A Calculation Method for Multiple Mineral Components Based on Single Acoustic Old Log Series

Abstract

The invention discloses a multi-mineral component calculation method based on a single acoustic wave old logging series, which belongs to the field of geophysical exploration, and solves the problem that the old wells of the electric combination series in the prior art only have four curves of AC, GR and RT / RXO. Unable to meet the problem of solving complex mineral components. The calculation method of the present invention is suitable for well logging where carbon and lime do not coexist in the same lithology, and includes the following steps: S1. Rock core homing; S2. Calculating shale content Vsh; S3. Establishing an effective porosity model; S4. Calculate the effective porosity Φ; S5. Mark the carbonaceous layer FLAG_COAL; S6. Mark the gray matter layer FLAG_CA; S7. Calculate the content of gray matter, carbonaceous and sandstone according to the rock volume physical model. The present invention utilizes the principle of sedimentology that carbon and lime do not coexist in the same lithology, uses the distributed solution method to calculate the components of multi-mineral tight sandstone, and solves the problem of solving multi-minerals in single acoustic logging series, in Jinhua ‑The Xujiahe Formation in the Qiulin block has achieved good application results.

Description

technical field [0001] The invention relates to the field of geophysical exploration, belongs to logging data processing and evaluation technology, in particular to a multi-mineral component calculation method based on single acoustic wave old logging series. Background technique [0002] In the Upper Triassic Xujiahe Formation of the Sichuan Basin, a set of continental coal-measure tight clastic strata developed, which is a key formation for exploration and development in the Sichuan Basin. The Xujiahe Formation can be divided into six layers from bottom to top, of which the Xu 2 and Xu 4 members are the main target layers, and the rest of the layers also have oil and gas shows, which belong to low-porosity, ultra-low permeability tight reservoirs. Its reservoirs are typically characterized by complex lithology, including black shale, coal, mudstone, calcareous limestone and quartz sandstone. Microscopic data such as thin sections and electron microscopes show that the min...

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Problems solved by technology

[0004] For old wells with only gamma, sonic and resistivity curves, the above methods cannot directly meet the conditions for solving multi-mineral components

There are generally two methods for old wells: one is to treat the complex lithology as a simple sand-shale formation, but the accuracy of the logging interpretation results is low, which does not meet the requirements of fine logging interpretation; the other is based on If there are existing curves, reconstruct one or more pseudo-curves and then perform multi-mineral solution. This method has strong uncertainty

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