The Experts below are selected from a list of 264 Experts worldwide ranked by ideXlab platform
Ian Lerche - One of the best experts on this subject based on the ideXlab platform.
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A frontier Basin Analysis study based on limited data: the South Mozambique Graben
Structural and Tectonic Modelling and its Application to Petroleum Geology, 2013Co-Authors: J.e. Iliffe, Ian Lerche, M. DebuylAbstract:The South Mozambique Graben is assessed for hydrocarbon potential by reconstructing its structural, burial and thermal histories using a seismic line and an array of Basin modelling techniques. A depth converted cross-section is simultaneously restored palinspastically and backstripped at designated pseudowells for each chronostratigraphic package. The thermal history is predicted from extensional models which relate paleoheat flow to basement subsidence. Maturation potential cross-sections are derived by applying a generation model to each of the pseudowells, assuming each layer to be a potential source rock. The Basin is then analyzed by considering the timing of hydrocarbon generation relative to the deposition of potential source and seal rocks and the formation of trapping structures and migration pathways. When a range of uncertainty is allowed for in the development of these models, the exploration geologist can make a better judgement of the dynamic range of hydrocarbon potential of this frontier Basin. Also, this type of study determines the type of additional information required to reduce uncertainties significantly. In this paper we illustrate how mathematical modelling can enhance the understanding of the hydrocarbon potential of a Basin given only limited data. Formerly, one-dimensional burial history models (e.g., Guidish et al, 1984; Cao, 1985) have assumed that sediments must have been deposited, not deposited (hiatus) or eroded during each time phase; meanwhile, the structural development has been largely ignored. The primary goal is to demonstrate a Basin Analysis technique which unites the structural, depositional and thermal histories of an area. Such an integrated approach may greatly contribute to an exploration geologist's understanding and assessment of the hydrocarbon potential of a speculative Basin. The method consists of simultaneously removing depositional layers and reconstructing structural cross-sections in sequential chronostratigraphic steps back in time. Before the technique was applied to real field data from the South Mozambique Graben, the problems of backstripping wells which penetrate faults were investigated by means of a series of tests on synthetic examples and this aspect is discussed first.
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Risking Basin Analysis Results II. The Influence of Erosion Uncertainties
Energy Exploration & Exploitation, 2003Co-Authors: Ian LercheAbstract:This paper considers erosion variables and their uncertainties in terms of their influence on outputs of interest in Basin Analysis calculations. While one often knows with some considerable precision the initial deposition time and final end time of an erosion event, one does not know (as opposed to surmise) when erosion commenced during that time interval, nor does one know the amount of material that was deposited and later removed, nor does one know the lithologic properties of the eroded material. All three of these factors can be of importance in Basin development. Using a recently developed extremely fast Excel burial history program, in conjunction with the very fast Monte Carlo program Crystal Ball, one can now rapidly sort out various uncertain factors for their influence on burial history outputs.Two sets of examples illustrate how one can determine which parameters associated with an erosion event dominate in their impact on Basin Analysis uncertainties. The first example allows the amount of ...
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Risking Basin Analysis Results
Energy Exploration & Exploitation, 2003Co-Authors: Ian Lerche, F. Rocha-legorettaAbstract:The work presented here uses a Basin Analysis code, developed for Excel, to handle burial history, fluid flow, fracturing, overpressure development with time, erosion events, kerogen breakdown to oil and gas, hydrocarbon volumetrics for both oil and gas including source retention, migration loss, and area changes with time of source rocks for each formation. The code is remarkably fast, requiring about 0.2 seconds on a laptop to perform all the above calculations for ten formations as well as producing pictorial representations of all variables with space and time. The code seamlessly interfaces with the Monte Carlo risking program Crystal Ball so that a total uncertainty Analysis can be done with as many uncertain inputs as required and as many outputs of interest as needed without increasing the computer time needed. A thousand Crystal Ball runs take only about 200 seconds, allowing ones to investigate many possible scenarios extremely quickly. We show here with four basic examples how one goes about identifying which parameters in the input (ranging from uncertain data, uncertain thermal history, uncertain permeability, uncertain fracture coefficients for rocks, uncertain geochemistry kinetics, uncertain kerogen amounts and types per formation, through to uncertain volumetric factors) are causing the greatest contributions to uncertainty in any and all outputs. The relative importance, relative contributions and relative sensitivity are examined to show when it is necessary to know more about the underlying distributions of uncertain parameters, when it is necessary to know more about the dynamic range of a parameter to narrow its contribution to the total uncertainty, and which parameters are necessary to first focus on to narrow their uncertainty in order to improve the dynamical, thermal or hydrocarbon outputs. An interface of such a coupled pair of very fast Excel codes with an Excel economics package can also now easily be undertaken so that one ties scientific uncertainty and economic uncertainty together for hydrocarbon exploration and identifies the global parameters dominantly influencing the combined economic/Basin Analysis system.
