Method for calculating filling degrees of carbonate fracture-cave reservoir

Abstract

The invention discloses a method for calculating filling degrees of a carbonate fracture-cave reservoir, and the method is used for seismic attribute (such as amplitude) exploration. The method comprises steps of extracting seismic attribute plane diagrams of a research zone along seismic interpretation horizons; acquiring filler and filling degree information in the carbonate fracture-cave reservoir; selecting sample points having similar fillers but different filling degrees and positioning geodetic coordinates of the sample points; determining the effective sample points and calculating seismic attribute differentials between the effective sample points; performing cross analysis on sandy filler filling amount differentials and the seismic attribute differentials between the effective sample points so as to acquire a function relation; calculating the filling degree of each effective sample point in the fracture-cave reservoir, and obtaining an operation relation between the seismic attribute differentials and the sandy filler filling degrees according to the function relation and the filling degrees; selecting seismic reflection zones having beaded reflection on seismic sections; and finally calculating the filling degrees of the fracture-cave reservoir in the seismic reflection zones through the operation relation.

Description

technical field [0001] The invention relates to the technical field of geophysics, in particular to a method for calculating the filling degree of fracture-cavity reservoirs in carbonate rocks in seismic amplitude type attribute exploration. Background technique [0002] Seismic attributes refer to those special measurement values ​​related to the geometry, kinematics and statistical characteristics of seismic waves derived from pre-stack or post-stack seismic data through mathematical transformation. Depending on the algorithm, different attributes have different geological significance, and some attribute values ​​may be good at revealing lithological changes that are not easy to detect, while others can be directly used for hydrocarbon detection. [0003] The research and use of seismic attributes began in the 1970s, and the earliest ones were mainly instantaneous attributes based on amplitude, which were used to directly indicate the distribution of oil and gas and diffe...

AI Technical Summary

Problems solved by technology

However, traditional exploration techniques are not easy to detect changes in lithology, and cannot be directly used for hydrocarbon detection. Finding remaining oil and improving recovery have become the focus and difficulty of oilfield development, and are also the key to stable production.

[0005] At present, the methods for calculating porosity in carbonate fracture-cavity reservoirs known at home and abroad are generally the average porosity method, which does not take into account the differences in filling degrees in different fracture-cavity reservoirs. Large errors are caused to the calculation of the actual underground resources, which in turn affects the actual deployment of oilfield exploration and development work, resulting in economic losses

Images