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67th EAGE Conference & Exhibition
- Conference date: 13 Jun 2005 - 16 Jun 2005
- Location: Madrid, Spain
- Published: 13 June 2005
51 - 100 of 683 results
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Multi-Component Ocean Bottom Seismic Data Acquired with an Autonomous Node System
Authors P. Docherty, D. Hays, R. Shurtleff and J. PaffenholzB022 Multi-component Ocean Bottom Seismic Data Acquired with an Autonomous Node System Abstract 1 Multi-component ocean bottom seismic (OBS) data for oil and gas exploration have traditionally been acquired with systems in which many seismometers are physically linked with a cable. An alternative approach is to record data utilizing a set of distributed nodes each operating autonomously. In such a system each node marks time and records the sensor outputs continuously for the duration of its deployment on the seafloor which may be days or weeks. The high degree of flexibility in the receiver geometry permitted by a node based
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Imaging Sihil with Full Azimuth Ocean Bottom 4C Node Data
Authors M. Vázquez Garcia, G. Garcia, F. Maya, C.F. Ruiz Torres, E.W. Berg, C. Vuillermoz and A. Fyhn1 B023 IMAGING SIHIL WITH FULL AZIMUTH OCEAN BOTTOM 4C NODE DATA Marco Vázquez Garcia¹ Francisco Maya² Carlos Federico Ruiz Torres² Eivind W. Berg³ Claude Vuillermoz³ Atle Fyhn³ ¹Pemex CNPS Villahermosa ²Pemex Exploración y Producción Región Marina Noreste Ciudad del Carmen Mexico ³SeaBed Geophysical Trondheim Norway. Summary A large 4C OBS seismic program was acquired for Pemex over the Cantarell field offshore Mexico to improve the structural definition of the deeper Sihil field underlying the giant Akal field. The acquisition was made using autonomous receivers planted with accurate positioning on a regular grid in the seabed. The data is acquired
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Vp/Vs Ratios through Multicomponent Velocity Analysis
Authors E. Stucchi, A. Grandi and A. MazzottiB024 Z-99 Vp/Vs Ratios through Multicomponent Velocity Abstract 1 A key step in the multicomponent data processing is the computation of the Vp/Vs ratios. In this paper we show that a multicomponent velocity analysis can combine information from horizontal and vertical components into a single panel and can therefore improve the accuracy of the velocity estimate. In addition a multicomponent velocity analysis followed by Common Conversion Points binning can indicate the Vp/Vs ratios that produce the optimum focusing of the coherence panel in the case of dipping reflectors. The multicomponent panel in which the velocity analysis is performed is obtained
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A Southern North Sea Multi-Survey PreSDM
Authors I.F. Jones, A.G. Campbell, E. Evans, D. Judd and S. ElamB025 A Southern North Sea Multi-Survey preSDM 1 A. G. CAMPBELL 1 E.EVANS 2 .D.JUDD 2 I. F.JONES 2 S.ELAM 1 Abstract Exploration in the Southern North Sea using conventional imaging techniques is hampered by complexities in the Mesozoic overburden and the Zechstein evaporites with dolomitic rafting overlying potential targets. 3D preSDM imaging has come into widespread use in recent years in an attempt to resolve such problems. Here we present case history from the ConocoPhillips acreage over block 49/14a where a four survey merge covering some 430sq.km (figure 1) was reprocessed to yield a coherent single input volume for
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Application of Pre-Stack Wave Equation Depth Migration in North West Europe
Authors S. Pharez, N. Jones, S. Zimine, H. Prigent, K. Ibbotson and J.-P. GruffeilleB026 Application of Pre-stack Wave Equation Depth Migration in North West Europe Introduction 1 Travel-time based PreSDM methods are known to only image only part of the wavefront in the presence of high velocity layers or complex/rugose structure. For such environments in the Gulf of Mexico and more recently offshore Angola wave equation PreSDM has proven to be beneficial yielding significantly improved imaging. The technique has also been applied in the North Sea and North West Europe. We present and discuss case studies from the latter comparing and contrasting our observations with results from standard 3D Kirchhoff PreSDM. Method The
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Wave Equation Migration and Illumination on a 3-D GOM Deep Water Dataset
Authors B. Fontechha, W. Cai, F. Ortigosa, Q. Liao and S. JinB027 Wave equation migration and illumination on a 3-D GOM deep water dataset 1 BRIGIDA FONTECHHA WENYING CAI FRANCISCO ORTIGOSA QINGBO LIAO 1 AND SHENGWEN JIN 2 1 Repsol YPF The Woodlands Texas USA 2 Screen Imaging Technology Inc. Houston Texas USA Summary The generalized screen propagator (GSP) is a one-way wave equation based wide-angle propagator. The dual domain implementation of GSP migration provides a fast and accurate 3-D wavefield extrapolation and produces high-resolution and high-fidelity subsalt images. This migration technology was applied to a 3-D GOM deep water dataset and was compared with Kirchhoff PSDM. A wave equation illumination
