CN108387930B - A METHOD FOR SEALING EVALUATION OF CARBONATE FRACTURE ZONE - Google Patents

Abstract

The invention discloses a method for evaluating the sealability of fractured zones of carbonate rock faults. Taking the Ordovician carbonate rocks in the Tarim Basin as an example, in the oil and gas areas that were filled with oil in the early stage and filled with natural gas in the late stage, or in the oil and gas areas that were filled with oil and gas at the same time, by selecting fluids that reflect oil and gas migration Statistical analysis and normalization processing of parameters or geochemical parameters to obtain conduction coefficient, conduction distance and conduction attenuation coefficient. On this basis, the quantitative analysis of the oil and gas transport capacity of different carbonate fault fracture zones, or different parts of the same fracture zone, different fault plates, and different horizons is carried out, so as to judge the sealing of fault fracture zones. The method of the present invention is simple and easy to implement, and is suitable for exploration and evaluation blocks and development blocks with more oil and gas data, and is suitable for fractured zones of carbonate rock faults with strong heterogeneity and large heterogeneous compact clastic rocks The sealing evaluation of the fault fracture zone provides a fast and convenient new way for the sealing evaluation of the fault fracture zone.

Description

A METHOD FOR SEALING EVALUATION OF CARBONATE FRACTURE ZONE

technical field

The invention belongs to the evaluation technical field of exploration and development of oil and gas resources. More specifically, it relates to a method for evaluating the sealability of fractured carbonate fault zones.

Background technique

For fault-related oil and gas migration, accumulation and preservation, faults are not only pathways for oil and gas migration, but also barriers for oil and gas accumulation and accumulation. The sealing of faults is the core issue and the main factor controlling the scale and distribution of oil and gas. The evaluation of fault sealability includes vertical sealability and lateral sealability, which not only involves the vertical seepage transport channel of the discontinuous structure inside the fault zone, but also is closely related to the sealing performance on both sides of the fault (Yielding, et al., 2010 ).

Fault sealing mechanisms are complex and diverse, mainly including mudstone smearing, cementation, fragmentation, and depolymerization (Yielding, et al., 2010; Pei et al., 2015). The sand-mudstone butt joint method, mudstone smear method, and cross-sectional stress analysis method are relatively popular quantitative evaluation methods for fault sealing, and have achieved good results in the application of clastic rock fault sealing evaluation. In the case of a fault opening laterally, the fluids on the two sides of the fault often have uniform oil-gas-water properties and oil-gas-water contact, while the fluids on both sides of the closed side are often quite different, so the fluid detection on both sides of the fault can also be qualitatively distinguished Fault sealing. The method of judging fault sealing by fluid characteristics is usually suitable for oil and gas reservoirs with butt joints on both sides of the fault, and this method is mainly for qualitative judgment. In the long geological history, the opening of faults is absolute, while the sealing of faults is relative and temporary. Therefore, the sealing of faults is often relative, and there is no universal and accurate judgment method.

Recent studies have shown that large-scale fault zones often have complex three-dimensional structures and formation and evolution processes, usually including narrow fault cores and broad fault fracture zones (Faulkner et al., 2010). Fluids tend to be transported through broader fault fracture zones rather than densely deformed fault cores (Caine et al., 1996; Aydin, 2000; Childs et al., 2009; Choi et al., 2016). The difference in fracture zone structure becomes one of the main factors that cause difficulties in fault sealing evaluation.

In oil and gas bearing basins, carbonate fault fracture zones are more developed, with a width of up to several thousand meters, complex and diverse diagenesis, more intense cementation and dissolution, and strong heterogeneity. Moreover, the fault core is often filled with fault gouge or carbonate rock cement, and oil and gas are mostly transported and accumulated through the fault fracture zone. Therefore, conventional evaluation methods for two-dimensional sections in clastic rocks are often not suitable for fractured zones of carbonate faults with complex three-dimensional structures.

Although it is the most direct method to study the sealing of faults from the internal structure of the fault zone, due to the complexity of the structure of the fault fracture zone in carbonate rocks, the docking relationship between the tight layer inside the carbonate rock and the transport layer, and the smearing of mudstone , cementation, etc. are difficult to carry out effective identification, and there are few samples available for testing and analysis in the underground, which is still in the research and exploration stage.

