Carbonatite fault-karst body contour detection method

Abstract

The invention discloses a method for detecting the contour of a carbonate rock fault-karst body, comprising: constructing a gradient structure tensor based on a three-dimensional seismic data body and calculating the eigenvalues ​​of the gradient structure tensor; determining the gradient structure according to the characteristics of the actual fault-karst body A smoothing parameter of the eigenvalue of the tensor, and using the smoothing parameter to smooth the eigenvalue of the gradient structure tensor; and using the horizontal well drilling time curve of the area related to the carbonate rock fault-karst body to calibrate the feature value, so as to obtain the outline of carbonate fault-karst bodies.

Description

technical field [0001] The invention relates to the field of prediction of carbonate rock fracture-cavity reservoirs, in particular to a method for detecting the contour of carbonate rock fault-karst bodies. Background technique [0002] Fault-karst body is a unique trap type of carbonate rocks, which is defined as: Affected by multi-stage structural compression, local brittle limestone fracture zones developed along deep fault zones, and multi-stage karst water seeps down along the faults Or the fracture-cavity system formed by dissolution in the fracture zone caused by the upwelling of local hydrothermal fluid, which is an irregular fault-controlled system formed under the sealing of the overlying marl, mudstone and other caprocks and the lateral tight limestone cover. Karst trap type, referred to as fault-karst trap. Existing carbonate rock fault-karst body detection technologies mainly focus on discontinuity detection attributes, among which fine coherence technology an...

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Problems solved by technology

However, the quality requirements for seismic data are relatively high, and good detection results can be obtained through high-quality data. The fine characterization of small faults is more accurate than fine coherence, but the characterization of large-scale fault outlines is not as good as fine coherence.

[0006] The existing carbonate fault-karst body detection technology still has the following problems: the attribute anomaly of the previous fault detection technology mainly reflects the boundary between the fault-karst body and the bedrock, and is mainly linear, but the carbonate rock fault-karst body has a certain width. According to the actual drilling analysis of multiple horizontal wells in the Tahe Oilfield, its development width can reach more than 100m-1000m, so the previous detection results are far from the concept of "body" in the fault-karst body; fine coherence technology and ant body tracking The fault detection technology is seriously affected by the events of 3D seismic data, and the attribute anomalies of intervals with strong event energy are more obvious, which does not conform to the development law of Ordovician faults, and cannot reflect the characteristics of fault-karst bodies in space; The detected shape is quite different from the actual geological body, and the attribute value is not calibratable

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