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Comprehension and Evaluation of PSDM Algorithms for Subsalt Imaging
Authors Q. Liao, B. Fontecha, W. Cai and F. OrtigosaB028 Comprehension and Evaluation of PSDM Algorithms for Subsalt Imaging Abstract 1 As pre-stack depth migration becomes a routine process in hydrocarbon exploration of subsalt areas of the Gulf of Mexico poor subsalt images obtained by conventional Kirchhoff migration become industry’s major concern and various wave equation migration implementations are introduced to improve subsalt images. We present a simple and effective method to examine Kirchhoff and wave equation operators through study of migration impulse responses and analysis of forward wavefield propagation using the Sigsbee2A model. The single value wavefront approximation of Kirchhoff migration fails in subsalt areas of complex geology
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Deepwater Imaging beneath Gas Anomalies – A Case Study
Authors O. Khan, U. Klein-Helmkamp and T. ChapmanB029 Deepwater imaging beneath gas anomalies – a case study. Abstract 1 Seismic structural imaging for the target reservoir at the ‘Kikeh’ Oil Field offshore Malaysia is severely affected by the presence of shallow gas anomalies. Conventional pre-stack time migration (PreSTM) cannot handle the lateral velocity variations introduced by these anomalies; the gas introduces sufficient velocity contrast to cause deterioration of the image and pronounced ‘sags’ in the depth-converted seismic data. This poses problems for interpretation as well as reserve estimation. We used a processing flow incorporating detailed velocity modeling and isotropic pre-stack depth migration (PreSDM) to alleviate this problem.
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Prestack Depth Migration of Dual-Azimuth Surveys Incorporating Azimuthal P-Wave Anisotropy
Authors P. Whitfield, F. Dewey and M. KingB030 Prestack Depth Migration of Dual-Azimuth Surveys incorporating Azimuthal P-wave Anisotropy Abstract 1 It is standard practice now to build velocity models for prestack depth migration that include polar anisotropy (vertical or tilted transverse isotropy “VTI” or “TTI”). In this paper we discuss a dualazimuth North Sea dataset that exhibits significant azimuthal anisotropy as well as polar anisotropy. We present a practical production workflow using innovative analysis techniques (“butterfly gathers”) and solve for the azimuthal anisotropy using two sets of anisotropic parameters with a single velocity field taking advantage of the fact that we are dealing with only two dominant
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Hild, Multi Azimuth Seismic Experiment
Authors A. Riou, K. Kravik, P. Sexton, L. Lemaistre, V. Aubin and F. BertiniZ-99 HILD MULTI AZIMUTH SEISMIC EXPERIMENT B031 Abstract 1 K. KRAVIK 1 P. SEXTON 2 L. LEMAISTRE 2 V. AUBIN 2 A. RIOU 2 and F. BERTINI 1 1 TOTAL E&P NORGE AS Geosciences Division PO Box 168 4001 Stavanger Norway 2 TOTAL E&P France Seismic imaging is a major challenge over the Hild discoveries in blocks 29/6 9 30/4 and 7 offshore Norway due to the compartmentalisation of the reservoir section and presence of a gas dis-migration in the overlaying Cretaceous series. The original 3D survey covering Hild has been reprocessed to try to improve the quality of the
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Improving Seismic Imaging Using Global Offset, Geo-Electric and Electromagnetic Methods
More LessB032 Improving seismic imaging using global offset geo-electric and electromagnetic methods 1 Introduction In many complex geological settings imaging accurately the shallow sedimentary sequences is a key step in order to interpret properly also the deeper part of the seismic sections. In fact processing work-flows that are not focused in solving imaging problems in the shallow part of the data (first 300-500ms) can prevent a satisfactory imaging also at target depth. That is the case when the presence of shallow high-velocity layers and near surface geological complexity can cause sharp lateral and vertical velocity variations. Due to the low signal
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Integrated Pore-Pressure Prediction Using High-Resolution Seismic Velocity and Rock Physics
Authors J. Khazanehdari, N. Dutta, M. Portet and R. BachrachB033 Integrated pore-pressure prediction using highresolution seismic velocity and rock physics Abstract 1 The present seismic-based geopressure techniques use calibrated seismic velocity to pressure as a means of estimating background shale pressure. These methods lack the necessary highresolution velocity and pressure information required for drilling proposes. A fully integrated seismic pore-pressure prediction (iPPP) that can be used for drilling requires important elements such as high-resolution velocity a rock-physics-based pressurevelocity model and a sound understanding of lithology structure and fluid types. This paper describes a practical workflow that uses both seismic inversion and velocity analysis to obtain a high-resolution seismic velocity.
