bluuebunny/crossref_metadata_2025_split huggingface dataset:
Drillbit SWD Reverse Walkaway Using Downhole Reference Signal
Authors: Naville Charles , Serbutoviez Sylvain , Throo Alexandre , Batini Fausto , Dini Ivano , Cecconi Fabio 
Published: December 2007

Abstract
Development drilling occurs sometimes in areas where the surface seismic quality is poor. Drilling in such areas is risky enough to justify the application of drillbit SWD for seismic illumination ahead of the bit. A multidisciplinary project partially supported by the EC was undertaken combining the following techniques:
Drillbit SWD, Seismic While Drilling survey using the drillbit as seismic source and many lines of surface receivers. The Bottom Hole Assembly (BHA) includes a roller cone bit, a shock absorber and a downhole reference sensor in between. EMWD, as Electro-Magnetic While Drilling wireless transmission surface to downhole. GEOSERVICES built a new Downhole Recorder Unit (DRU) integrated in the BHA in order to record the random axial drillbit vibrations in synchronization with a Surface Command Unit (SCU). Most of the commercial surface seismic recorders can be interfaced with the SCU. Large amount of uncorrelated seismic data are memorized both on surface and downhole while drilling, as the drillbit signal is available only when the drillstring is pulled out of the well.
The objective of the method is to produce a seismic image of the geological structure around the first well in order to confirm the target structure, or to indicate the drilling targets of the following directional wells. The field operation is limited to one or two drilling runs around mid-target depth, due to operational and cost constraints.
A full scale SWD reverse walkaway was recorded in this fashion around an ENEL well in a " no seismic result " area, near Larderello, using the OGS SEISBIT surface seismic recorder with 170 channels deployed over 6 radial lines.
The whole chain of field equipment behaved successfully and good seismic reflections have been obtained. The present SWD reverse walkaway technique does not disturb the drilling process significantly. The time delay for processing needs to be reduced in order to render the method even more attractive.
Dynamic Simulation of a Realistic 3-D Model of the Brent Slumps
Authors: Dijk H. , Arnott S. , Ozoglu S. , Pritchard D. W. , Price S. , Snippe J. 
Published: December 2007

Abstract
The Brent Slumps of the Brent Field were formed by crestal collapse of the main Brent reservoir during the late Jurassic. Production from the Brent Slumps has been dominated by two main factors: varying levels of connectivity with the West Flank of the field through cross-fault juxtaposition and preferential production via prolific high-permeability zones. Remaining Brent Slumps undeveloped reserves represent a significant fraction of the field total.
In order to improve the understanding of historical production performance and to address the remaining hydrocarbon volumes in place, a new realistically faulted 3-D simulation model has been constructed for the Slumps. The model contains over 140 listric and antithetic faults and utilises Shell's proprietary reservoir simulator (MoReS).
The model basis is a very fine cellular 3-D static model that contains a detailed description of both reservoir structure and facies-controlled permeability architecture. Simulation models are extracted at various scales, ranging from coarse (quick look at material balance and pressures), to very fine (investigation of flushing patterns), using upgridding and upscaling algorithms that guarantee consistency of volumetrics, connectivity and well data.
The simulation model is defined in terms of geological entities, i.e., individual faults, fault blocks, horizons and zones. This enables a high-level and systematic treatment of fault transmissibility and allows for monitoring of, e.g., material balance/pressures per fault block and flow across individual fault surfaces. This greatly facilitates sharing of simulation results within the multi-disciplinary development team.
The integrated static/dynamic model is now used to help identify and rank the portfolio of remaining development targets, in addition to underpinning the planning of complex, multi-target horizontal wells. Many infill targets are relatively small and lie close to the economic threshold. The improved technical integrity provided by the new model has been critical in providing sufficient confidence to support an infill drilling programme.
After outlining the particular development challenges for the Brent Slumps, the paper sketches the static model (seismic, analogues, structure, rock properties), explains the philosophy behind the integrated static/dynamic model and illustrates its utilisation (and successes) with a number of examples.
Hysteresis in Three-Phase Flow: Experiments, Modeling and Reservoir Simulations
Authors: Egermann P. , Vizika O. , Dallet L. , Requin C. , Sonier F. 
Published: December 2007

