阅读说明：本技术 一种地质时期断层封闭性评价方法及系统 (Geological period fault sealing evaluation method and system ) 是由 苏玉平 卫平生 陈广坡 张斌 洪亮 景紫岩 李娟� 谢明贤 张亚军 于 2021-05-31 设计创作，主要内容包括：本发明提出了一种地质时期断层封闭性评价方法及系统,其中,该方法包括：采集石油地震勘探数据；根据石油地震勘探数据,建立地下断层模型,并计算出断层的断距、断面上每个点的断层倾角值和垂直断距；根据地下断层模型确定待评价的目的层段在断面上的空间投影窗口位置,并选取断面上要进行封闭性评价的计算点；计算断面上每个点的断层倾角校正因子；计算计算点的有效断层岩的泥质含量ESGR值；根据断层活动速率计算得到在一地质时期的断面上每个点的归一化活动速率；计算代表地质时期的断层封闭能力的参数P-f；统计勘探区域上已发现油藏断层封闭下限阈值,将P-f值与封闭下限阈值进行比较,根据比较结果定量评价断层在一地质时期的封闭性能。(The invention provides a geological period fault sealing evaluation method and system, wherein the method comprises the following steps: collecting petroleum seismic exploration data; according to petroleum seismic exploration data, an underground fault model is established, and fault distance, fault dip angle value of each point on a section and vertical fault distance of the fault are calculated; determining the position of a space projection window of a target layer section to be evaluated on a section according to the underground fault model, and selecting a calculation point to be subjected to closure evaluation on the section; calculating a fault dip angle correction factor of each point on the section; calculating the mud content ESGR value of the effective fault rock of the calculated point; calculating the normalized activity rate of each point on the section of a geological period according to the fault activity rate; calculating a parameter P representing fault blocking capability of a geological time period f (ii) a Counting the lower limit threshold value of the closure of the oil reservoir fault on the exploration area, and calculating P f Comparing the value with a closed lower threshold, and quantifying according to the comparison resultThe sealing performance of a fault in a geological period is evaluated.)

1. A method for evaluating fault seal in geological period is characterized by comprising the following steps:

collecting petroleum seismic exploration data;

according to the petroleum seismic exploration data, an underground fault model is established, and fault distance, fault dip angle values of all points on a section and vertical fault distance are calculated;

determining the position of a space projection window of a target layer section to be evaluated on a section according to the underground fault model, and selecting a calculation point to be subjected to closure evaluation on the section;

calculating to obtain a fault dip angle correction factor of each point on the section according to the fault dip angle value of each point on the section;

calculating to obtain the shale content ESGR value of the effective fault rock of the calculated point according to the petroleum seismic exploration data and the vertical fault distance;

obtaining fault activity rate according to fault distance, and calculating to obtain normalized activity rate of each point on a section of a geological period according to the fault activity rate;

calculating to obtain a parameter P representing fault sealing capability of a geological period according to a fault dip angle correction factor of each point on the section, a calculated effective fault rock argillaceous content ESGR value of the point and a normalized activity rate of each point on the section of the geological period_f；

Counting the closure lower limit threshold of the oil deposit fault found in the exploration area, and determining the geological period closure P of the fault to be evaluated_fThe value is compared with a sealing lower limit threshold value, and the sealing performance of the fault in a geological period is quantitatively evaluated according to the comparison result.

2. The geological time fault closure evaluation method according to claim 1, wherein the step of determining the position of a spatial projection window of a target interval to be evaluated on a section according to the underground fault model and selecting a calculation point to be subjected to closure evaluation on the section comprises the following steps:

establishing a stratum model according to petroleum seismic exploration and drilling data;

and coupling the stratum model with an underground fault model, determining the position of a spatial projection window of a target layer section to be evaluated on the section, and selecting a calculation point to be subjected to closure evaluation on the section.

3. The geological time fault closure evaluation method according to claim 1, wherein the step of calculating a fault dip correction factor for each point on the fracture surface according to the fault dip value of each point on the fracture surface comprises:

the calculation formula of the fault dip angle correction factor of each point on the section is as follows:

wherein f (theta) is a fault dip angle correction factor and is dimensionless;

θ is the fault dip value, °.