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Real Time Update of 3D Velocity Model for Steering Wells on Seismic Data
Authors F. Pivot, F. Bertini, F. Mansanne, G. Morin and N. KeskesB034 Real time update of 3D velocity model for steering wells on seismic data Abstract 1 Quality enhancement of seismic data allows to build seismic attributes (like lithoseismic cubes) that are precious for predicting encountered geology during the drilling of the well. However these data are often poorly used because all drilling operations are conducted in depth while seismic data are in two-way time. Of course it is possible to apply time to depth conversion in order to obtain seismic information in depth. However during the drilling phase the time-depth conversion mismatches rapidly. We propose here a strategy suited for
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The 2004 BP Velocity Benchmark
Authors F.J. Billette and S. Brandsberg-DahlB035 The 2004 BP Velocity Benchmark Abstract 1 In 2004 BP conducted a 2D velocity model estimation benchmark study. The study was open to all interested parties and was constructed as a blind test of available velocity model estimation/building techniques. The test was based on a 2D synthetic (finite-difference) dataset generated by BP which was made available to the interested parties. After receiving the data the participating groups were offered to present their results at the 2004 EAGE workshop and/or provide the results to BP to partake in the overall evaluation. In this paper we will present the model used
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New Quality Metric for Validation of Velocity Models
Authors F. Ljones, M. Nickel, G.G. Borgos, L. Sonneland and R. MjeldeB036 Abstract 1 The crucial analysis step in seismic processing is to establish an optimal velocity model. The quality of the velocity model has a major influence on the quality of the final processing result. The quality of the velocity model can be measured by how well the velocities NMOcorrect the common reflection-point gathers (CRP). However after transformation of the CRP-gathers to zero offset it is impossible to validate the quality of the velocity model without invoking the prestack CRP-gathers. It is prohibitive to pass an undecimated prestack seismic data volume to the interpretation stage. As a result of this
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Automatic, Dense and Volumetric Picking for High-Resolution 3D Tomographic Model Building
Authors V. Dirks, B. Wang, D. Epili, D. Wheaton, P. Guillaume and F. AudebertZ-99 Automatic dense and volumetric picking for high-resolution 3D tomographic model building B037 Abstract 1 As survey sizes are steadily increasing 3D tomography as the key component of today’s velocity model building workflows has to be performed on large data volumes within acceptable turnaround times. To provide high-resolution velocity models dense volumetric picking is required. This leads to even larger data volumes. It is therefore paramount to automate as many processing steps as possible to free the time of the geophysicist for the necessary QC. In this paper we present a modified workflow for high-resolution 3D tomography addressing the need
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3D Grid Tomography Based on Focusing Analysis
Authors B. Wang, F. Qin, V. Dirks, P. Guillaume, F. Audebert and D. EpiliZ-99 3D grid tomography based on focusing analysis B038 Abstract 1 We have developed a new 3D grid tomography based on the analysis of focusing errors. The seismic input to this new velocity analysis is a set of migration panels that are stack images formed at various imaging conditions zero-time or non zero-time. By comparing these different common focusing error panels the best focused events and their corresponding focusing errors are picked. The picked focusing errors and associated local reflector attributes (position and dip) are then fed into the existing 3D grid tomography to update the velocity model. This new
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Tomographic Residual Moveout Inversion of PreSTM Common-Image-Gathers
More LessZ-99 Tomographic residual moveout inversion of PreSTM common-image-gathers B039 Abstract 1 We present a new tomographic inversion technique for 3D anisotropic velocity-depth model building which inverts the residual moveout in PreSTM image gathers in a horizon consistent manner using the interpretations in the corresponding time migrated image. Our experience shows that tomographic inversion of PreSTM residual moveout provides velocity-depth models that require only small final updates via PreSDM residual moveout inversion in case of moderately complex structures. Since tomography after PreSTM uses time domain data it allows full non-linear inversion which shortens considerably the PreSDM cycle on industrial projects. Another
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3-D Inversion with Kinematic Wavefield Attributes
