CN115877475A - A method for structural-multi-attribute structural paleogeographic reconstruction of deep buried areas in superimposed basins - Google Patents

Abstract

The invention relates to the technical field of basin formation dynamics and oil exploration, in particular to a method for reconstructing a stacked basin deep-buried region structure-multi-attribute structure ancient geography, which comprises the steps of establishing an outcrop region, a drilling stratum sequence grid and a sedimentary facies pattern; determining a vertical structure-stratum unit of a deep buried region of the superposed basin; determining the spatial distribution of the unconformity structure under the movement of the single structure of the deep buried region; determining the fracture and the magma activity of main paleo-activities in a deep-buried area; identifying and determining spatial distribution of seismic stratigraphic features and attributes within a single tectonic-stratigraphic unit; rebuilding the ancient geography of the structure under the movement of the single structure in the overlapped basin deep-buried area, carrying out comprehensive geological and geophysical analysis by using outcrop data, drilling, well logging and other data, recovering the ancient geography of the structure in the deep-buried area by using the basin structure and the geophysical multiple attributes in different periods, and providing scientific, reliable and high-precision evidence for the cognition and resource exploration of the deep and ultra-deep layers under the dual condition that the ancient geography and the ancient geography are mutually constrained.

Description

A method for structural-multi-attribute structural paleogeographic reconstruction of deep buried areas in superimposed basins

technical field

The invention relates to the field of basin formation dynamics and petroleum exploration technology, in particular to a method for reconstructing palaeogeography of structure-multi-attribute structures in superimposed basin deep buried areas.

Background technique

The study of structural paleogeography is the reconstruction of paleogeography under the control of multi-scale structures from plate tectonics to intra-basin structures, reflecting the constraints of basin formation dynamics on the development of tectonic-sedimentary strata. The structural paleogeographic reconstruction of the deep buried area of superimposed basins is to reshape the development process of the deep part of the basin, which is extremely lack of knowledge, to clarify the structure-sedimentary development and genesis, and to evaluate the potential of deep and ultra-deep oil and gas resources and oil and gas in new fields. Exploration is of great economic importance.

The current international paleogeography is mainly under the guidance of the plate tectonic theory, relying on paleomagnetism, paleontology and geochemistry, etc., to reconstruct the continental position, plate boundary, sea and land distribution in the geological history period, and restore the plate tectonic paleogeography at the plate scale; more emphasis Analyze the changes of paleogeography from the time scale of the earth, and gradually integrate structure, topography, climate change, basin-mountain coupling, source-sink system, catchment basin characteristics, paleontology, paleo-ocean, etc. into paleogeography research (Hall, 2009 ; Kanygin et al., 2009; Li Jianghai and Jiang Hongfu, 2013; Chen Hongde et al., 2017). The study of paleogeography in China began in the 1930s, and Feng Zengzhao (1988, 2004, 2007, 2016) proposed the use of single-factor analysis and multi-factor comprehensive mapping methods, which are divided into first-level (ancient land and ancient ocean) and second-level (basin and platform), third-level (beach, collection, flat, lake, reef) and other paleogeographic units, and establish quantitative paleogeographic maps. Wang Hongzhen (1985, 1990) was guided by the "activity theory" of global structure and the "stage theory" of historical evolution, and used the paleomagnetic pole shift curves to map the three platforms of China, North Korea, Yangtze, and Tarim, and compiled a global paleocontinent reconstruction map. In addition, the restoration of paleogeography and paleoenvironment under the coupling of the deep process of the earth and the earth's surface system, the restoration of prototype basins in different geological periods, and the restoration of lithofacies and paleogeography based on stratum development, biological fossils, and sedimentary filling characteristics, And for mineral resources exploration services.

