bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fully-Rotating Rotary Steerable and Concentric Reamers Technology Combination Eliminate Wellbore Threading in Deepwater
Authors: Lenamond Chris , da Silva Augusto Carvalho 
Published: December 2007

Abstract
Improving hole quality is a major factor for accurate formation evaluation and reduced well construction costs in deepwater. Further optimization of the borehole quality using new generation drilling assemblies is now possible. Not only to improve formation evaluation, increase penetration rates, and reduce the risk of drill string failure, but also to reduce the load points of salt formations on completions. Concurrent drilling and reaming techniques have been successfully used to mitigate the effect of non-uniform, transverse loading of salt formations on completions as well as improve hole quality for higher wireline log success rates.
During the execution of deepwater wells in offshore Brazil, multiple bottomhole assembly configurations were deployed to drill the various hole sections and the use of logging-while-drilling (LWD) imaging and wireline calipers provided a direct comparison of hole quality performance of each drilling system. A culmination of various drilling systems were evaluated, during a drill-off test, in a single well while performing enlarging-while-drilling (EWD) of a 12 ¼" to 14 ¾" hole. Salt formations were drilled to fully compare each system in a common drilling environment without variations due to formation types.
Experimental Investigation of Steam/Methane Flooding in a Heavy Oil Reservoir
Authors: Sola Sedaee 
Published: December 2007

Abstract
The application of steam injection in different forms of processes is widely used for thermal heavy oil recovery. Several studies have been carried out to evaluate the effect of injecting steam with gaseous additives such as, Hexane, Nitrogen, Carbon Dioxide, Propane and air. However there is very little literature about addition of methane or natural gas to steam in order to improve steam injection process.
This experimental study, investigates the effect of methane as an additive to steam. A consolidated core sample of an Iranian carbonate heavy oil reservoir (12°API) was used. The experiments involved injecting steam with methane in various methane/steam ratios ranging from 0:100 to 10:100 at reservoir conditions pressure and fluid saturations. Superheated steam was injected at 1200 psi which is higher than reservoir pressure at datum depth. Oil production rates, pressure drops and methane/steam ratios were measured to compare the effect of methane on oil recovery and other parameters at various fluid injection rates as well as steam temperatures.
With optimum methane/steam ratio it was noticed that oil production is accelerated, steam injectivity is increased and also recovery is higher when compared to injection of pure steam.
Optimizing Production from Fractured Damaged Reservoirs
Authors: Mufarji Said S. , Oyeneyin M. B. , Jihan S. 
Published: December 2007

Abstract
Formation impairment due to fines migration during production continues to cause inflow reduction. Proper fines management can optimise productivity, safeguard facilities and cut down on well maintenance cost. Today’s core flood test limitations keep us away from being capable of limiting or avoiding fracture damage. The limitations include: safety aspects which prevent utilisation of hydrocarbon gas in multiphase fluids in confined laboratories, core sample conditions due to recovery problems, reliability of scaling up to field extent, and so forth. Hence based on such limitations, unique approaches were carried out for damage risk assessments.
This paper presents unique techniques to analyse conditions leading to fracture damage, ability to characterise the damage impact and prediction of well performance. The techniques incorporate a CFD and 3D reservoir simulation packages.
Results suggest that in high permeability sands, the finer the grain size (10-100microns) the lesser the pressure decline rates. When 150 - 200 fines microns were simulated, the declines in pressure were comparatively sharper. The sensitivity of grain size in normal matrix formation is less compared to that found in fractured or very permeable formations as in the letter, higher magnitudes of permeability decline were revealed in which case possible shallow invasion damage mechanisms were likely. Unlike the grain size influence to pressure drop and permeability declines, the simulated fines concentration ranging from 20% to 50% by volume of crude along horizontal direction, did have different impact compared to results of same concentration across the width of the sand body. Water cut sensitivity on the other hand revealed significant permeability drops between 0% and 10% water cut at fixed fines concentration.
In these analyses, solid fines velocities were exclusively being monitored in the multiphase flow and could be distinguished from fluid velocities.
Milling of Isolation Valve with Wireline Conveyed Technology
Authors: Krüger C. , Sælensminde T. , Myrmel S. 
Published: December 2007

