CN-116879945-B - Stratum pinch-out line prediction method based on geological-seismic combination

CN116879945BCN 116879945 BCN116879945 BCN 116879945BCN-116879945-B

Abstract

The invention relates to a stratum pinch-out line prediction method based on geological-seismic combination, which comprises the following steps of collecting data, selecting lithology-electrical property mark layers according to logging electrical curves and cores, establishing lithology-electrical property relations, determining development characteristics and interface identification marks, establishing a regional continuous well section, defining a stratum spreading rule of a stratum sequence, constructing a stratum transverse change geological mode, drawing a stratum pinch-out trend line of the section based on the three-dimensional seismic work area and the regional continuous well section, refining the pinch-out line position by adopting a stratum thickness method, defining stratum pinch-out line geological characteristics, calculating an included angle and an included angle average value of the pinch-out trend line at a pinch-out point by utilizing single well stratum thickness and inter-well horizontal distance, calculating and determining the position of the pinch-out line by adopting an included angle extrapolation method, identifying and finely describing the pinch-out point by adopting a seismic phase rotation processing method, comprehensively predicting the pinch-out trend line position based on the determined pinch-out trend, and defining the spreading range of the stratum pinch-out line by combining the analysis result.

Inventors

XIONG LIANG
SONG XIAOBO
LONG KE
CAI ZUOHUA
LIU YONG
Su Chengpeng

Assignees

中国石油化工股份有限公司
中国石油化工股份有限公司西南油气分公司

Dates

Publication Date: 20260512
Application Date: 20230620

Claims (10)

1. The stratum pinch-out line prediction method based on geological-seismic combination is characterized by comprising the following steps of: S1, collecting geological background, drilling and logging, core, open-air outcrop section and seismic data; S2, selecting a lithology-electrical property mark layer according to the logging electrical property curve and the rock core, and establishing lithology-electrical property relation by adopting a lithology-logging curve comparison method; s3, based on a study area drilling and logging work area, establishing an area well-connecting section according to a geological background of the study area and an open-air outcrop section, defining a spreading rule of a stratum of an interval in the transverse direction, and constructing a stratum transverse change geological mode; S4, based on the three-dimensional earthquake work area, combining the area well connection section, drawing a section stratum pinch-out trend line, adopting stratum thickness legal prediction stratum distribution range, combining the known distance between the well drilling and the tip pinch-out point and the earthquake section characteristic, further refining the pinch-out line position of the research area, and defining the geological characteristics of the stratum pinch-out line; s5, calculating an included angle theta n of the pinch-out trend line at the pinch-out point by using the thickness of the single well stratum and the horizontal distance between wells, and obtaining an average value theta of the included angles of the pinch-out line; s6, selecting drilled positions of adjacent pinch-out lines, determining the bottom boundary depth of a target layer, and calculating and determining the positions of the pinch-out lines according to the average value theta of the pinch-out line included angles through a pinch-out line angle extrapolation method; S7, selecting a piece of three-dimensional seismic data, and identifying and finely describing the pinch-out points of the stratum on the instantaneous phase section of the earthquake by adopting an earthquake phase rotation processing method; S8, based on the determined pinch-out line position, combining with the geological mode and geological knowledge of the stratum transverse change, comprehensively predicting the stratum pinch-out line by adopting a geological-seismic combination technical means according to analysis results of a stratum thickness method, a pinch-out line angle extrapolation method and a seismic phase rotation processing method, and determining the spreading range of the stratum pinch-out line.
2. The geological-seismic combination-based stratigraphic pinch-out line prediction method of claim 1, wherein in S1, the study object attributes are determined based on the collection of data from the study area.
3. The geological-seismic combination-based stratum pinch-out line prediction method according to claim 1, wherein in the step S2, after lithology-electrical relation is established, rock structure characteristics and deposit indication significance of a rock core are analyzed, four-level sequence lithology combination types are determined, and development characteristics and interface identification marks of different types of four-level sequence on the rock core and a logging curve are summarized.
4. The geological-seismic combination-based stratum pinch-out line prediction method of claim 1, wherein in the S3, based on a study area drilling and logging area, an area well connection section is established according to a study area geological background and a field outcrop section, a four-level layer sequence is subjected to transverse comparison analysis by adopting a spectrum analysis method in combination with a high-frequency layer sequence identification mark, the distribution rule of a layer sequence stratum in the transverse direction is clarified, the layer sequence stratum isochronous interface is determined, and then a stratum transverse change geological mode is constructed.
5. The geological-seismic combination-based stratum pinch-out line prediction method of claim 1, wherein in S4, based on a three-dimensional seismic work area and a combined area well connection section, the method is characterized in that the synthesized record calibration of the existing well is utilized, the middle-strong peak seismic reflection characteristics of the bottom boundary are used as marks, horizon tracking and interpretation are carried out, the stratum bottom boundary of the adjacent well positions is used as a base point, stratum thickness changes are used as the basis, a stratum pinch-out trend line of the section is drawn, the stratum distribution range is predicted quantitatively by the stratum thickness, the single well stratum bottom boundary vertical depth and the inter-well horizontal distance are determined, the pinch-out line position of a research area is further refined by combining the known well distance from the tip pinch-out point and the seismic section characteristics, and the geological characteristics of the stratum pinch-out line are defined.
6. The geological-seismic combination-based stratum pinch-out line prediction method according to claim 1, wherein in S5, according to stratum pinch-out trend lines and geological characteristics of stratum pinch-out lines, a stratum leveling technology is selected, an angle thetan of the pinch-out trend lines at pinch-out points is calculated by using single-well stratum thickness and inter-well horizontal distance and an inverse trigonometric function formula, an average value theta of the pinch-out line angles is obtained by using an average formula, and the average value theta is determined as a standard value of regional pinch-out line angles.
7. The geological-seismic combination-based stratum pinch-out line prediction method of claim 1, wherein in S6, the drilled positions of adjacent pinch-out lines are selected, the bottom boundary depth of a target layer is determined, a pinch-out line angle extrapolation method is selected, and the positions of the pinch-out lines are quantitatively determined by utilizing a trigonometric function formula.
8. The stratum pinch-out line prediction method based on geological-seismic combination according to claim 1 is characterized in that in S7, a two-dimensional seismic section based on horizon interpretation is processed by a frequency expansion processing method, development characteristics of the pinch-out line on a transverse section are analyzed, a piece of three-dimensional seismic data is selected by taking the data as a datum line, pinch-out points of a stratum are identified and finely delineated on an earthquake instantaneous phase section by a 90-degree phase rotation processing method, and mutual verification and correction are performed by combining quantitative recovery of pinch-out line positions.
9. The method for predicting the stratum pinch-out line based on geological-seismic combination according to claim 1, wherein in the step S8, based on the determined pinch-out line position, the stratum transverse change geological mode and geological knowledge are combined, and according to analysis results of a stratum thickness method, a pinch-out line included angle quantitative extrapolation method and a seismic phase attribute method, comprehensive prediction is carried out on the stratum pinch-out line by adopting a geological-seismic combination technical means, so that the spread range of the stratum pinch-out line is further defined.
10. The use of a geological-seismic combination-based formation pinch-out line prediction method according to claim 1 in carbonate formation pinch-out line prediction.