4. The method of claim 3, wherein the step of calculating the effective fault formation shale content ESGR value of the calculation point according to the petroleum seismic exploration data and the vertical fault distance comprises the following steps:

wherein, ESGR is the shale content of the effective fault rock,%;

i is the ith rock stratum sliding over the breakpoint;

T_ito slide overThe thickness m of the ith layer of rock layer of the breakpoint;

V_shithe shale content of the i-th rock layer sliding over the breakpoint is percent;

d is the vertical fault distance of the fault, m.

5. The method of claim 4, wherein the step of obtaining a fault activity rate from fault distances of faults and calculating a normalized activity rate of each point on a section of a geological time from the fault activity rates comprises:

calculating the ratio of the accumulated fault distance after fault activity to the time length of the corresponding activity period according to the fault distance of a fault in a geological period, wherein the ratio is the fault activity rate in the geological period;

the normalized activity rate is calculated as:

wherein, V_fNormalized activity rate, dimensionless,%;

v is the fault activity rate of a geological period, m/Ma;

V_maxand V_minThe maximum activity rate and the minimum activity rate, m/Ma, of the fault to be evaluated in the historical activity period are respectively.

6. The method according to claim 5, wherein the parameter P representing the fault blocking capability of the geological time is calculated according to the fault dip correction factor of each point on the fracture surface, the mud content ESGR value of the effective fault rock of the calculated point and the normalized activity rate of each point on the fracture surface of the geological time_fThe method comprises the following steps:

parameter P representing fault blocking capability of geological time_fThe calculation formula of (A) is as follows:

wherein, P_fIs a parameter representing the fault blocking capability of a geological time period.

7. The method for evaluating the sealing performance of the faults in the geological period according to claim 6, wherein a reservoir fault sealing lower limit threshold value is found in a statistical exploration area, the geological period sealing performance Pf value of the fault to be evaluated is compared with the sealing lower limit threshold value, and the sealing performance of the fault in the geological period is quantitatively evaluated according to the comparison result, and the method comprises the following steps:

will P_fComparing with a closed lower threshold; wherein, if P_fIf the lower limit threshold value is larger than the closed lower limit threshold value, the fault is laterally closed, otherwise, the fault is laterally opened;

capacity of closure by P_fAnd characterizing the difference value with the closing lower threshold, wherein if the difference value is larger, the fault closing capability is stronger, otherwise, the fault closing capability is weaker.

8. A geologic time fault seal evaluation system, comprising:

the data acquisition module is used for acquiring petroleum seismic exploration data;

the model establishing module is used for establishing an underground fault model according to the petroleum seismic exploration data and calculating fault distance of a fault, fault dip angle values of all points on a section and vertical fault distance;

the calculation point selection module is used for determining the position of a spatial projection window of a target layer section to be evaluated on the section according to the underground fault model and selecting a calculation point to be subjected to closure evaluation on the section;

the correction factor calculation module is used for calculating and obtaining a fault dip correction factor of each point on the section according to the fault dip value of each point on the section;

the argillaceous content calculation module is used for calculating and obtaining the argillaceous content ESGR value of the effective fault rock of the calculation point according to the petroleum seismic exploration data and the vertical fault distance;

the activity rate calculation module is used for obtaining fault activity rates according to fault intervals and calculating the normalized activity rate of each point on a section of a geological period according to the fault activity rates;

a sealing capacity calculation module for calculating a parameter P representing the sealing capacity of the fault in a geological period according to the fault dip angle correction factor of each point on the section, the mud content ESGR value of the effective fault rock of the calculated point and the normalized activity rate of each point on the section in the geological period_f；

The closure evaluation module is used for counting the closure lower limit threshold of the oil deposit fault found in the exploration area and evaluating the closure P of the geological period of the fault to be evaluated_fThe value is compared with a sealing lower limit threshold value, and the sealing performance of the fault in a geological period is quantitatively evaluated according to the comparison result.

9. A computer device comprising a memory, a processor and a computer program stored on the memory and executable on the processor, wherein the processor implements the method of any one of claims 1 to 7 when executing the computer program.

