Issues of the journals for 2007 y.

Detailed 3D Seismic Studies of Crystalline Basement Structure and Reservoir Properties

(Graf S.Y. Averbukh A.G. Arapova A.I. Akhmetova E.R. Garnov A.V. Gritsenko A.M. Kirnos D.G. Oberemechenko I.S. )

This article highlights treatment of exploration data acquired from several areas outside Russia where search for oil within crystalline basement plays an essential role in the exploration and production of hydrocarbons. The internal structure of the crystalline basement has been studied by determining the energy and directions along which weak coherent reflections emanate and by following the episodic coherent reflections from structure-forming faults. 3D models have been built for hydrocarbon reservoirs showing reservoir surface reliefs, basement fault configurations and zones of different fracturing degrees. Wells drilled using our recommendations lapped fractured reservoirs and flowed commercial fluids from the prospects where earlier drilling failed.......

  • 2007  № 4, pp. 66-73

Problems of 3D Seismic Geometry Optimization

(Belousov A.V. Zacharyev Yu.M. Pleshkevich A.L. Musagaliyev M.Z. Tsypyshev N.N. )

The article focuses on the comparison of common 3D acquisition geometries - cross, brick, slant and zigzag. Distributions of source-to-receiver offsets and azimuths are analyzed, with effective fold maps under specified maximum offset constraints, and the effects of acquisition geometry on seismic data quality are discussed. The cross and brick acquisition patterns with one-roll source template are found to be preferable provided that the recorded shot density is fixed and the nominal fold of coverage is predetermined. The zigzag pattern and multi-roll source template were found to be worse. A technique of the accurate definition of a seismic survey the outer outline, based on ray tracing for structural maps construction accounting for spatial seismic migration was developed.......

  • 2007  № 4, pp. 74-81

Basic Factors Influencing Field Seismic Data Quality and Their Estimation

(Zacharyev Yu.M. Pleshkevich A.L. Ryaboshapko S.M. Musagaliyev M.Z. Tsypyshev N.N. Marutyan V.G. Ryabov V.Yu. )

Critical overview of techniques and methods, commonly used to assess vibroseis data quality for field trials and seismic surveying, is presented. A quantitative S/N ratio assessment technique is offered based on computing the ratio of mean amplitude to amplitude standard deviation along a reflection pattern. This technique was used to examine experimental vibroseis data. It was found that traditional vibroseis parameters subjected to selection, such as sweep length, sweep frequency band, the number of sweeps and initial sweep taper size, practically do not affect seismic data quality. The major factor found to affect the field data quality is source-receiver grouping. Practical group optimization techniques are proposed and examples are shown. Data quality monitoring and assessing technique for major production phases is considered. The authors conclude that more attention should be paid to monitoring and mapping not only amplitudes and frequencies of field records by their window estimates, but also to the recording instrument parameters present in logfiles and headers. Such control is to be used for proper subsequent amplitude-preserving processing.......

  • 2007  № 4, pp. 82-92

New Approach Towards Seismic Sources and Geophones Grouping while 3D Land Seismic

(Pleshkevich A.L. )

The theory of grouping the sources along with receivers is discussed. Joint linear orthogonal groups of sources and receivers in the cross-spread are shown to be equivalent to areal (2D) receiver groups, with a source being fixed. Such groups display characteristics for passing and suppressing seismic events close to those of azimuth-independent groups. It is examined how such groups affect both coherent noise - surface waves - and useful reflections. As the spatial frequency aliasing prevents 2D filtering of major noise - ground roll - by use of F-K filtering or Radon transform, the technique of grouping which provides 2D antialiasing filter capabilities for spatial frequencies continues to be an efficient tool of ensuring good quality of seismic data. Linear source-receiver groups are effective in operation only if they are orthogonal, and their length and the spacing between group elements (typically less than 5 m) are correctly determined.......

  • 2007  № 4, pp. 93-102

Techniques of Neural Network Modelling Aimed at Hydrocarbon Reserves Mapping

(Nekrasova L.A. Loginov D.V. Lavrik A.S. Yarlykov M.Y. )

One of the most important issues of integrated seismic and well data interpretation these days is generation of maps of basic reservoir characteristics: effective thickness and porosity. This article descripts new neural network modeling algorithms implemented in two oilfields, one in Western Siberia, and the other - in the Perm Region. In both fields 3D seismic survey has been performed. In case of the Perm oilfield not only the maps of reservoir parameters - H j and K were generated, but also the prediction porosity data cube was calculated.......

  • 2007  № 4, pp. 103-107