Abstract
A revolutionary drilling technique has emerged allowing drilling with electric wireline utilising metal machining technology in combination with field proven Well Tractor technology.
As the Well Tractor technology evolved and confidence was gained during the past several years, the application of a cost efficient method for milling of specific downhole hardware (i.e. valves, plugs etc.) as an alternative to existing methods has emerged. The technology is specifically needed on offshore installations where the logistical limitations are high. The article will describe the actual operation and the process of developing the technology.
The first ever operation involving the milling of a blocked borehole on wireline was conducted in late 2003 in an oil producer on a North Sea platform. A single plate isolation valve was stuck in closed position and it was imperative to get the oil producing well on-stream at short notice. During the tests leading up to the actual operation, the concept had been tested onshore in a test-loop with an estimated drilling time of 35 minutes to drill an 80 mm (3.15") hole trough a 2 cm (0.79") thick "super chrome" single flapper. The total operational time in the well for the entire milling operation was 11.5 hours from rig-up to rig down while the milling itself only took 7 minutes. During this operation all milled material was retrieved and the challenges of controlling stalling and actual control of the retrieval of the milled out plate were met. The development of wireline drilling used the Well Tractor features to achieve Weight On Bit and reactive torque control, while the limited total power available was addressed by designing specific bits for specific applications based on an approach of "surgical" intervention. The added advantage is that the risk of getting stuck by wedging the BHA in the object or in cuttings has been virtually eliminated by targeting a well defined area within the object itself.
Field Application in the Development of Low-Cost 3D Rotary Steerable Systems
Authors: Burnett W. T. (Tom) , Travis John T. (Tim) , Samuell John G. 
Published: December 2007

Abstract
The benefits of continuous rotary drilling in directional wells through application of 3-Dimensional Rotary Steering Systems (3D RSS) are well documented in the industry. ExxonMobil Development Company (ExxonMobil) continues to expand application of these systems where economic incentive exists. ExxonMobil's targeted strategy to influence the development of low-cost 3D RSS has been published1 and has generated further discussions with 3D RSS providers. This strategy is intended to accelerate the development of low-cost 3D RSS in order to capture benefits of this technology to improve drilling performance and economics, particularly in lower-margin projects.
This paper describes the results to date of the application of our stated strategy. Systematic usage of the tools in various modes (maintaining verticality, building/dropping angle, holding angle and azimuth, etc.) have given the provider valuable real-world testing to validate and improve tool design and to improve reliability of components. The role of field testing in support of the development plan, results of applying this technology at its current level of development and an assessment of its value will be discussed.
Compressed Natural Gas (CNG): An Alternative to Liquid Natural Gas (LNG)
Authors: Economides M. J. , Kai S. , Subero G. 
Published: December 2007

Abstract
Natural gas is becoming one of the most important resources of energy, with its share in the world consumption expected to increase dramatically over the next two decades. Currently, natural gas is transported to the markets by pipelines and as liquefied natural gas (LNG). Transporting the natural gas by pipelines is convenient and economically attractive onshore. For the offshore transport of natural gas, pipelines become challenging as the water depth and the transporting distance increase. LNG, an effective means of transporting gas for long distances across the seas, constitutes 25% of the world gas movement. But LNG projects require large investments along with substantial natural gas reserves and are economically viable for distances such as 2500 miles and beyond.
Compressed natural gas (CNG) technology provides an effective way for shorter-distance transport of gas. The technology is aimed at monetizing offshore reserves, which cannot be produced because of unavailability of pipeline or because the LNG option is very costly. Technically, CNG is easy to deploy with lower requirements for facilities and infrastructure. "Coselle" and "VOTRANS" are two would-be commercial, high-pressure gas storage and transport technologies for CNG. Technical and economic analyses of these two technologies were done in this study and a comparison is provided. The results show that for distances up to 2500 miles natural gas can be transported as CNG at prices ranging from $0.93 to $2.23 per MMBTU compared to LNG, which can cost anywhere from $1.5 to $2.5 per MMBTU depending on the actual distance. At distances above 2500 miles the cost of delivering gas as CNG becomes higher than the cost for LNG because of the disparity in the volumes of gas transported with the two technologies.
Evaluation of Matrix-Fracture Transfer Functions for Countercurrent Capillary Imbibition
Authors: Babadagli T. , Hatiboglu C. U. , Hamida T. 
Published: December 2007

