Method for accurately evaluating targets containing oil gas in clastic rock basin

Abstract

The invention relates to a geophysical oil gas prospecting method which is capable of accurately evaluating targets containing oil gas in clastic rock basin and based on resistivity and induced polarization effect and comprises the specific steps of collecting data from a target area, processing the collected data on time domain and frequency domain, obtaining all-time apparent resistivity and phase curve, drawing a plane anomaly chart of polarization effect, and comparing the chart with the anomaly mode of an oil gas reservoir to determine oil-bearing trap as well as the position border of the oil reservoir and accurately recognize the favorable targets containing oil gas. The invention adopts a high-precision artificial source time frequency deep sounding method for sounding the solid change of electric properties from shallow to deep, including resistivity R and polarizability IP, thus being capable of accurately recognizing the favorable targets containing oil gas and further improving the success ratio of drilling.

Description

technical field [0001] The invention relates to geophysical oil and gas exploration technology, and is a method for accurately evaluating oil and gas targets in clastic rock basins based on high-precision electromagnetic exploration comprehensive research target resistivity and induced polarization effect integrated (IPR) oil and gas anomaly information. Background technique [0002] In oil and gas exploration, especially in the exploration of subtle oil and gas reservoirs, direct oil and gas detection methods have always been valued. The commonly used "bright spot" technology has been applied in seismic exploration to identify oil and gas targets, but this method is not very accurate in determining the seismic attributes of oil and gas, and the drilling success rate has not been significantly improved. The main reason is that oil and gas There is no obvious difference between the wave impedance with water and the wave impedance between filled with oil and gas and not filled...

AI Technical Summary

Problems solved by technology

As early as the middle of the last century, the induced polarization method was popular for oil prospecting. However, its main detection object is near-surface pyritization. It is believed that pyritization is related to the chimney effect formed by oil and gas penetration, and the pyritization zone The induced polarization effect is very strong. After decades of practice, it has been shown that induced polarization anomalies can be found above known oil and gas reservoirs, but the discovery of induced polarization anomalies may not necessarily lead to oil and gas drilling. There are various reasons for iron mineralization. The second is that the pyrite mineralization produced by oil and gas chimneys is too far away from the deep oil and gas reservoir itself. Due to the changeable underground geological structure, it is easy to cause deviation, so the prediction success rate is low

Although oil and gas detection methods with attractive commercial benefits have been widely valued, a convincing and effective method has not yet emerged

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