bluuebunny/crossref_metadata_2025_split huggingface dataset:
Re-habilitation Plan for a Mature Oilfield On-shore Azerbaijan – Working Both Ends of the Spectrum
Authors: Maxwell Phil , Haskell Joe , Eisenbart Allan , Larijani Ray , Bischke Dick , Berent Louis , Butter Machiel 
Published: December 2007

Abstract
Old oil fields with a many years of productions and large mostly low productive well-stock present a new owner/operator with an interesting challenge in defining the its strategy. The low risk approach is an extensive work over recompletion program to bring back shut-in production and reduce water-cut. However in some cases this can be considered throwing good money after bad with insignificant incremental increase in production. The second approach is extensive infill and possibly exploration drilling to open new zones in the deeper part of the structure or adjacent structure. This is considered the higher risk strategy but the rewards in incremental increase in production can be great, as this could be many time larger that current production of the field.
This paper supports a two pronged strategy from both end of the spectrum namely geology and production engineering for optimium short and long term benefits and NPV supported by the following maxims ❖Know what you do not know about the geology and dynamics of the field❖Get the data that you need, eg invest in 3D seismic, run PLT's❖Take an integrated geoscience/engineering approach❖Use your gained knowledge to understand risk and options, vanilla solutions do not always present the best ROI
This paper demonstrate how this two pronged strategy was applied to the Kurovdag field in Azerbaijan and how a rejuvenation and re-development plan for the field was developed in conjunction with the operator of the field.
Chemical Stimulation of Gas/Condensate Reservoirs
Authors: Kumar V. , Bang V. , Pope G. A. , Sharma M. M. , Ayyalasomayajula P. S. , Kamath J. 
Published: December 2007

Abstract
Significant productivity loss occurs in gas-condensate wells when the bottom hole flowing pressure drops below the dewpoint pressure. The decline in productivity is due to nearwell accumulation of condensate in the reservoir rock, which is significant even for wells producing very lean gas with liquid dropout values less than 1%. Many different methods such as hydraulic fracturing, dry gas injection and solvent injection have been proposed and implemented to stimulate such wells. However, all of these methods offer short-lived stimulation and are sometimes not profitable. New experimental core flooding data using chemical treatments show that the steady-state gas and condensate relative permeability in both outcrop and reservoir sandstones can be increased by a factor of 2 to 3 over a wide range of temperature (145 to 275 °F). Spectroscopic data show that the sandstone surface remains modified by the chemical even after flooding the core with large volumes of gas. A relative permeability model that includes effects such as the decrease in the residual condensate saturation after treatment and the effect of capillary number is presented. Fine-grid compositional simulations of a single-well treatment were done using the calibrated relative permeability model to investigate the performance of chemical treatments under field conditions as a function of variables such as treatment radius. These simulations show that chemical treatments have the potential to greatly increase production at low cost relative to the increased revenue since only the near-well region blocked by the condensate needs to be treated.
Effect of Reservoir Mineralogy and Texture on Acid Response in Heterogeneous Sandstones
Authors: Morgenthaler L. N. , Zhu D. , Mou J. , Hill A. D. 
Published: December 2007

Abstract
A series of core flood experiments with the sequence of fluids typically used in HCl/HF stimulation (HCl pre-flush, followed by HCl/HF main flush, followed by NH4Cl post flush) have been conducted on a suite of cores from several Gulf of Mexico Miocene turbidite reservoirs. Using thin section petrography and computer tomography (CT) scans; the samples were characterized as more or less heterogeneous. Samples ranged from reasonably homogeneous to highly laminated. Sample mineralogy was assessed by X–ray diffraction (XRD). Core compositions ranged from relatively clean (quartz rich) to relatively "ratty" (clay and feldspar rich) and some cores contained abundant clinoptololite zeolite.
Acid response was assessed based on permeability change and effluent chemical analysis and varied dramatically among the samples. In the poorer quality, more laminated samples, channeling with significant permeability increase was observed during HC1 treatment with little additional change during later stages of the treatment. Selective pore enlargement with little alteration of the matrix framework was observed in post treatment thin sections. In more homogeneous sand samples, more general acid attack was observed. Core effluent indicated carbonate dissolution during the HCl pre-flush, while HCl/HF clearly attacked alumino-silicates and was roughly half spent during transit through the core. Comparison of thin sections before and after acidization revealed changes in sample quality. In the better quality samples, near complete (greater than 80 percent) dissolution of carbonate and an extensive "cleaning" of clays and fines from the pore space was apparent.
We used a fine-scale simulator of sandstone acidizing to match the responses observed in these experiments. The model corroborates the effects of heterogeneities in the permeability field and in the mineral distribution on the sandstone acidizing process. These model results show how characterization of fine-scale heterogeneity in sandstone can improve the design of matrix stimulation treatments.
Compositional and Grid Orientation Effects in History Matching
Authors: Eydinov D. , Aanonsen S. I. , Haukås J. , Aavatsmark I. 
Published: December 2007

