CN110579803A

CN110579803A - earthquake interpretation method for identifying biological reef body

Info

Publication number: CN110579803A
Application number: CN201910999333.2A
Authority: CN
Inventors: 郭庆; 陈思歉; 余小雷; 聂建伟; 夏常亮; 阴钰毅
Original assignee: BGP Inc
Current assignee: BGP Inc
Priority date: 2019-10-21
Filing date: 2019-10-21
Publication date: 2019-12-17

Abstract

the invention relates to the technical field of oil exploration, in particular to an earthquake interpretation method for identifying a biological reef body, which comprises the following steps: the abnormal reflector depicting technology is characterized in that a one-dimensional plane point segment representing an abnormal reflector of a biological reef is precisely depicted by using various seismic attributes; an abnormal time difference identification technology, wherein the abnormal time difference identification technology utilizes biological reef top surface reflection and earthquake T_C2marking the characteristic of low abnormal time difference between the reflecting layers, performing variable speed mapping, and preliminarily realizing the two-dimensional planar distribution of the reefs. On the basis of comprehensive well logging-geology-seismic data analysis, a main body utilizes a seismic profile to conclude and determine the seismic response characteristics of the reef bodies in Otao Cujiki period in the Erdos basin, and then a set of three-anomaly identification method is explored, so that a good effect is achieved in the application and well position deployment of actual data. The application has good effect.

Description

Earthquake interpretation method for identifying biological reef body

Technical Field

The invention relates to the technical field of oil exploration, in particular to an earthquake interpretation method for identifying a biological reef body.

Background

Exploration practices show that the reef flat reservoir stratum has high abundance and high capacity, the reserve size accounts for more than 10% of the total reserve volume found by oil and gas in the world, and the reef flat reservoir stratum is always the target of key research in the field of oil and gas exploration. At present, the reef flat exploration in China is mainly concentrated in southern areas, the prediction of reef flat reservoir beds with sediments at the edge of the Clalmori stage of the Ordovician Otto system in the ancient kingdom under the Orldos basin is in the initial recognition stage, and no mature reference technical means exists.

In the period of Otaojicri Molii in the Ordors basin, the basin receives a large area of marine invasion. After experiencing sea level rising, not only the sea water cloth cover is expanded, the water body is deepened, but also the stratum has obvious difference, some places are raised and some places are sunken due to the structure movement. The water at the ridge is shallow, the illumination condition is good, and the method is suitable for the growth and the propagation of organisms and the development of the organism reefs. Referring to fig. 1, the controlled feature of positive landform of the reef determines the geophysical response characteristics of the reef to the upper marker layer with low time difference and reef-to-reef overlap. In addition, the biological reef lithology is mainly limestone, and the later period can receive dolomitic transformation, but the velocity difference between the limestone and the dolomitic is small, so that an obvious wave impedance interface is difficult to form, and the interior of the reef has the characteristic of weak amplitude.

In combination with the background of formation of the biosphere at the edge of the kreim stage and the corresponding characteristics of the biosphere on the seismic section, the present invention summarizes five characteristics of the biosphere, and please refer to fig. 2: the integral display of hill-shaped reflection characteristics; secondly, obvious overlapping contact relation can be seen on two sides of the reef body; thirdly, the time difference between the top of the reef body and the main marker layer of the basin is reduced by the earthquake TC2 reflection layer; fourthly, the interior of the reef body is blank-chaotic reflection; the interior of the reef body is in the characteristic of weak amplitude reflection;

Research and analysis recognize that the main technical means for current reef body reservoir prediction is to identify the reflection characteristics thereof by using seismic profiles, and generally comprises direct and indirect identification methods. The direct identification is mainly to distinguish and depict the reef body from the external form and the internal reflection characteristics of the reef body; the indirect identification mainly utilizes the phenomena of coating, overspread and the like existing above the reef body development position to further analyze the speed difference and indirectly predict the distribution and development of the reef body reservoir. In any identification method, the seismic profile is the comprehensive reflection characteristic of the underground rock stratum and the geologic body, and has certain multi-solution, so that the disposition of the well position in the oil and gas exploration process is obviously still insufficient. The identification of the visible reef bodies is a relatively difficult matter, and then it is more difficult to find the effective reservoir of the reef bodies rich in oil and gas reservoirs. On the basis of comprehensive well logging-geology-seismic data analysis, a main body utilizes a seismic profile to conclude and determine the seismic response characteristics of Oerdos basin Ordovic Kilmori period reef bodies, a set of three-anomaly identification method is further explored, and good effects are achieved in the application of actual data and well position deployment. The application has good effect.

