Reservoir identification method through element leaching indexes

Abstract

The invention discloses a reservoir identification method through element leaching indexes. The reservoir identification method comprises the following steps that a, element logging data corresponding to well section characteristic elements are selected; b, the SAF index and the SAFF index are calculated through the element logging data; c, the SAF index and the SAFF index are combined to establish an ELF cross plot; and d, the developmental condition of a reservoir is distinguished according to the response characteristics of the ELF cross plot. According to the reservoir identification method through the element leaching indexes, the advantages that logging while-drilling explanation is timely, efficient, authentic and rapid can be played, and the element logging data are processed through the mathematical method in order to achieve the target of reservoir identification during while drilling.

Description

technical field [0001] The invention relates to an interpretation and evaluation method for identifying reservoirs by using element logging data, and belongs to the application field of drilling-while-drilling data processing technology in the field of oil and gas industry exploration and development in the electromechanical field. Background technique [0002] Element mud logging is an emerging on-site analysis-while-drilling technique for mud logging. Its principle is to use high-potential X-rays to bombard the sample to cause vacancies to escape from the electrons outside the nucleus. X-rays with different energies are emitted according to the atomic number. The type and relative content of the sample elements are output by analyzing the energy of X-ray fluorescence. [0003] In recent years, it has been widely used in various fields. After a lot of research, the application and existing problems of element logging are explained as follows: [0004] 1. Reservoir identif...

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Problems solved by technology

Previous studies on elemental mud logging mainly focused on the identification of weathering crust, and there were no related technologies and reports on identifying reservoirs.

[0005] 2. Limitations of the existing interpretation technology: At present, Sinopec Group has an interpretation technology that uses element logging to identify physical properties. It uses fitting technology to establish a linear relationship between some elements and porosity parameters to calculate reservoir physical parameters, but its limitations The main performances are as follows: First, the discriminant analysis method has high requirements for calibration samples; second, the empirical statistical method is difficult to be popularized and applied in the exploration area with insufficient data. In addition, China National Petroleum Corporation also has similar technology, and the relevant indicators are close to those of Sinopec. no longer repeat

[0006] 3. Error characteristics of data sources: Reservoir identification technology based on element logging technology must fully consider the limitations of this technology. First, the data comes from cuttings returned from the bottom of the well. The validity of the data has a great impact. Secondly, because the critical excitation potential required for X-ray excitation of elements is proportional to the atomic weight, therefore, using constant voltage excitation under the current technical conditions may lead to the analysis of some elements with too low and too high atomic numbers. Accuracy suffers to some extent

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