10. A computer-readable storage medium, characterized in that the computer-readable storage medium stores a computer program which, when executed by a processor, implements the method of any one of claims 1 to 7.

Technical Field

The invention relates to the technical field of oil and gas field exploration and development, in particular to a geological period fault sealing evaluation method and system.

Background

Fault fractures are filled with fault rocks with uneven thickness, lithology and other distributions, the lateral sealing capacity of the fault is not determined by the butt joint condition of two lithologies, but by the displacement pressure difference between the fault rocks and a target reservoir, for a clastic rock stratum, the displacement pressure of the fault rocks is mainly determined by the mud content of the fault rocks, and the larger the mud content of the fault rocks is, the stronger the lateral sealing capacity of the fault is; the weaker the opposite. Researchers have attempted to indirectly or directly evaluate the ability of a fault to laterally trap hydrocarbons by studying the shale content of the fault rock.

The muddiness in the fault rocks are mainly mudstone smear and sand-mud mixed filler of shale layers.

At present, two methods for evaluating the mudstone smearing development degree are accepted by scholars at home and abroad, one is a mudstone smearing factor SSF, and the other is a mudstone smearing potential CSP, but the method has the defects that only the distance and the thickness of the mudstone layer are considered, the mudstone smearing quantity at different positions is not considered, and the objective phenomenon that the dip angles at different positions of a fault are changed is not considered. For the research of sand-mud mixed fillings in the fault, an effective fault mud ratio ESGR method is mainly adopted, namely, the ratio of the accumulated thickness of the mud-rock layer sliding over a certain point in the fault moving process to the fault distance is obtained, the contribution of mud (silicate) in sandstone to the ratio of the mud in the fault zone in the actual fracture action process is considered, and the ESGR can more accurately predict the mud content in the fault zone and the smearing degree of mud-rock.

The domestic and foreign research methods focus on the sealing performance of the fault under the current geological conditions, are static evaluation of the current state, do not consider the historical activity of the fault, and cannot determine the ancient sealing performance of the fault. For the evaluation of fault block entrapment, the paleoseal of a fault is a significant geological exploration risk. The current research state considers that the most fundamental factor of fault lateral sealing capability is the content of shale components in a fracture zone, and the fault lateral sealing capability is characterized by a parameter SGR, wherein the parameter is a function of three parameters, namely vertical fault distance, thickness of rock stratums on two sides of a fracture and the content of the shale of a stratum. The defects of the parameters are that only the closure of the current state can be evaluated, the historical activity and the evolution process of the fault are not considered, the ancient closure of the fault cannot be determined, and the difference of the high-steep fault and the low-angle gentle fault in the closure is not considered.

In view of the above, a technical solution capable of accurately evaluating fault blocking in various periods by overcoming the above defects is needed.

Disclosure of Invention

In order to solve the technical problems mentioned in the background technology, the invention provides a method and a system for evaluating fault closure in a geological period, and the method and the system are suitable for quantitatively judging the fault closure of a clastic rock stratum; by establishing a fault closure quantitative evaluation geological and mathematical model considering dynamic activity factors and fault dip angle factors in fault evolution, the normalized activity rate V of each point of a certain geological period on a section is calculated_fCalculating the shale content ESGR value of the effective fault rock of the calculated point and calculating the fault dip angle correction factor of each point on the section; and using the geological factors represented by the 3 parameters to obtain an ancient sealing evaluation parameter P_fCounting the lower limit threshold value of the reservoir fault closure found in the region, and calculating the geological time closure P of the fault to be predicted_fValue and closureAnd comparing the lower threshold, quantitatively evaluating whether the fault is sealed in a certain geological period and the sealing capacity, improving the accuracy of fault sealing evaluation so as to reduce the fault trapping drilling risk and provide geological evaluation reference for optimizing a fault block oil and gas reservoir development scheme in a development stage.