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Inverse Methods and Uncertainties in Stratigraphy and Basin Analysis
Energy Exploration & Exploitation, 2001Co-Authors: Ian LercheAbstract:Quantitative models are often constructed in attempts to uncover the evolution of stratigraphic and Basinal systems from present-day data. These models contain parameters related to the imposed boundary and initial conditions, as well as intrinsic parameters connected to the intrinsic evolution of the systems through equations of state taken to describe dynamical, chemical and flow processes. The use of inverse methods to determine these parameters is often undertaken by optimizing the model development in order to minimize the disagreement of the model with observations. We show here that several methods of optimization are possible, and we compare and contrast their intrinsic assumptions and relative numerical speeds. The problems of finite data sampling, with uncertainty of precision, accuracy, sensitivity and sampling frequency and distribution also play a major role in attempting to obtain the parameters required. In addition, different choices of control functions chosen for the minimization are shown to lead to different optimum parameter values, so that there is also a uniqueness problem in any inverse method chosen. The three methods considered here are simulated annealing, genetic algorithms, and the fast path tomographic method. Newton line search methods and Simplex solvers are also mentioned, but they are already known to be very much slower than any of the other three methods. The implications of the investigation reported here are that extreme care must be exercised in using data, models, and methods in attempts to uncover the evolution of a system. Failure to be absolutely sharp in what is being done can easily lead to overstating the results of an inverse method beyond its level of ability to resolve the problem. And the manner in which a problem fails to be resolved is also one of the crucial factors to be determined from any inverse method applied to such problems.
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An integrated quantitative Basin Analysis study of the northern part of the Arctic national Wildlife Refuge, Northeastern Alaska
Journal of Geodynamics, 1992Co-Authors: Z. Yu, Ian LercheAbstract:Abstract An integrated Basin Analysis was conducted using one- and two-dimensional quantitative dynamic models (1-D and 2-D) in the northern part of the Arctic National Wildlife Refuge (ANWR), Northeastern Alaska. Exploratory well data have been used in the reconstructions of: (1) geohistory including basement subsidence, sediment deposition, change of porosity and compaction, permeability, fluid pressure and fluid flow with time and depth; (2) thermal history including heat flux evolution with time, temperature change with time and depth, and thermal maturation history; and (3) hydrocarbon generation history including the change in the amount of hydrocarbons generated with time and depth, and determining the time and depth of peak hydrocarbon generation. 1-D and 2-D Basin modeling codes were used with selected wells, and also with a 18 km section, west of ANWR, with five well controls. It is concluded that: (1) the main source rock west of ANWR area matured first about 40-30 Ma ago in the south and gradually to the north about 10-8 Ma ago on the coastal plain; (2) the modeled erosion thickness at Beli Unit-1 location, northeastern Brooks Range, was 1500–3000 m and at least 3000 m at Canning River Unit B-1; and (3) an overpressure zone within the Hue shale and the lowest part of the Canning Formation caused by rapid Tertiary deposition retained porosity, increased the temperature and speeded hydrocarbon generation in the lower part of the coastal plain.
Paul Veeken - One of the best experts on this subject based on the ideXlab platform.
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Seismic Stratigraphy, Basin Analysis and Reservoir Characterisation
Handbook of Geophysical Exploration: Seismic Exploration, 2007Co-Authors: Paul VeekenAbstract:This chapter introduces stratigraphy. Conventional stratigraphy deals with data obtained from studies of outcrops, rock samples and petrophysical measurements from boreholes. It allows determination of lithofacies, environment of deposition and assignment of ages to these discrete observation points. The reflection seismic method creates a geophysically sampled picture of the subsurface, which has to be interpreted in a geologically meaningful manner. Seismic information is unique and it is fundamental for assessing the amount of geological change between well calibration points. Moreover, the reflection seismic method represents a convenient remote sensing technique, whereby the object under investigation is examined without being destroyed. The scope of seismic stratigraphic studies is ranging from large-scale Basin Analysis to detailed reservoir mapping, with as ultimate goal the “Lateral Prediction” of the reservoir porefill (reservoir characterization). The chapter discusses basic seismic stratigraphic principles, with the reflection termination mapping and proper well calibration. Various depositional environments and their models are described. Basin Analysis gives a means to reconstruct the Basin evolution. The dynamics of depositional systems and sea level changes are discussed. The chapter focuses on different elements of petroleum systems, hydrocarbon plays, ranking of prospects and some financial aspects of the petroleum business.
