bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Study of the Friction Pressure and Proppant Transport Behavior of Surfactant-Based Gels
Authors: McElfresh P. M. , Wood W. R. , Williams C. F. , Shah S. N. , Goel N. , Zhou Y. 
Published: December 2007

Abstract
Surfactant-based gels (SBGs) exhibiting viscoelastic properties have been introduced recently for sand control and stimulation applications. However, limited data are available on their friction pressure losses through tubing and proppant transport behavior. Therefore, an experimental investigation was performed to study the friction pressure and proppant transport behavior of SBG fracturing and sand control fluids. The friction pressure of the clean and slurry fluids were evaluated in tubing of various configurations and lengths up to 1000 ft. The proppant transport behavior of the fluids was observed through a transparent slot and a High Pressure Fracture simulator, and proppant settling in small-scale laboratory tests. The friction pressure results show that the SBGs exhibit stable and significant drag reduction under most of the flow conditions. The presence of sand in the solutions increases the friction losses through tubing, but to different amounts depending on tubing geometry and configuration. The proppant transport behavior of the SBGs was observed to be comparable to the behavior of the 35- and 40-lbm/Mgal crosslinked gels evaluated under similar slot flow conditions.
This study of SBGs provides unique results obtained in a large-scale test facility and in a small-scale laboratory environment. These experimental results, in turn, provide information to aid field personnel in designing gravel packs, frac packs, and other completion and stimulation treatments. These data also will aid in the eventual development of friction pressure and proppant transport prediction methods for SBGs.
Adaptive Fuzzy Clustering for Efficient Segmentation of Wellbore Resistivity Images
Authors: Finol Jose , Romero Carlos , Valbuena Johnny 
Published: December 2007

Abstract
Resistivity image segmentation allows mapping of similar regions in a scene leading to the recognition of distinct geological features such as rock fractures and thin beds. Recognition of similar patterns embedded in resistivity image data is the basis of clustering regions in an image. Therefore an efficient clustering technique is a natural choice for image segmentation. Efforts to develop algorithms for adaptive and less computationally complex classification of data have led to the implementation of neural network classifiers of both supervised and unsupervised learning. Such neural network architectures are ways to achieve autonomous processing of patterns but are not considered to incorporate intelligent decision processes offered by various techniques of fuzzy clustering. Integration of fuzzy membership values of objects into neural network processing generates more robust models for intelligent pattern recognition.
This paper presents and efficient object extraction method for resistivity image segmentation based on neuro-fuzzy clustering algorithms. The neuro-fuzzy approach retains the basic properties and architectures of neural networks and fuzzifies some other elements, enhancing the learning speed and generalization capabilities.
Expanding the Envelope of Coiled Tubing Collapse Ratings in High-Pressure/High-Temperature Wells
Authors: Luft H. B. , Wright R. , Bouroumeau-Fuseau P. 
Published: December 2007

Abstract
It has been recognized for some time that recommended practices for determining the collapse strength of coiled tubing (CT) predict conservative ratings (see API 5C7-1996). As well, the effects of plastic fatigue cycling and elevated temperatures on CT collapse resistance, are currently not being incorporated in any collapse prediction models. This paper summarizes all of the major findings of an extensive experimental and theoretical research program on collapse of coiled tubing conducted jointly between TotalFinaElf Exploration UK PLC and BJ Services Company. The research studied the effects of temperature and changes in tensile properties induced by low cycle bend fatigue, that are presently not considered with respect to coiled tubing collapse. Changes in CT geometry, wall thickness and collapse pressure were accurately measured as functions of plastic bending cycles and applied axial loading.
The results of this research showed that the effects of loading history on coiled tubing collapse strength can not be neglected. It also showed that the collapse ratings of coiled tubing can be significantly increased above those obtained by the method described in the current issue of API 5C7. A better understanding of the collapse failure mechanism enabled a new formulation to be derived for plastic collapse of CT having a D/t ratio less than 14. Several examples are presented to illustrate the application of the research results and to compare these with existing theoretical models currently in use for the prediction of CT collapse.
Influence of Bit-Rock Interaction on Stick-Slip Vibrations of PDC Bits
Authors: Richard T. , Detournay E. , Fear M. , Miller B. , Clayton R. , Matthews O. 
Published: December 2007