Contents of the invention

The technical problem to be solved by the present invention is to overcome the defects and deficiencies of the above-mentioned prior art, and obtain the transport coefficient, transport attenuation coefficient, so as to carry out quantitative analysis of the oil and gas transmission capacity of different carbonate rock fault fracture zones, or different parts of the same fault zone and different fault plates, and provide a method to analyze carbonate rock fault fracture zones based on fluid differences. A method for evaluating and predicting lateral closure.

The purpose of the present invention is to provide a method for evaluating the sealability of fractured zones of carbonate rock faults.

Another object of the present invention is to provide the application of the method for evaluating the sealability of fractured zones of carbonate rock faults.

The above object of the present invention is achieved through the following technical solutions:

A method for evaluating the lateral sealing of carbonate fault fracture zones, which is to use fluid properties in oil-gas areas that are filled with oil in the early stage and gas-filled in the late stage, or in oil-gas areas that are filled with oil and gas at the same time. (Gas-oil ratio is selected in the example area) to obtain the conductance coefficient, conduction distance, and conduction attenuation coefficient, so as to carry out the analysis of different carbonate rock fault fracture zones, or different parts of the same fault fracture zone and different fault disks. Quantitative analysis of oil and gas transport capacity, so as to judge the sealing of fault fracture zone.

Wherein, the method for obtaining the conductance coefficient is: on the carbonate rock fault zone of oil and gas exploration and development, layering along the carbonate rock fault fracture zone, and counting the fluid properties of oil and gas wells/reservoirs in different regions (examples are gas oil For the same block or the same fault zone, the fluid properties are normalized, and the normalized value is in the range of 0 to 1; oil and gas filled with oil in the early stage and filled with natural gas in the late stage In the region, the difference of some fluid property parameters (such as gas-oil ratio) can reflect the transport capacity of the fault fracture zone, and this kind of normalized parameter reflecting the transport performance of the fault fracture zone is called the transport coefficient.

The method for obtaining the conduction distance is as follows: the inflection point where the conductance coefficient drops to the lowest in the surrounding rock area is determined as the outer boundary of the fault fracture zone conduction, and the distance from the outer boundary to the fault core is determined as the conduction distance.

On the fault fracture zone and its surrounding unified conduction path, the conductance coefficient decreases with the increase of the distance from the drilling to the fault core. The method for obtaining the conductance attenuation coefficient is as follows: through the correlation analysis of the conductance coefficient and the distance from the drilling to the fault core, the slope of the decline of the conductance coefficient can be obtained; the larger the slope, the faster the conduction attenuation of the fault fracture zone, The absolute value of the slope is normalized, and the obtained value is the conduction attenuation coefficient.

Preferably, as a specific implementable embodiment, the method for evaluating the lateral sealing of the fractured carbonate fault zone includes the following steps:

S1. Determine the study area, and determine the distribution of fault zones through seismic structure interpretation and mapping;

S2. Statize the gas-oil ratio of oil and gas wells/reservoirs in layers and zones along both sides of the fracture zone of carbonate rock faults;

S3. For the same block or the same fault zone, the gas-oil ratio is normalized to obtain the conductivity coefficient of different wells/reservoirs/blocks;

S4. Correlation analysis between the conduction coefficient and the distance, and the inflection point where the conductance coefficient drops to the lowest in the surrounding rock area is determined as the outer boundary of the conduction of the fault fracture zone;

S5. The distance from the outer boundary of the conduction to the fault core is determined as the conduction distance;

S6. Through the correlation analysis of the conductance coefficient and the distance from the drilling to the fault core, the slope of the conductance coefficient decline is obtained, and the conductance attenuation coefficient is determined;

S7. Comparing the conduction coefficient and conduction attenuation coefficient of different carbonate fault fracture zones, or different parts of the same fault zone and different fault plates, to determine the relative size of the seal of the fault fracture zone.

