CN-121978773-A - Three-dimensional quantitative characterization method for delta front edge interlayer

CN121978773ACN 121978773 ACN121978773 ACN 121978773ACN-121978773-A

Abstract

The invention relates to the technical field of quantitative characterization, in particular to a three-dimensional quantitative characterization method for a delta leading edge interlayer, which adopts a seismic wave impedance inversion technology to obtain single sand plane distribution characteristics; the method comprises the steps of taking plane distribution characteristics of a single sand body as plane trend constraint, adopting a sequential indication simulation algorithm in Petrel to establish a sand shale rock facies three-dimensional model, carrying out three-dimensional configuration modeling on an underwater diversion river channel to obtain a configuration model, setting long variation in the direction of the river channel and short variation in the direction perpendicular to the river channel in the configuration model, and carrying out random simulation to obtain the interlayer three-dimensional distribution model. The method solves the problem of large uncertainty of the interlayer model built by the existing method, establishes a unique hierarchical step-by-step constraint modeling method, accurately clears the three-dimensional distribution rule of the interlayer in the layer, provides reliable basis for simulation and prediction of the residual oil of the high-water-content oilfield, and is a necessary prerequisite for later-stage excavation potential effect of the oilfield, development cost reduction and benefit development realization.

Inventors

LI SHENGYU

Assignees

重庆科技大学

Dates

Publication Date: 20260505
Application Date: 20260123

Claims (4)

1. The three-dimensional quantitative characterization method of the delta leading edge interlayer is characterized by comprising the following steps of: obtaining single sand body plane distribution characteristics by adopting a seismic wave impedance inversion technology; Taking the plane distribution characteristics of a single sand body as plane trend constraint, and establishing a sand shale lithofacies three-dimensional model in Petrel by adopting a sequential indication simulation algorithm; modeling the three-dimensional configuration of the underwater diversion river to obtain a configuration model; and setting a long variation range along the river direction and a short variation range perpendicular to the river direction in the configuration model, and performing random simulation to obtain the sandwich three-dimensional distribution model.
2. The three-dimensional quantitative characterization method of the delta leading edge interlayer according to claim 1, wherein in the modeling of the three-dimensional configuration of the underwater diversion river channel to obtain a configuration model, the method comprises the following steps: Generating a single sand body top surface structure diagram in a sand shale lithofacies model; Generating a single sand thickness map; setting a sandstone thickness threshold; Zero and smooth are given to the thickness outside the boundary, and an underwater diversion river sandstone equal-thickness map is generated; Subtracting the top surface structural diagram from the equal thickness diagram to obtain an underwater diversion river bottom surface structural diagram; And (3) assigning the grid between the top and the bottom surfaces as underwater diversion channel phase codes by using the Petrel 'Assign between surface' function, and establishing a three-dimensional configuration model with the top and the bottom protruding.
3. The delta leading edge interlayer three-dimensional quantitative characterization method according to claim 2, wherein in the setting of the sandstone thickness threshold, the thickness threshold is 2.6m.
4. The delta leading edge interlayer three-dimensional quantitative characterization method according to claim 1, wherein in the modeling of the three-dimensional configuration of an underwater diversion river channel to obtain a configuration model, the configuration model is used for predicting the distribution of residual oil of a high-water-content oilfield.

Description

Three-dimensional quantitative characterization method for delta front edge interlayer Technical Field The invention relates to the technical field of quantitative characterization, in particular to a three-dimensional quantitative characterization method for a delta leading edge interlayer. Background An interval refers to a thin layer of lithology units within a reservoir that is impermeable or low-permeable, typically sandwiched between active reservoirs (e.g., sandstone), and has a significant impact on the flow of fluids such as oil, water, etc. within the reservoir. The oil field is developed by water injection for decades, the inside of the reservoir is in a high water content state, but due to the interlayer in the layer, the in-layer seepage structure is complex, and in the water injection development process, a relatively enriched region of residual oil is easy to form at the development position of the interlayer, so that the three-dimensional spreading of the interlayer in the fine characterization layer is an important precondition for the development, prediction and full diving of the residual oil in the high water content oil field. The method is characterized in that in different deposition environments, the distribution forms and rules of interlayers are different, a side beach sand body developed on the convex side in a curved-flow river sand body is a main reservoir unit, the sand body is a plurality of sets of stacked sand bodies formed by lateral migration of the convex side of the curved-flow river, and a argillaceous interlayer is developed between the plurality of sets of stacked sand bodies in an inclined state. The sand bodies of the front edge of the delta are divided into far sand, front edge and underwater diversion channels, wherein the far sand and the front edge sand bodies are thinner, an interlayer does not develop in the layers, the sand bodies of the underwater diversion channels are thicker, and the interlayer develops in the layers, so that the interlayer in the sand bodies of the front edge of the delta mostly develops in the underwater diversion channels, and the morphology is controlled by the range and the length of the underwater diversion channels. Interlayer geologic modeling is a main technical means of three-dimensional quantitative characterization, more researches are carried out on the aspect of interlayer modeling of the curvelet at present, and the technology is mature, such as the China Petroleum university Wu Sheng and team research and development of the modeling software of the curvelet. The three-dimensional modeling technology of the interlayer in the delta front edge phase zone is still immature, and the current main method is to directly develop random simulation on the basis of well point interlayer identification, so that uncertainty of interlayer distribution is increased, and reliability of the later residual oil simulation is affected. Therefore, it is necessary to propose a delta leading edge interlayer modeling method to reduce uncertainty of three-dimensional quantitative characterization of the interlayer. Disclosure of Invention The invention aims to provide a three-dimensional quantitative characterization method for a delta front edge interlayer, which aims to solve the problems that the existing interlayer model does not take the three-dimensional configuration of an underwater diversion river channel as constraint, so that the three-dimensional distribution uncertainty is large, and the fine excavation requirement of residual oil of a high-water-content oilfield can not be met. In order to achieve the above purpose, the invention provides a three-dimensional quantitative characterization method of a delta leading edge interlayer, which comprises the following steps: obtaining single sand body plane distribution characteristics by adopting a seismic wave impedance inversion technology; Taking the plane distribution characteristics of a single sand body as plane trend constraint, and establishing a sand shale lithofacies three-dimensional model in Petrel by adopting a sequential indication simulation algorithm; modeling the three-dimensional configuration of the underwater diversion river to obtain a configuration model; and setting a long variation range along the river direction and a short variation range perpendicular to the river direction in the configuration model, and performing random simulation to obtain the sandwich three-dimensional distribution model. Wherein, in the modeling of the three-dimensional configuration of the underwater diversion river to obtain the configuration model, the method comprises the following steps: Generating a single sand body top surface structure diagram in a sand shale lithofacies model; Generating a single sand thickness map; setting a sandstone thickness threshold; Zero and smooth are given to the thickness outside the boundary, and an underwater diversion river sandstone equal-thickness map i