Abstract
A method for automatic history matching of a compositional reservoir simulator is presented. By coupling a gradient minimization algorithm with a forward simulator and an adjoint equation solver, permeability and porosity fields may be conditioned to production data and prior geological information, provided the permeability and porosity can be described by Gaussian random fields. However, the validity of permeability and porosity fields obtained from history matching relies on an accurate forward modeling. We have developed an automatic history matching code, based on the adjoint method, with a fully compositional, 3-dimensional, simulator utilizing a general, IMPSAT or fully implicit solver, as well as advanced discretization techniques based on the Multipoint Flux Approximation (MPFA). The compositional IMPSAT formulation reduces to a traditional black-oil formulation when the number of hydrocarbon components is equal to the number of hydrocarbon phases. Application of the simulator to several synthetic history matching cases is presented. It is shown that if the grid is distorted, permeabilities estimated using a simulator based on the traditional two-point flux approximation (TPFA) may be significantly wrong. It is also demonstrated that information about fluid component rates may be useful in the history matching process.
Improving Hydraulic Frac Diagnostics by Joint Inversion of Downhole Microseismic and Tiltmeter Data
Authors: Warpinski N. R. , Griffin L. G. , Davis E. J. , Grant T. 
Published: December 2007

Abstract
Downhole microseismic and downhole tiltmeter mapping are the primary direct diagnostic techniques for monitoring the geometry of hydraulic fractures at depth. Although these techniques have seldom been used together because of a lack of available monitor wells, the advent of new hybrid arrays having both microseismic receivers and downhole tiltmeters has now made application of both technologies from a single well possible. This paper discusses algorithms for joint inversion of the combined data along with the development of hybrid arrays for combined tiltmeter and microseismic. Examples from several data sets show how the combined results can be used to improve velocity models and obtain better constrained-height estimates, as well as improved confidence in other fracture geometry parameters.
Field Tests of Sulfide Removing Biologically in Surface Systems
Authors: Dongsheng L. , Hongqi Z. , Jianxing C. , Xishou S. , Wang Z. 
Published: December 2007

Abstract
Biogenic sulfide is really troublesome in many produced water associated surface systems. The problems include iron sulfide (FeS) pluggings (equipment and near-borehole formation), excess solids, emulsion, and H2S related corrosion, toxicity, and reservoir souring as well. Cost effectively mitigating the serial problems is quite challenge and very costly because sulfide related problems often occur in produced water treatment systems, oily sludge system, injection system and extent to reservoir. Waterflooded reservoirs can offer conditions for growth of the sulfate reducing bacteria (SRB) that would convert sulfate to sulfide constantly, and polymer and chemical tertiary recovery implementation contributes sulfide in the reservoir as well.
In recent years, many surface facilities including three-phase separators, produced water treatment stations, oily sludge systems and injection systems in Daqing oilfield not only have server the sulfide problems, but also cause electric dehydrator systems power-off because of the high conductivity FeS layer forming, which resulted of FeS emulsified with skimmed oil returning to the dehydrator systems. As a result, normal operation has been disrupted constantly and safety has been a major concern as well in those facilities.
In this paper, we present test results from three fields using the microbial technique for sulfide removing in the produced water and oily sludge, and how we did it to achieve better results in a very cost-effective manner.
By applying this microbial sulfide removal technique efficiently prevents floating/skimmed and sludge oil aging in gathering systems, and improved produced water treatment efficiency and reduced the facility corrosion for the entire oil produced fluid treatment plants. In other word, the proposed application technique can effectively put sulfide related problems under control not only in isolated facilities and short term, but also in the entire system and long term.
Modeling and Analyzing Source and Interference Data from Packer-Probe and Multiprobe Tests
Authors: Larsen L. 
Published: December 2007