However, the previous lithofacies and paleogeographic mapping often used a large number of field outcrops and drilling data. However, due to the difference in the distribution density of drilling wells, it is difficult to form high-quality paleogeographic maps in areas that have not been revealed by drilling, especially in areas lacking contemporaneous tectonic processes. control. As for the deep buried areas of superimposed basins, due to the unclear distribution of the prototype basins and uncertain preservation of residual basins, coupled with very few drilling data, most of the paleogeographic maps are of medium to small scale, resulting in most areas being almost It is difficult to provide scientific, direct and practical evidence for in-depth resource evaluation without data and data-supported speculation and extension.

Therefore, this application designs a method for reconstructing palaeogeography of deep buried areas in superimposed basins, based on the restoration of ancient structures, qualitatively and semi-quantitatively reconstructing the palaeogeography of deep buried areas in different periods.

Contents of the invention

The purpose of the present invention is to fill in the gaps in the prior art and provide a method for reconstructing paleogeography of superimposed basin deep buried area structure-multi-attribute structures. Paleogeographic methods of the period.

In order to achieve the above object, the present invention provides a kind of superimposed basin deeply buried area structure-multi-attribute structure paleogeographic reconstruction method, comprises the following steps:

S1, establish the sequence framework and sedimentary facies model of the outcrop area and drilling strata;

S2, determine the vertical structure-stratigraphic unit in the deep buried area of the superimposed basin;

S3, determine the spatial distribution of unconformity structures under a single tectonic movement in the deep buried area;

S4, determine the main paleoactive faults and magmatic activities in the deep buried area;

S5, identify and determine the spatial distribution of seismic stratigraphic features and seismic attributes within a single structure-stratigraphic unit;

S6, based on S3, S4 and S5, reconstruction of structural paleogeography under a single tectonic movement in superimposed basins.

Step S1 is: according to the field geological survey of the outcrop profile at the edge of the basin, identify and clarify the existing regional unconformity and local unconformity, use the regional unconformity as the boundary of the stratigraphic sequence framework, and analyze the petrological and sedimentological characteristics of the stratigraphic sequence , to establish a sedimentary facies model.

Step S2 is: compare the stratigraphic sequence development characteristics in the outcrop area, and combine the comprehensive analysis of drilling, logging, and seismic data in the basin to establish a comparable stratigraphic sequence framework in the outcrop area and downhole; Buried structure - stratigraphic unit.

Step S3 is: according to the structural-stratigraphic unit division scheme of the deep buried area, use drilling, logging and seismic data to make synthetic seismic records, determine each structural-stratigraphic unit on the cross-well section, and develop each structural-stratigraphic unit in the deep buried area. Identification and interpretation of stratigraphic units, dissection of main unconformity ternary structures, including structural deformation of unconformity underlying strata, planar distribution of unconformity structure types, sedimentary structure and initial deposits of unconformity overlying strata and their Systematic analysis of provenance, etc.; qualitative and semi-quantitative identification and analysis of main unconformity structure types and deformation characteristics in deep-buried areas by stratum square method, and marking on the plan according to different structural-stratigraphic units to determine the scale of the basin Spatial distribution of disjointed structures.

Step S4 is: based on drilling, logging, reflection seismic and other data, through the interpretation of structural-stratigraphic units in deep buried areas, identify the main faults, and use the balanced section method to qualitatively and semi-quantitatively determine the structural activities and effects of faults in different periods ; combined with gravity, magnetic, electrical and other geophysical data, identify the magmatic rock records existing in the structural-stratigraphic unit, clarify the possible magmatic events, and superimpose the results of step S4 on the unconformity structural distribution map of each major tectonic movement , to obtain paleostructure-paleogeomorphology maps in different periods.

Step S5 is: using synthetic records and velocity analysis to finely calibrate the interface of the seismic reflection layer, analyze the seismic reflection characteristics of each structural-stratigraphic unit in the deep buried area, and draw the seismic reflection structure and multi-attribute characteristics such as reflection amplitude, frequency, and continuity. Floor plan. Through seismic wavelet extraction, low-frequency model establishment, and multi-time window layered wave impedance inversion, the structural-stratigraphic unit wave impedance profiles obtained by constrained sparse pulse inversion are obtained, and converted into structural-stratigraphic unit wave impedance profiles according to S1, S2, and S3. Sedimentary profile.

