bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Unified Theory on Residual Oil Saturation and Irreducible Water Saturation
Authors: Valenti Nick P. , Valenti R. M. , Koederitz L. F. 
Published: December 2007

Abstract
In many mature fields, there is a growing debate as to how much of the remaining oil is mobile in the unswept regions versus immobile in the swept regions. Log measured oil saturations behind the flood front are substantially lower than the residual oil saturations measured from special core analysis. In order to explain this contradiction, data from several fields is analyzed with special emphasis on capillary pressure. The concept of irreducible water saturation, connate water saturation, residual oil saturation and "critical water saturation" are discussed. The conclusions which are supported by experiment and theory, have substantial commercial implications concerning the location of remaining reserves – in the immobile region or the unswept region. Based on these results, entirely different depletion strategies should be recommended. The concepts presented in this paper help to explain, in part, why reservoirs continue to produce past their forecasted abandonment, and why perfectly "history-matched" reservoir simulation models tend to grossly under-estimate incremental reserves through improved sweep efficiency. These issues are critical in optimizing the depletion strategy of oil and gas reservoirs.
The discussion throughout this paper refers to an oil-water system in a water-wet or mixed-wet reservoir; however, these basic concepts can be applied to gas-water systems, three-phase systems, or other immiscible displacement systems and and oil-wet reservoirs.
An Alternative Method to Calculate Reserves Distribution for Geologically Dependent Layers
Authors: Wang Shie-Way 
Published: December 2007

Abstract
This study presents an alternative method, which can be used to estimate conditional probabilities and reserves distributions for geologically dependent layers, horizons or fault blocks. This paper contains two examples to demonstrate the methodologies. Example 1 illustrates how to analyze a drilling prospect using an existent method to determine the reserves distribution and the probability of each possible outcome for a project with three dependent layers. Example 2 presents an alternative method which can be used to calculate all intermediate conditional probabilities of dependent events and how to design Monte Carlo simulation in order to determine P10, P50, P90 reserves distribution. Comparison of these two methods and estimation of conditional probabilities for more than three layers is discussed in the end of this paper.
Applied Production Optimization: i-Field
Authors: Sengul Mahmut , Bekkousha Miloud A. 
Published: December 2007

Abstract
Middle East hydrocarbon reservoirs are getting matured. The remaining recoverable reserves are in geologically complex challenging areas, poor reservoir quality, dynamical fluid properties are varying from one zone to another drastically. Under these circumstances it is very difficult not only increase but also sustain the current hydrocarbon production. There is an increasing need for introducing new technologies and fresh look to wells’ deliverable potentials by applying state of art tools and processes.
The current and projected state of the E&P industry finds both operating and service companies squeezed by volatile oil prices and higher operating costs. Oil companies are responding to these market dynamics by re-engineering their workflow processes seeking new ways to reduce Capex and Opex, focusing their core business activities. Applied production optimization is a step forward for providing new enabling tools to achieve the intelligent field (i-Field) concept. The main elements of the model are as following: Monitoring through subsurface and surface sensorsReal time or near real-time data deliveryIntegration of data at field level, generate local tasksSend feedback to field via remotely operated toolsDistributed decision making via expert systemsInterface with corporate portal for live MISBusiness process automation
The enablers of the applied production optimization process are; downhole reservoir and production sensors and integration with surface data at well site. The seamless passage from data to production model has been achieved through the combination of a data driven expert systems and flow simulation. This would yield an unprecedented level of operational efficiency. The integration at enterprise level through portal will bring applied production optimization and intelligent field concept to reality. The ultimate objective is to empower operating company to improve real-time operation decision-making and production optimization.
Mudline Tubing Hanger Experience in Auger-Gulf of Mexico Wells
Authors: Stuckey Joe , Urban Larry , King James , Melancon Andy 
Published: December 2007

Abstract
This paper describes development and application of a new design mudline tubing hanger (MLTH) for suspending tubing weight below the mudline in offshore wells. The new design has been deployed in fifteen Auger wells with 100% success. A total of 1,005,000 lbs of tubing weight is currently isolated from the tension leg platform (TLP) using these devices. Though there were notable lessons learned throughout the deployment of the MLTH in the Auger development, there have been no failures of this equipment throughout the project.
The Shell deepwater Auger development in the Gulf of Mexico consists of six main reservoirs ranging in depth from 15,000 ft to 19,500 ft. The TLP lies in 2,860 ft of water, 137 miles off the Louisiana coast. (Figure 1, 2) The TLP was installed and development commenced in 1994, with the completion of the A-6 well. To date nineteen producers have been drilled in the field. On record days the field has produced 109,000 BO/day and 431 MMcf/day. Current production flows from 13 wells, including 6 subsea.
The Auger TLP has 32 subsea slots with twenty slots predrilled for wells. The TLP displaces 73,000 tons. Suspension of weight below the mudline permits more efficient use of buoyancy capacity. A device known generically as a Mudline Tubing Hanger (MLTH) is used to accomplish this by suspending tubing weight into the casing below the mudline. In July 1997, following experience on two Auger wells with another tubing hanger system, a new Mudline Tubing Hanger design was deployed for the first time on the A-20 well.
Project Portfolio Management – A Low Cost, High Return Business Solution
Authors: Davidson J. W. , Erdogan M. , Dowty T. , DiPaolo E. J. , Garrison C. 
Published: December 2007