Abstract
Different functions describing matrix-fracture transfer were tested for counter-current capillary imbibition interaction. The recovery curves obtained from capillary imbibition experiments were used to fit the transfer functions. The exponential coefficients yielding the best fit to the experimental data were obtained and correlated to the effective parameters such as the viscosity, IFT, matrix length and diameter, matrix permeability and porosity, and wettability using multivariable regression analysis.
To obtain the recovery curves, experiments were conducted on Berea sandstone and Indiana limestone samples. Cylindrical samples with different shape factors were obtained by cutting the plugs 1, 2.5, and 5 cm in diameter and 2.5, 5, and 10 cm in length. All sides were coated with epoxy except one end. More than fifty static imbibition experiments were carried out on vertically and horizontally situated samples where the imbibition took place upward and lateral directions, respectively. Brine-air, brine-kerosene, brine-mineral oil, and surfactant solution-mineral oil pairs were used as fluids. For many matrix shape factors (especially longer and small diameter ones), dividing the recovery curve into three parts were needed as the early, intermediate, and late times, which are typically distinguished by the time required for the imbibition front to reach the closed boundary at the end of the core.
Correlations amongst the exponential coefficients and rock/fluid properties were developed. It was observed that different rock/fluid properties and transfer mechanisms (capillary imbibition and gravity drainage) govern the process for each part. Hence, the analyses done in this study were useful not only for developing explicit transfer functions but also identifying the physics of the counter-current imbibition recovery.
Experimental Determination of Time-Dependent Matrix-Fracture Shape Factors for Different Geometries and Fracture Filling Regimes
Authors: Chaobal Aditya N. , Rangel-German Edgar R. , Kovscek Anthony R. 
Published: December 2007

Abstract
The multiple continuum framework for fluid flow in fractured porous media typically employs matrix to fracture transfer functions. Historically, transfer functions were developed from rather oversimplified assumptions such as pseudosteady state flow and a fracture network that is instantly and completely filled with water. This approach results in constant, time independent shape factors and pessimistic predictions of recovery. This paper presents a study designed to measure and interpret multiphase matrix-fracture transfer in two geometries: i) small-cubic matrix blocks with an external fracture and ii) large-cylindrical core samples with intersecting fractures. Water is injected into the fractures to observe the physical process of imbibition and flow through fractures in multidimensions. X-ray computerized tomography is employed to measure in-situ water-phase saturation and observe the progress and pattern of imbibition. Results are classified as either filling-fracture or filled-fractured depending on the fracture aperture and injection flow rate.
A new methodology arising from dimensional analysis is used to interpret the time dependence of the shape factor. Significant time dependence is found. Interestingly, plots of shape factors versus dimensionless time display similar characteristic behavior despite the much different experimental geometry. The time-dependent portion decreases linearly with a slope determined by the fracture aperture, fracture width normal to the flow direction, and the flow rate in the fracture. At a dimensionless time of roughly 0.1, shape factors became constant for all cases. The methodology proposed is promising for obtaining the shape factor for any fracture geometry, length and dimension, as well as water rate. No upscaling of the shape factor functions is required because they are obtained from dimensional analysis.
Microvisual Analysis of Matrix-Fracture Interaction
Authors: Rangel-German Edgar R. , Kovscek Anthony R. 
Published: December 2007

Abstract
A micromodel employing a two-dimensional representation of the pore space of a fractured sandstone was used to investigate matrix-fracture interactions and water imbibition into the matrix. Pore-level mechanisms of wetting and nonwetting fluid flow are observed directly with a microscope.
The rate of water flow through fractures is shown to be relevant to displacement at the pore level. A "filling-fracture" regime is marked by relatively slow flow of water through fractures, rapid fluid transfer from the fracture to the matrix, imbibition that is microscopically cocurrent, and recovery of the nonwetting phase that scales linearly with time. On the other hand, a "filled fracture" regime is noted when fractures fill relatively quickly with water and recovery scales with the square root of time. Additionally, imbibition is found to be microscopically countercurrent. Within a single field of view, some pores are responsible for the uptake of water while immediately adjacent pores expel nonwetting phase into the fracture. The cocurrent flow mode in the filling fracture regime was more efficient with respect to recovery of the nonwetting phase versus the volume of water injected.
Wetting and nonwetting fluids flowed simultaneously in both the fractures and the matrix. These observations provide insight into the discrepancies among fracture relative permeability curves presented in the literature. It is suggested that fracture relative permeability is sensitive to the total fluid velocity within fractures and the rate of uptake of water by the matrix.
Extending Rotary Steerable Capabilities to Locate Thin, Complex Sands
Authors: Lee Andrew 
Published: December 2007

Abstract
This paper will describe the challenges, solutions, and technology applications for drilling and positioning directionally complex wells into thin, complex sands from the Ringhorne platform. The concept of a Multi-Penetration Pilot (MPP) was proposed by the integrated work team to increase the number of reservoir penetrations. By drilling an undulating pilot with LWD and penetrating the top and bottom of the reservoir multiple times, sand mapping would be substantially improved and geologic risk of the prospect would be thereby reduced.
True Hybrid Operations Combining Coiled Tubing Drilling and Conventional Rig Workover Techniques and Practices
Authors: Cassee Udo , Rock Devin , Kara Dan , McLaughlin Sean 
Published: December 2007

