Detailed correlation medium and small breakpoint identification method for delta front deposit

Abstract

The invention provides a detailed correlation medium and small breakpoint identification method for delta front deposit. The detailed correlation medium and small breakpoint identification method for delta front deposit comprises the following steps: determining a source direction serving as a comparison direction, and comparing each well in sequence according to the comparison direction; selecting a well which is relatively closer to a source as a standard well, and judging whether a research well has stratum loss or not by comprehensively utilizing multiple logging curves; when the research well has stratum loss according to judgment, judging whether the stratum loss part of the research well and a corresponding part of the standard well belong to the same element or not; when the stratum loss part and the corresponding part belong to the same element according to judgment, determining that tiny geological information about the loss of the research well is breakage caused by a geological fault. According to the detailed correlation medium and small breakpoint identification method for delta front deposit, small breakpoints of which the breakage thicknesses are 2-5 meters are identified effectively during detailed correlation, a deposit rule is combined closely, the objectivity is emphasized, the subjectivity is overcome, the scientificity is improved remarkably, and the operation steps are clear and reasonable.

Description

technical field [0001] The invention relates to the field of sublayer correlation research, in particular to a method for identifying small and medium breakpoints in delta front sedimentary sublayer correlation. Background technique [0002] Delta front deposits are an important type of reservoir deposition in continental oilfields in my country. Therefore, the study of sublayer correlation of this type of reservoirs has always been an important basic work for oilfield development geology. Previous studies used the correlation method of "cycle correlation, hierarchical control, and different treatment of different facies zones". This method can better realize the isochronous correlation division of small layers, and has always been an important stratigraphic correlation method in continental oilfields in my country. However, since many oilfields are typical complex fault-block oilfields with many faults, small fault blocks and low-sequence faults, a well often encounters mul...

AI Technical Summary

Problems solved by technology

When the thickness of the fault is large, the breakpoint can be easily identified by comparison, but it is difficult to identify such a "small breakpoint" when the thickness of the fault is small, especially when it is below 5m

The main reason is that the deposition of continental strata changes quickly, and it is often difficult to judge whether the lack of tiny geological information is caused by small breakpoints or sedimentary changes.

The previous methods are mainly empirical methods, which are highly subjective and lack clear, reliable and scientific operation steps.

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