Disclosure of Invention

In order to solve the above problems, the present invention provides an earthquake interpretation method for identifying a biological reef body.

The technical problem to be solved by the invention is realized by adopting the following technical scheme:

a seismic interpretation method of identifying a biological reef body, the method comprising the steps of:

Step 1, an abnormal reflector depicting technology, wherein the abnormal reflector depicting technology is used for precisely depicting a one-dimensional plane point segment representing an abnormal reflector of a biological reef by using various seismic attributes;

Step 2, an abnormal time difference identification technology, wherein the abnormal time difference identification technology is implemented by utilizing biological reef top surface reflection and earthquake T_C2Marking the characteristic of low abnormal time difference between the reflecting layers, performing variable speed mapping, and preliminarily realizing two-dimensional planar distribution of the reefs;

and 3, an abnormal amplitude prediction technology, wherein the abnormal amplitude prediction technology is used for counting the earthquake amplitude change rule on the basis of the variable-speed imaging, finely predicting an abnormal low-amplitude area and finishing fine distribution prediction of a target body plane.

further, the seismic attributes refer to specific metrics derived from the seismic data regarding geometry, kinematics, dynamics and statistical properties. Aiming at the reef-shaped appearance of the living beings, geometric attributes and physical attributes can be used for describing; wherein the content of the first and second substances,

On a texture attribute section in geometric attributes, the hill-shaped form of the Ordovician biological reef is obvious in performance, reef cores and reef wings are easy to distinguish, meanwhile, instantaneous phase attributes in the geometric attributes are integrated, the external form of a hill-shaped body is further implemented, meanwhile, the reflection characteristic of the overlarge from two sides to the reef cores is also very obvious, and a good foundation is laid for implementing one-dimensional point sections of the abnormal reflector plane of the biological reef.

Further, step 2 comprises:

step 201, tracing and explaining an earthquake TC2 reflecting layer and a reef top reflecting layer on a seismic section;

step 202, changing the two reflecting layers into graphs and performing subtraction operation on the two layers of structural graphs;

and 203, obtaining a plane rule with the reduced thickness of the reflecting layer through grid operation on the basis of the planar one-dimensional point section of the implemented biological reef abnormal reflector, and determining the two-dimensional planar distribution and the thickness of the reef.

Further, step 3 comprises:

step 301, extracting an amplitude attribute profile of a seismic profile target layer;

Step 302, counting the abnormal amplitude;

Step 303, thinning the amplitude abnormal area of the reef two-dimensional plane distribution area,

And step 304, defining the reef plane distribution rule.

compared with the prior art, the invention has the beneficial effects that: on the basis of comprehensive well logging-geology-seismic data analysis, a main body utilizes a seismic profile to conclude and determine the seismic response characteristics of Oerdos basin Ordovic Kilmori period reef bodies, a set of three-anomaly identification method is further explored, and good effects are achieved in the application of actual data and well position deployment. The application has good effect.

drawings

FIG. 1 is a cross-section of pre-stack time migration of the survey line S097079;

FIG. 2 is a pattern diagram of a biological reef;

FIG. 3 is a cross section of the H135629 line instantaneous cosine and H157259 line instantaneous phase attribute;

FIG. 4 is a pre-stack time migration profile of H135629 and 07HL5229 lines;

Fig. 5 shows the pre-stack time, average amplitude attribute profile and average amplitude statistics for the S097079 survey line.