By N.-A. MüllerB040 0-00 3-D INVERSION WITH KINEMATIC WAVEFIELD ATTRIBUTES N.-A. Müller Geophysical Institute University of Karlsruhe Hertzstr. 16 76187 Karlsruhe Germany Summary. The 3-D Common-Reflection-Surface (CRS) stack provides an entire set of kinematic wavefield attributes which may be used for Dix-type inversion algorithms. These methods iteratively evaluate velocity models of the subsurface starting from the measurement surface. In general the models obtained are characterized by blocks of constant velocities separated by smooth first-order interfaces. Due to the iterative nature of this methods implementations suffer from error accumulation with increasing number of interfaces. In order to avoid this problem the Dix-type method
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Pore- to Field-Scale Multi-Phase Upscaling for IOR (SPE94191)
Authors T.R. Lerdahl, A.B. Rustad, T.G. Theting, J.Å. Stensen, P.E. Øren, S. Bakke, T. Boassen and B. PalatnikSPE 94191 Pore- to Field-Scale Multi-Phase Upscaling for IOR T.R. Lerdahl SPE A.B. Rustad SPE T.G. Theting SPE J.Å. Stensen SPE P.E. Øren SPE S. Bakke SPE T. Boassen SPE and B. Palatnik SPE Statoil Copyright 2005 Society of Petroleum Engineers This paper was prepared for presentation at the SPE Europec/EAGE Annual Conference held in Madrid Spain 13-16 June 2005. This paper was selected for presentation by an SPE Program Committee following review of information contained in an abstract submitted by the author(s). Contents of the paper as presented have not been reviewed by the Society of Petroleum Engineers and
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Improved Fluid Characterization for Miscible Gas Floods (SPE94034)
Authors A.M. Egwuenu, R.T. Johns and Y. LiSPE 94034 Improved Fluid Characterization for Miscible Gas Floods A.M. Egwuenu R.T. Johns and Y. Li SPE The U. of Texas at Austin Copyright 2005 Society of Petroleum Engineers This paper was prepared for presentation at the SPE Europec/EAGE Annual Conference held in Madrid Spain 13-16 June 2005. This paper was selected for presentation by an SPE Program Committee following review of information contained in an abstract submitted by the author(s). Contents of the paper as presented have not been reviewed by the Society of Petroleum Engineers and are subject to correction by the author(s). The material as presented does
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Effect of Geologic Parameters on CO2 Storage in Deep Saline Aquifers (SPE93952)
Authors S. Mo, P. Zwiegel, E. Lindeberg and I. AkervollSPE 93952 Effect of Geologic Parameters on CO2 Storage in Deep Saline Aquifers S. Mo SPE P. Zweigel E. Lindeberg SPE and I. Akervoll SPE SINTEF Petroleum Research Copyright 2005 Society of Petroleum Engineers This paper was prepared for presentation at the SPE Europec/EAGE Annual Conference held in Madrid Spain 13-16 June 2005. This paper was selected for presentation by an SPE Program Committee following review of information contained in an abstract submitted by the author(s). Contents of the paper as presented have not been reviewed by the Society of Petroleum Engineers and are subject to correction by the author(s).
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The Impact of Pertinent Parameters on the Design of Hydraulic Fracturing in Gas Condensate Reservoirs (SPE94074)
Authors G.A. Carvajal, A. Danesh, M. Jamiolahmady and M. SohrabiSPE 94074 The Impact of Pertinent Parameters on the Design of Hydraulic Fracturing in Gas Condensate Reservoirs G.A. Carvajal A. Danesh M. Jamiolahmady and M. Sohrabi Petroleum Engineering Inst. Heriot-Watt U. Copyright 2005 Society of Petroleum Engineers This paper was prepared for presentation at the SPE Europec/EAGE Annual Conference held in Madrid Spain 13-16 June 2005. This paper was selected for presentation by an SPE Program Committee following review of information contained in an abstract submitted by the author(s). Contents of the paper as presented have not been reviewed by the Society of Petroleum Engineers and are subject to correction
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Productivity Assessment of Fractured and Non-Fractured Wells in a Lean/Intermediate Low Permeability Gas Condensate Reservoir (SPE93136)
Authors T. Baig, U. Droegemueller and A.C. GringartenSPE 93136 Productivity Assessment of Fractured and Non-Fractured Wells in a Lean/Intermediate Low Permeability Gas Condensate Reservoir T. Baig and U. Droegemueller Wintershall AG and A.C. Gringarten Imperial College London Copyright 2005 Society of Petroleum Engineers This paper was prepared for presentation at the SPE Europec/EAGE Annual Conference held in Madrid Spain 13-16 June 2005. This paper was selected for presentation by an SPE Program Committee following review of information contained in an abstract submitted by the author(s). Contents of the paper as presented have not been reviewed by the Society of Petroleum Engineers and are subject to correction by
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Integrating Continuous 4D Seismic Data Into Subsurface Workflows
