Method for quantitatively representing pressurization and pressure release strength of bending slip fault
阅读说明：本技术 一种定量表征弯曲走滑断层增压、释压强度的方法 (Method for quantitatively representing pressurization and pressure release strength of bending slip fault ) 是由 李伟 陈兴鹏 吴智平 张晓庆 幽鹏飞 于 2019-10-09 设计创作，主要内容包括：本发明公开了一种定量表征弯曲走滑断层增压、释压强度的方法,涉及石油地质勘探技术领域,包括以下步骤：S1：对弯曲走滑断层的三维数据体进行层位和走滑断层解释、建模,获得不同层位断层线；S2：获得区域走滑作用方位角；S3：对断层线进行重采样；S4：重采样坐标旋转至区域走滑方向获得新坐标值；S5：计算各点增压、释压强度。本发明以构造解析为基础,结合了统计学原理和力学分析,实现对弯曲走滑断层增压、释压强度的精确计算,计算方法简单,计算精确度高,操作方便,适用范围广,为油田勘探领域走滑断层研究提供方便。(The invention discloses a method for quantitatively representing the pressurization and pressure release strength of a bending slip fault, which relates to the technical field of petroleum geological exploration and comprises the following steps: s1: performing position and slip fault interpretation and modeling on the three-dimensional data body of the bending slip fault to obtain fault lines of different positions; s2: obtaining an azimuth angle of the region walking and sliding action; s3: resampling the fault line; s4: rotating the re-sampling coordinate to the region sliding direction to obtain a new coordinate value; s5: and calculating the pressurizing and pressure-releasing strength of each point. The invention is based on structural analysis, combines the statistical principle and the mechanical analysis, realizes the accurate calculation of the pressurization and pressure release intensity of the bending slip fault, has simple calculation method, high calculation accuracy, convenient operation and wide application range, and provides convenience for the research of the slip fault in the field of oil field exploration.)
1. A method for quantitatively representing the pressure increasing and releasing intensity of a bending slip fault is characterized by comprising the following steps:
s1: determining a walk-slip fault needing to analyze walk-slip pressurizing and pressure releasing strength, obtaining a three-dimensional seismic data volume of the bending walk-slip fault, carrying out horizon calibration according to well drilling and logging data, further carrying out horizon and fault interpretation, carrying out gridding processing on the interpreted horizon and fault data to obtain structural models of the bending walk-slip fault and different horizons, and obtaining fault lines of different horizons of the bending walk-slip fault by taking an intersection line of a hanging disc of the fault and the bending walk-slip fault as a fault line;
s2, obtaining the included angle α from the sliding direction of the region to the east direction by using the regional stress field data and the GPS data;
s3: resampling the fault line obtained in S1 (the sampling interval should be between 1m and 0.5 m), and obtaining X, Y coordinate values (X1, Y1, X2, Y2, X3, Y3, X4, Y4, … …, Xn-2, Yn-2, Xn-1, Yn-1, Xn, Yn) on the fault line;
s4: rotating the X coordinate axis to the region sliding direction to obtain the X 'and Y' values of the fault line in the new coordinate system,
X’＝X*cos(-α)-Y*sin(-α)；Y’＝X*sin(-α)+Y*cos(-α)；
s5, calculating the angle β (β 1, β 2, … …, β n-1 and β n) of the counterclockwise rotation of the normal direction of each point of the fault line to the sliding direction of the region,
β(i)＝atan2((y’(i+1)-y’(i-1)),(x’(i+1)-x’(i-1)))
and calculating to obtain cos β (i), which is the pressure increasing and releasing strength of the bending slip fault at the point, wherein the positive value represents the pressure increasing, the negative value represents the pressure releasing, and the absolute value represents the relative magnitude of the pressure increasing and releasing strength.
