, there has been some dissension about the relative practical application of behavior and attitude in terms of real prevention of injuries, collisions and incidents. Sustaining systems of injury prevention need to be based on stimulating individual decisions that heightened awareness about individual attitudinal, attentional, and behavioral control. Leadership for Safety Excellence (LSE) is a process to sustain the "passion" and "relentless follow-up" needed for continuous improvement of health, safety and environmental systems. LSE is a way to use forward thinking and leading indicators to impact every aspect of Health, Safety and Environmental (HSE) related activities in the workplace. The LSE process enables everyone to make proactive preventive decisions daily on the job, on the way to/from work, and at home.
Self-Learning Reservoir Management
Authors: Saputelli L. , Nikolaou M. , Economides M. J. 
Published: December 2007

Abstract
In this work, we present an industrial automation framework for control and optimization of hydrocarbon producing fields while satisfying business and physical constraints.
The all-encompassing reservoir management problem is decomposed into a series of different-time-scales optimization exercises. A model predictive control strategy is used to regulate well and field instrumentation. The optimum field operating point, which changes with time, satisfies the maximum economic return.
The work is a starting point for further development in automatic intelligent reservoir technologies.
Gas Cycling and the Development of Miscibility in Condensate Reservoirs
Authors: Jessen K. , Orr F. M. 
Published: December 2007

Abstract
This paper presents a detailed analysis of the development of miscibility during gas cycling in condensates and the formation of condensate banks at the leading edge of the displacement front.
Dispersion-free, semi-analytical one-dimensional (1D) calculations are presented for enhanced condensate recovery by gas injection. The semi-analytical approach allows investigation of the possible formation of condensate banks (often at saturations that exceed the residual liquid saturation) and also allows fast screening of optimal injection gas compositions. We describe construction of the semi-analytical solutions, a process which differs in some ways from related displacements for oil systems.
We use an analysis of key equilibrium tie lines that are part of the displacement composition path to demonstrate that the mechanism controlling the development of miscibility in gas condensates may vary from first-contact miscible drives to pure vaporizing and combined vaporizing/condensing drives. Depending on the compositions of the condensate and the injected gas, multicontact miscibility can develop at the dew point pressure, or below the dew point pressure of the reservoir fluid mixture.
Finally, we discuss the possible impact on performance prediction of the formation of a mobile condensate bank at the displacement front in near-miscible gas cycling/injection schemes.
Application of Convolution Theory for Solving Non-Linear Flow Problems: Gas Flow Systems
Authors: Mireles T. J. , Blasingame T. A. 
Published: December 2007

Abstract
In this paper we present the development of a rigorous approach for the solution of non-linear partial differential equations by use of the Laplace transformation — in particular, the convolution theorem for Laplace transforms. While the rigor of this new approach is general, our paper is devoted to the development, verification, and application of this method for the case of real gas flow in porous media. This paper focuses on verification of real gas flow solutions using the results of numerical simulation.
The major results of this work are: Development of a general analytical approach in the Laplace domain for solving non-linear partial differential equations.Verification and application of this new approach for the flow of a real gas in porous media.
We observe excellent agreement between the numerical and analytical results for the case of a single well produced at a constant rate in a closed reservoir. We conclude that this approach could be adopted as a method of verification for numerical simulation, as well as for analytical modelling of the gas flow case — in particular, for modelling future performance directly and accurately, without numerical simulation or some weak approximation (p or p2 approximations, etc.).
In addition to the specific problem considered in this work, the flow of a real gas in porous media, we believe that it may be possible to extend this work for the development of analytical solutions for multiphase flow.
Toe-To-Heel Waterflooding. Part II: 3D Laboratory Test Results
Authors: Turta Alex , Goldman Jon , Singhal Ashok , Zhao Litong 
Published: December 2007

Abstract
A new waterflooding process, Toe-To-Heel Waterflooding (TTHW) was developed, partly based on recently developed thermal toe-to-heel displacement processes: THAI and CAPRI. TTHW is a novel oil recovery process utilizing a horizontal producer (HP) and a vertical injector (VI). The HP has its horizontal leg located at the top of formation, while its toe is close to the VI, which is perforated at the lower part of the formation.
TTHW realizes a gravity stable displacement, where water/oil mobility ratio becomes less important, and its detrimental effect on sweep efficiency is diminished. The main advantage of TTHW process is that the water always breaks-through at the toe, following which water cut gradually increases.
A systematic investigation of the TTHW process in a Hele Shaw laboratory model mimicking a simulated porous medium showed that the process substantially improved the vertical sweep efficiency as compared to conventional waterflooding. Following these semi-quantitative tests, a more comprehensive 3-D model testing was undertaken in order to investigate the overall sweep efficiency of the process. The 3-D model consists of a metal box filled with glass beads and saturated with oil at connate water saturation; the thickness of "oil layer" is 16 cm and the length is 42 cm. Oil was displaced with a high salinity brine, either in a toe-to-heel configuration, or in a conventional array, using only vertical wells.
A staggered line drive was used, by injecting water in two vertical wells located at one side of box and producing oil through either a horizontal producer with its toe close to injection line, or by using a vertical producer located at the horizontal producer's heel position.
Several TTHW tests were carried out at different injection rates. For a given injection rate, the TTHW results were compared to those of conventional waterflooding tests. For the same amount of water injected, the ultimate oil recovery increased by a factor of up to two, as compared to that for conventional waterflooding. Numerical simulation models successfully matched the observed performance in the laboratory.
All in all, the results of laboratory investigations and numerical simulations show that the novel TTHW process is sound, and can be further optimized.
Water Injection Optimization Using a Streamline-Based Workflow
Authors: Thiele Marco R. , Batycky Rod. P. 
Published: December 2007

Abstract
This paper describes a novel approach to optimize injection and production well rates in a waterflood using streamline-based (SL) flow simulation. The method provides engineers with an approach that is well beyond the traditional field management workflows offered by standard surveillance and finite difference (FD) simulation. The method is automated and therefore applicable to very large fields with many wells. Streamline based flow simulation is unique in that it allows to quantify the amount of injected and produced fluids between well pairs via well allocation factors (WAF's). WAF's allows calculating the efficiency of injection wells as the ratio of injected water to the oil produced at offset wells. With injection efficiencies known across the field for each injector, water can be reallocated from low-efficiency to high efficiency wells, thereby optimizing production for each barrel of water injected.