Step S6 is: on the basis of paleostructural-paleogeomorphological maps of different periods, according to drilling and sedimentary facies models, combine the seismic attributes of structural stratigraphic units with the wave impedance profile to form the spatial distribution of sedimentary facies controlled by paleostructures. Based on the tectonic activities at the margin and deep of the basin in different periods, the basin-scale structural paleogeography of each single tectonic movement period is restored.

Compared with the prior art, the present invention makes full use of outcrop data, drilling, well logging and various geophysical data to conduct comprehensive geological and geophysical analysis, and utilizes basin structures and geophysical multi-attributes in different periods to restore deep buried areas Structural paleogeography provides scientific, reliable and high-precision evidence for deep and ultra-deep cognition and resource exploration under the dual conditions of mutual constraints of paleostructure and paleogeography.

Description of drawings

Figure 1 is a schematic diagram of the method of the present invention.

Fig. 2 a is the establishment process figure of paleostructure-sedimentary section of the embodiment of the present invention, and the section diagram of leveling the reflection layer at the bottom of the Cambrian in the southeastern section AA' of the Tarim Basin;

It annotates the structural characteristics of the unconformity structure, the type of the unconformity structure, and the seismic stratigraphy characteristics are also marked in the section. H, M, and L represent high, medium, and low, respectively; A, F, C, and I represent a single structure-stratum Amplitude, frequency, continuity, wave impedance, etc. of the seismic reflection wave of the unit;

Fig. 2b is a sectional view of the sparse pulse wave impedance inversion of the section AA' of the embodiment of the present invention.

Fig. 2c is the structural-sedimentary cross-sectional view obtained according to the sequence stratigraphic framework, sedimentary facies and comprehensive analysis of b and c according to the embodiment of the present invention, and the cross-sectional position is shown in Fig. 3.

Fig. 3 is a spatial distribution map of unconformity structure and seismic attributes in a single structural-stratigraphic unit in a deeply buried area, and a schematic plan view of the multi-attribute distribution of Nanhua System and Sinian unconformity structures and Nanhua System seismic strata in the Tarim Basin.

Fig. 4 is the reconstructed palaeogeography map of the single tectonic movement in the deeply buried area, and a schematic diagram of the palaeogeography before the deposition of the Sinian in the Tarim Basin. Among them, ①～⑩ are the ages of magmatic events obtained.

Detailed ways

The present invention will be further described now in conjunction with accompanying drawing.

Referring to Fig. 1～Fig. 4, the present invention discloses the method that the present invention provides a kind of superimposed basin deeply buried area structure-multi-attribute structure paleogeography reconstruction, comprises the following steps:

S1, establish the sequence framework and sedimentary facies model of the outcrop area and drilling strata;

S2, determine the vertical structure-stratigraphic unit in the deep buried area of the superimposed basin;

S3, determine the spatial distribution of unconformity structures under a single tectonic movement in the deep buried area;

S4, determine the main paleoactive faults and magmatic activities in the deep buried area;

S5, identify and determine the spatial distribution of seismic stratigraphic features and seismic attributes within a single structure-stratigraphic unit;

S6, based on S3, S4 and S5, reconstruction of structural paleogeography under a single tectonic movement in superimposed basins.

Step S1 is: according to the field geological survey of the outcrop profile at the edge of the basin, identify and clarify the existing regional unconformity and local unconformity, use the regional unconformity as the boundary of the stratigraphic sequence framework, and analyze the petrological and sedimentological characteristics of the stratigraphic sequence , to establish a sedimentary facies model.

Step S2 is: compare the stratigraphic sequence development characteristics in the outcrop area, and combine the comprehensive analysis of drilling, logging, and seismic data in the basin to establish a comparable stratigraphic sequence framework in the outcrop area and downhole; Buried structure - stratigraphic unit.

