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Vol. 1 (1998 year), No. 1
Blyas E.A., Sereda A.-V.I.
Definition of Layered Medium Parameters on Borehole Seismic Observation Data by the Inverse Dynamic Task Method
The given paper deals with the problem of definition of the 1-D layered medium parameters from zero-offset VSP data. The solution of the problem has two steps: first, the acoustic parameters between the receivers are defined, then the impedance and absorption below the borehole bottom are forecasted. To solve the first problem the equalities have been obtained that correlate the wave spectra with the layered parameters. As soon as the number of equalities exceeds the number of unknown parameters the method of least squares is applied and the functional minimum is achieved with the help of conjugated gradients' method. The given work shows the principal opportunity to define the strata densities and velocities within the section between the receivers. In the second part the minimum meansquare non-coincidence between the medium reaction (that is determined after the first task solution) and the reflection coefficients for the set of non-elastic horizontal layers has been defined. The conjugated gradients' method is applied to achieve the numerical solution for both problems.
(in Russian, стр.14, fig. 3, tables. 0, ref 16, MS Word 95, MS Word 95 356 Kb)
Vol. 3 (2000 year), No. 1
Madatov A.G., Sereda A.-V.I.
The forward and inverse fluid dynamic problems of pore pressure prediction in sedimentary basins. 1. The theoretical aspect
In the paper the numerical solutions of the forward and inverse fluid dynamic problems for geological time scale have been considered in connection to excess pore pressure (EPP) prediction. The set of the most sensitive to the EPP evolution model parameters has been introduced. The forward problem of the fluid dynamics describes the compaction, HC-saturation and overpressure evolution vs. time and depth. The corresponding real well data set is used as an input for the inversion routine. The 1.5D reduction of the 3D inverse problem is developed. Such approach allows to achieve a more unique and stable inverse problem solution in reasonable computing time. The particular forward modelings for a homogeneous and layered medium are discussed. Applications of the approach to the EPP prediction are demonstrated on the practical examples.
(in Russian, стр.26, fig. 17, tables. 1, ref 29, MS Word 95, MS Word 95 2410 Kb)
Vol. 3 (2000 year), No. 2
Madatov A.G., Sereda A.-V.I.
The forward and inverse fluid dynamic problems of pore pressure prediction in sedimentary basins. 2. The practical aspect
The new method of the pore pressure prediction based on calibration of the basin model has been introduced. The theory of relevant forward and inverse problems solution was given in part one of the work published before in this issue. The review of the present day practice used for pore pressure prediction includes classical approaches (drill engineering) as well as modern approaches (basin modelling). The intrinsic non-uniqueness and noise stability of these methods have been analysed. The proper position of the new method among the existing one is determining. The concept has been illustrated by the practice example from the different sedimentary basins in the world (the Timano-Petchora oil and gas province, the North Sea, the Gulf of Mexico deep water). A description of the functionality of the relevant computer technology PANDAВ® has been given. The new technology capacities have been illustrated by the example of the quantitative pore pressure prediction before and during drilling (North Sea).
(in Russian, стр.16, fig. 15, tables. 1, ref 33, MS Word 95, MS Word 95 464 Kb)
Vol. 8 (2005 year), No. 1
Madatov A.G., Sereda A.-V.I.
The effective basin model concept and fast 3-D overpressure modelling in basin time scale
The approaches and background Earth model applicable for overpressure phenomenon investigation have been reviewed and systemised in the context of their applicability for pre-drill and while-drill prediction. An Effective Basin Model (EBM) concept has been introduced basing on the successive assumption simplifying full-scale basin modelling solutions. The EBM concept allows to incorporate 1-D and 2-D approaches to overpressure modelling in basin time scale. The relevant combine 3-D overpressure modelling operator has been designed. The operator has been capable to account for the main overpressuring mechanisms including 3-D pressure communication phenomena (centroid effect, dipping aquifer beds, pressure drop across the sealing faults, etc.). A stable implicit scheme has been developed for numerical pressure solutions. The scheme reveals absolute numerical stability within the practically important range of model parameters and combined grid properties. The benefits of the developed combined 3-D HD approach versus full scale 3-D regular grid solution in computing speed is estimated to be about NЧ(105-106) times for the Earth model cube based on about 109 cells. The applicability of the new fast 3-D modelling scheme has been tested on real geology settings and has been checked against real data. The Gulf of Mexico basin has been used for prototyping of the centroid effect on salt induced positive Cainozoic structures. The North Sea tectonics has been used for simulating overpressured fault sealed compartments.