Abstract
This paper describes a new approach to understand the causes of stick-slip vibrations experienced by PDC bits. This new model takes into consideration not only the axial and torsional modes of vibration, but also the coupling between these two modes through bit-rock interaction laws, which are consistent with laboratory results from single cutter experiments. These interaction laws, which account for both frictional contact and cutting processes at the bit-rock interface, are formulated in terms of the depth of cut, a variable that brings into the equations the position of the bit at a previous a priori unknown time. They also account for potential loss of frictional contact between the wear-flats and the rock. The delayed and coupled nature of this interaction is ultimately responsible for the occurrence of self-excited vibrations, which can degenerate into stick-slip oscillations under certain conditions. The features of the torsional vibrations that are predicted with this model are well in accordance with field observations. Furthermore, the results reveal that the model predicts apparent rate effects as an inherent outcome of the nature of the bit-rock interface.
Use of Downhole Production/Reinjection for Zero-Emission Well Testing: Challenges and Rewards
Authors: Hollaender Florian , Filas Jim G. , Bennett Curtis O. , Gringarten Alain C. 
Published: December 2007

AbstractIn recent years, HSE concerns have been a driving force pushing towards emission-free well testing. Several methods have been proposed in order to attain that objective, the two most known being closed-chamber testing and downhole production/reinjection. With closed-chamber testing being of limited interest because of the reduced radius of investigation it offers, and harmonic testing being impractical due to time requirements, downhole production/reinjection appears as the only way of fully replacing conventional well testing.Planning such a test requires greater care than for a conventional test because the selection of an adequate injection interval is of major importance to the success of such an operation. The injected fluids must be contained within the disposal zone so as to avoid surface leakage but also so that the test data are not affected by an interference effect due to the injection process. There is also a great concern regarding the quality of the data because of hard downhole conditions.But if these challenges can be overcome, downhole production/reinjection can provide the same information as a conventional well test but with improved safety, no direct emission of pollutants and at reduced cost and test duration.
Subsea Well Testing at the Subsea Tree
Authors: Waldman Nathan , Fair Chris , Tyrrell Charlie , Kumar Rakesh 
Published: December 2007

Abstract
Operators are often presented with a dilemma when installing instrumentation in a subsea well. Do they install permanent downhole gauges? If so, is there a back-up plan in the eventuality that the downhole gauge fails. In the past, when a downhole gauge on a subsea well failed, the back-up plan has either been to "fly blind" or to rely on low-accuracy measurements from subsea tree gauges or pipeline gauges (which can also fail). While tree or pipeline gauges may be adequate to determine if the well is flowing, they are rarely of sufficient accuracy and resolution to optimize production from the well. The need for high resolution, accurate pressure data is greatest in high permeability wells and in unconsolidated sandstones, where the production of sand can be catastrophic.
In 2001, a solution to this problem was developed. It allows an operator to temporarily install a highly accurate pressure recording system on the well in order to perform diagnostic tests on the well bore, completion and/or reservoir. This option is available to any subsea tree equipped with an Industry Standard "Hotstab" port. Typically, subsea trees are fitted with at least one female hotstab port conforming to ISO/CD 13628-8 enabling a remotely operated vehicle (ROV) to connect instrumentation specifically designed for this application. The ROV is then used to operate the isolation valves to allow well bore communication via the hotstab port. Once pressure communication with the well bore is established, diagnostic tests may begin.
The purpose of this paper is to introduce a mobile high-precision, high-accuracy pressure recorder for pressure transient testing at subsea well heads. First, the instrument and subsea tree specifications will be discussed. Then, a detailed procedure for installing this instrument on the subsea tree will be presented. Next, the issue of wellhead to bottomhole pressure conversion will be addressed. Results from field tests with the system will be presented. This new tool makes it possible to test subsea wells in which downhole gauges were not installed or where they have ceased to operate. The tool has also proven useful for pressure integrity tests when commissioning sub sea pipelines.
Real-Time Petrophysical Analysis in Siliciclastics From the Integration of Spectroscopy and Triple-Combo Logging
Authors: Herron Michael M. , Herron Susan L. , Grau James A. , Seleznev Nikita V. , Phillips John , El Sheriff Ahmed , Farag Sherif , Horkowtiz John P. , Neville Thomas J. , Hsu Kai 
Published: December 2007

Abstract
There is a long history of wanting to provide a petrophysical answer, comprising at least porosity and saturation, either in real time or within, at most, a couple of hours after logging. Past attempts to provide such a product have been plagued by the need to define numerous parameters and well zonations that would ordinarily be selected by a skilled interpreter. With the introduction of elemental concentration logs obtained from nuclear capture spectroscopy tools, the number of interpretation parameters can be dramatically reduced. This is because the accuracy of the lithology and matrix properties is a significant advance over values determined from conventional techniques. Consequently, it is much easier to directly apply scientific conductivity and permeability models for petrophysical evaluation.
The Development Of Bottom Discharge Submersible Pumps
Authors: Al-Jeboury F.A. 
Published: December 2007