Detailed Description

the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is apparent that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The present invention provides a preferred embodiment:

On the basis of defining five response characteristics of the geophysical of the biological reef, three abnormal identification methods of the seismic of the biological reef, namely an abnormal reflector depicting technology, an abnormal time difference identification technology and an abnormal amplitude prediction technology, are summarized;

Specifically, one-dimensional plane point segments representing the abnormal reflector of the biological reef are finely depicted by using various seismic attributes; by using biological reef top surface reflection and earthquake T_C2marking the characteristic of low abnormal time difference between the reflecting layers, performing variable speed mapping, and preliminarily realizing two-dimensional planar distribution of the reefs; and finally, on the basis of the variable-speed mapping, counting the earthquake amplitude change rule, and finely predicting an abnormal low-amplitude area to finish fine spread prediction of the target body plane.

The biological reef is in a hill-like reflection form on the seismic section and has obvious difference with the normal sedimentary stratum reflection, and by using the characteristic, the seismic attribute analysis technology is developed to implement the point section distribution rule representing the abnormal reflection of the biological reef.

Seismic attributes refer to special measures derived from seismic data regarding geometry, kinematics, dynamics and statistical properties, which can be characterized for a biosystock-like shape using geometric and physical attributes.

Referring to fig. 3, on the texture attribute section in the geometric attribute, the mound-like form of the aotao biological reef is obvious, and the reef core and the reef wing are easily distinguished. Meanwhile, instantaneous phase attributes in the physical attributes are integrated, the external form of the dune is further implemented, meanwhile, the reflection characteristics of the reef core from two sides are very obvious, and a good foundation is laid for implementing one-dimensional point sections of the plane of the abnormal reflector of the biological reef.

The reef has positive landform characteristics, top reflection and upper earthquake T_C2the reflection layer is significantly reduced in cross section compared to both sides. Analysis shows that the LT1 belongs to the top reflecting layer of the reef and the earthquake T_C2the reflection layer has a minimum time difference of only 50ms, and the reef wing reflection layer and the earthquake T_C2The reflection layer time difference is substantially 150 ms.

Referring to FIG. 4, the top, wing and T of the reef are utilized_C2Predicting the plane position of the reef by the characteristic that the time difference of the reflecting layers is reduced, firstly, tracing and explaining an earthquake TC2 reflecting layer and a reef top reflecting layer on an earthquake section, secondly, performing variable-speed mapping on the two reflecting layers and performing subtraction operation on the two layers of structural diagrams, and finally, obtaining a plane rule with the reduced thickness of the reflecting layers and the two-dimensional plane distribution and the thickness of the reef on the basis of the one-dimensional point section of the plane of the implemented biological reef abnormal reflector through grid operation.

referring to fig. 5, the impedance difference between the limestone of the biological reef in the krimo mile period and the limestone and the dolomite is small, the amplitude on the seismic section is not obviously changed, the interior of the reef body is blank-disordered reflection, and the reef body is compared with surrounding rocks on two sides on the seismic section and has the characteristic of weak amplitude, so that the amplitude abnormal area of the two-dimensional plane distribution area of the reef body is refined by extracting the amplitude attribute section of the target layer of the seismic section and counting the abnormal amplitude, and the plane distribution rule of the reef body is determined.

in the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the present invention, unless otherwise expressly stated or limited, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through an intermediate. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

while the invention has been described above with reference to an embodiment, various modifications may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In particular, the various features of the embodiments disclosed herein may be used in any combination, provided that there is no structural conflict, and the combinations are not exhaustively described in this specification merely for the sake of brevity and conservation of resources. Therefore, it is intended that the invention not be limited to the particular embodiments disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.

Claims

1. A seismic interpretation method for identifying a biological reef body is characterized by comprising the following steps:

2. The method of claim 1, wherein the seismic attributes are specific metrics derived from seismic data regarding geometric, kinematic, kinetic and statistical properties. Aiming at the reef-shaped appearance of the living beings, geometric attributes and physical attributes can be used for describing; wherein the content of the first and second substances,

3. the seismic interpretation method of identifying the biological reef bar as recited in claim 2, wherein the step 2 comprises:

4. the seismic interpretation method of identifying the biological reef body of claim 2, wherein step 3 comprises:

Step 302, counting the abnormal amplitude;

step 303, refining an amplitude abnormal area of the reef two-dimensional plane distribution area;

and step 304, defining the reef plane distribution rule.