Abstract
A proper modeling of tertiary recovery processes such as gas injection or WAG (Water Alternating Gas) requires an adequate three-phase flow model. This allows to better predict the recovery efficiency, gas storage reservoir performance as well as the well injectivity.
For gas drainage, a previous paper [25] presented a new three- phase flow model based on a theoretical analysis and validated through experimental approach. For WAG injection, there is an additional complexity due to the need to model the imbibition that occurs when gas saturation decreases. To tackle the modeling of hysteresis problem, a comprehensive approach was followed. First, successive drainage and imbibition experiments were conducted under various conditions of initial saturations. A new three-phase model taking into account the hysteresis is presented and validated on the experiments.
Indeed, as shown in previous experimental studies, hysteresis was found to depend not only on the drainage/imbibition process (saturation history) but also on the cycle considered (displacement history) where cycle names the association of two consecutive displacements (drainage and imbibition). In this study, a relevant analytical expression of the hysteresis is proposed avoiding any negative effect of numerical instabilities. The new formulation was implemented in a reservoir simulator and WAG experiments have been successfully simulated. The impact on breakthrough time, overall recovery efficiency was tested through large scale reservoir simulations.
Vertilog - A Down-Hole Casing Inspection Service
Authors: Haire John N. , Heflin Jearald D. 
Published: December 2007

American Institute of Mining, Metallurgical, and Petroleum Engineers, Inc.

Abstract
In California the shortages and resulting economics of new oil has intensified the search for new sources. With casing and drilling costs increasing, this search has resulted in a renewed interest and re-evaluation of many existing wells.
A knowledge of the condition of the existing casing is necessary for repairs, workovers, and possible developement of additional zones.
The Vertilog is a casing inspection service which is now available to the oil and gas industry to determine the condition of the casing in existing wells. It is a quantitative measurement of corrosive damage, indicating if the metal loss is internal or external, and if it is isolated or circumferential. Holes in the casing can be identified as well as parted casing. This survey in conjunction with other measurements, can be used to detect, monitor, and establish preventive techniques for corrosive problems.
This paper is intended to familiarize the industry with tool specifications, theory of operations, calibrations, applications, interpretation principles, and field examples.

Introduction
The Vertilog is a downhole casing inspection service. The recordings produced allow identification of damaged intervals and severity of corrosion. Measurements taken determine if corrosion or damage is internal or external and if it is isolated or circumferential.
Due to instrument design, casing inspection covers the full circumference and minor elongation does not elect the reliability of the measurements. Anomalies as small as 1/8" in diameter with as little as 20% penetration of the nominal bodywall of the casing penetration of the nominal bodywall of the casing can be detected.
All casing sizes, weights, and grades from 4-1/2" O.D. through 8-5/8" O.D., except 6-5/8" O.D., can be inspected at the present time.
The tools are temperature rated at 250 deg. F and pressure rated at 10,000 PSI. pressure rated at 10,000 PSI. The logging speed is 125 feet per minute and no special borehole fluids are required for the survey. It is recommended that the casing be scraped just prior to the survey for the most definitive measurements.
PRESENTATION PRESENTATION The data is presented in a standard log format, however, the usual depth scale is 10" per 100 feet of borehole for improved definition. The measurements are presented on a four track log grid as illustrated in Figure 1.
Track one and two are designated as Flux Leakage-1 (FL-1) and Flux Leakage-2 (FL-2) and correspond to the two rings of shoes on the Vertilog instrument. Recorder deflections in these tracks indicate the severity of corrosion that has taken place and also the location of the collars.
Constraining 3D Static Models to Seismic and Sedimentological Data: A Further Step Towards Reduction of Uncertainties
Authors: Marion D. , Insalaco E. , Rowbotham P. , Lamy P. , Michel B. 
Published: December 2007