In a first aspect of an embodiment of the present invention, a method for evaluating fault closure during geological periods is provided, the method including:

collecting petroleum seismic exploration data;

according to the petroleum seismic exploration data, an underground fault model is established, and fault distance, fault dip angle values of all points on a section and vertical fault distance are calculated;

determining the position of a space projection window of a target layer section to be evaluated on a section according to the underground fault model, and selecting a calculation point to be subjected to closure evaluation on the section;

calculating to obtain a fault dip angle correction factor of each point on the section according to the fault dip angle value of each point on the section;

calculating to obtain the shale content ESGR value of the effective fault rock of the calculated point according to the petroleum seismic exploration data and the vertical fault distance;

obtaining fault activity rate according to fault distance, and calculating to obtain normalized activity rate of each point on a section of a geological period according to the fault activity rate;

calculating to obtain a parameter P representing fault sealing capability of a geological period according to a fault dip angle correction factor of each point on the section, a calculated effective fault rock argillaceous content ESGR value of the point and a normalized activity rate of each point on the section of the geological period_f；

Counting the closure lower limit threshold of the oil deposit fault found in the exploration area, and determining the geological period closure P of the fault to be evaluated_fThe value is compared with a sealing lower limit threshold value, and the sealing performance of the fault in a geological period is quantitatively evaluated according to the comparison result.

Further, determining the position of a spatial projection window of the target layer section to be evaluated on the section according to the underground fault model, and selecting a calculation point to be subjected to closure evaluation on the section, wherein the calculation point comprises the following steps:

establishing a stratum model according to petroleum seismic exploration and drilling data;

and coupling the stratum model with an underground fault model, determining the position of a spatial projection window of a target layer section to be evaluated on the section, and selecting a calculation point to be subjected to closure evaluation on the section.

Further, calculating to obtain a fault dip correction factor of each point on the cross section according to the fault dip value of each point on the cross section, including:

the calculation formula of the fault dip angle correction factor of each point on the section is as follows:

wherein f (theta) is a fault dip angle correction factor and is dimensionless;

θ is the fault dip value, °.

Further, according to the petroleum seismic exploration data and the vertical fault distance, calculating to obtain the shale content ESGR value of the effective fault rock of the calculation point, wherein the method comprises the following steps:

wherein, ESGR is the shale content of the effective fault rock,%;

i is the ith rock stratum sliding over the breakpoint;

T_ithe thickness m of the i-th layer rock layer sliding over the breakpoint;

V_shithe shale content of the i-th rock layer sliding over the breakpoint is percent;

d is the vertical fault distance of the fault, m.

Further, obtaining a fault activity rate according to a fault distance of a fault, and calculating a normalized activity rate of each point on a section of a geological period according to the fault activity rate, wherein the method comprises the following steps:

calculating the ratio of the accumulated fault distance after fault activity to the time length of the corresponding activity period according to the fault distance of a fault in a geological period, wherein the ratio is the fault activity rate in the geological period;

the normalized activity rate is calculated as:

wherein, V_fNormalized activity rate, dimensionless,%;

v is the fault activity rate of a geological period, m/Ma;

V_maxand V_minThe maximum activity rate and the minimum activity rate, m/Ma, of the fault to be evaluated in the historical activity period are respectively.

Further, calculating to obtain a parameter P representing fault sealing capability of a geological time according to a fault dip angle correction factor of each point on the section, the mud content ESGR value of the effective fault rock of the calculated point and the normalized activity rate of each point on the section of the geological time_fThe method comprises the following steps:

parameter P representing fault blocking capability of geological time_fThe calculation formula of (A) is as follows:

wherein, P_fIs a parameter representing the fault blocking capability of a geological time period.

Further, counting a lower limit threshold of reservoir fault closure found in an exploration area, comparing a geological time closure Pf value of a fault to be evaluated with the lower limit threshold, and quantitatively evaluating the closure performance of the fault in a geological time according to a comparison result, wherein the evaluation comprises the following steps:

will P_fComparing with a closed lower threshold; wherein, if P_fIf the lower limit threshold value is larger than the closed lower limit threshold value, the fault is laterally closed, otherwise, the fault is laterally opened;

capacity of closure by P_fTable of difference from closed lower thresholdAnd the larger the difference value is, the stronger the fault sealing capacity is, and the weaker the fault sealing capacity is otherwise.

