Method for improving computing precision of rock fracture parameters

Abstract

The invention provides a method for improving computing the precision of rock fracture parameters, for performance evaluation and drilling of oil and gas reservoirs in oil exploration. The method comprises the following steps of: working out fracture directions and the fracture density by using more than two seismic attributes for uniformization treatment, computing the coefficients of rank correlation of the fracture directions in pairs to obtain the rank correlation and fracture density coefficient, and if the correlation coefficient is over 0.9, determining that the density or direction is the density or direction with highest precision; otherwise, computing absolute error values of the fracture directions corresponding to all attributes at the well point, and sorting the absolute error values according to an order from small to large; computing the coefficients of rank correlation of the fracture density corresponding to the attributes and the coherency attributes, sorting the coefficients of rank correlation according to an order from small to large, and finally computing the fracture directions with the highest precision. The method can ensure the leading position of basic attributes and correct the final result to varying degrees according to the data quality so as to improve the forecast precision by using the existing information.

Description

Technical field [0001] The invention relates to oil and natural gas exploration and development technology, in particular to a method for improving the calculation accuracy of rock fracture parameters which can provide parameters for the performance evaluation of oil and gas reservoirs, the calculation of reserves, and the drilling. Background technique [0002] In the oil and natural gas exploration and development industry, the layer where underground oil and gas accumulate is called the reservoir, and the sealing layer on the reservoir that prevents the oil from escaping upward is called the caprock. Fractures in the reservoir can increase the connectivity between pores in the reservoir, increase the permeability of the reservoir, and at the same time expand the storage space; the more developed the fractures, the better the storage performance. Cracks in the caprock will cause oil and gas to escape; the more developed the cracks, the worse the oil and gas sealing ability. [0...

AI Technical Summary

Problems solved by technology

[0006] The first type of method is mature in theory, simple and fast in operation, and can correctly predict the macroscopic law of fracture development, but cannot predict the direction of fracture development

The second type of method can predict the direction and density of fracture development on each seismic bin in theory, which has great advantages; Influenced by the errors generated and accumulated in the process of collection and processing, the reliability of the prediction results is unstable, and the results obtained from different data are quite different; so far, it is still in the stage of active exploration and research, and there is no large-scale application in industrial production

The shortcoming of this method is that one-sidedly emphasizes the ability of a certain attribute to reflect anisotropy, while ignoring various errors that are inevitable in the collection and processing process due to various assumptions and actual production conditions. , and did not make use of other information to make up for these errors, so it is possible to lose the opportunity to further improve the prediction accuracy

However, all the above-mentioned articles analyze and study various attributes one by one, and do not propose a technical solution for predicting and correcting using multiple information at the same time.

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