Description

Stratum pinch-out line prediction method based on geological-seismic combination Technical Field The invention belongs to the technical field of petroleum exploration and development, and particularly relates to a stratum pinch-out line prediction method based on geological-seismic combination. In particular to the identification and prediction of the deep carbonate pinch-out line, and has important guiding significance for petroleum and gas exploration and exploitation. Background In recent years, a three-fold thunderport slope group in a Chuan-xi sea phase is a hot spot and key field of natural gas exploration, a batch of structure gas reservoirs and structure-stratum gas reservoirs with certain reserve size are discovered successively, a great breakthrough of the Chuan-xi Lei Kou slope group tidal flat-phase carbonate natural gas exploration is obtained, and the fact that structure-stratum trap can be effectively hidden is confirmed, so that the accurate identification and depiction of stratum pinch-out lines of the gas reservoirs are particularly important. The structure-stratum gas reservoir often has the characteristics of large burial depth of a target layer, rapid lithology combination change and uncertain thickness change trend, and is influenced by the adverse factors of low main frequency of seismic data, less drilling data and the like, so that the identification difficulty of stratum pinch-out lines is high. In particular, the deep carbonate rock stratum structure with the burial depth of more than 4500 meters has the problems that the acquisition of the seismic data is difficult due to the combined change characteristics of the burial depth and lithology, and the analysis is difficult even if the seismic data is acquired. In addition, unlike clastic reservoirs, the development of carbonate reservoirs is not limited by depth, deep carbonates lack preset judgment attributes, and there is no necessary correspondence between reservoir properties and depth, and reservoir properties cannot be analyzed through deep carbonate depth correlation. The existing identification methods of the pinch-out lines, such as a spectrum analysis method, a forward modeling method and the like, cannot effectively identify the pinch-out lines of the deep carbonate strata. The accurate identification of the pinch-out line is an important foundation for exploration deployment and evaluation of the formation trap gas reservoir, so that a geological-seismic combined pinch-out line comprehensive identification method is very necessary to be established, and the accuracy of the formation trap gas reservoir identification is further improved. Disclosure of Invention Aiming at the defect that a prediction method capable of effectively identifying the deep carbonate stratum pinch-out line is lacked in the prior art, the invention provides a geological-seismic combination-based stratum pinch-out line identification and prediction method, and the method can be suitable for identifying and predicting the deep carbonate stratum pinch-out line. In order to achieve the above purpose, the technical scheme adopted by the invention is as follows: the stratum pinch-out line prediction method based on geological-seismic combination comprises the following steps: s1, collecting geological background, drilling and logging, core, open-air outcrop section and seismic data. S2, selecting lithology-electric property mark layers according to the logging electric property curve and the rock core, establishing lithology-electric property relation by adopting a lithology-logging curve comparison method, and summarizing development characteristics and interface identification marks of the layer sequence on the rock core and the logging curve. S3, based on a study area drilling and logging work area, an area well connection section is established according to a geological background of the study area and a field outcrop section, a spreading rule of stratum of an interval in the transverse direction is defined, and a stratum transverse change geological mode is established. And S4, drawing a stratum pinch-out trend line of the profile based on the three-dimensional earthquake work area and the combined area well-connecting profile, quantitatively predicting the stratum distribution range by adopting the stratum thickness, further refining the pinch-out line position of the research area by combining the known distance between the well drilling and the pinch-out point and the earthquake profile characteristics, and defining the geological characteristics of the stratum pinch-out line. S5, calculating an included angle theta n of the pinch-out trend line at the pinch-out point by using the thickness of the single well stratum and the horizontal distance between wells, and obtaining the average value of the included angles of the pinch-out line And S6, selecting drilled positions of adjacent pinch-out lines, determining the bottom boundary depth of a tar