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seismic stratigraphy Basin Analysis and reservoir characterisation
2007Co-Authors: Paul VeekenAbstract:1. Introduction. 2. The seismic reflection method and its constraints. 3. Seismic stratigraphic techniques. 4. Dynamics of Basinwide Sedimentation Patterns and Sea level Changes. 5. Hydrocarbon habitat. 6. Seismic Reservoir characterisation. 7. Volumetrics and Prospect Evaluation. 8. Concluding remarks.
Sigit Sukmono - One of the best experts on this subject based on the ideXlab platform.
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Work-Flow for Selecting the Best Seismic Attributes for Effective Basin Analysis
2020Co-Authors: Sigit SukmonoAbstract:In an effective Basin Analysis, one crucial step is how to delineate the geometry of source, reservoir and seal rocks and understand their physical properties in an efficient way. Since well and seismic data is normally limited, then the challenge is how to select the best, most applicable seismic attributes which suit the unique geological conditions of the studied Basin. The problem is that there are abundant seismic attributes available and not every attribute is applicable for all geological conditions. Thus the selection of the best applicable attributes is often a very time consuming effort with unclear final results. This paper discusses a workflow for intelligent and efficient selection of the best seismic exploration techniques for an effective Basin Analysis. The work-flow is developed based on the criteria of target characterization objectives (geometry delineation and/or physical properties description), the nature of the seismic data, the mathematical-physical basis of each attribute and their geological meaning. Cases studies from three major producing Basins in Indonesia: Central Sumatra, South Sumatra and Northwest Java Basins are discussed to show the efficient applicability of the work-flow. In the Central Sumatra Basin the challenge is to map fluvio-deltaic sand deposits which are undetectable using normal seismic. In the Northwest Java Basin, the objective is to map sand channels controlled by growth faults as well as carbonates where the porosity is controlled by sealevel changes. In the South Sumatra Basin, the primary focus is to map the net-pay and porosity of sands which onlap granitic basement and form a combination of structural and stratigraphic traps. The study concludes that to find the best attributes, understanding the relationship between the targeted reservoir properties and the nature of elastic properties is very important. Key-words: seismic attributes, Basin Analysis, field exploration *Institute of Technology Bandung INTRODUCTION Effective Basin Analysis is important for successful petroleum Basin exploration. The prime objective in Basin Analysis is generally to map the geometry of targeted layers and understand the physical properties in an efficient way. On the other hand, the common problem faced during exploration is that the availability of well and seismic data is limited. Therefore the challenge is how to select the best, most applicable seismic techniques which suit the objective and unique geological conditions of the studied Basin. Nowadays there are abundant seismic attributes available but not every attribute is applicable for all geological conditions. The selection of the best applicable attribute is often a very time consuming effort with unclear final results. This paper discusses a work-flow for intelligent and efficient selection of the best seismic exploration techniques for effective Basin Analysis. The workflow is developed based on the criteria of target characterization objectives (geometry delineation and/or physical properties description), the nature of the seismic data, the mathematical-physical basis of each attribute, and their geological meaning. Case studies from three major producing Basins in Indonesia: Central Sumatra, South Sumatra and Northwest Java Basins are discussed to show the efficient applicability of the work-flow.
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PROCEEDINGS, INDONESIAN PETROLEUM ASSOCIATION Thirty-third Annual Convention & Exhibition, May 2009 WORK-FLOW FOR SELECTING THE BEST SEISMIC ATTRIBUTES FOR EFFECTIVE Basin Analysis
2020Co-Authors: Sigit SukmonoAbstract:In an effective Basin Analysis, one crucial step is how to delineate the geometry of source, reservoir and seal rocks and understand their physical properties in an efficient way. Since well and seismic data is normally limited, then the challenge is how to select the best, most applicable seismic attributes which suit the unique geological conditions of the studied Basin. The problem is that there are abundant seismic attributes available and not every attribute is applicable for all geological conditions. Thus the selection of the best applicable attributes is often a very time consuming effort with unclear final results. This paper discusses a workflow for intelligent and efficient selection of the best seismic exploration techniques for an effective Basin Analysis. The work-flow is developed based on the criteria of target characterization objectives (geometry delineation and/or physical properties description), the nature of the seismic data, the mathematical-physical basis of each attribute and their geological meaning. Cases studies from three major producing Basins in Indonesia: Central Sumatra, South Sumatra and Northwest Java Basins are discussed to show the efficient applicability of the work-flow. In the Central Sumatra Basin the challenge is to map fluvio-deltaic sand deposits which are undetectable using normal seismic. In the Northwest Java Basin, the objective is to map sand channels controlled by growth faults as well as carbonates where the porosity is controlled by sealevel changes. In the South Sumatra Basin, the primary focus is to map the net-pay and porosity of sands which onlap granitic basement and form a combination of structural and stratigraphic traps. The study concludes that to find the best attributes, understanding the relationship between the targeted reservoir properties and the nature of elastic properties is very important.