In a second aspect of an embodiment of the present invention, there is provided a geological time fault seal evaluation system, including:

the data acquisition module is used for acquiring petroleum seismic exploration data;

the model establishing module is used for establishing an underground fault model according to the petroleum seismic exploration data and calculating fault distance of a fault, fault dip angle values of all points on a section and vertical fault distance;

the calculation point selection module is used for determining the position of a spatial projection window of a target layer section to be evaluated on the section according to the underground fault model and selecting a calculation point to be subjected to closure evaluation on the section;

the correction factor calculation module is used for calculating and obtaining a fault dip correction factor of each point on the section according to the fault dip value of each point on the section;

the argillaceous content calculation module is used for calculating and obtaining the argillaceous content ESGR value of the effective fault rock of the calculation point according to the petroleum seismic exploration data and the vertical fault distance;

the activity rate calculation module is used for obtaining fault activity rates according to fault intervals and calculating the normalized activity rate of each point on a section of a geological period according to the fault activity rates;

a sealing capacity calculation module for calculating a parameter P representing the sealing capacity of the fault in a geological period according to the fault dip angle correction factor of each point on the section, the mud content ESGR value of the effective fault rock of the calculated point and the normalized activity rate of each point on the section in the geological period_f；

The closure evaluation module is used for counting the closure lower limit threshold of the oil deposit fault found in the exploration area and evaluating the closure P of the geological period of the fault to be evaluated_fThe value is compared with a sealing lower limit threshold value, and the sealing performance of the fault in a geological period is quantitatively evaluated according to the comparison result.

In a third aspect of embodiments of the present invention, a computer device is presented, comprising a memory, a processor and a computer program stored on the memory and executable on the processor, the processor implementing a method for geologic time period fault seal evaluation when executing the computer program.

In a fourth aspect of embodiments of the present invention, a computer-readable storage medium is presented, which stores a computer program that, when executed by a processor, implements a geologic time fault seal evaluation method.

The method and the system for evaluating the fault closure in the geological period introduce a factor of fault activity rate which is related to the historical evolution of the fault, and reflect the fault closure characteristic in a certain geological period; and the influence of factors of fault dip angle change on the shale content calculation of the fault rock is considered, the evaluation effect brought by the method is more consistent with the actual geological rule, the accuracy of fault closure evaluation is effectively improved, the fault trap drilling risk is reduced, and a geological evaluation reference is provided for optimizing a fault block oil and gas reservoir development scheme in a development stage.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Fig. 1 is a schematic flow chart of a method for evaluating the fault closure during geological periods according to an embodiment of the invention.

FIG. 2 is a diagram illustrating an influence relationship of a change in a fault dip on a fault dip correction factor according to an embodiment of the present invention.

Fig. 3A to 3C are graphs showing calculation results of the sealing capacity parameter Pf for different geological times according to an embodiment of the present invention.

FIG. 4 is a schematic diagram of a geological time fault closure evaluation system according to an embodiment of the invention.

Fig. 5 is a schematic structural diagram of a computer device according to an embodiment of the present invention.

Detailed Description

The principles and spirit of the present invention will be described with reference to a number of exemplary embodiments. It is understood that these embodiments are given solely for the purpose of enabling those skilled in the art to better understand and to practice the invention, and are not intended to limit the scope of the invention in any way. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

As will be appreciated by one skilled in the art, embodiments of the present invention may be embodied as a system, apparatus, device, method, or computer program product. Accordingly, the present disclosure may be embodied in the form of: entirely hardware, entirely software (including firmware, resident software, micro-code, etc.), or a combination of hardware and software.

According to the embodiment of the invention, a geological time fault sealing evaluation method and system are provided.

The principles and spirit of the present invention are explained in detail below with reference to several representative embodiments of the invention.