Authors O.I. Barkved, J.H. Kommedal, T.G. Kristiansen, K. Buer, R.M. Kjelstadli, N. Haller, M. Ackers, G. Sund and R. BakkeC001 Integrating Continuous 4D Seismic Data Into Subsurface Workflows Summary 1 In the period from October 2003 to November 2004 four seismic surveys have been acquired across the permanently installed seismic array (LoFS) at the Valhall Field Offshore Norway [1]. The installation followed the demonstration of significant production induced 4D seismic response when matching a marine streamer 4D survey acquired in 2002 to a survey acquired in 1992 [2]. Capturing the value of the continuous 4D seismic monitoring scheme implemented at Valhall is contingent on multidisciplinary integration of the 4D seismic products with other subsurface data. The potential and limitations
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Reservoir Management of the Njord Field (SPE92419)
Authors S. Talukdar and L.H. BrusdalSPE 92419 Reservoir Management of the Njord Field S. Talukdar SPE and L.H. Brusdal SPE Hydro Oil and Energy Copyright 2005 Society of Petroleum Engineers This paper was prepared for presentation at the SPE Europec/EAGE Annual Conference held in Madrid Spain 13-16 June 2005. This paper was selected for presentation by an SPE Program Committee following review of information contained in an abstract submitted by the author(s). Contents of the paper as presented have not been reviewed by the Society of Petroleum Engineers and are subject to correction by the author(s). The material as presented does not necessarily reflect any
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History Matching Using 4D Seismic and Pressure Data on the Norne Field
Authors M. Lygren, O. Husby, B. Osdal, Y. El Ouair and M. SpringerC003 HISTORY MATCHING USING 4D SEISMIC AND PRESSURE DATA ON THE NORNE FIELD Abstract 1 The Norne reservoir simulation model was history matched to time-lapse seismic data (acoustic impedance) and downhole pressure data (RFT) using the method of computerassisted history matching. The mismatch of the reservoir simulator was reduced compared to history matching of well data only. This led to an increased understanding of the flow in the reservoir and to increased confidence in the 4D interpretations which are important input to the well-planning at Norne. Introduction The Norne Field is situated in the southern part of the Nordland II
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The Geochoke Well Test Response in a Catalogue of Systematic Geotype Curves (SPE93992)
Authors P.W.M. Corbett, Y. Ellabad, J.I.K. Egbert and S. ZhengSPE 93992 The Geochoke Well Test Response in a Catalogue of Systematic Geotype Curves P.W.M. Corbett SPE Y. Ellabad 1 J.I.K. Egert 2 and S. Zheng SPE Heriot-Watt U. Copyright 2005 Society of Petroleum Engineers This paper was prepared for presentation at the SPE Europec/EAGE Annual Conference held in Madrid Spain 13-16 June 2005. This paper was selected for presentation by an SPE Program Committee following review of information contained in an abstract submitted by the author(s). Contents of the paper as presented have not been reviewed by the Society of Petroleum Engineers and are subject to correction by the
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Reservoir Monitoring with Pulsed Neutron Capture Logs (SPE94199)
Authors C. Morris, T. Aswad, F. Morris and T. QuinlanSPE 94199 Reservoir Monitoring with Pulsed Neutron Capture Logs C. Morris SPE Schlumberger T. Aswad SPE BP America Inc. and F. Morris and T. Quinlan SPE Schlumberger-PTC Copyright 2005 Society of Petroleum Engineers This paper was prepared for presentation at the SPE Europec/EAGE Annual Conference held in Madrid Spain 13-16 June 2005. This paper was selected for presentation by an SPE Program Committee following review of information contained in an abstract submitted by the author(s). Contents of the paper as presented have not been reviewed by the Society of Petroleum Engineers and are subject to correction by the author(s). The
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Fracture Mapping Using Microseismic Monitoring Data Recorded from Treatment Well – Results Based on 20 Hydro-Fracturing Jobs
Authors E. Gaucher, C. Maisons, E. Fortier and P. KaiserC008 Z-99 Fracture mapping using microseismic monitoring data recorded from treatment well – Results based on 20 hydro-fracturing jobs Abstract 1 To stimulate their oil recovery oil companies carry out hydraulic fracturing jobs for which the fracture characterization as fluid path is crucial. Microseismic monitoring of such experiments is used for fracture mapping; nevertheless monitoring from treatment well is still a challenge. Over these last five years using the field experience gained over 20 jobs we managed to collect a significant database/catalogue of frac jobs results monitored from the injection well (treatment well). Various configurations of the tools in the
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Estimation of Horizontal Permeability Using Pressure Changes Derived from 4D Seismic Data
Authors M. Floricich, Y. Almaskeri and C. MacBethC009 Z-99 Estimation of horizontal permeability using pressure changes derived from 4D seismic data Abstract 1 MARIANO FLORICICH* YAHYA ALMASKERI AND COLIN MACBETH Institute of Petroleum Engineering Heriot-Watt University Edinburgh UK EH14 4AS There are now several methods available for delivering separate estimates of pressure and saturation from time-lapse seismic data. A natural step beyond these procedures is to use the pressure component to estimate horizontal permeability this then being used to constrain the reservoir model. Here tests of this particular extension are performed on synthetic data examples typical of hydrocarbon reservoirs in the North Sea. The results indicate that
