bluuebunny/crossref_metadata_2025_split huggingface dataset:
Remotely Controlled In-Situ Gas Lift on the Norne Subsea Field
Authors: Al-Kasim Ferid T. , Tevik Synøve , Jakobsen Knut Arne , Tang Yula , Jalali Younes 
Published: December 2007

Abstract
The paper discusses the design and installation of remotely controlled in-situ gas lift in the horizontal well B-4 BH on the Norne subsea field. The importance of proper design i.e.; sizing the valve small enough to avoid high pressure gas from the gas cap flowing back into the oil zone and large enough to optimise lift efficiency within the gas processing capacity is emphasized. Both a numerical and an analytical design analysis approach are presented. Examples of current and predicted well performance with and without gas lift are included.
A Case Study: Using Modern Reservoir Characterization to Optimize Future Development of a Mature Asset
Authors: Campanella John D. , Sonnenfeld Mark D. , Zahm Laura C. , Gilman James R. , Conrad Lara , Siemens Craig , Zaitlin Brian A. 
Published: December 2007

Abstract
Enhancements in software, hardware, expertise, data collection and interpretation have continued to improve the industry's ability to build detailed 3D geologic and dynamic flow models of the subsurface. These models in turn have improved our ability to make optimum reservoir engineering decisions for reservoir development. While such characterization has proved its worth for large assets over and over again, there continues to be much skepticism about the ability to use this process for mature or marginal assets.
This paper describes a field example showing how a truly integrated approach can shorten the time frame and reduce the cost of the characterization process. This ensures that all the available data is being used in an efficient manner to optimize future recovery.
Application of modern 3D reservoir characterization on mature fields is very problematic because of data quality issues, such as poor log quality, missing production data or lost cores. However, this lower quality data often provides bounds that are important in understanding the field performance and therefore should not be discarded. These data quality issues are addressed in this paper.
Additionally this paper shows how a truly integrated approach shortens the time frame for development of detailed 3D geologic and dynamic models. For example early conceptual flow modeling and engineering analysis provides valuable input for constraining the static geologic model.
Modern software tools and analysis techniques are greatly improving the ability to combine many scales of data. This provides a better understanding of the reservoirs and improved decision-making. The value of these tools is often a direct result of efficient analysis and visualization of the data and interpretations. These powerful capabilities should not be limited to large assets, as they can be cost effectively applied to mature properties also.
Integrated Reservoir Characterization and Simulation for Reservoir Management using a Web-Based Collaborative Technical Workflow Manager
Authors: Meng Hai Zui , Godbey Kevin S. , Gilman James R. , Uland Michael J. 
Published: December 2007

Abstract
Integrated reservoir characterization-simulation studies have repeatedly demonstrated reservoir management productivity gains. This is recorded in the literature1,2, and demonstrated by the increasing use of integrated 3-D project software for characterizing reservoir assets. The next level of productivity gains for integrated reservoir studies will be to improve the ‘technical workflow management’ of this complex, multi-disciplinary, iterative process. Technical workflow management will reduce the project cycle time, improve the quality of the reservoir model, provide early access to the most current interpretation, and help the operator select the appropriate level of reservoir technology for field optimization.
The future of cost-effective ‘technical workflow management’ lies in the appropriate use of the Internet and company Intranets to collectively manage project data, technical results, and the project objectives. The individual technical experts, who provide characterization-simulation results, can no longer expect to be working in the same office as the main asset team. Adaptive and distributed technical team members can provide an asset team with a competitive advantage by delivering over the internet, the best-in-class technology, skills, and workflows for collaborative team-based integrated technical studies.
This article discusses how a WEB based ‘technical workflow manager’ can provide an environment where all project disciplines can share project data, up-to-date technical interpretations, current and historical documentation, and can monitor the state of the technical project workflow. It introduces the concept of quality-control (QC) tools to allow review of the technical data and results at any stage of the project completion. The QC tools work without requiring detailed user knowledge or access to the technical software used to create the interpretation. This WEB based approach results in a dynamically maintained reservoir model, which is available on-demand to make business unit decisions using the most up-to-date technical interpretations from anywhere in the world.
Real-Time Downhole-Mixed Stimulation Fracturing Process
Authors: Scott George , Covatch Gary , Carrasco Art 
Published: December 2007