A. T. Lytviak - One of the best experts on this subject based on the ideXlab platform.
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A Quantitative Basin Analysis System for Petroleum Exploration
Computer Applications in the Earth Sciences, 1993Co-Authors: S. Bachu, A. T. LytviakAbstract:A computer-based Quantitative Basin Analysis System (QBAS) has been developed for the study of sedimentary Basins. The QBAS consists of three major components: database, data processing, and modeling. Usually available data in a sedimentary Basin, such as stratigraphic picks, core analyses, drillstem tests, analyses of organic matter, bottomhol temperatures, and analyses of formation waters, are stored and manipulated in a relational well database. The data are processed and synthesized to higher levels using different graphical and mathematical techniques. The data processing also provides the regional and local scale information of geological, geochemical, geophysical, geothermal, and hydrogeological parameters which are prerequisites for Basin modeling. In the modeling module, both one- and two-dimensional models are used for the simulation of sediment compaction and fluid flow, and for the reconstruction of burial history; a thermal inversion method is used for the reconstruction of thermal history; and a kinetic approach is used for the simulation of hydrocarbon generation from organic matter. Hubbert’s method is used for the evaluation of hydrodynamic entrapment of hydrocarbons. The QBAS provides the explorationists with the past and present-day conditions in a sedimentary Basin in terms of geology, geothermics, hydrogeology, and hydrocarbon generation, migration, and accumulation.
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A Quantitative Basin Analysis System and Its Application
AAPG Bulletin, 1991Co-Authors: A. T. LytviakAbstract:A computer-based quantitative Basin Analysis system (QBAS) has been developed for the study of sedimentary Basins. The QBAS consists of three major components: database, data processing, and modeling. Commonly available data in a sedimentary Basin, such as stratigraphic picks, core analyses, drill-stem tests, analyses of organic matter, bottomhole temperatures, and analyses of formation waters, are stored and manipulated in a relational well database. The data are processed and synthesized to higher levels using different graphical and mathematical techniques. The data processing also provides the regional and local scale information of geological, geochemical, geophysical, geothermal, and hydrogeological parameters, which are prerequisites for Basin modeling. In the modelling module, both one- and two-dimensional models are used for the simulation of sediment compaction and fluid flow, and for the reconstruction of burial history; a thermal inversion method is used for the reconstruction of thermal history; and a kinetic approach is used for the simulation of hydrocarbon generation from organic matter. Hubbert's method is used for the evaluation of hydro dynamic entrapment of hydrocarbons. The QBAS provides the explorationists with the past and present-day conditions in a sedimentary Basin in terms of geology, geothermics, hydrogeology, and hydrocarbon generation migration and accumulation. The QBAS wasmore » applied to the Peace River arch area (approximately 64,000 mi{sup 2}) in the Western Canada sedimentary Basin. Data from some 27,000 wells drilled in the area were processed and synthesized at Basin scale. The extensive data control allowed reliable parameter characterization and model calibrations. The results obtained show that the QBAS can be a useful tool to target the exploration for hydrocarbons in sedimentary Basins.« less
Knut Bjørlykke - One of the best experts on this subject based on the ideXlab platform.
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Seismic Stratigraphy, Sequence Stratigraphy and Basin Analysis
Petroleum Geoscience, 2020Co-Authors: Knut BjørlykkeAbstract:Seismic records are based on measurements of the time sound waves (seismic waves) take to travel through rock. The sound or signal is produced by explosives or compressed air (air guns). Rock is an elastic medium and the velocity of sound conveys a lot of information about the properties of the rock. Normal sound waves (P-waves) travel through both the solid phase, which for the most part consists of minerals or rock fragments, and the liquid or gas in the pores. Shear waves (S-waves) on the other hand can only go through the solid phase.