Abstract
The prediction of the spatial distribution of petrophysical properties within a heterogenous reservoir is affected by significant uncertainties when based only on well information. However, integrating additional constraints such as 3D seismic data and sedimentary concepts can significantly improve the accuracy of reservoir models and help reduce uncertainties on predictions away from wells.
This paper addresses these issues with an approach for 3D modelling of static reservoir properties that involves the combined use of sedimentary modelling and seismic inversion techniques. The final results are multiple 3D petrophysical models with associated uncertainties. These models are coherent with the sedimentary model and consistent with seismic amplitude data. These results may then be used as an input to uncertainty analysis on static properties such as distribution of pore volume and hydrocarbon in place.
An example from a North Sea shallow-water siliciclastic reservoir is presented. This example demonstrates how integration of seismic and sedimentological can effectively influence the reservoir model both in terms of spatial distribution of reservoir properties and volumetric calculations.
Successful Multidisciplinary Teamwork Increases Income. Case Study: The Sleipner East Ty Field, South Viking Graben, North Sea
Authors: Hansen Helga , Westvik Kristin 
Published: December 2007

Abstract
Seismic and well data, such as cores, logs and production tests, are the vital input data used to build geological models for exploration and development of hydrocarbon fields. However, once a field is put on stream, production data itself gives valuable and important additional knowledge that improves geological insight and understanding. In particular, pressure observations, tracer data, together with production logs provide essential information about recoverable hydrocarbon volumes, communication routes, flow barriers, and drainage pattern within the reservoir.
A multidisciplinary team consisting of geophysicists, geologists, petrophysicists, reservoir and production engineers, together with drilling and completion engineers, cooperated for the last three years evaluating the Sleipner East Ty Field, which is a gas-condensate reservoir situated in the South Viking Graben, North Sea. During the work process, there has been a continuous feedback loop from the production data to the geological model. Changes of the geological model were carried out in order to match the dynamic reservoir model with actual production data. The resulting new models have been the basis for accelerated gas sales commitments and for increased condensate production from the reservoir. The integration of production and well engineers in the reservoir modelling team has lead to valuable focus on alternative drainage strategies, including drilling of new, challenging wells and more economically viable well interventions.
Reconciliation of Time-Lapse Seismic Data with Production Data for Reservoir Management: A Gulf of Mexico Reservoir
Authors: Huang Xuri , Will Robert , Waggoner John 
Published: December 2007

Abstract
Integration of time-lapse seismic and production data provides an effective tool for reservoir management. However, extensive work is required to build a "common" earth model1,2 honoring both types of data. This typically leads to longer turnaround times for time-lapse seismic projects. This paper demonstrates a method to shorten this time by reconciling production data with time-lapse seismic data in the data domain rather than in the earth model domain. The results from this method demonstrate that this quick evaluation can reveal whether or not the observed seismic differences represent reservoir changes associated with production, and can provide a basis for a more extensive model based evaluation. This method was applied to a gas reservoir in the Gulf of Mexico where preliminary rock physics modeling showed that water replacement would lead to more than 10% impedance change for approximately 30% of gas saturation change. The saturation-amplitude relation used to threshold the seismic difference volume was calibrated at the well or predefined locations. The threshold was optimized through solving the material balance relation obtained from production data with the time-lapse seismic data, thus making it more likely that the seismic differences are representative of saturation changes in the reservoir. This work: (1) provides a new procedure for gas reservoir time-lapse analysis under certain geological and production conditions; and (2) demonstrates a new first order method to reconcile time-lapse seismic data and production data without employing time consuming reservoir characterization and flow simulations. This approach greatly reduces the turnaround time involved in the use of time-lapse seismic information for reservoir management. Further, the result could lead to better subsequent model based analyses1,2.
Compositional Integrated Subsurface-Surface Modeling
Authors: Weisenborn A.J. (Toon) , Schulte A.M. (Tom) 
Published: December 2007

