Oily water layer recognition method and device

Abstract

The invention discloses an oily water layer recognition method and device. The method comprises the following steps: analyzing main influencing factors of the well log response characteristic of a reservoir bed; reading well log response characteristic values of a well log interpretation layer corresponding to a test oil layer, and integrating and processing the well log response characteristic values according to the main influencing factors; calibrating the reservoir bed and a non-reservoir bed according to a physical property cross plot and a lithologic character cross plot; recognizing a typical hydrocarbon zone by utilizing an electrical property cross plot and the lithologic character cross plot; eliminating a water layer by using a resistivity ratio and the physical property cross plot; and judging whether an atypical oil layer and an oily water layer are the same layer by utilizing the apparent formation water resistivity and a lithologic character index cross plot. According to the method and device, conventional well log information is mainly utilized, cross plot techniques capable of reflecting cause factors are respectively adopted according to different causes so as to manufacture oily water layer recognition layouts, the main influencing factors of an upper grade are gradually weakened, and the main influencing factors of a next grade are highlighted, so that the oil layer, the oily water layer and the water layer and the like are respectively separated out from different cross plot layouts, thus realizing accurate recognition of the oily water layer under a bad ground condition.

Description

technical field [0001] The invention relates to the technical field of well logging evaluation in petroleum exploration, in particular to a method and device for identifying oil and water layers. Background technique [0002] Accurate identification of fluid properties is the core content of logging interpretation and evaluation of complex reservoirs, and it is also a key difficulty in logging interpretation and evaluation of complex reservoirs. With the continuous deepening of exploration and development, the geological conditions have become more and more complex. The complex geological conditions have bred various types of oil and gas layers, and subtle lithologic oil and gas reservoirs have been discovered continuously. With the further enrichment of oil testing data, there are not only easily identifiable typical oil layers in the discovered subtle lithologic reservoirs, but also atypical oil layers such as low resistivity and low contrast, accompanied by the emergence ...

AI Technical Summary

Problems solved by technology

If these reservoirs are placed on the conventional oil-water layer identification chart, it is found that some oil-gas layers are mixed with oil-water layers and even water layers in the conventional chart, which brings great difficulties to the interpretation of oil-water layers in well logs. Difficulty, resulting in misjudgment of oil and water layers

[0003] In the evaluation of oil and water layers in traditional methods, most of them use qualitative and semi-quantitative methods for discrimination, and often use a certain crossplot to assist in the identification of oil and water layers on the basis of qualitative identification. This method is relatively fast and simple. , but the scope of application is relatively narrow, it is only applicable to relatively single formations such as lithology and water, that is to say, it is only applicable to the identification of oil-water layers with relatively single origin

However, with the continuous deepening of exploration, it is difficult to encounter typical oil-water layers with a relatively single origin. The complex reservoirs encountered at present are often the result of multiple genetic factors, such as typical oil layers, atypical oil layers, and oil-water layers. It is difficult for traditional methods to make accurate and reasonable judgments on complex reservoir fluid identification.

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