In addition, more specifically, the method for evaluating the lateral sealing of the carbonate fault fracture zone includes the following content:

(1) Fluid parameter statistics:

In the carbonate rock fault zone with a relatively high level of oil and gas exploration and development, stratify along the carbonate rock fault fracture zone, and count the gas-oil ratio of oil and gas wells/reservoirs, crude oil density, dryness coefficient and other fluid parameters, as well as the fluid earth chemical composition etc.

(2) Selection of parameters

In oil and gas areas that are filled with oil in the early stage and filled with natural gas in the late stage, or in oil and gas areas that are filled with oil and gas at the same time, through the comparative analysis of fluid properties such as oil, gas, water, and geochemical components, etc., select effective fluids Migration parameters, examples using gas-oil ratio.

(3) Obtain the conductance coefficient:

For the same block or the same fault zone, the gas-oil ratio (or other parameters, similar to the following) is normalized; the normalized value of the gas-oil ratio is in the range of 0 to 1; In the oil and gas areas charged with natural gas in the late stage, the normalized value of the gas-oil ratio reflects the strength of the fault fracture zone for natural gas transport, which is called the transport coefficient, and the calculation formula of the transport coefficient is as follows:

Tci=(Gi-Gmin)/(Gmax-Gmin) (1)

In the formula, Tci is the conductivity coefficient of the i-th gas-oil ratio, Gi is the statistical value of the i-th gas-oil ratio (or other parameter values), and Gmax and Gmin are the values of the maximum and minimum gas-oil ratios (or other parameter values). parameter value);

The conductance coefficient can be used to represent the conduction ability of the fault fracture zone, and the strength of the conduction ability of the fault fracture zone can be evaluated according to the value of the conductance coefficient; the larger the conductance coefficient, the stronger the conduction capacity of the fault fracture zone, indicating that The sealing of the fault fracture zone is worse.

(4) Obtain the conduction distance:

In the study area, the inflection point at which the conductance coefficient of the drilling target layer drops to the lowest in the surrounding rock area is determined as the outer boundary of the fault fracture zone, and the vertical distance from the outer boundary to the fault core is determined as the conduction distance (Ml) ; The sealability of the fault fracture zone can be evaluated according to the size of the conduction distance; the larger the conduction distance, the worse the sealability of the fault fracture zone and the higher the degree of opening.

(5) Obtain the conduction attenuation coefficient:

Generally speaking, on the fault fracture zone and its surrounding uniform transport path, the transport coefficient decreases with the increase of the distance from the drilling to the fault core; the transport coefficient may decrease to the background value (basically no change), and the background value is taken as The correlation analysis between the above conduction coefficient and the distance from the fault core can obtain the slope of the decrease of the conductance coefficient. The larger the slope, the faster the conduction capacity of the fault fracture zone is attenuated. The absolute value of the slope is normalized Processing, the obtained value can be called the conduction attenuation coefficient (Ma);

In the same migration-accumulation system, the transport-attenuation coefficients usually have similar values, and the value ranges that deviate from the attenuation trend line of the transport-accumulation coefficient may not belong to the same migration-accumulation system and have relatively closed properties.

(6) Evaluation of fault sealing:

Statistical analysis of the transport coefficient, if the transport coefficient has a local abnormally low value, it indicates that the place is a local closed area; if the transport coefficient has a local abnormally high value, it may indicate the occurrence of local oil and gas accumulation and high-speed passage;

The larger the conduction attenuation coefficient, the better the opening and connectivity of the fault fracture zone; the smaller the conduction attenuation coefficient, the faster the conduction capacity weakens and the faster the sealing of the fault fracture zone is; The sudden change value, away from the distribution trend of the transport coefficient, indicates that it is not the same migration-accumulation system, and it is likely to be a relatively independent oil and gas reservoir, and the broken zone of the fault fault has a strong seal;

Through the transport coefficient and transport attenuation coefficient, the oil and gas transport capacity of different carbonate fault fracture zones, or different parts, different layers, and different fault plates of the same fault zone can be compared, so as to judge the fault fracture zone. closedness.

In addition, the application of the above-mentioned method for evaluating the sealability of fractured carbonate fault zones in judging the sealability of fractured carbonate fault zones is also within the protection scope of the present invention.

Preferably, the carbonate rock fault fracture zone refers to a carbonate rock fault fracture zone with strong heterogeneity or a large heterogeneous compact clastic rock fault fracture zone.