2. The method for quantitatively characterizing the pressurization and pressure release strength of the bending slip fault according to claim 1, wherein the cosine value of an included angle β formed by counterclockwise rotating the tangent direction of each point of the bending slip fault to the region slip direction is the pressurization strength of the point.
Technical Field
The invention relates to the technical field of petroleum geological exploration, in particular to a method for quantitatively representing pressurization and pressure release strength of a bending slip fault.
Background
The slip fault is structural deformation of the earth crust or rock ring under the action of shear stress with a displacement vector close to the horizontal, and comprises a slip main displacement zone and various accompanying or derived structures caused by the slip of the main displacement zone. In the process of forming the walk-slip fault, the walk-slip fault is not absolutely straight due to the reasons of lithological difference between two faults, local displacement obstruction, fault connection growth and the like, and is often in a weak bending form, and the bending phenomenon of the walk-slip fault is very common. The previous researches have considered that in the process of geologic body movement at two sides of a sliding fault, local pressure increasing areas and pressure releasing areas are formed due to bending of the sliding fault, and further different secondary fault combinations are developed at different positions of the bending sliding fault. Meanwhile, the dredging performance of the fault is further influenced by the pressurization and pressure release effects caused by the bending of the sliding fault, so that the lateral plugging property and the vertical dredging property of different positions of the sliding fault are obviously different, and further the migration and enrichment of oil and gas at different positions of the sliding fault are influenced. The previous research considers that the lateral blocking performance of a pressurization area of a bending slip fault is good, the vertical dredging capability is poor, oil gas is enriched in a deep layer, and the oil gas enrichment degree is higher when the pressurization strength is higher; the vertical dredging capability of the pressure release area is strong, the lateral plugging property is poor, oil gas is gathered in a shallow layer, and the larger the pressure release strength is, the higher the oil gas shallow layer gathering degree is.
Different positions of the bending slip fault have different pressurization and pressure release states and strengths, a great deal of research is carried out on the pressurization and pressure release strengths of the bending slip fault by the predecessors, and a plurality of methods for representing the pressurization and pressure release strengths are provided, wherein the methods mainly comprise a fault morphology method, a fault curvature method and a fault curvature method. The existing methods for representing the pressurization and pressure release strength of the bending slip fault have the following defects: (1) the fault morphology method can only qualitatively analyze the pressurization and pressure release parts of the bending slip fault and cannot quantitatively represent the pressurization or pressure release strength of different parts; (2) the fault tortuosity method can only quantitatively represent the strength of a certain pressurizing section or a certain pressure releasing section, and cannot accurately describe the strength of different positions in the certain pressurizing section or the certain pressure releasing section; (3) the curvature method cannot distinguish a pressure increasing section from a pressure releasing section, and a pressure increasing area and a pressure releasing area of the curvature method need to be analyzed through a fault morphology method. In addition, the three methods only consider the form of the fault, and neglect the influence of the region sliding direction on the pressurization and pressure release strength of the bending sliding fault.
Disclosure of Invention
The invention aims to solve the defects in the prior art, and provides a method for quantitatively representing the pressurization and pressure release strength of a bending slip fault.
