CN-117270037-B - Oil-gas migration prediction method based on seepage structure fine description

CN117270037BCN 117270037 BCN117270037 BCN 117270037BCN-117270037-B

Abstract

The invention provides an oil-gas migration prediction method based on seepage structure fine description. The method comprises the steps of carrying out local maximization treatment on the distribution probability of the cracks through the earthquake azimuth, and simultaneously restraining the earthquake inclination to obtain the maximum probability inclination of the cracks, further finely describing the distribution of an internal seepage structure in the reservoir, then calculating seepage channels of oil and gas migration and a high-probability oil and gas gathering area by combining the oil and gas probability of the reservoir, and determining the layout position of a well to be drilled. The method has very important significance for fine description of the internal seepage structure of the buried hill fracture reservoir and evaluation of oil and gas migration, and can effectively guide exploration and development of the buried hill fracture type oil and gas reservoir.

Inventors

LV BINGNAN
CHEN XUEHUA
WU HAOJIE
ZHAO QINGWEI
Qie Cuncai
JIANG WEI

Assignees

成都理工大学

Dates

Publication Date: 20260508
Application Date: 20230922

Claims (1)

1. The oil-gas migration prediction method based on seepage structure fine description is characterized by mainly comprising the following steps of: (1) Inputting an original seismic data body U, and establishing a crack distribution probability body S, an earthquake dip angle body D and an earthquake azimuth angle body A of the U; (2) Setting a rectangular window function W with a side length d, wherein the coordinates of the central point of the rectangular window function W are (x 0 ,y 0 ,t 0 ), and x 0 、y 0 and t 0 respectively represent the coordinate positions of the central point in the x, y and t directions, and the seismic azimuth angle of the central point The earthquake dip angle θ=d (x 0 ,y 0 ,t 0 ), the earthquake dip angle body D is constrained by the earthquake azimuth angle body a and the crack distribution probability body S, the crack distribution position is delineated, and the crack maximum probability dip angle D SA （x 0 ,y 0 ,t 0 ) is determined according to the following formula: in the formula, And Respectively represent azimuth angles of the center points Coordinates of the sample points in the x, y and t directions, A probability value representing the crack distribution at the point, Null indicates null processing; (3) Moving the rectangular window function W in the x, y and t directions respectively until the calculation of the crack maximum probability dip angle of the whole original seismic data body U is completed, and obtaining a crack maximum probability dip angle body D SA ; (4) Performing seismic instantaneous spectrum energy decomposition on U by using a high-precision seismic signal time-frequency analysis method: Wherein ω is angular frequency, U (ω) is instantaneous spectrum of the seismic data U, and M represents the result of energy decomposition of the instantaneous spectrum of the seismic data; (5) Determining dominant frequency omega 0 of the seismic data U, and calculating the oil and gas probability G of a reservoir by using the result M of the instantaneous spectrum energy decomposition of the seismic: G=ω 0 M 2 , (6) And calculating a seepage channel for oil and gas migration and a high-probability oil and gas-containing gathering area by using the data of the maximum probability earthquake inclination angle body D SA of the crack and the oil and gas-containing probability G of the reservoir, and determining the layout position to be drilled by using the high-probability oil and gas-containing gathering area.

Description

Oil-gas migration prediction method based on seepage structure fine description Technical Field The invention belongs to the field of oil and gas exploration and development, and particularly relates to an oil and gas migration prediction method based on seepage structure fine description. Background The ancient buried hill fracture hydrocarbon reservoir has great potential for oil and gas exploration and development, but due to complex geological structure, strong heterogeneity of the reservoir, disordered phase of seismic reflection and poor continuity, and through multi-period evolution, reservoir space of the reservoir is various, and great challenges are brought to determining reservoir fluid transformation, oil and gas migration process and the like. On the other hand, engineering implementation of subsurface reservoir exploration also faces many challenges due to the influence of complex geological conditions, and various difficulties result in high drilling costs. Therefore, under complex geological conditions, in order to realize breakthrough of deep subsurface mountain exploration, a prediction technology of a subsurface mountain complex reservoir seepage structure needs to be perfected, and the prediction technology comprises geological model construction required by geological engineering construction of the subsurface mountain exploration, so that the integration of exploration development engineering and earthquake geology is realized. In exploration and development, due to complex geological structure and low quality of seismic data, the conventional seismic attributes are utilized to identify the existence of multiple solutions and uncertainties of cracks and fractures in the submarine mountain, and the prediction of the oil gas activity in the submarine mountain is difficult to effectively guide. In order to determine the law of oil and gas migration, the seepage structure characteristics inside the submarine mountain need to be described finely, so that a more definite technical support is provided for the prediction of oil and gas further migration and the drilling engineering design construction in oil and gas development, the effective oil and gas reservoir exploration and drilling development operation is guided, and a foundation is laid for safe, efficient and high-quality implementation of oil and gas development. The invention realizes the fine description of the internal seepage structure in the complex reservoir, provides more reliable support for determining the migration of the oil and gas in the stratum, and has very important application value. Disclosure of Invention In order to realize fine description of a seepage structure in a reservoir and prediction of an oil and gas migration rule, the invention provides an oil and gas migration prediction method based on fine description of the seepage structure, which is used for carrying out reverse constraint on seismic dip angle information through fracture probability, defining seepage structure characteristics, and then carrying out combined interpretation with a reservoir gas-containing result obtained by calculation so as to predict the oil and gas migration rule and guide reservoir evaluation and oil and gas efficient exploration and development. The invention discloses an oil-gas migration prediction method based on seepage structure fine description, which comprises the following steps of: (1) Inputting an original seismic data body U, and establishing a crack distribution probability body S, an earthquake dip angle body D and an earthquake azimuth angle body A of the U; (2) Setting a rectangular window function W with a side length d, wherein the coordinates of the central point of the rectangular window function W are (x 0,y0,t0), and x 0、y0 and t 0 respectively represent the coordinate positions of the central point in the x, y and t directions, and the seismic azimuth angle of the central point The earthquake dip angle θ=d (x 0,y0,t0), the earthquake dip angle body D is constrained by the earthquake azimuth angle body a and the crack distribution probability body S, the crack distribution position is delineated, and the crack maximum probability dip angle D SA(x0,y0,t0) is determined according to the following formula: in the formula, AndRespectively represent azimuth angles of the center pointsCoordinates of the sample points in the x, y and t directions,A probability value representing the crack distribution at the point,Null indicates null processing; (3) Moving the rectangular window function W in the x direction, the y direction and the t direction respectively until the calculation of the maximum probability dip angle of the crack of the whole original seismic data body U is completed, and obtaining a maximum probability dip angle body D SA of the crack; (4) Performing seismic instantaneous spectrum energy decomposition on U by using a high-precision seismic signal time-frequency analysis method: Wherein ω is angu