AbstractA field-tested reservoir fracturing process comprised of carbon dioxide (CO2), fluid, and proppant was mixed downhole to generate a composite fracturing fluid that was modified in real time at the reservoir. This fracturing system provides numerous advantages over present industry fracturing practices, including reduced friction pressures and lower pumping-treatment pressures. In addition, this downhole-mixing process improves wellsite safety, reduces equipment horsepower requirements, and enables the operator to alter treatment mixture and proppant concentrations concurrent with the reservoir fracturing stimulation procedure in real time.The first field application of this fracturing process was performed in September 2000 in an abandoned 12,300-ft Morrow gas well in the Sand Point field of Eddy County, New Mexico. The fracturing treatment consisted of methanol gel with 7,000 lb of bauxite proppant that was pumped down the annulus and blended above the perforations with 40 tons of liquid CO2 which was pumped down the tubing. A post-fracture tracer log showed that the treatment was placed in the objective reservoir as designed. Initial production from the well was approximately 250 Mcfd.A common problem during fracturing is high surface treating pressures, which may prevent the pumping of fracturing treatments in their entirety. Typically, surface-mixed fracturing treatments are pumped at pressures that may exceed 10,000 psi. At these higher pressures, the stimulation treatment is aborted prematurely unless extra-strength tubulars are deployed. However, during the first downhole-mixed treatment, tubing pressures were observed at less than 6,000 psi, and casing pressures at less than 5,000 psi.A second field application of the downhole-mixed fracturing system was performed in March 2002 in a stripper oil well (Delaware formation). Gelled lease oil, proppant, and CO2 were mixed downhole in an attempt to improve production from this well while avoiding fracturing out of zone. The detailed results from both test wells are presented in this paper.
Large-Scale Hydraulic Fracturing in a Frontier Area in China
Authors: Jin L. , Veltri D. , Krause D. , Weller T. 
Published: December 2007

Abstract
Four large-scale hydraulic fracturing treatments have been successfully conducted in a tight sand gas reservoir in Sichuan, China ranging from 300,000 to 700,000 lbs of proppant per well. Production of gas has been significantly enhanced. Previous hydraulic fracture operations conducted by both western service companies and Chinese Oil Companies did not meet the expected production rate to develop the field. This paper will focus on how the engineering challenges were identified and the designs implemented.
Fiber Optic Monitoring in Openhole Gravel Pack Completions
Authors: Corbett Gary , Fagervik Egil , Christie Stewart , Smith Bob , Falcon Keith 
Published: December 2007

AbstractFiber optic technology for real-time monitoring of down-hole well conditions is advancing rapidly in the oilfield. Discrete fiber optic sensors or fiber optic for distributed temperature measurements are relatively easy to deploy in conjunction with the production tubing string. Incorporating fiber optics into a gravel pack assembly is considerably more complex and requires several specialized equipment components. A method to mount the fiber optic conduit to the screen and protect the conduit during screen deployment, gravel packing and production is required. A sand control packer with feed- throughs for the conduit and compatible with crossover tool gravel placement methods is also required. Finally, a method to reconnect the production tubing to the gravel pack packer and establish a continuous fiber optic conduit from the surface to the end of the screen is needed. This paper describes the development and application of a gravel packing system that incorporates a conduit for fiber optics. The primary components of the system and lessons learned from a full- scale stack-up test are discussed. Technology gaps relating to fiber optic deployment tools and techniques are outlined.
An Account of Decline-Type-Curve Analysis of Vertical, Fractured, and Horizontal Well Production Data
Authors: Araya Anibal , Ozkan Erdal 
Published: December 2007

Abstract
This paper presents an account of decline-type-curve analysis of production data from vertical, fractured, and horizontal wells. It is discussed that the decline-type-curve analysis techniques presented in the literature are based on an approximate deconvolution of the production data and therefore have some limitations. In addition, decline-type-curve analysis inherits the limitations of both conventional pressure-transient and decline-curve analysis techniques. Because of the theoretical and practical limitations, decline-type-curve analysis may need to be supported by pressure transient analysis to yield meaningful and reliable results. In this paper, we also present an alternate approach to construct and analyze the decline type curves and present new decline type curves for horizontal wells. The application of the new horizontal-well decline type curves is demonstrated by examples.
Installation of In-Well Fiber-Optic Monitoring Systems
Authors: Kragas Tor K. , Pruett Eddie , Williams Brock 
Published: December 2007

Abstract
Over the past two years, there has been a dramatic increase in the number of permanent, in-well fiber optic monitoring systems installed worldwide. Systems have been deployed in a wide variety of locations, including the North Sea, Alaska, Gulf of Mexico, Middle East, and South America. These include installations on land and from offshore platforms, in environmental conditions ranging from the arctic to the jungle to the desert, to depths of over 22,000 feet, and to conditions up to 150°C and 15,000 psi. Fiber optic systems have been installed in wells for monitoring pressure, temperature, flow rate, phase fraction, and seismic.
This paper discusses recent experiences with installations of in-well fiber optic pressure, temperature, and flowmeter sensing systems. All aspects of the installations are described, including planning, logistics, run-in-hole during completion, and system commissioning. Elements common to and different from conventional monitoring system installations are examined. In particular, special requirements for fiber optic installations in different operating environments and lessons learned from past installations are discussed.
Simulation of Gas/Oil Gravity Drainage in a Stack of Interacting Blocks: Pseudo Relations for a Limited Number of Gridblocks
Authors: Wit Krijn , Clemens Torsten , Rijkels Lex 
Published: December 2007