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Estimation of Layer Thickness and Velocity Changes Using 4D Prestack Sesimic Data
More LessC010 Estimation of layer thickness and velocity changes using 4D prestack seismic data Abstract 1 0 0 th EAGE 67 Conference & Exhibition — Madrid Spain 13 - 16 June 2005 1 1 1 T.RØSTE A.STOVAS AND M. LANDRØ 1 Dep. Of Petroleum Engineering and Appl. Geophysics NTNU 7491 Trondheim Norway For some hydrocarbon reservoirs severe compaction of the reservoir rocks is observed. This compaction is caused by the production and is often associated with changes also for the overburden. Time-lapse seismic data can be used to monitor this compaction process. Since the compaction causes both changes in layer thickness
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Linking Geomechanics and Seismics – Stress Effects on Time-Lapse Multicomponent Seismic Data
Authors J. Herwanger and S. HorneC011 Linking geomechanics and seismics: Stress effects on time-lapse multicomponent seismic data Abstract 1 Time-lapse stress effects on seismic data can have a similar magnitude as time-lapse effects caused by changes in saturation and pore pressure. Production-induced stress changes occur not only in the reservoir interval itself but are also manifested in the overburden. Furthermore because stress fields caused by reservoir production are directionally dependent the resulting changes in the elastic properties yield an anisotropic seismic response. To study effects in seismic data we have developed a workflow that allows the prediction/estimation of changes in (anisotropic) seismic observations from stress
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Integrating 4D Seismic, Geomechanics and Reservoir Simulation in the Valhall Oil Field
Authors P.J. Hatchell, R.S. Kawar and A.A. SavitskiC012 Integrating 4D seismic geomechanics and reservoir simulation in the Valhall oil field. 1 P.J. HATCHELL R.S. KAWAR AND A.A. SAVITSKI Shell International Exploration and Production Rijswijk The Netherlands Summary Time-lapse seismic monitoring of compacting reservoirs measures changes that occur both inside and outside of the reservoir interval. Inside the reservoir changes in saturation porosity velocity and layer thickness alter the reflection coefficients and intra-reservoir travel times that result in both amplitude and travel time changes. Outside of the reservoir the compaction creates long-wavelength changes in the stress and strain fields that perturb the seismic velocity and produce additional changes
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Investigating the Overburden Effect on Time-Lapse Seismic by Geomechanical Modeling
Authors P.V. Angelov, R. Arts, J. Spetzler and K. WapenaarC013 Z-99 INVESTIGATING THE OVERBURDEN EFFECT ON TIME-LAPSE SEISMIC BY GEOMECHANICAL MODELLING. Introduction PETAR VLADOV ANGELOV 1 ROBARTS 1 2 JESPER SPETZLER 1 and KEES WAPENAAR 1 1 Delft University of Technology Department of Geothechnology Delft The Netherlands 2 TNO Uttrecht The Netherlands In time-lapse seismic experiments it is important to estimate accurately the rock physics parameters at reservoir level. To solve the inverse problem (i.e. invert the rock parameters from the seismic data) additional information is needed. This extra information is obtained by solving the forward problem (e.g. using synthetic reservoir models Angelov et al. 2004). The lack of
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Effect of Navigation Attributes on 4D Seismic Repeatability
Authors C. Lacombe and E. RenouxC014 Effect of Navigation Attributes on 4D Seismic Repeatability Abstract 1 A methodology has been implemented to study the influence of variations in navigation parameters on seismic repeatability for marine 4D surveys. Synthetic seismic traces representative of real acquisition geometry are generated for base and monitor surveys using a wavefront propagation technique. The same velocity-depth model and source characteristics are used to simulate the seismic response of the two data vintages. Consequently all differences observed on synthetics are due to changes in acquisition parameters between base and monitor surveys. We establish statistical relationships between seismic repeatability and changes in acquisition
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Repeatability Monitoring during Marine 4D Streamer Acquisition
More LessC015 Repeatability monitoring during marine 4D streamer acquisition Abstract 1 The quality of 4D seismic data depends partially on the repeatability of source and receiver positions between the baseline and monitor survey. It is therefore important that positioning repeatability requirements are determined at the survey design stage and that they are monitored during acquisition. A software tool has been developed to monitor 4D positioning repeatability during marine acquisition. For each trace of a monitor survey a matching function is used to search for the most similar trace in the baseline dataset. For each pair of matching traces a number of