(in English, стр.39, fig. 17, tables. 1, ref 113, Adobe PDF, Adobe PDF 2500 Kb)
Vol. 8 (2005 year), No. 1
Madatov A.G., Sereda A.-V.I.
A multi-well data inversion purpose-built for calibration of an effective basin model at overpressure prediction
The calibration of a basin scale hydro-dynamic model based on a multi-well data set has been introduced as an ill-posed inversion problem. Global and local optimisation strategies have been reviewed in this connection. In terms of the conditionally unique definition according to Tikhonov this problem is getting a range of locally unique e-equivalent solutions. All of them are a potentially resolve calibration problem. It is shown that for the multi-well case the relevant inverse problem solution can be arranged with additional criteria, which provide globalisation and lead to the area unique solution of the calibration problem. The approach, strategy and computation algorithm have been developed. The approach implies inverting of porosity - pore pressure data sets attached to the calibration well positions within the range of established and upscaled in the advance effective basin model. The numerical implementation has been checked on theoretical and real data examples. It reveals acceptable converging speed at practically justified data quality stop criterion. The application of the developed algorithm and numerical scheme for the 12-wells real data example (the North Sea) has been discussed in details.
(in English, стр.40, fig. 21, tables. 3, ref 88, Adobe PDF, Adobe PDF 1400 Kb)
Vol. 9 (2006 year), No. 3
Madatov A.G., Sereda A.-V.I.
The pre-drill and real time while drilling overpressure prediction based on Effective Basin Model concept
The problem of the pre-drill predictability of an overpressure phenomenon has been considered within the range of the Effective Basin Model concept. The inherent and numerical origins of the relevant prediction scenarios have been analysed. The solutions of numerical problems are attached in the form of the appendixes. The approach to the stabilisation of an inherent prediction error has been proposed. The real time correction of a pre-drill prediction in during drilling ("Look Ahead") mode has been considered in the context of the re-calibration or/and adjustment of a prediction model and a framework earth model respectively. The re-calibration problem has been introduced as an extension of the single-well data inversion problem. The corresponding ill-posed task has been formulated and the approach to getting its locally unique solution has been discussed. The relevant computer algorithm has been described in details. The applicability of the new approach and solution to the real time drilling conditions have been tested based on the speculative (North Sea area) and real data (Gulf of Mexico) examples. These tests confirm high converging speed of the updating routine and flexibility of the algorithm. The achieved results correspond to higher accuracy in comparison with available standard methods.
(in English, стр.28, fig. 8, tables. 3, ref 52, Adobe PDF, Adobe PDF 1610 Kb)
Vol. 9 (2006 year), No. 3
Blyas E.A., Sereda A.-V.I.
Determination of reflectivity coefficients of longitudinal and transverse waves using seismograms of longitudinal waves
A new approach for prestack inversion of NMO CDP gathers has been described. The main difference of conventional approach is that we combine two steps (AVO analysis and inversion) into one procedure. This approach has an advantage of using wavelet at the very beginning while the conventional approach utilizes wavelet only at the second stage. We also use the linearization approach for reflectivity inversion and reflectivity constraints, which allows us to reduce essentially cost of operations. This approach also gives us the possibility to take into account wavelet from the very beginning. The approach of taking into account priory information about density-velocity relations has been suggested. It also uses thick layer properties as constraints to stabilize the solution. Two modifications (in the time and frequency domain) have been suggested.
(in Russian, стр.14, fig. 8, tables. 1, ref 12, Adobe PDF, Adobe PDF 378 Kb)
Vol. 13 (2010 year), No. 4
Sereda A.-V.I.
Effective approach to numerical modeling of natural dynamic systems' characteristics
In the paper the methodology of effective numerical modeling of characteristics of natural dynamic systems has been discussed with reference to the problem of prediction of values of the investigated system target characteristic. This characteristic has the predicted values in the specified spatial area now. The methodology was successfully used for the problem of prediction of characteristics in sedimentary basins of the Earth.
(in Russian, стр.17, fig. 1, tables. 0, ref 14, Adobe PDF, Adobe PDF 0 Kb)
Vol. 16 (2013 year), No. 4
Zaporozhtsev I.F., Sereda A.-V.I.
Artificial neural networks application to temporal variability forecast of ocean surface characteristics spatial distribution
Ocean surface characteristics maps forecasting methodology has been suggested and implemented in a series of numerical experiments (with altimetry samples). Maps dataset has been considered to be a multivariate time series constructed with regularly gridded values. The methodology is based on the idea of multilayer perceptron application to the forecasting problem.
(in Russian, стр.7, fig. 3, tables. 2, ref 10, Adobe PDF, Adobe PDF 0 Kb)