Step S3 is: according to the structural-stratigraphic unit division scheme of the deep buried area, use drilling, logging and seismic data to make synthetic seismic records, determine each structural-stratigraphic unit on the cross-well section, and develop each structural-stratigraphic unit in the deep buried area. Identification and interpretation of stratigraphic units, dissection of unconformity ternary structure of main structure-stratigraphic units, including structural deformation of unconformity underlying strata, planar distribution of unconformity structure types, overlying strata sedimentary structure and initial sediments Systematic analysis of the unconformity and its provenance, etc.; using the layer leveling method, the main unconformity structure types and deformation characteristics in the deep buried area were further identified and analyzed qualitatively and semi-quantitatively (as shown in Figure 2a), according to different structural-stratigraphic units Marked on the plan to determine the spatial distribution of unconformity structures at the basin scale.

Step S4 is: based on drilling, logging, reflection seismic and other data, through the interpretation of structural-stratigraphic units in deep buried areas, identify the main faults, and use the balanced section method to qualitatively and semi-quantitatively determine the structural activities and effects of faults in different periods ; combined with gravity, magnetic, electrical and other geophysical data, identify the magmatic rock records existing in the structural-stratigraphic unit, clarify the possible magmatic events, and superimpose the results of step S4 on the unconformity structural distribution map of each major tectonic movement , to obtain paleostructure-paleogeomorphology maps in different periods.

Step S5 is: using synthetic records and velocity analysis to finely calibrate the interface of the seismic reflection layer, analyze the seismic reflection characteristics of each structural-stratigraphic unit in the deep buried area, and draw the seismic reflection structure and multi-attribute characteristics such as reflection amplitude, frequency, and continuity. Plane distribution map (as shown in Figure 3); through seismic wavelet extraction, low-frequency model establishment, and multi-time window layered wave impedance inversion, the wave impedance profiles of each structural-stratigraphic unit obtained by constrained sparse pulse inversion are obtained (Figure 2b) , and convert it into a structural sedimentary section according to S1, S2 and S3 (Fig. 2c).

Step S6 is: on the basis of paleostructural-paleogeomorphological maps of different periods, according to drilling and sedimentary facies models, combine the seismic attributes of structural stratigraphic units with the wave impedance profile to form the spatial distribution of sedimentary facies controlled by paleostructures. Based on the tectonic activities at the margin and deep of the basin in different periods, the basin-scale tectonic paleogeography of each single tectonic movement period is restored (Fig. 4).

The above are only preferred embodiments of the present invention, and are only used to help understand the method and core idea of the present application. The scope of protection of the present invention is not limited to the above-mentioned embodiments, and all technical solutions belonging to the thinking of the present invention belong to the present invention scope of protection. It should be pointed out that for those skilled in the art, some improvements and modifications without departing from the principle of the present invention should also be considered as the protection scope of the present invention.

The present invention solves the problems in the prior art that due to the difference in distribution density of drilling wells, it is difficult to form high-quality paleogeographic maps in areas not revealed by drilling, especially because of the lack of synchronous structural action control. As for the deep buried areas of superimposed basins, due to the unclear distribution of the prototype basins and uncertain preservation of residual basins, coupled with very few drilling data, most of the paleogeographic maps are of medium to small scale, resulting in most areas being almost Speculation and extension without data and data support, it is difficult to provide scientific, direct and practical evidence for deep resource evaluation. By making full use of outcrop data, drilling, logging and various geophysical data, comprehensive geological and geophysical Analysis, using the basin structure and geophysical multi-attributes in different periods, restores the structural paleogeography of the deep buried area, and provides information for deep and ultra-deep cognition and resource exploration under the dual conditions of paleostructure and paleogeography. Scientific, reliable and high-precision evidence.

Claims (7)

1. A method for reconstructing ancient geography by using a congruent basin deep buried region structure-multi-attribute structure is characterized by comprising the following steps:

s1, establishing an outcrop area, a drilling stratum sequence grid and a sedimentary facies mode;

s2, determining a vertical structure-stratum unit of the deep buried region of the superposition basin;

s3, determining the spatial distribution of the unconformity structure under the movement of the single structure of the deep buried area;

s4, determining the fracture of main paleo-activities and the magma activities in the deep buried area;

s5, identifying and determining the spatial distribution of seismic stratigraphic characteristics and seismic attributes in the single structure-stratigraphic unit;

and S6, reconstructing the ancient geography constructed under the single construction movement of the superposed basin according to the S3, the S4 and the S5.

