Identification method and system for complex basin edge super-stripped belt subtle trap boundary

Abstract

The invention discloses an identification method and system for a complex basin edge super-stripped belt subtle trap boundary. The identification method includes the following steps that firstly, structural features of a plane of unconformity are analyzed and defined with data of earthquakes, well drilling, well measuring, well logging and the like as the basis; secondly, a geologic model is designed, forward modeling of earthquake responses is conducted, instantaneous phase earthquake attributes are extracted along the stratum, and a stratum super-stripped line for earthquake identification is depicted; thirdly, a geologic model capable of reflecting the super-stripped concept of the stratum is selected, earthquake forward modeling is conducted, and main factors affecting an error distance are defined; fourthly, an error distance formula under the stratum super-stripped condition is established; fifthly, the stratum subtle strap boundary is described according to the stratum super-stripped line and the error distance for the earthquake attribute identification. According to the identification method and system for the complex basin edge super-stripped belt subtle trap boundary, the position of the super-stripped line for earthquake identification can be accurately described, the subtle trap boundary is quantitatively identified based on an extrapolation formula built through multi-model forward modeling, an oil-gas accumulation boundary can be easily and accurately determined, and the oil exploration risk can be effectively lowered.

Description

technical field [0001] The invention belongs to the field of oil and gas geological exploration, and in particular relates to an identification method and an identification system for a hidden trap boundary of a complex basin edge overstripping zone based on an overstripping point extrapolation technology. Background technique [0002] The stratigraphic overlapping point is the boundary point between the sedimentary area of ​​the basin and the eroded or non-sedimentary area outside the basin. Due to the influence of structural uplift, sea level drop or the combination of the two, the stratigraphic overlapping point of the basin margin often suffers from different degrees of denudation. There are two situations in the distribution of the original sedimentary thickness of the strata on the sedimentary dip profile. The first situation is common in depression basins, increasing sequentially from the edge of the basin to the center of the basin; the second situation is common in p...

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Problems solved by technology

However, this method does not consider the stratum thickness that can be identified by the resolution of seismic data. The premise of its extrapolation is to extrapolate according to the change trend of the seismic reflection event. The selection of the extrapolation starting point is often different from person to person. In areas with complex relationships, it is difficult to identify unconformities. There is no conclusion on how to determine the dip angle of formations and unconformities, and there is no discussion on how to determine denudation lines. Therefore, this method still has certain subjectivity and limitations.

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