Abstract
Naturally fractured carbonate fields contain a large portion of the world's light oil reserves. A number of these fields which are produced by gas/oil gravity drainage contain several billion barrels of oil.
To simulate naturally pervasively fractured fields, dual-permeability simulation programs are used. To achieve reasonable simulation times for huge fields, the number of gridblocks has to be restricted. However, reducing the number of gridblocks in vertical direction in a draining matrix column in gas/oil gravity drainage simulations lead to systematic underestimation of the oil drainage rate.
The simulation error due to limited number of gridblocks can be quantified. Knowing the error, the error can be corrected by modifying the (input) relation that links the oil drainage rate of a gridblock to its (average) oil saturation.
In this article, a procedure is presented to arrive at (pseudo) relative permeability relations for gridblocks in gas/oil gravity drainage simulations. By assigning to each gridblock in a stack a different pseudo relative permeability relation depending on its position in the stack, it is possible to largely reduce and in some cases completely remove the simulation error. This procedure enables using a very limited number of gridblocks in the vertical direction (in the extreme case only one gridblock).
Experimental Study of Two-Phase Pumping in a Progressive Cavity Pump Metal to Metal
Authors: Olivet Aurelio , Gamboa José , Kenyery Frank 
Published: December 2007

Abstract
Progressive cavity pump metal to metal has its two elements, rotor and stator, made from a metallic material. It has been demonstrated that this pump can reach an acceptable volumetric efficiency with high viscosity fluids. However, the performance of the pump with two-phase flow has never been investigated. There are not field or experimental tests which provide tools to predict the behavior of the pump in such applications. If progressive cavity pump metal to metal were able to handle high viscosity fluids with gas void fractions, as well as conventional progressive cavity pumps, it could be found a range of application for using this pump in heavy oil production. Its advantages would be valious, since it doesn't have the problems due to the use of elastomer stators.
In this research the progressive cavity pump metal to metal performance has been studied. Characteristic curves and instantaneous pressure profiles along the pump with single-phase and two-phase flow have been obtained experimentally. The results show that the internal slip with two-phase flow is a function of gas void fraction, differential pressure and rotational speed. Under some conditions an increase in volumetric efficiency occurs when the gas void fraction is increased. Instantaneous pressure profiles explain the changes of internal sealing lines when gas void fraction changes, also show that longitudinal pressure distribution along the pump have a linear behavior for single-phase and two-phase pumping.
The knowledges acquired with this research are useful for understanding the progressive cavity pump metal to metal performance in two-phase pumping applications and also can be used in the future for theorical modeling of the pump.
Stability Analysis of Continuous-Flow Gas-Lift Wells
Authors: Poblano E. , Camacho R. , Fairuzov Y. V. 
Published: December 2007

Abstract
Flow instability (heading) in gas-lift wells is examined in the present paper. A review of previous work done in this area is given. A model of a gas-lift well was developed. The model was validated using the field data obtained in tests of a gas-lift well in the Maloob field. Based on the model developed and existing stability criteria, theoretical gas-lift stability maps were developed and compared with field data. The effect of the injected gas flow rate, the injection port size and the tubing diameter on the flow stability was studied using the stability maps obtained in this work. It is shown that the proposed maps can be used as a simple and efficient method for predicting the stability threshold in designing gas-lift systems.
Construction of Fracture Network Model Using Static and Dynamic Data
Authors: Tamagawa T. , Matsuura T. , Anraku T. , Tezuka K. , Namikawa T. 
Published: December 2007

Abstract
This study reports a new process of constructing a discrete fracture network (DFN) model, which reflects various statistical properties of fractures extracted from static data such as borehole images and dynamic data such as pressure derivative curves.
A DFN model is constructed by generating a number of disc-shaped fractures based on their statistical properties. The process of constructing DFN model proposed consists of two streams. One stream is for the fractures with wide apertures, which work as main flow path of fluid. Another stream is for the fractures with narrow apertures, which work as main storage of fluid. In the each stream, a DFN model is constructed by applying fractal theory and geostatistics that define the size and spatial distribution of fractures, respectively. The overall DFN model is obtained by merging the two types of DFN models. Then, the DFN model is converted to a continuum model with equivalent permeable blocks based on cubic law and is evaluated by the fluid-flow behavior.
Japex has been operating the Yufutsu fractured basement gas reservoir since 1996. A total of approximately 8,000meters of electrical borehole images from eleven wells is measured to understand the fracture system. According to the proposed process, the DFN models are constructed. To evaluate the DFN models by comparing the simulated pressure derivative curves with the observed curve, flow simulations are carried out as a simulation of a single porosity type. The observed pressure derivative curve shows a concave shaped curve like a dual porosity behavior, but the curve never reaches the second flat state. Through the parameter studies of the statistical properties, which relate to the size distribution and the spatial distribution of fractures, the observed curve was successfully reproduced and the quantitative relationship between the fractures with wide apertures and the fractures with narrow apertures was found.
Encapsulated Breaker Release Rate at Hydrostatic Pressure and Elevated Temperatures
Authors: Lo Sho-Wei , Miller Matthew J. , Li Jack 
Published: December 2007