2. The method for reconstructing the stacked basin deep-buried region structure-multi-attribute structure paleogeography according to claim 1, wherein the step S1 is as follows: according to field geological survey of the open-head section of the basin edge, identifying and determining existing regional unconformity and local unconformity, analyzing the lithology and sedimentology characteristics of a stratigraphic sequence by taking the regional unconformity as a boundary of a stratigraphic sequence framework, and establishing a sedimentary facies pattern.

3. The method for reconstructing the stacked basin deep-buried region structure-multi-attribute structure paleogeography according to claim 1, wherein the step S2 is as follows: comparing the stratum sequence development characteristics of the outcrop area, and establishing an outcrop area and underground comparable stratum sequence framework by combining comprehensive analysis of drilling, logging and seismic data in a basin; and determining a deep-buried region structure-stratum unit according to the main structure movement period.

4. The method for reconstructing the stacked basin deep-buried region structure-multi-attribute structure paleogeography according to claim 1, wherein the step S3 is: according to the deep-buried area structure-stratum unit division scheme, utilizing drilling, well logging and seismic data to synthesize seismic records and make, determining each structure-stratum unit on a cross-well section, and developing the identification and explanation of each structure-stratum unit in the deep-buried area to carry out main unconformity ternary structure anatomy, including carrying out system analysis on the structure deformation of unconformity stratums, the plane distribution of unconformity structure types, unconformity overburden sedimentary structures, initial sediments, sources thereof and the like; and qualitatively and semi-quantitatively identifying and analyzing the main unconformity structure types and deformation characteristics of the deep buried area by adopting a layer leveling method, respectively marking the main unconformity structure types and the deformation characteristics on a plane graph according to different structure-stratum units, and determining the spatial distribution of each unconformity structure in the basin scale.

5. The method for reconstructing the stacked basin deep buried region structure-multi-attribute structure paleogeographic according to claim 1, wherein the step S4 is: according to data such as drilling, well logging, reflection earthquake and the like, main fractures are identified through interpretation of a deep burial zone structure-stratigraphic unit, fracture structure activities and effects in different periods are qualitatively and semi-quantitatively determined by adopting a balanced section method, a magma record existing in the structure-stratigraphic unit is identified by combining geophysical data such as gravity, magnetism, electricity and the like, possible magma events are determined, and the result of the step S4 is superposed on a non-integrated structure distribution diagram of each main structure motion to obtain an ancient structure-ancient geographical map in different periods.

6. The method for reconstructing the stacked basin deep-buried region structure-multi-attribute structure paleogeography according to claim 1, wherein the step S5 is as follows: the method comprises the steps of finely calibrating a seismic reflection layer interface by adopting synthetic recording and velocity analysis, analyzing seismic reflection characteristics of each structure-stratum unit in a deep-buried area, drawing a plane distribution diagram of seismic reflection structures and multi-attribute characteristics such as reflection amplitude, frequency, continuity and the like, obtaining wave impedance profiles of each structure-stratum unit obtained by constraint sparse pulse inversion through seismic wavelet extraction, low-frequency model establishment and multi-time window layered wave impedance inversion, and converting the wave impedance profiles into structure-deposition profiles according to the S1, the S2 and the S3.

7. The method for reconstructing the congruent basin deep buried region structure-multi-attribute structure ancient geography according to claim 1, wherein the step S6 is: on the basis of an ancient structure-ancient apparent map in different periods, the seismic attributes of the stratigraphic units are combined with the wave impedance profile according to the drilling and sedimentary facies modes to form sedimentary facies band space distribution controlled by the ancient structure. And restoring the scale of the basin in each single-structure movement period to construct the ancient geography according to the structure activities of the edge and the deep part of the basin in different periods.

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