Abstract
Portfolio management is an ill-defined and, often, overused term. According to CIO magazine1, "ask seven Chief Information Officer's what portfolio management is, and you'll get ten answers." Whether a company's portfolio solution entails consolidating data into a spreadsheet or employing modern portfolio theory to develop an efficient frontier, the goal is to ensure long-term business success by optimizing return at the minimum risk.
In a recent survey, CIO Magazine2 explored factors influencing long-term business success. Magazine editors interviewed executives from 100 companies identified by them as the most innovative in the world. Many executives contended that success depends on uncontrollable influences such as macroeconomics and pure dumb luck, never the less, chances for success can be maximized by leveraging tools and processes to anticipate and capitalize on macroeconomic factors.
A proof-of-concept case study describing a project portfolio management engagement with a Fortune 500 client is presented. Engagement objectives were to develop a business screening and portfolio planning solution that Minimizes reliance on luckProvides a holistic view of all investment opportunitiesConsistently quantifies riskLeverages modern portfolio theoryEnables cash flow and revenue forecastingDelivers the tools and processes for management to stabilize and grow revenue in a highly volatile market.
The business solution was applied to the client's 111 West Africa investment opportunities and entailed quantifying the risked value of investments, stochastically evaluating opportunities in a consistent manner, constraining the portfolio with investment thresholds, and portfolio optimization to balance risk and return.
The study demonstrates that project portfolio management can be a low-cost, high-return solution. Compared to the client's initial West Africa profit-to-investment portfolio (discounted P/I), the optimized case study portfolio (B) reduced Net Present Value (NPV) by 11% while eliminating 50% of the risk. Furthermore, opportunities were identified for immediate savings of $8 million dollars. The cost to develop and apply the solution was approximately $130,000.
Integration of Horizontal Wells In Reservoir Models: Input from an Outcrop Study
Authors: Lerat O. , Doligez B. , Desaubliaux G. , Daniel J. -M. , Eschard R. , Garcia F. , Chauvin H. , Coureaud B. , Nussbaumer C. , Rouvroy P. 
Published: December 2007

Abstract
The integration of horizontal well data in static reservoir models results in better reservoir characterization in terms of structural geometry, facies and fracture distribution, and the quantification of heterogeneities. This improved characterization may have an impact on the dynamic reservoir model, and hence on production performance. An outcrop study was carried out at the reservoir scale, in order to address the principal issues to be resolved when integrating horizontal well data in a reservoir geological model, with emphasis on two key points: 1/ the loss of well information after discretization to a fine grid and 2/ the impact of the uncertainties associated with the well trajectory on the reservoir modeling.
The chosen case study is the Upper Ismay interval of the Pennsylvanian Paradox Formation, whose depositional setting corresponded to a very shallow, mixed carbonate / siliciclastic platform. The geometry of the sedimentary bodies is roughly tabular at outcrop scale. Detailed sedimentological sections are described along the trajectory of several horizontal pseudo-wells logged on a continuous outcrop, with a horizontal length of around 200 meters. In this approach, the siliciclastic intervals, around 5 meters thick, are assumed to be reservoir targets. Shale breaks constitute internal heterogeneities and the carbonate layers are inter-reservoir barriers.
A detailed geological reservoir model has been built from the outcrop database using a geostatistical approach. The type and volume of the data lost after discretization has been evaluated for different sizes of grid mesh.
The influence of the uncertainties associated with the well location within the reservoir grid has been illustrated and quantified using several different trajectories described on the outcrop panel. For each pseudo-well included in the domain of uncertainty, geostatistical simulations have been performed and compared with a reference simulation, using the overall porous volume generated after simulation for quantification.
This approach leads to key recommendations for the integration of horizontal well data in subsurface reservoir studies.
Implementing Successful Mergers in the Oil and Gas Industry
Authors: Knabe Steven P. 
Published: December 2007