Abstract
Adequate modeling of a hydrocarbon production system may require integration of several reservoir models with a model for the surface network and a model for the processing facilities. The degree of detail in each model should be in accordance with its impact on the business case.
Compositional modeling of the hydrocarbon streams is usually highly desirable for volatile oils, gas-condensates and production systems in which different streams are mixed. However, compositional modeling is notoriously involved and CPU-intensive. Hence it has so far only been applied in an approximate way, with a few lumped components and reduced detail in the geological reservoir model(s). These approximations will often defeat the purpose for which compositional modeling was brought in.
Compositional modeling has been implemented in Shell#x0027;s proprietary Hydrocarbon Field Planning Tool to enable adequate modeling of gas-condensate and volatile oil systems. Surface network modeling was accomplished by interfacing with the compositional mode of the commercial network solver Pipephase. The compositional well streams were generated by extension of Shell's multi-purpose reservoir simulator MoReS with a delumping scheme. This scheme is in essence postprocessing of the well streams calculated on the basis of a two-component reservoir fluid representation. It requires a marginal amount of CPU time, independent of the number of components. In all applications so far the delumping scheme was found to be unexpectedly accurate: the mass rates of the 20-odd well stream components were reproduced with an average relative accuracy of about 0.5 %. The well streams consist of all components mentioned explicitly in the PVT report(s) and typically about 10 pseudo-components to represent the heavy fraction.
In this paper the physical considerations are described, which underly the delumping scheme. Also provided are a detailed validation study and the key results of field studies of gas-condensate fields in Australia's North-West Shelf area and in the North Sea.
Linking Reservoir and Surface Simulators: How to Improve the Coupled Solutions
Authors: Barroux C. C. , Duchet-Suchaux P. , Samier P. , Nabil R. 
Published: December 2007

Abstract
A full analysis of the problem of coupling two independent industrial simulators, a reservoir simulator and a steady-state network simulator, has been performed. A classification of the industrial needs has been obtained from the examination of several actual cases studies (fields at development, or production stage, requiring performance optimization through short to long term forecasts). Several coupling configurations and specific requirements, for both reservoir and surface software, have been identified to satisfy the industrial needs. Various commercial solutions have been screened to evaluate the adequacy between the software functional capacities and the identified configurations and requirements. Limitations have been brought to evidence.
The paper, issued from the work of a multidisciplinary team, presents the details of each step described briefly here above. Practical solutions for improving coupled solutions, i.e. to go beyond the identified limitations and to reduce the elapsed times of the coupled simulations, are provided. An improved mutual understanding of the needs of each discipline concerned by the integration of reservoir and surface has been experienced as essential for a successful integrated approach of field optimization. It is intended in the paper to contribute to a better communication between the various upstream petroleum skills: reservoir, production, surface and process engineers.
Water Management in a Closed Loop - Problems and Solutions at Brage Field
Authors: Andersen K. I. , Halvorsen E. , Sælensminde T. , Østbye N. O. 
Published: December 2007

Abstract
Brage field offshore Norway is producing off plateau at 8500 Sm3/d oil. Associated daily produced water rates are in excess of 16000 m3.
Following a change in injection scheme from seawater to aquifer water in 1997, two water supply wells were drilled and completed in the Utsira reservoir. Artifical lift from Utsira was achieved by installation of Electric Submersible Pumps. In parallel, the topside system was upgraded to facilitate complete PWRI (Produced Water Reinjection) in the Statfjord sandstone reservoir.
The Utsira aquifer, located 600 m below seabed, has showed excellent properties with respect to productivity and deliverability. ESP equipment installed in A-24 and A-29 has had a continuous improvement in reliability since 1998.
Topside, PWRI has resulted in wear on the injection pumps as a consequence of high particle content. Corrosion has lately been detected in the Utsira water producers, injection flowlines and 3 injection well tubings.
Sulphate scaling resulting from early seawater injection has been moderate at Brage. No problems associated with H2S have been seen following the change in water management philosophy. Carbonate scale in the upper tubing is successfully removed by a new acid deflection tool run on wireline while bullheading HCl. Bullhead squeeze treatments is utilized to control further scale buildup.
The closed loop approach to water handling at Brage has proven environmentally favourable, and has prevented the discharge of 9 500 000 m3 produced water to sea.
Evolution Tendencies of Physico-Chemical EOR Methods
Authors: Altunina L. K. , Kuvshinov V. A. 
Published: December 2007

