Ilościowa ocena własności zbiornikowych profili wierceń drogą przetwarzania danych geofizycznych

Janusz Frydecki

Abstract


SYSTEM OF QUANTITATIVE EVALUATION OF RESERVOIR CAPACITIES OF BOREHOLE PROFILES BY GEOPHYSICAL DATA PROCESSING

Summary
A new system of well-Iogging data interpretation from the point of view of bitumen prospecting is described by use of block technique. In this model, the methodology of evaluation of basic interpretative interprendances, proposed by the present author, is utilized. The methodology takes into account only the geophysical borehole surveys of resistance, gamma-gamma, and neutron-gamma. Interpretative interdependences estimated in this-way are characterized by a remarkable accuracy and are independent of both a number of factors influencing surveys and of the conditions under which the surveys were performed. The system of interpretation discussed herein gives continuous profiling of the following parameters: claying of rock, Ci, porisity, Ø, bitumen content, Srg, and index of resources, ØSrg. Operations in this system are divided into four blocks. The first block has to prepare data for further processing; geophysical profiles are transformed to numerical form by the use of analogue-numerical converter, and specific resistance is calculated by the use of computer techniques. The second block has to prepare interpretative methodology; exponents of cohesiveness (cementation) and claying of rocks (m and α, respectively), and quotient of extremal "neutron porosities, wØ1, are estimated by correlative comparisons using sets of numerical data on resistance of rock (R, δ), intensity of natural gamma radiation and gamma radiation induced by neutrons, the latter being given in the form of relative differential intensity parameters (dIg and dIng, respectively). The third block is of interpretative character; computer calculates changes of such parameters as zailenie of rocks, porosity (according to electrometric and radiometric data), bitumen content and linear resources; taking place along the profile. These changes are estimated on the basis of electrometric and radiometric data transformed to numerical form and on the values of interpretative constants estimated in the IInd block and traced by computer at intervals corresponding to quantification step accepted. The fourth block has to present the results of interpretation in the form of print (all constant values and errors of estimation) and in the form of courves - profiles (results of interpretation); for this purpose, press and analogue-numerical converter are used. The interpretative system presented herein is universal and requires neither the knowledge of basic interpretative constants nor standardization of surveys. Errors in estimations are essentially dependent on size of populations used for statistical purposes only.

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