Fig. 1 is a schematic flow chart of a method for evaluating the fault closure during geological periods according to an embodiment of the invention. As shown in fig. 1, the method includes:

step S1, collecting petroleum seismic exploration data;

step S2, establishing an underground fault model according to the petroleum seismic exploration data, and calculating fault distance, fault dip angle value of each point on the section and vertical fault distance;

step S3, determining the position of a spatial projection window of a target layer section to be evaluated on the section according to the underground fault model, and selecting a calculation point to be subjected to closure evaluation on the section;

step S4, calculating to obtain a fault dip angle correction factor of each point on the section according to the fault dip angle value of each point on the section;

step S5, calculating to obtain the mud content ESGR value of the effective fault rock of the calculated point according to the petroleum seismic exploration data and the vertical fault distance;

step S6, obtaining fault activity rate according to fault distance, and calculating to obtain normalized activity rate of each point on the section of a geological period according to the fault activity rate;

step S7, calculating to obtain parameter P representing fault sealing capability of geological time according to fault dip angle correction factor of each point on the section, effective fault rock argillaceous content ESGR value of the calculated point and normalized activity rate of each point on the section of the geological time_f；

Step S8, counting the lower limit threshold value of the reservoir fault closure found in the exploration area, and determining the geological period closure P of the fault to be evaluated_fThe value is compared with a sealing lower limit threshold value, and the sealing performance of the fault in a geological period is quantitatively evaluated according to the comparison result.

In order to explain the method for evaluating the fault closure in the geological period more clearly, each step is described in detail below.

Step S1:

and collecting petroleum seismic exploration data.

Step S2:

according to the petroleum seismic exploration data, an underground fault model is established, and fault distance, fault dip angle values of all points on a section and vertical fault distance are calculated;

step S3:

establishing a stratum model according to petroleum seismic exploration and drilling data;

and coupling the stratum model with an underground fault model, determining the position of a spatial projection window of a target layer section to be evaluated on the section, and selecting a calculation point to be subjected to closure evaluation on the section.

Step S4:

and calculating to obtain a fault dip angle correction factor of each point on the section according to the fault dip angle value of each point on the section.

Fig. 2 is a schematic diagram illustrating an influence relationship of a change in a fault dip on a fault dip correction factor according to an embodiment of the present invention.

The calculation formula of the fault dip angle correction factor of each point on the section is as follows:

wherein f (theta) is a fault dip angle correction factor and is dimensionless;

θ is the fault dip value, °.

Step S5:

calculating to obtain the mud content ESGR value of the effective fault rock of the calculated point according to the petroleum seismic exploration data and the vertical fault distance, wherein the ESGR value comprises the following steps:

wherein, ESGR is the shale content of the effective fault rock,%;

i is the ith rock stratum sliding over the breakpoint;

T_ithe thickness m of the i-th layer rock layer sliding over the breakpoint;

V_shithe shale content of the i-th rock layer sliding over the breakpoint is percent;

d is the vertical fault distance of the fault, m.

Step S6:

the method comprises the following steps of obtaining fault activity rate according to fault distance of a fault, and calculating and obtaining the normalized activity rate of each point on a section of a geological period according to the fault activity rate, wherein the normalized activity rate comprises the following steps:

calculating the ratio of the accumulated fault distance after fault activity to the time length of the corresponding activity period according to the fault distance of a fault in a geological period, wherein the ratio is the fault activity rate in the geological period;

the normalized activity rate is calculated as:

wherein, V_fTo normalize the activity rate, dimensionless%；

V is the fault activity rate of a geological period, m/Ma;

V_maxand V_minThe maximum activity rate and the minimum activity rate, m/Ma, of the fault to be evaluated in the historical activity period are respectively.

Step S7:

calculating to obtain a parameter P representing fault sealing capability of a geological period according to a fault dip angle correction factor of each point on the section, a calculated effective fault rock argillaceous content ESGR value of the point and a normalized activity rate of each point on the section of the geological period_fThe method comprises the following steps:

parameter P representing fault blocking capability of geological time_fThe calculation formula of (A) is as follows:

wherein, P_fIs a parameter representing the fault blocking capability of a geological time period.

Step S8:

counting the lower limit threshold of the reservoir fault closure found in the exploration area, comparing the geological time closure Pf value of the fault to be evaluated with the lower limit threshold, and quantitatively evaluating the closure performance of the fault in a geological time according to the comparison result, wherein the evaluation comprises the following steps:

will P_fComparing with a closed lower threshold; wherein, if P_fIf the lower limit threshold value is larger than the closed lower limit threshold value, the fault is laterally closed, otherwise, the fault is laterally opened;

capacity of closure by P_fAnd characterizing the difference value with the closing lower threshold, wherein if the difference value is larger, the fault closing capability is stronger, otherwise, the fault closing capability is weaker.