Abstract
Mergers and acquisitions have become major strategic levers for oil and gas companies to strengthen their technical and financial resource base and reduce cost structures. However, oil and gas companies have found that expected synergies from mergers are difficult to achieve: Merged organizations often operate in a cumbersome fashion, with poorly defined work processes and inadequate understanding of how the organization matrix should functionTechnical and administrative functions remain fragmented, resulting in limited information sharing and poor integration of functional expertise into operational decisions.
This paper examines how these and other merger-related issues can be addressed in planning and executing oil and gas company mergers.
Simulation of Lithologically Complex and Fracture-Dominated Monterey Production from the South Ellwood Reservoir
Authors: Zahedi A. , Abdassah D. , Ershaghi I. , Steve Horner 
Published: December 2007

AbstractThe Monterey Formation in the oilfields of California Offshore represents a unique flow system where the major fractures and faults serve as conduits and a system of microfractures supports these major channels. A rendering of the seismic and sub-seismic faults on a 3-D geological model was used to build a flow system representing this formation for the South Ellwood Field. On the basis of core data, outcrop information and other downhole surveys, the bulk matrix is believed to not contribute to either the flow or to the storativity. Through the application of the concepts presented in the paper, the case study of the South Ellwood field is reviewed in terms of the extraneous information that guided the selection of a realistic conceptual model for history matching purposes.The uneven rise of oil water contacts in various faulted intervals and uneven gas liberation pockets characterized from fluid entry surveys, have served as effective information in conceptualizing and modeling the bottom aquifer influx and delineation of various non-communicating compartments. Comparison of this model with two other conventional fractured reservoir simulation models shows a better history match can be achieved with the proposed compartmentalized system.
A Streamtube Approach for Modeling Mass and Heat Migration for Thermal Recovery Methods
Authors: Usman Usman , Arihara Norio 
Published: December 2007

Abstract
This paper presents a new reservoir simulator for mass and heat migration based on the streamtube technique. The current version of the program focuses on characterizing migration of the injected fluid. The method is heavily based on the distribution of the pore volume along each streamtube calculated by using the Time-of-Flight method. This information and the 1D solution of mass and energy equations are used to determine thermal migration as well as temperature changes at production wells. The streamtubes are derived from an underlying velocity field, which is obtained from the solution of the pressure equation under the assumption of incompressibility. The compressibility effects are accounted for in the 1D solutions along periodically changing streamtubes.
Simulations are carried out for a five-spot well pattern in 2D areal domains with various types of heterogeneity under different injection scenarios. We confirmed that the results from the streamtube approach had a reasonable balance between its ability to provide an insight into the behavior of mass and heat flow and the computational efficiency. Comparisons with a commercially available simulator both validated the method and illustrated the cases in which this method is more useful to reservoir engineers.
Accurate and Effective Simulation for Reservoirs of Complex Geological Features
Authors: Sutopo Sutopo , Arihara Norio 
Published: December 2007

Abstract
Heterogeneous geological features, such as fractures, faults, shale laminae, and cross-stratified beds, can exert significant effects on the flow performance. Accurate simulation of these complexities requires two model functions, i.e. abilities to accurately compute both pressure and velocity and to efficiently handle permeability tensor. In this paper, a flux continuous model incorporating full tensor permeability was developed for two -phase flow of immiscible and incompressible fluids. Flow systems were split into two subsystems of configurations, one for elliptic equation of global pressure and the other for parabolic equation of saturation, and solve both sequentially by means of the mixed finite volume element (MFVE) method.
Numerical examples of simulating flow in sand-shale system and fractured reservoirs are presented to prove the effectiveness and robustness of the model demonstrating particular suitability for handling high heterogeneities and accurately resolving steep pressure gradients. The MFVE method can accurately calculate the flow variables, and generate more realistic streamlines than the standard finite difference method for a discontinuous permeability field. Applications to naturally fractured reservoirs validate the use of full-tensor effective permeability for accurate and effective simulation.
Weight Reduction of Off-Shore Natural Gas Liquids Processing Facilities
Authors: Westover J. , Hoadley A. , Dyson A. E. S. 
Published: December 2007

Abstract
The oil and gas producing and processing industry is unique in that many of its facilities are not land-based factories. The processing schemes are very similar to land based factories, but the need to build the factories in the water is unique. Structural engineering and construction engineering costs are much higher, simply because there is no soil to hold the complex up out of the water.
There have been several publications on different methods to reduce and manage weight of these facilities by optimizing the equipment or structural design. These include larger turbo-machinery (allowing one unit to perform the task of two), combining two valves into one body (allowing weight reduction where double block and bleed isolation is required) and the use of High Integrity Pressure Protection Systems (HIPPS). However, a literature review shows that there is very little work published on how process engineers systematically synthesize a process flow scheme with a view to weight reduction. Process integration offers one possible method to obtain weight reduction.
This paper examines some process integration issues and techniques in an effort to systematically reduce weight, using two case studies of different feed composition to support the findings. Three areas were investigated, ranging from very simple utility modifications to managing turbo-machinery exergy.
For the case where the feed gas had a relatively low condensate component (lean gas), minor utility modifications and aggressively managing energy transfer across the process and utility pinches reduced equipment list weight by 22%. For the rich gas example, the same methodologies reduced equipment list weight by 6.5%, with potential for further reduction up to 9.5%.
This paper is a summary of the work of Westover1.
Some Advances in Near Wellbore Geomechanics
Authors: McLennan John D. , Abou-Sayed Ahmed S. 
Published: December 2007