A method for quantitatively representing the pressure increasing and releasing intensity of a bending slip fault comprises the following steps:
s1: determining a walk-slip fault needing to analyze walk-slip pressurizing and pressure releasing strength, obtaining a three-dimensional seismic data volume of the bending walk-slip fault, carrying out horizon calibration according to well drilling and logging data, further carrying out horizon and fault interpretation, carrying out gridding processing on the interpreted horizon and fault data to obtain structural models of the bending walk-slip fault and different horizons, and obtaining fault lines of different horizons of the bending walk-slip fault by taking an intersection line of a hanging disc of the fault and the bending walk-slip fault as a fault line;
s2, obtaining an included angle α from the clockwise rotation of the sliding direction of the region to the east direction according to the stress field data and the GPS data of the region;
s3: the fault line obtained in S1 is resampled (the sampling interval should be 1m-0.5 m), and X, Y coordinate values (X) on the fault line are obtained1，Y1，X2，Y2，X3，Y3，X4，Y4，……，Xn-2，Yn-2，Xn-1，Yn-1，Xn，Yn)；
S4: rotating the X coordinate axis to the region sliding direction to obtain the X 'and Y' values of the fault line in the new coordinate system,
X’＝X*cos(-α)-Y*sin(-α)；
Y’＝X*sin(-α)+Y*cos(-α)；
s5, calculating the angle β (β) of the normal direction of each point of the fault line rotating anticlockwise to the sliding direction of the area1，β2，……，βn-1，βn)，
β(i)＝atan2((y’(i+1)-y’(i-1)),(x’(i+1)-x’(i-1)))
And calculating to obtain cos β (i), which is the pressure increasing and releasing strength of the bending slip fault at the point, wherein the positive value represents the pressure increasing, the negative value represents the pressure releasing, and the absolute value represents the relative magnitude of the pressure increasing and releasing strength.
The invention provides a method for quantitatively representing the pressurization and pressure release strength of a bending slip fault, which is based on structural analysis and combines the statistical principle and mechanical analysis to realize the accurate calculation of the pressurization and pressure release strength of the bending slip fault.
Detailed Description
The invention is further explained below with reference to the specific embodiment of the No. 1 fault on the hollow Liaodong bay.
The invention provides a method for quantitatively representing the pressurization and pressure release strength of a bending slip fault, which comprises the following steps:
s1: obtaining a three-dimensional seismic data volume of a No. 1 fault in Liaoning, calibrating horizons in petril software, performing seismic interpretation on the horizons and the faults, obtaining an interpretation grid of a horizon and a break point of a bending and sliding fault, performing gridding processing on the interpretation grid, establishing a structural model of the horizon and the No. 1 fault in Liaoning, and obtaining fault lines of the No. 1 fault in Liaoning at different horizons;
s2, obtaining 34 degrees in the northeast of the depressed region of the Liaodong bay according to the regional stress field data and the GPS data, and obtaining α degrees in 56 degrees
S3: resampling the fault line obtained in the step S1 by using 3Dmove software, wherein the sampling interval is 1m, and obtaining X, Y coordinate values of each point on the fault line;
s4: rotating the X coordinate axis to the region sliding direction to obtain the X 'and Y' values of the fault line in the new coordinate system,
X’＝X*cos(-α)-Y*sin(-α)；
Y’＝X*sin(-α)+Y*cos(-α)；
the data were obtained as follows:
s5, calculating the angle β (β) of the normal direction of each point of the fault line rotating anticlockwise to the sliding direction of the region by using MATLAB software1，β2，……，βn-1，βn) And calculates cos β (i),
β(i)＝atan2((y’(i+1)-y’(i-1)),(x’(i+1)-x’(i-1)))
the value is the pressurizing and pressure releasing strength of the bending slip fault at the point, wherein a positive value represents pressurizing, a negative value represents pressure releasing, and an absolute value represents the relative magnitude of the pressurizing and pressure releasing strength, and the data are as follows:
in the invention, the fault adopts the No. 1 fault in Liaodong bay depressed in Bohai Bay basin.
The embodiment of the invention quantitatively represents the pressurizing and pressure-releasing strength of the T0 horizon of the No. 1 fault in Liaozhong. Compared with the pressurization and pressure release strengths represented by a fault morphology method, a curvature method and a bending method, the method provided by the invention is finer and more accurate.
The invention provides a method for quantitatively representing the pressurization and pressure release strength of a bending slip fault, which is based on structural analysis and combines statistical analysis with a statistical principle and mechanical analysis to realize accurate calculation of the pressurization and pressure release strength of the bending slip fault.
The above description is only for the preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art should be considered to be within the technical scope of the present invention, and the technical solutions and the inventive concepts thereof according to the present invention should be equivalent or changed within the scope of the present invention.