It should be noted that although the operations of the method of the present invention have been described in the above embodiments and the accompanying drawings in a particular order, this does not require or imply that these operations must be performed in this particular order, or that all of the operations shown must be performed, to achieve the desired results. Additionally or alternatively, certain steps may be omitted, multiple steps combined into one step execution, and/or one step broken down into multiple step executions.

For a clearer explanation of the method for evaluating the fault closure of the geological time period, a specific example is provided below, but it should be noted that the example is only for better explaining the present invention and is not to be construed as an undue limitation on the present invention.

Taking a certain fault of a depressed west slope of Sudan Muglad basin Kaikang as an example, the fault sealing evaluation method in the geological period is adopted to evaluate the fault sealing.

Referring to FIG. 3A, normalized activity rates for faults are illustrated; FIG. 3B illustrates an exemplary P fault at the key time of oil and gas accumulation at the end of the Chalkbrood period_fDistribution conditions; FIG. 3C illustrates exemplary P of a fault at end of the ancient epoch_fP_fDistribution of (2).

The dip angle of the fault is between 40 and 60 degrees, and the corresponding fault dip angle correction factor f (theta) is between 1.12 and 1.08;

the other parameter SGR is respectively 24% -29%, 28% -31% and 34% -38% in the interval of the lower chalky system, the upper chalky system and the ancient system.

Calculating the target interval V_fThe geological history time windows corresponding to the required lower chalky system, upper chalky system and ancient system are respectively 17, 20.6 and 44.8Ma, and the fault distance is calculated according to the tectonic chart.

The fault is extended in the north-west-south-east direction, is about 120km long from north to south, and has the characteristic of sectional growth in the transverse direction, and can be divided into three sections on a plane as shown in fig. 3A: wherein the formation reservoir of the upper chalky system is found in the second segment; in the third section the chalk system drilling is lost and the hydrocarbon display is found in the ancient system; the first section has not yet been drilled.

The fault geology period is subject to 3 evolution periods: early chalkiness, late chalkiness, and the age of the old. FIG. 3A shows that the activity rate of the fault is generally higher than that of the late early and late chalkiness in the whole, which indicates that the key migration and accumulation period (late chalkiness) in the region is stronger, the fault is correspondingly weaker in sealing performance, and oil gas generated by the source rock of the lower chalkiness system is facilitated to vertically migrate to the main target layer of the upper chalkiness system along the cross section; but the ability to seal differs at different locations of the transverse segments.

In fig. 3B, a second piecewise closure parameter P is shown during the key oil and gas accumulation period (late chalkiness)_fThe whole is less than the third section, which shows that the second section has obviously weaker sealing property than the third section, which shows that the section is favorable for oil and gas migration, and the fact that the oil and gas are gathered in the second section is consistent with the fact that the oil and gas are actually found, and on the contrary, in the key period of the oil and gas migration, the third section has higher sealing property than the second section, and is unfavorable for the migration of the oil and gas at the moment.

The overall stronger closure is shown in FIG. 3C, in the second section P_fThe integral expression is a high value, which indicates that the fault has good sealing property in the ancient period, and is beneficial to the storage of oil gas; but in the third section P_fThe value is low (according to the second segment oil gas distribution condition, counting P is taken here_fThreshold of 5.2), indicating that the third segment is poorly closed, which is caused by the segment's increased activity rate at an ancient age (see fig. 3A); therefore, the oil and gas reservoir formed in early stage can be adjusted upwards along the part with poor fault closure, and finally the oil and gas is scattered on the earth surface or dispersed in the ancient system trap, which is consistent with the fact that the drilling is disfavored aiming at the chalky system trap target in the third section and the oil and gas display is found in the ancient system, and the invention has the advantages of conforming to geological rules and having reliability.

Having described the method of an exemplary embodiment of the present invention, a geologic time period fault seal evaluation system of an exemplary embodiment of the present invention is next described with reference to FIG. 4.