Abstract
This paper addresses practical aspects of modeling and analyzing source and interference data from tests with a dual packer or a single or double probe source combined with a single interference probe along a vertical or deviated wellbore. Although several authors have addressed such models, there are practical issues and problems that have not been discussed in detail. The present paper addresses all aspects of such tests, starting with simple analytical models and emphasis on the use of both diagnostic loglog, semilog and Cartesian plots to match and interpret the test response. The paper also addresses effects of uniform and non-uniform layering, and the use of probe data to choose the effective thickness for the source response, e.g., for a dual-packer test.
Effects of non-uniform layering are important since such cases cannot be analyzed with a consistent single layer model with packer or probe(s) source and a point (probe) for the interference response. Of special interest are cases with low-permeability layers between the source and the probe, with the source and probe data affected quite differently by changes in the location of such layers.
Also addressed in the paper are restrictions on rate, test duration and formation properties to obtain analyzable data. This has to do with gauge resolution and the inherent low rate in such tests. Screening guidelines are presented to determine if a good test can be obtained based on expected formation properties. This involves both the source and probe data.
Field data from three packer-probe tests from the Norwegian Continental Shelf have also been included in the paper to highlight some of the practical issues associated with such tests. All three cases were successful, although one is clearly affected by formation complexities that cannot be handled by a simple homogeneous model.
Boundary Effects and Depth of Investigation from Long Buildups Following Short Flow Tests
Authors: Larsen L. 
Published: December 2007

Abstract
Slug tests and other tests with the buildup period greatly exceeding the flow period have been addressed in the literature by several authors over the last 30 years. The present paper takes a new look at such tests with a primary objective to investigate the possibility of drawing conclusions about boundary effects. Although some of the standard techniques used to analyze slug tests in principle can detect boundaries at distances far beyond the distance affected by the flow period, special approaches must be used to avoid the need for a highly accurate estimate of the formation pressure. The problem is that the pressure change relative to the initial formation pressure is often used as a fundamental quantity in analyses. For cases with small pressure changes at the end of the buildup, the characteristics of the pressure response is highly sensitive to the choice of formation pressure, making it difficult to distinguish boundary effects from effects of erroneous input.
Because of the problem alluded to above, other and more robust methods should be used to analyze buildup data following short flow tests. This paper shows that straightforward derivative methods can be used to this end without the formation pressure as a key input parameter. This allows us to use two distinctly different approaches to analyze the data, thus reducing the uncertainty in the results. The methods do not overlap, and actually "favor" different data sets, but both require high quality data to reduce uncertainty and maximize the depth of investigation from analyses. In essence, the alternative approaches seek to move uncertainties from methodology (initial pressure estimation) to technology (data quality).
Although well-known derivative methods are advocated, the results deviate to some extent from the expected. The point is that the results look familiar but are not exactly what they appear to be. Also, the derivative approach does not work for all types of models in a theoretical sense, but it does work for all cases of practical interest.
The importance of the results should be obvious with increased interest in "green tests" with limited production without flow to surface, for instance by restricting flow to the wellbore with subsequent bullheading of hydrocarbons back into the formation. But these are not the only data sets of interest. The results apply to any data set with a shut-in period much longer than the flow period, for instance with days of flow and months of shut-in data. Another category of data comes from after-closure analyses (ACA), but such data have not been treated specifically in this paper.
How Do We Get There From Here? Global Energy Transitions Planning
Authors: Ebenhack B. W. 
Published: December 2007

ABSTRACT
How shall we craft an energy future that is less dependent on petroleum? And what role will oil and gas play in that scenario? In spite of an impressive 150 year track record of increasing hydrocarbon production to meet exponential growth in demand, constraints have emerged. There will be a pinch in production rates relative to growing demand, necessitating the development and deployment of alternative energy technologies from more sustainable resources. As of yet there is no consensus on how to transition to alternative fuels, despite a great deal of talk about the need to do so. Nor is adequate consideration being paid to the pivotal role that oil and gas will continue to play well into the transition.
This paper addresses global energy planning at all organizational levels, as well as within energy producing corporations. Since future energy services will draw from an evolving mix of production sources and technologies, we propose a way for energy regulators and energy companies to optimize energy mixes, by evaluating the value added over time of each resource and applicable technology.
This paper maintains that oil and gas will continue to be important components in any energy mix for the foreseeable future. Alternative fuels will be hard-pressed to provide comparable net values either in terms of work from energy produced or in terms of environmental impact. As petroleum engineers, it is imperative that we make clear the character of the coming petroleum peak and the necessary role that petroleum must play in the coming transition period. It is essential to characterize clearly the energy value provided by our current resources and the value that will be demanded from alternatives as they do take up larger market shares.
Water Separation From Wellstream in Inclined Separation Tube with Distributed Tapping
Authors: Rivera R. M. , Golan M. , Friedemann J. D. , Bourgeois B. 
Published: December 2007

