Complex petrophysical correction in the adaptation of geological hydrodynamic models (on the example of Visean pool of Gondyrev oil field)

The authors review a method of combined porosity and volume density correction in the process of modeling the distribution of reservoir permeability. Basing on petrophysical investigations of core samples from Bashkir fold deposits, an association between rock porosity, density and permeability has been analyzed. Significant correlation has been observed for the above mentioned parameters in porous collectors in contrast to reduced correlation for dense rocks and intervals of anomalously high poroperm characteristics. For terrigene porous collectors the authors propose a model of permeability assessment based on combined porosity and density correction. A modified model was developed for Visean pool of Gondyrev oil field, where collector permeability had been calculated as a function of rock porosity and density. The modified model has been compared to the conventional one; significant differences have been detected. In the modified version maximum permeability is associated with the southern part of the pool, whereas the conventional method points out the central part and predicts lowering permeability closer to the periphery. Geological model in the modified version is more homogenous than the conventional one and has no sharp peaks and valleys.  The calculations have been made that reproduce the history of field development for both permeability volumes. Authors demonstrate that total oil production obtained using the modified model has a much better correlation with the actual data. The best results from using suggested method apply to the initial stage of development due to better convergence of high-rate wells. On the whole, comparison of two methods shows that for the purposes of production history adaptation the modified model is significantly better than the conventional one. Hence, the method of density correction allows for better justification of differences in the lithology of Visean collectors, which ultimately results in higher accuracy of data on residual oil reserves in the deposit

Design of a Cherenkov telescope for the measurement of PCR composition above 1 PeV

The problem of PCR Composition at super high energies is far from being solved.EAS Cherenkov light spatial-angular distribution (CL SAD) can yield important information on the primary mass. In order to use EAS CL SAD for the study of PCR composition one needs a set of imaging telescopes with the appropriate parameters supported by a dense net of fast optical detectors capable of measuring EAS Cherenkov light pulses. On the basis of full Monte-Carlo simulations the pixel size of imaging telescopes is optimized for a specific observation level ∼4km which is typical for the Eastern Pamir mountains. Another goal to be pursued by the new detector array is the search for ultra high energy gamma ray sources and this is where the imaging technique can help a lot. A simple criterion is introduced to recognize gamma-quanta against the proton background and its performance, once again analyzed using simulated events, sets certain limits to the pixel size

Quark-antiquark potential with retardation and radiative contributions and the heavy quarkonium mass spectra

The charmonium and bottomonium mass spectra are calculated with the systematic account of all relativistic corrections of order v^2/c^2 and the one-loop radiative corrections. Special attention is paid to the contribution of the retardation effects to the spin-independent part of the quark-antiquark potential, and a general approach to accounting for retardation effects in the long-range (confining) part of the potential is presented. A good fit to available experimental data on the mass spectra is obtained.Comment: 20 pages, revtex, 2 Postscript figure

Collective modes for an array of magnetic dots in the vortex state

The dispersion relations for collective magnon modes for square-planar arrays of vortex-state magnetic dots, having closure magnetic flux are calculated. The array dots have no direct contact between each other, and the sole source of their interaction is the magnetic dipolar interaction. The magnon formalism using Bose operators along with translational symmetry of the lattice, with the knowledge of mode structure for the isolated dot, allows the diagonalization of the system Hamiltonian giving the dispersion relation. Arrays of vortex-state dots show a large variety of collective mode properties, such as positive or negative dispersion for different modes. For their description, not only dipolar interaction of effective magnetic dipoles, but non-dipolar terms common to higher multipole interaction in classical electrodynamics can be important. The dispersion relation is shown to be non-analytic as the value of the wavevector approaches zero for all dipolar active modes of the single dot. For vortex-state dots the interdot interaction is not weak, because, the dynamical part (in contrast to the static magnetization of the vortex state) dot does not contain the small parameter, the ratio of vortex core size to the dot radius. This interaction can lead to qualitative effects like the formation of modes of angular standing waves instead of modes with definite azimuthal number known for the insolated vortex state dot

Estimate of Radial Drilling Technology Efficiency for the Bashkir Operational Oilfields Objects of Perm Krai

The radial drilling technology efficiency for carbonate bashkir deposits of Perm Krai is considered. The geological structure of a productive part of bashkir layer is characterized by high degree of heterogeneity that promotes while drilling radial channels involvement in development additional interlayers that earlier was not drained. During the analysis the main geological process parameters affecting drilling technology efficiency were revealed. According to the dynamics of average daily oil production growth, palettes were built to forecast additional oil production as a result of radial drilling activities. Using the pallets, it is possible to predict the total additional oil production, well operating time with the effect of radial drilling and average daily oil production growth for each year. It was found that hydrochloric acid treatments performed on wells prior to radial drilling significantly reduce the effectiveness of radial drilling technology. For such wells, the value of the correction is statistically substantiated, which reduces the predictive estimate of the increase in oil production. A model was built to assess the increase in oil production in the first year after the event and an algorithm for calculating the total additional oil production was developed using linear discriminant analysis. For the resulting model, errors are calculated that are compared with the forecast efficiency of standard methods for oil-producing enterprises. This model shows a much more accurate correspondence of forecast results to actual technology application results. The probability of the event high efficiency increases significantly with a more detailed approach to the selection of wells for radial drilling. According to the forecast methodology, the technology’s efficiency was calculated and recommendations for its implementation for the wells of the Bashkir production objects were made in the interests of an oil-producing enterprise

Development of the methodology for evaluation of possibilities to determine reservoir types based on pressure build-up curves, geological and reservoir properties of the formation (case study of famen deposits of Ozernoe field)

One of the features of geological structure of Famen deposits of Ozernoe field is naturally fractured reservoir zones. Results of hydrodynamic study of wells on unsteady regime that were processed by Warren-Root model show that naturally fractured zones are oriented North-East. In order to prove existence of zones with different reservoirs statistical analysis was performed. Wherein geological and physical reservoir parameters (absolute elevation, thickness, permeability), several parameters of well performance (initial rate, productivity index) and litho-facial analysis (on cores and seismic) were additionally involved. In this paper interval probabilities that belong to naturally fractured and pore types are determined. Average values of varying intervals compared with interval probabilities. Based on that data pair correlation coefficients calculated and regression equations are built taking into account all studying parameters. Correlation between probability values and addition values are shown on graph. Graphs show probability of naturally fractured reservoir existence for different values of geological and technological parameters. To build the optimal forecast model using individual probability generalized probability were calculated. Scheme that reflect its change on the area of the deposit is built. Analysis show that wells belong to cavitation type determined base on pressure build-up curves in accordance with Warren-Root model is proved by obtained reservoir characteristics. The methodology for reservoir type determination has several advantages, can be implemented on the other fields that are similar in terms of geological structure and Oil and Gas province

Supersymmetry, quark confinement and the harmonic oscillator

We study some quantum systems described by noncanonical commutation relations formally expressed as [q,p]=ihbar(I + chi H), where H is the associated (harmonic oscillator-like) Hamiltonian of the system, and chi is a Hermitian (constant) operator, i.e. [H,chi]=0 . In passing, we also consider a simple (chi=0 canonical) model, in the framework of a relativistic Klein-Gordon-like wave equation.Comment: To be published in Journal of Physics A: Mathematical and Theoretical (2007