Abstract
This paper documents the results of a new stage of development in the application of coiled tubing drilling. Combining coiled tubing drilling technology with a conventional jointed pipe workover capability represents the next step change in providing low-cost reserves access solutions through selection of the most efficient tool for the application.
Drilling sidetracks using coiled tubing is an established practice in Alaska's North Slope oil fields. During these operations the use of jointed pipe, except for running liners, with the coiled tubing drilling rig was avoided. A conventional workover rig was the preferred approach to prepare the coiled-tubing-candidate well when it required a change out of production tubing or other workover activity.
In 2001 a North Slope operator evaluated the opportunity to utilize one rig to perform both operations. In 2002 a workover rig was modified to fit the need.
Although it appears very obvious and straightforward to combine two established technologies, there are many challenges to overcome. Specialized equipment, multidisciplinary personnel, and control of overall well cost are just a few of the many parts of the operation that had to be planned. This paper details the results, problems encountered, solutions, and a quantification of the real benefits achieved combining coiled tubing drilling with a jointed pipe workover.
Jade North Sea HPHT Development: Innovative Well Design Generates Best In Class Performance
Authors: Palmer I. A. C. 
Published: December 2007

Abstract
The UK North Sea Jade Phase I development project demonstrates that high rate HPHT wells can be consistently drilled and completed within a £18.5mm well cost. Compared to other North Sea HPHT developments Jade is unique in providing the first experience of simultaneous drilling and production, with proven depletion levels up to 1600-psi, and no well integrity issues disrupting production. At the core of this success is a well design that is unconventional in comparison to other North Sea HPHT developments. This design was the basis upon which Best In Class (BIC) drilling performance was achieved.
Automated Parameter Estimation from Well Test Data Using the Signal Theory
Authors: Martínez-Romero Néstor , Samaniego V. Fernando , Cinco-Ley Héber , Villagrán Jorge Arévalo 
Published: December 2007

Abstract
This paper presents a new methodology for the automated parameter estimation from well test data, based on type curve matching using the Signal Theory. This procedure solves the inverse problem faster than the conventional techniques, with the additional advantage that the results are not affected by noisy data.
The new procedure has been proved with hundred of synthetic and field cases, and it can be used for the interpretation of all the different tests currently of common use in the field. In the present paper this technique is applied to three tests, all already published in the literature.
The methodology derived in the study surpasses the currently available matching theory based on non linear regression, since it requires a smaller computing time and its assured convergence (selection) of the correct (best) model that describes the physical conditions of the formation on the vicinity of the well. On the other hand, the conventional regression methods require large computing times for the solution of the system of non linear equations; in addition, they are affected by the presence of noise in the recorded pressure response and usually present convergence problems when the initial solution for the unknown parameters is not close enough to the searched solution.
The conventional type curve matching procedure inherently introduces interpretation subjectivity and the possibility of errors, because of the close similarity of the different pressure responses, and to its visual solution approach, which currently is not well understood; thus, it is not possible to develop fully efficient codes that could emulate this human function.
Based on a comprehensive set of type curves, the technique proposed in this paper allows an automated match of the pressure response, without the need of the visual effort of the analyst. The Signal Theory has been modified for the automated interpretation of well test data. The new matching correlation derived in this work, based on rules of shift, multiply and sum, solves the matching of pressure data in an improved way.
Development Modeling—Matching Rigs With Programs
Authors: Keener C. , Keji-Ajayi I. 
Published: December 2007

Abstract
Transocean's 28-rig deepwater fleet has logged more than 375 years of service. Within that population, the 13 newbuild 5th-Generation rigs have accumulated more than 60 years of well-construction experience. On the depth and breadth of that experience, the company is uniquely positioned to assess the merits of various rig types and equipment suites in relation to different programs.
In a paper presented at this forum two years ago, we introduced a performance modeling initiative grounded in the review of 80 exploration wells from 15 rigs. On that early work, we were able to predict relative timeline performance, and ultimately program cost for each of the rigs assessed. In the last two years, we have introduced a number of refinements, particularly in relation to completion activity. To date, we have modeled more than a dozen development programs with several operators, and are now able to make broad associations between rig specification and commercial advantage in relation to program attributes. It is evident that rig specification should factor significantly in preparing a subsea development strategy.