Abstract
This paper describes observations on water separation from wellstream in an inline separator using the concept of distributed water withdrawal from inclined tube section. The Physical observations were conducted in a laboratory using a 7" observation section applying flow rates compatible to North Sea single well rates. The distributed water withdrawal is achieved by placing a set of evenly spaced tapping points at the bottom of the tube section with facilities to control tapping rates. The observations were made in connection with a joint-industry project to validate and commercialize a new concept for downhole and seabed separations. The driver for the study is to verify possible water separation by distributed tapping from the bottom of the tube in high flow rates with high degree of agitation, turbulence and phase dispersion. Observations demonstrated that in a wide range of flow, comparable to the flow conditions in high rate oil wells, the high turbulence and phase dispersion do not erode and disperse completely a continuous layer of water on the bottom of the tube. This layer, flowing upwards or downwards depending on the flow conditions, facilitates a reasonable water separation when it is tapped properly. The scope of the test intended to capture the effect of flow and system variables on the separation efficiency. The experiments and the analysis validated the distributed separation concept. They demonstrated good separation at a wide range of flow stream conditions. They explained the reasons for good separation even in high degree of turbulence and phase dispersion. The mechanistic understanding of the separation allows a degree of predictability and guideness for separator design.
Environmental Advances in Drilling Fluids and Waste Operations Applying Novel Technology for Fluid Recovery and Recycling
Authors: Eia Jan Thore , Hernandez Edgardo 
Published: December 2007

Abstract
This paper presents a concept designed to meet and be compliant with the environmental legislation requirements of managing drilling fluids, completion fluids and waste from the oil and gas industry in the arctic and Barents Sea region. Data will be presented in this paper to document the reduction in direct environmental impact, reduced risk as well as the profitable returns; like cost savings for the operators and the drilling fluid supplier as a result from applying these novel technologies.
A total drilling fluid and waste management concept for drilling and well operations was developed to merge the operators cost reduction strategies and reduced environmental impact with the fluids and equipment supplier's technology and business incentives. Key elements in this concept was; (1) the development of both water based and oil based environmental friendly drilling fluids for challenging arctic conditions, (2) the EnviroUnit for separation, recovery and recycling on location, (3) CleanCut for enclosed cuttings containment completely reliable with no operational downtime or due to harsh weather conditions when drilling operations are distant from shore and finally (4) the onshore EnviroCenter with capacity and technology to receive, treat, store, manufacture and deliver drilling fluids and related liquid and cuttings waste streams.
Presented data show oil based drilling special waste reduction of over 90%. All recovered oil based drilling fluid has been recycled, upgraded and reused. A reduction in the new oil based drilling fluid consumption has been experienced reducing manufacturing, transport and storage cost. All separated waste water has been cleaned to well within the approved discharge regulations.
Whenever possible, the total fluids and waste management concept should be applied. Oil recovered from cuttings transported onshore and processed via thermal treatment has been successfully recycled as drilling fluid base oil. This total fluids and waste management concept has been established as a business "standard". The success is however closely linked to the close team-work with the operator and across the traditional service lines of fluids; solids control, waste management, associated waste handling logistics, processing, treatment and disposal. It will achieve full environmental impact and benefit when applied to large-scale operation.
Improved Understanding of Proppant Transport Yields New Insight to the Design and Placement of Fracturing Treatments
Authors: Brannon H. D. , Wood W. D. , Wheeler R. S. 
Published: December 2007

Abstract
Post-frac production analyses frequently suggest that effective fracture area is significantly less than that designed, implying either the existence of excessive proppant-pack damage or, that the proppant was not placed in designated areal location. The conductive fracture area is defined by the propped fracture height and the effective fracture length. Optimization of effective fracture area is among the principal tenets of fracturing design engineering. It is well understood that effective fracture area is a first order driver for well productivity, and optimization of such is often critical to economic exploitation of reservoir assets.
The results of extensive testing in a large-scale slot apparatus to delineate the relative effects of various component and treatment parameters on proppant transport capability were reported previously. In an extension of that effort, an empirical proppant transport model has been developed using the information gleaned from previous testing and then refined using newly generated data to expand the range of the various component parameters. The model has input parameters including fluid viscosity, proppant size, both fluid and proppant specific gravity, injection rate, and fracture geometry. The model output is the estimated propped fracture length of a given treatment design incorporating a fracturing fluid slurry having the input parameters.
Utilizing the new model, the most favorable combination of fracturing slurry component properties and pumping parameters can identified and incorporated in fracturing treatment design and applications to optimize effective propped fracture length, and thereby well performance.