Abstract
The evolution of physico-chemical EOR methods in Russia is connected with the use of oil-displacing systems capable to retain and to self-regulate a complex of colloidal-chemical properties optimal for the purposes of oil displacement. The dominating role belongs to EOR technologies increasing conformance by flooding or by steam-heat treatment. Promising are such physico-chemical methods, in which heat energy of the formation or that of the injected heat carier is used to generate in situ alkaline buffer systems and CO2, as well as to form gels capable to increase oil displacement and conformance. Hydrolysis, hydrolytic polycondensation and coagulation processes proceeding in the system carbamide – aluminium salt – surfactants – water are used to prepare inorganic gels. To prepare thermoreversible polymer gels one uses solution – gel phase conversion in the system cellulose ether with a lower critical dissolution point – water. Presented are the results obtained on the employment of physicochemical EOR technologies, developed at the Institute of Petroleum Chemistry SD RAS, in the oil fields of Russia. The tehnologies proved to be effective and ecologically safe. The period of payback is 5-12 months.
Contribution of the Coupled HydroMechanical Theory in the Estimate of Reservoir Production
Authors: Bévillon D. , Boutéca M. J. , Longuemare P. , Shahrour I. 
Published: December 2007

AbstractThis paper includes a study of the exploitation of soft highly compacting reservoirs using a coupled poromechanical model. The numerical results show that the exploitation of the reservoir induces instantaneous stresses in the totality of the reservoir, which produce pore-pressure variation in a zone located far from the pore-pressure diffusion area of the well. The evolution of the pore-pressure and the stress- and strain- paths are examined as a function of the stiffness ratio between the surrounding materials and the reservoir. The influence of the geometry of the reservoir (plane or axi-symmetric) and of the sideburden on the magnitude of stresses transferred by the overburden to the reservoir is also examined. Finally, the response of a heterogeneous reservoir is analyzed. The main results obtained with the poromechanical model are compared to those obtained with a conventional reservoir model.
Ranking R&D Projects in the Petroleum Area: New Tools for Economic Evaluation
Authors: Gottardi Giorgio , Maglione Roberto , Donati Franco , Broccia Patrizia 
Published: December 2007

AbstractRecent non-optimistic fluctuations related to the oil price1 highlight the tendency of most of the oil companies in a cost-effective policy. The technology development is one of the key factors in the cost reduction strategy. As a consequence, the strategic scenario expected for the next future in the petroleum industry is an increase in finding new innovative technology solutions.As of today in this scenario R&D activities, besides to greatly affect the strategic technologies portfolio, could have more influence than ever on the business.However, future R&D projects could have an increasing onerousity and complexity related to greater technical and financing risks.Introduction of new assessment techniques, in particular of economic and financial evaluation, might become decisive. In this paper a new tool supporting the selection of R&D project proposals related to strategical needs, expected economical benefits and expected redditivity, is shown. This is a computerised system that supports the decision-maker in the construction of the necessary estimates following an incremental procedure. R&D project are compared and ranked on the basis of a multiattribute evaluation. The economic and financial performance is evaluated on the basis of NPV, IRR and payback; probabilistic analysis and risk assessment also is carried out. Examples of ranking of R&D project proposals from internal R&D Dpt are also presented.