Abstract
Abu Dhabi Company for Onshore Oil Operations (ADCO) employs water injection for pressure maintenance in its three major oil-producing fields. An auto-dump injection scheme is used to naturally inject water from overlying aquifers into the reservoir due to the differential pressure. A paired water supply/injection well system is also used, by which the water is lifted to surface by Reda electric submersible pumps and injected by surface pumps driven by electric motors.
ADCO has tested a unique approach to boost the dump flood in the field. A bottom-discharge submersible pump has been designed to increase the water available from the aquifer for dump flooding, providing a combination of both dump and power injection.
The approach offers the advantage of reduced power requirements and eliminates the need for a water supply well and surface injection equipment. Also it utilises the natural dump when a pump fails.
A proto type M 675 (26-stage) bottom discharge submersible pump was ordered from Reda and was first tested in February 1975. This pump, powered by a 500 HP motor developed a pressure boost of 1000 psi and increased the natural dump of 5000 bw/d to a powered injection rate of 15,000 bw/d.
Selection of pump size with the appropriate number of stages showed that most well requirements could be met by J-600 or J-400 bottom discharge pumps which can be set inside 9.5/8 inch casing.
In order to carry out more tests a 55-stage J-600 submersible bottom discharge pump was installed in well Bu-114. Many changes in the design of the downhole equipment were carried out to simplify running and improve reliability and, although further improvements may be necessary, it is clear that the bottom-discharge concept of injection is a highly viable and economic proposition where surface water is not available or at a premium for other uses.

Introduction
Abu Dhabi Company for Onshore Oil Operations (ADCO) is currently injecting some 1,600,000 barrels of water per day for reservoir pressure maintenance in the three main producing fields. Powered injection is by means of a paired water supply/injection well system, with water lifted by 18 stage N-1050 Reda pump powered by a 500 HP motor (fig. 1). The water is injected into the reservoir using surface pumps up to a pressure of 2400 psi.
The typical installation of a Reda N-1050 submersible pump is shown in fig. 2. The pump has an operating range from 22,000–35,000 bw/d.
ADCO is expanding its water injection capability by equipping some existing dump injection wells with bottom-discharge submersible pumps. They offer the following advantages over the conventional "up and over" paired injection/water supply well configuration:–Very low capital investment, in respect of power generation, overhead transmission lines, surface pumping equipment and elimination of a separate water supply well.–A higher overall operating factor since many wells will continue to dump if a pump fails.
The First Successful Fracture Treatment Campaign Conducted in Japan: Stimulation Challenges in a Deep, NaturallyFractured Volcanic Rock
Authors: Weijers L. , Griffin L. G. , Sugiyama H. , Shimamoto T. , Takada S. , Chong K. K. , Terracina J. M. , Wright C. A. 
Published: December 2007

Abstract
In the summer of 2001, the first multi-stage completion in a deep, hot, and naturally fractured volcanic rock of the Minami-Nagaoka Field, Niigata Prefecture, Japan, was successfully completed using six propped fracture treatment stages.
While successful development of the northern part of the Minami-Nagaoka reservoir could significantly impact Japan's domestic natural gas production, successful proppant placement in this field has proved extremely difficult in the past1–2. During two propped fracture treatments pumped more than a decade ago, treatments failed miserably with only about 20% of the designed proppant placed before job termination due to premature screen-outs. These treatments exhibited net pressures up to 4,000 psi before pumping any proppant - the highest net pressure level that we have ever observed, indicating extremely complex fracture growth. Post-frac evaluation confirmed that proppant placement problems mainly occurred due to simultaneous propagation of very narrow multiple hydraulic fractures. Detailed pressure build- up and production test analysis confirmed the diagnosis of narrow multiple hydraulic fractures, which resulted in extremely poor (and vanishing) propped fracture conductivity and non-economic gas production.
The new treatments in Minami-Nagaoka focused on the ability to mitigate the adverse effects of multiple hydraulic fracture propagation and the accompanying severe near- wellbore fracture tortuosity. Major equipment mobilization was required for this treatment to be possible as part of this concerted effort. Many unconventional changes, including completion changes to obtain highest possible injection rates to enhance proppant placement, aggressive proppant slug strategy, real-time fracture treatment analysis, gel testing for minimization of proppant damage, careful perforation placement, quality control, extreme overbalance perforating, and use of small-grained proppant, resulted in successful stimulation and favorable production response. This paper discusses all these design changes in detail, and provides final results regarding the fracture geometries obtained.
Quantification of Displacement Mechanisms in Multicomponent Gasfloods
Authors: Johns R. T. , Yuan H. , Dindoruk B. 
Published: December 2007