Abstract
Encapsulated breakers for water-based fracturing fluids have been widely used for the past decade. These breakers provide a delayed break because the reactive chemical is separated from the fracturing fluid by a water-resistant coating. Higher breaker concentrations can be used, resulting in improved proppant pack conductivity. However, the coating is not completely impermeable. The breaker material can release through the coating under certain conditions when placed in an aqueous environment.
This paper shows the breaker release rate as a function of temperature, hydrostatic pressure and aqueous fluid pH. A breaker release apparatus was developed, and tests were performed from 150°F to 225°F, 0 to 8000 psig, and fluid pH of 4, 7, and 9.5. The major findings were that the breaker release rate is a very strong function of pressure and temperature, but is independent of aqueous fluid pH. Fifteen percent of the encapsulated breaker is released after 6 hours at 150°F and 0 psig, whereas only 8% and 7% of the breaker is released at 2000 psig and 8000 psig, respectively. Sixty percent of the breaker is released after 1 hour at 225°F and 500 psig, while the 8000 psig breaker release is 12% after 1 hr. These findings suggest that tests evaluating the stability of fracturing fluids at low hydrostatic pressure conditions (such as using Model 35 or Model 50 rheometers) do not represent the actual breaker performance under fracturing conditions. Breaker schedules based on these low-pressure tests underuse encapsulated breakers and jeopardize the proppant pack cleanup process. Using the correlations developed in this study, it is possible to calculate the wellsite breaker schedule from low-pressure rheology tests using encapsulated breakers.
Polymer-induced fracture damage will be reduced and well productivity increased.
Maximizing Well Production with Unique Low Molecular Weight Frac Fluid
Authors: Peles J. , Wardlow R. W. , Cox G. , Haley W. , Dusterhoft R. , Walters H. G. , Weaver J. 
Published: December 2007

AbstractEffective fracture length is the portion of the propped fracture that cleans up after hydraulic fracturing procedure and contributes to well productivity. Studies indicate that this effective length is often less than 10% of the total propped fracture length. A large portion of our fracture stimulation dollars are wasted!This paper presents a comparative well study performed in the Cement field in south central Oklahoma. Stimulation of the Springer Sands using hydraulic fracturing with conventional low polymer fluids was compared with the use of low molecular weight polymer fracturing fluid. The depth of the three Springer Sands (Cunningham, Britt, and Boatwright) ranges from 12,500 feet to 15,500 feet and have an average permeability range of 0.1 to 5.0 md.This evaluation includes several components. Well production history matching and pressure analyses are used to determine effective fracture length. Results of these analyses are compared with calculated values based on laboratory generated cleanup data for the two fluid systems. Flowback rate, pressure, accumulated volume, viscosity, and polymer content were collected following the fracture stimulation treatments.The fluid systems compared in this study are a conventional low polymer system with gel breakers and a new, low molecular weight polymer system that requires no breakers. Both fluids use borate cross-linking chemistry. The low molecular weight fluid system creates transient, high molecular weight polymer chains at higher pH conditions. After exposure to the formation minerals, the pH drops and it reverts to a clean, nearly Newtonian, low viscosity fluid that causes little conductivity damage.The results of this study show that the use of low molecular weight fracturing fluid provides significant improvements in the effective fracture length over conventional low polymer fracturing fluids. Simple engineering tools have also been developed to evaluate both fluid and proppant selection and job design to achieve improved well performance. It also demonstrated that improved recovery of the fracturing fluid can be achieved at excellent rates without the use of conventional gel breakers.
Mechanical Response and Characterization of Well Cements
Authors: Philippacopoulos A. J. , Berndt M. L. 
Published: December 2007

Abstract
It has been identified that well cement design and selection procedures require more sophistication than simple compressive strength criteria. In order to meet this need, it is necessary to characterize experimentally certain mechanical and thermal properties of cements and to develop appropriate modeling techniques for subsequent structural response analysis. This paper examines the properties of different well cements and how tensile strength can be improved by addition of fibres. The transient thermoelastic response of the various cements was investigated by finite element models to determine how stresses can vary with time and location, in addition to material properties.