Preferably, the method is applicable to exploration and evaluation blocks and development blocks with a lot of oil and gas data.

Since fault sealing is often relative, quantitative evaluation of the sealing of fault fracture zones can be carried out according to the relative size of the transport performance of fault fracture zones. The present invention is based on the characteristics of carbonate rock fault fracture zone development, in the fault fracture zone of early oil filling, late natural gas filling, or fault fracture zone of simultaneous oil and gas filling, through the quantitative analysis of gas-oil ratio change, thereby It achieves the effect of evaluating the sealing performance of the fault fracture zone.

The present invention has the following beneficial effects:

Based on the spatial variation of the fluid, the present invention provides more discrimination data for the oil and gas transport in the wide deformation zone and its periphery. In the tight matrix carbonate rock, through the statistical analysis of the fluid properties and mathematical processing, It is used to evaluate the lateral sealing of fault fracture zone.

The method of the present invention is simple and easy to implement, and is suitable for exploration and evaluation blocks and development blocks with more oil and gas data, and is suitable for fractured zones of carbonate rock faults with strong heterogeneity and large heterogeneous tight clastic rocks The sealing evaluation of fault fracture zone provides a fast and convenient new way for the sealing evaluation of fault fracture zone, and can guide the well location deployment of oil and gas exploration and development.

Description of drawings

Fig. 1 is a scatter diagram of the transport coefficient of three sections of the same Ordovician carbonate fault fracture zone.

Fig. 2 is a graph showing the correlation between the transport coefficient and the distance from the oil source fault in the 3rd section of the fracture zone of the same carbonate rock fault.

Fig. 3 is a model map of the sealing properties of fractured zones of different carbonate rock faults.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments, but the embodiments do not limit the present invention in any form. Unless otherwise specified, the reagents, methods and equipment used in the present invention are conventional reagents, methods and equipment in the technical field.

Example 1 Method for Evaluation of Lateral Sealing of Carbonate Fault Fracture Zones

A method for evaluating the lateral sealing of a carbonate rock fault fracture zone, comprising the following steps:

S1. Determine the study area, and determine the distribution of fault zones through seismic structure interpretation and mapping;

S2. Statize the gas-oil ratio of oil and gas wells/reservoirs in layers and zones along both sides of the fracture zone of carbonate rock faults;

S3. For the same block or the same fault zone, the gas-oil ratio is normalized to obtain the transport coefficient;

S4. Correlation analysis between the conduction coefficient and the distance, and the inflection point where the conductance coefficient drops to the lowest in the surrounding rock area is determined as the outer boundary of the conduction of the fault fracture zone;

S5. The distance from the outer boundary of the conduction to the fault core is determined as the conduction distance;

S6. Through the correlation analysis of the conductance coefficient and the distance from the drilling to the fault core, the slope of the conductance coefficient decline is obtained, and the conductance attenuation coefficient is determined;

S7. Comparing the conduction coefficient and conduction attenuation coefficient of different carbonate fault fracture zones, or different parts of the same fault zone and different fault plates, to determine the relative size of the seal of the fault fracture zone.

Specifically include the following:

(1) Fluid parameter statistics:

In the carbonate rock fault zone with a relatively high level of oil and gas exploration and development, stratify along the carbonate rock fault fracture zone, and count the gas-oil ratio of oil and gas wells/reservoirs, crude oil density, dryness coefficient and other fluid parameters, as well as the fluid earth chemical composition etc.

(2) Selection of parameters

In oil and gas areas that are filled with oil in the early stage and filled with natural gas in the late stage, or in oil and gas areas that are filled with oil and gas at the same time, through the comparative analysis of fluid properties such as oil, gas, water, and geochemical components, etc., select effective fluids Migration parameters, examples using gas-oil ratio.