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Repeatability Using a Permanently Installed Seismic Array
Authors J.H. Kommedal, O.I. Barkved and K. HennebergC016 Repeatability using a permanently installed seismic array Abstract 1 The paper presents an assessment of repeatability of 4D data from a permanently installed seismic array. We compare the geometry of this acquisition with streamer and VSP acquisition and address effects of non-repeatable noise and its impact. Introduction Over the last years 4D seismic has become an increasingly important tool for reservoir management. Consequently a lot of work has been put into trying to develop acquisition technology which will improve our ability to detect production induced seismic changes. One way to achieve a high degree of repeatability of acquisition geometry
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Effects of the Earth Model’s Low Frequency Trend in Time-Lapse Seismic – Some Practical Considerations
Authors M. Verkeyn, A. Sturniolo and F. MelchioriC017 Effects of the Earth model’s low frequency trend in time-lapse seismic: some practical considerations Abstract 1 Time-lapse seismic is becoming a more widely used tool for reservoir monitoring. Apart from qualitative information reservoir engineers are also looking for quantitative information. A classic approach to achieve this goal is to invert the seismic data into acoustic or elastic impedance data and derive properties from those indirect measurements. A problem with this approach is that absolute measurements are needed while the seismic data itself can only provide relative information: the low frequencies are missing. The low frequency component is obtained from
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4-D Stratigraphic Inversion of the Girassol Field – Towards a More Quantitative Approach
Authors Y. Lafet, P. Duboz, B. Deschizeaux, F. Lefeuvre and C. HubansC018 4-D STRATIGRAPHIC INVERSION OF THE GIRASSOL FIELD - TOWARDS A MORE QUANTITATIVE APPROACH Summary 1 As applications of 4-D seismic technology become more mature there is a growing need for quantitative 4-D inversion workflows where base and monitor surveys are jointly inverted to estimate time-lapse changes in elastic properties which are then linked to changes in reservoir pressure and fluid saturation. In practice quantitative 4-D elastic inversion is made difficult by the presence of time-variant misalignments between corresponding seismic reflections in base and monitor surveys. These time-shifts are often the result of production-related velocity changes within the reservoir interval.
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Improving Drainage Interpretation Using a New Bayesian Time-Lapse Inversion
Authors Y. El Ouair, A. Buland, B. Osdal and A.-K. FurreC019 T-11 Improving drainage interpretation using a new Bayesian time-lapse inversion Abstract 1 An inversion technique for time-lapse seismic data has been developed to estimate changes of elastic properties (e.g. P-impedance S-impedance and density) of a reservoir due to production. The new aspects of this method is the direct and simultaneous inversion of prestack seismic difference data in addition to the Bayesian setting formalism applied to timelapse. This method provides posterior uncertainties by combining the a priori information of both the elastic properties changes and the seismic difference data. Until now this inversion has been successfully applied on real post-stack
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Matching of Multiple Time-Lapse Data Using Multi-Coherence Analysis
Authors H. Hoeber, D. Lecerf, H. Zaghouani and D. WhitcombeC020 Matching of multiple time-lapse data using multi-coherence analysis Abstract 1 We show how spectral coherence analysis and the multiple coherence technique can be used to extract reliable signal and noise spectra when more than two vintages of seismic time-lapse data have been recorded. We compare this method to other coherency-based approaches and we discuss matching strategies for multi-vintage seismic data. Introduction Matching is a key technique for time-lapse processing. Matching filters are applied to the seismic data in order to attenuate variations of the signal and to optimise the production related 4D signature. The operators are commonly designed to
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Imaging of Passive Seismic Sources by Reverse Modelling
Authors D. Gajewski and E. TessmerC021 Summary IMAGING OF PASSIVE SEISMIC SOURCES BY REVERSE MODELLING D. GAJEWSKI and E. TESSMER Institute of Geophysics University of Hamburg Germany The passive seismic method for reservoir monitoring and characterisation and monitoring of hydraulically induced fractures is developing into a main stream technology in the oil business. Current techniques rely on the fact that the recorded event is detectable at most of the stations of the recording array. Weak events not visible in the individual seismogram of the array are missed out. We present a new approach where no picking of events in the seismograms of the recording array