Abstract
There has been substantial recent progress in coupling geomechanical effects to reservoir response, thus dramatically improving representation of the consequences of rock response to pressure changes. New reserves have been identified from compaction. Injection geomechanics has gained an increase in interest due to its impact on the reservoir, faults and well hardware. Changes in transmissibility are now seriously implemented in reservoir engineering tools with more attention directed at the presence of compaction and dilatant bands around producers or injectors. Efforts are progressing to ensure adequate coupling between the local effects of the rock deformation near the wellbore, as well as along faults or bedding planes, and the evolving stresses and deformation in the reservoir.
This paper attempts to discuss current gaps in understanding the intricacies and details of coupling farfield deformation to well completion. Examples are shown where reservoir compaction or dilatancy is explicitly coupled to near-wellbore behavior, with specific application for assessing well performance and survivability. The analyses can use reservoir simulations coupled with analytical predictions of stresses and deformations in individual simulator blocks. The predicted stresses and deformations form the boundary conditions for finite element modeling that can focus in on the details around the completion itself. This is in contrast to the current approaches that use explicit coupling of pressure and deformation in complete massive finite element representations, with refined gridding around the completion.
The intimate details of coupling reservoir deformation to the completion require more intensive consideration. For example, "How can the cement sheath be represented?" or "What are some of the constitutive considerations in the near-wellbore region that impact integrity?" and "How is varying transmissibility related to well integrity?" These issues are considered. There are three goals: Start to recognize completion and production management practices that will improve completion longevity and optimize well productivity.Identify reasonable methodologies for representing the coupling between the completion and the reservoir, including yielded zones (dilatant and/or compactant), compaction bands with varying transmissibility, the cement sheath with or without a microannulus and the mud cake.Delineate approximate methods that will adequately forecast completion distress and permeability impairment without the necessity of expensive and time-consuming detailed finite element simulations.
Influence of Pore Pressure, Composition and Microstructure on the Acoustic Properties of Shales
Authors: Dewhurst David N. , Siggins Anthony F. , Raven Mark D. 
Published: December 2007

Abstract
The presence of smectitic shales can cause problems for drillers in the form of wellbore stability problems resulting from the presence of swelling clays and overpressures due to low permeability. Prediction of overpressures in such sediments is hampered by interlayer water in the mineral structure that is not accounted for in porosity determinations whether by wireline methods or laboratory drying techniques. This study looks at the composition and microstructural response to stress of acoustic properties of the Muderong Shale, a regional seal in the Carnarvon Basin on the Northwest Shelf of Australia. Physical properties and composition are intimately tied to the acoustic response of the Muderong Shale at both sonic and ultrasonic frequencies. Velocity variations from downhole shales in wells from the Carnarvon Basin can mainly be tied to smectite content but also to overpressure. The presence of smectite results in anomalously low velocities in the Mud-erong Shale and the development of both compaction fabrics and induced microfracture generation result in significant acoustic anisotropy. The high degree of anisotropy of the Muderong Shale at ambient pressure can be related to the presence of both a sedimentary compaction fabric and high aspect ratio compliant microfractures. Variations in velocity and elastic constants can be related to the microstructural response to imposed stresses. Determination of the relative contributions of these two causes of anisotropy in shales may provide a method by which to distinguish overpressure-generating mechanisms from acoustic data.
Use of the D3 Model for the Estimation of Forces Acting on a Cutter in Rock Cutting and Drilling
Authors: Dagrain F. , Tshibangu J. -P. 
Published: December 2007

Abstract
This paper reports applications of the D3 single cutter model developed by Dagrain (2001) [1,2] at University of Minnesota (UMN), based on the original phenomenological cutting model developed by Detournay and Defourny in 1992 [3].
This paper comes to present the continuity at the FPMs, of the researches performed at UMN. In the present paper, the D3 model has been used to model two different field cases studied in the past at the FPMs, in order to confirm the validity of the D3 model for simulating rock cutting with multi-cutters tools.
The model has also been applied to estimate the best parameters to use to optimize the cutting efficiency for both particular field cases. Finally some basic rules are given to design tools (drill bits or cutting chain) to minimize the specific energy and to maximize the rate of penetration. The model can also be used to estimate the power needed in rock cutting and drilling.