The implementation of the fault closure evaluation system in the geological period can be seen in the implementation of the method, and repeated details are omitted. The term "module" or "unit" used hereinafter may be a combination of software and/or hardware that implements a predetermined function. Although the means described in the embodiments below are preferably implemented in software, an implementation in hardware, or a combination of software and hardware is also possible and contemplated.

Based on the same inventive concept, the invention also provides a geological period fault closure evaluation system, as shown in fig. 4, the system comprises:

a data acquisition module 410 for acquiring petroleum seismic exploration data;

the model establishing module 420 is used for establishing an underground fault model according to the petroleum seismic exploration data and calculating fault distance, fault dip angle value of each point on a section and vertical fault distance of the fault;

the calculation point selection module 430 is configured to determine a position of a spatial projection window of a target layer segment to be evaluated on a cross section according to the underground fault model, and select a calculation point to be subjected to closure evaluation on the cross section;

the correction factor calculation module 440 is configured to calculate a fault dip correction factor of each point on the section according to the fault dip value of each point on the section;

the argillaceous content calculation module 450 is used for calculating and obtaining an ESGR value of the effective fault rock of the calculated point according to the petroleum seismic exploration data and the vertical fault distance;

the activity rate calculation module 460 is used for obtaining a fault activity rate according to the fault distance of the fault and calculating a normalized activity rate of each point on the section of a geological period according to the fault activity rate;

a sealing capacity calculating module 470, configured to calculate a parameter P representing the sealing capacity of the fault in the geological period according to the fault dip correction factor of each point on the fracture surface, the mud content ESGR value of the effective fault rock of the calculated point, and the normalized activity rate of each point on the fracture surface in the geological period_f；

The sealing evaluation module 480 is used for counting the lower limit threshold of the sealing of the oil deposit fault found in the exploration area and evaluating the sealing P of the geological period of the fault to be evaluated_fThe value is compared with a sealing lower limit threshold value, and the sealing performance of the fault in a geological period is quantitatively evaluated according to the comparison result.

It should be noted that although several modules of the geologic time fault seal evaluation system are mentioned in the above detailed description, such partitioning is merely exemplary and not mandatory. Indeed, the features and functionality of two or more of the modules described above may be embodied in one module according to embodiments of the invention. Conversely, the features and functions of one module described above may be further divided into embodiments by a plurality of modules.

Based on the aforementioned inventive concept, as shown in fig. 5, the present invention further provides a computer device 500, which includes a memory 510, a processor 520, and a computer program 530 stored on the memory 510 and operable on the processor 520, wherein the processor 520 executes the computer program 530 to implement the aforementioned method for evaluating the geological time fault closure.

Based on the foregoing inventive concept, the present invention proposes a computer-readable storage medium storing a computer program which, when executed by a processor, implements the foregoing geological time fault closure evaluation method.

The method and the system for evaluating the fault closure in the geological period introduce a factor of fault activity rate which is related to the historical evolution of the fault, and reflect the fault closure characteristic in a certain geological period; and the influence of factors of fault dip angle change on the shale content calculation of the fault rock is considered, the evaluation effect brought by the method is more consistent with the actual geological rule, the accuracy of fault closure evaluation is effectively improved, the fault trap drilling risk is reduced, and a geological evaluation reference is provided for optimizing a fault block oil and gas reservoir development scheme in a development stage.

As will be appreciated by one skilled in the art, embodiments of the present invention may be provided as a method, system, or computer program product. Accordingly, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.

The present invention is described with reference to flowchart illustrations and/or block diagrams of methods and computer program products according to embodiments of the invention. It will be understood that each flow and/or block of the flow diagrams and/or block diagrams, and combinations of flows and/or blocks in the flow diagrams and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

Finally, it should be noted that: the above-mentioned embodiments are only specific embodiments of the present invention, which are used for illustrating the technical solutions of the present invention and not for limiting the same, and the protection scope of the present invention is not limited thereto, although the present invention is described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: any person skilled in the art can modify or easily conceive the technical solutions described in the foregoing embodiments or equivalent substitutes for some technical features within the technical scope of the present disclosure; such modifications, changes or substitutions do not depart from the spirit and scope of the embodiments of the present invention, and they should be construed as being included therein. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.