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Advanced Microearthquake Analysis Techniques for Reservoir Monitoring
Authors D. Colombo and G.R. FoulgerC022 Abstract 1 MicroEarthQuakes (MEQs) can provide information concerning reservoir structure the migration of fluids and permeability. Production-related pressure gradients generate differential stress conditions in the reservoir that can be monitored by means of MEQ moment tensor solutions which include isotropic components. MEQs can be considered to be distributed seismic sources that occur at depth generate both P and S waves and are able to provide additional information on rock physics by illuminating the reservoir directly from beneath. Robust 3D tomographic methods allow the determination of parameters such as Vp Vs and the Vp/Vs ratio in the reservoir and enable
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Passive Seismic Monitoring Using a Migration Technique
Authors S. Rentsch, S. Buske, S. Lüth and S.A. ShapiroC023 Z-99 Summary PASSIVE SEISMIC MONITORING USING A MIGRATION TECHNIQUE SUSANNE RENTSCH STEFAN BUSKE STEFAN LÜTH and SERGE A. SHAPIRO Institut für Geologische Wissenschaften Fachbereich Geophysik Freie Universität Berlin Malteser Strasse 74-100 12249 Berlin Germany In this paper we present a new approach for location of seismic sources which is based on principles of wave field back-propagation using multicomponent data. The use of migration techniques for imaging of seismic sources has the advantage that precise picking of arrival times is not required. Our approach requires only a preliminary selection of event time intervals and is much less sensitive to this
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Characterization of Induced Seismicity in Petroleum Reservoir – A Case Study
Authors E.K.M. Sze, M.N. Toksoz, D.R. Burns and G.F. MuellerC024 CHARACTERIZATION OF INDUCED SEISMICITY IN PETROLEUM RESERVOIR: A CASE STUDY Abstract 1 Fluid production and injection in hydrocarbon and geothermal reservoirs generally results in induced seismic activity. In this paper we study the microseismic activity in the Yibal Field in Oman. The microearthquake data we used are those collected by a five-station digital network in the Yibal Field between 29 October 1999 and 18 June 2001. We relocated 405 high-quality microseismic events using P and S travel-times picked from waveform data by the global grid-search location method. The results reveal a complex seismic zone with a NE-SW trend. All
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Estimation of Long Term Gas Condensate Well Productivity Using Pressure Transient Data (SPE94065)
Authors R. Osorio, G. Stewart, A. Danesh, D. Therani and M. JamiolahmadySPE 94065 Estimation of Long Term Gas Condensate Well Productivity Using Pressure Transient Data R. Osorio G. Stewart A. Danesh D. Therani and M. Jamiolahmady Inst.of Petroleum Engineering Heriot-Watt U. Copyright 2005 Society of Petroleum Engineers This paper was prepared for presentation at the SPE Europec/EAGE Annual Conference held in Madrid Spain 13-16 June 2005. This paper was selected for presentation by an SPE Program Committee following review of information contained in an abstract submitted by the author(s). Contents of the paper as presented have not been reviewed by the Society of Petroleum Engineers and are subject to correction by
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A Semi-Analytic Model for Productivity Testing of Multiple Wells (SPE94153)
Authors P.A. Fokker, G.K. Brouwer, F. Verga and D. FerreroSPE 94153 A Semi-Analytical Model for Productivity Testing of Multiple Wells P.A. Fokker SPE and G.K. Brouwer TNO – NITG and F. Verga SPE and D. Ferrero SPE Politecnico di Torino Copyright 2005 Society of Petroleum Engineers This paper was prepared for presentation at the SPE Europec/EAGE Annual Conference held in Madrid Spain 13-16 June 2005. This paper was selected for presentation by an SPE Program Committee following review of information contained in an abstract submitted by the author(s). Contents of the paper as presented have not been reviewed by the Society of Petroleum Engineers and are subject to correction
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Integrated Workflow for Quantitative Use of Time-Lapse Seismic Data in History Matching – A North Sea Field Case (SPE94453)
Authors M.C. Haverl, M. Aga and E. ReisoSPE 94453 Integrated Workflow for Quantitative Use of Time-Lapse Seismic Data in History Matching: A North Sea Field Case M.C. Haverl M. Aga and E. Reiso Norsk Hydro ASA Copyright 2005 Society of Petroleum Engineers This paper was prepared for presentation at the SPE Europec/EAGE Annual Conference held in Madrid Spain 13-16 June 2005. This paper was selected for presentation by an SPE Program Committee following review of information contained in an abstract submitted by the author(s). Contents of the paper as presented have not been reviewed by the Society of Petroleum Engineers and are subject to correction by the
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