Abstract
Local displacement efficiency in gas floods depends strongly on the minimum miscibility pressure (MMP) or minimum miscibility enrichment (MME). The values for these design parameters depend in turn on the displacement mechanisms, vaporizing, condensing, or a combination of the two known as a condensing/vaporizing (CV) drive. Characterization of the displacement mechanism, however, is currently limited to these broad categories with little reference to the degree to which a CV displacement is condensing or vaporizing. The focus of this paper, therefore, is to present a method to quantify the fraction of a multicomponent gas flood that is vaporizing or condensing as the pressure or gas enrichment is increased.
The approach relies on finding key tie lines for a dispersion-free one-dimensional displacement using method of characteristic theory (MOC). We quantify the displacement mechanism for any number of oil or gas components by calculating the displacement path lengths along ruled surfaces bounded by these key tie lines. Several multicomponent fluid characterizations are considered, including a twelve-component enriched-gas flood and a thirteen-component CO2 flood. The results show that as the pressure or enrichment is increased condensation occurs at the expense of vaporization. We also show by numerical simulations that the sensitivity of the local displacement efficiency to dispersion depends on the condensing fraction of the displacement.
A Critical Overview of Artificial Neural Network Applications in the Context of Continuous Oil Field Optimization
Authors: Saputelli L. , Malki H. , Canelon J. , Nikolaou M. 
Published: December 2007

Abstract
A number of new technologies introduced into the oil field over the last couple of decades now provide the hardware basis for continuous field-wide optimization (CFO). CFO will require computer integration of field hardware (e.g., downhole sensors, remotely activated completions, surface facilities) for continuous decision-making in a feedback fashion (data acquisition, data processing, actuation). We introduce a hierarchy of oil field operations that identifies various levels of detail and time-scales for decision-making processes. We propose to use this hierarchy in a multi-level / multi-scale approach to CFO. An important element in that approach is the availability of predictive models that can be used at various levels of the hierarchy, so that optimal actions can be continuously selected through optimization over a moving horizon.. In this context, artificial neural networks (ANN) are a tool that has been used to build data-driven models. This paper is structured in two parts: (1) elements of CFO, and (2) brief review of ANN basics, known ANN applications in the petroleum industry, and a critical view of ANN capabilities.
Maximizing Production for Horizontal Wells in Hassi R'mel Field (Algeria) with Resistivity Interpretation and Modeling
Authors: Kloos Jannes , Munkholm Mette , Benallegue Fatiha , Bencherif Djaouid , Rabinovich Michael , Tabarovsky Lev 
Published: December 2007

Abstract
Water flooding and gas coning are potential problems in the horizontal wells drilled to penetrate the oil column in the channel sands of the Hassi R'Mel field. This field is operated by Sonatrach, the Algerian National Oil Company. High Definition Induction Logging (HDIL) in such environments has been used to build a reliable geological model along the wellbore, identify potential problem intervals, and minimize the risk of perforating and producing gas and/or water.
The new generation of induction tools – array induction tools – has an advantage of acquiring unfocused data that can be numerically focused to any part of the formation at the post-acquisition stage. Operating at low frequencies with relatively large transmitter-receiver spacings, the wireline array induction measurements can provide reliable information from geological targets up to a 6-m (20 ft) distance from the borehole, depending on resitivity contrasts.
In horizontal wells, the induction data may be influenced by adjacent layers located above or below the reservoir. In such cases, when evaluating the water saturation in the near wellbore region, we must, firstly, correct for the influence of the remote layers. Secondly, after correcting the deep HDIL measurements for the presence of the borehole and invasion, we use them to determine both the distance to and the resistivity of remote beds.
To integrate the HDIL results into the geological model, a number of issues must be considered. First of all, in the Hassi R'Mel field remote conductive shoulder beds may be either conductive shales or water-bearing horizons. Therefore, to distinguish between the two, their resistivities must differ and, in the interpretation stage, be compared with that of the remote shoulder bed interpretation. In addition, as the measurements do not have a sense of direction, they cannot distinguish between remote beds above or below. Interpretation of the location of an identified remote layer must therefore be based on the geological model for the field as well as other log data. Finally, although an interface between two resistive layers is more difficult to resolve, remote oil-gas contacts may in some cases be found from the interpretation.
Presently, every logging job in Hassi R'mel includes an HDIL tool in a string, and the data are usually processed within 48 hours. Providing the geological model and perforating recommendations prior to well completion improves the economics of the well due to increase in oil production and the reduced cost of well recompletion.