(3) Obtain the conductance coefficient:

For the same block or the same fault zone, the gas-oil ratio (or other parameters, similar to the following) is normalized; the normalized value of the gas-oil ratio is in the range of 0 to 1; In the oil and gas areas charged with natural gas in the late stage, the normalized value of the gas-oil ratio reflects the strength of the fault fracture zone for natural gas transport, which is called the transport coefficient, and the calculation formula of the transport coefficient is as follows:

Tci=(Gi-Gmin)/(Gmax-Gmin) (1)

In the formula, Tci is the conductivity coefficient of the i-th gas-oil ratio, Gi is the statistical value of the i-th gas-oil ratio (or other parameter values), and Gmax and Gmin are the values of the maximum and minimum gas-oil ratios (or other parameter values). parameter value);

The conductance coefficient can be used to represent the conduction ability of the fault fracture zone, and the strength of the conduction ability of the fault fracture zone can be evaluated according to the value of the conductance coefficient; the larger the conductance coefficient, the stronger the conduction capacity of the fault fracture zone, indicating that The sealing of the fault fracture zone is worse.

(4) Obtain the conduction distance:

In the study area, the inflection point at which the conductance coefficient of the drilling target layer drops to the lowest in the surrounding rock area is determined as the outer boundary of the fault fracture zone, and the vertical distance from the outer boundary to the fault core is determined as the conduction distance (Ml) ; The sealability of the fault fracture zone can be evaluated according to the size of the conduction distance; the larger the conduction distance, the worse the sealability of the fault fracture zone and the higher the degree of opening.

(5) Obtain the conduction attenuation coefficient:

Generally speaking, on the fault fracture zone and its surrounding uniform transport path, the transport coefficient decreases with the increase of the distance from the drilling to the fault core; the transport coefficient may decrease to the background value (basically no change), and the background value is taken as The correlation analysis between the above conductance coefficient and the distance from the drilling to the fault core can obtain the slope of the decline of the conductance coefficient. The larger the slope, the faster the conductance capacity of the fault fracture zone decays. The absolute value of the slope is normalized The obtained value can be called the conduction attenuation coefficient (Ma);

In the same migration-accumulation system, the transport-attenuation coefficients usually have similar values, and the value ranges that deviate from the attenuation trend line of the transport-accumulation coefficient may not belong to the same migration-accumulation system and have relatively closed properties.

(6) Evaluation of fault sealing:

Statistical analysis of the transport coefficient, if the transport coefficient has a local abnormally low value, it indicates that the place is a local closed area; if the transport coefficient has a local abnormally high value, it may indicate the occurrence of local oil and gas accumulation and high-speed passage;

The larger the conduction attenuation coefficient, the better the opening and connectivity of the fault fracture zone; the smaller the conduction attenuation coefficient, the faster the conduction capacity weakens and the faster the sealing of the fault fracture zone is; The sudden change value, away from the distribution trend of the transport coefficient, indicates that it is not the same migration-accumulation system, and it is likely to be a relatively independent oil and gas reservoir, and the broken zone of the fault fault has a strong seal;

Through the transport coefficient and transport attenuation coefficient, the oil and gas transport capacity of different carbonate fault fracture zones, or different parts, different layers, and different fault plates of the same fault zone can be compared, so as to judge the fault fracture zone. closedness.

Example 2 Evaluation of the sealability of fractured zones of carbonate rock faults in different sections of an Ordovician carbonate rock area in the Tarim Basin

In an Ordovician carbonate rock block in the Tarim Basin, in an oil and gas area that was filled with oil in the early stage and filled with natural gas in the late stage, through the quantitative analysis of gas-oil ratio, the transport coefficient, transport distance, and transport coefficient were obtained. Attenuation coefficient, so as to carry out quantitative analysis of the oil and gas transport capacity of different carbonate rock fault fracture zones, and judge the relative size of the sealing of fault fracture zones.

Wherein, the method for obtaining the conductance coefficient is:

In the fractured zone of carbonate faults with a relatively high degree of oil and gas exploration and development, the gas-oil ratio of oil and gas wells/reservoirs is counted in different regions, and the distance from the drilling to the fault core is counted.

For different sections of the same fault fracture, the gas-oil ratio was normalized to obtain the transport coefficient (Fig. 1). As shown in Fig. 1, the high conductance coefficient values of sections 1 and 2 are relatively large, while the conductance coefficient of section 3 is generally low, indicating that the fault fracture zones of sections 1 and 2 have relatively strong conductivity , the worse the sealing performance is, while the section 3 fault fracture zone has weaker conduction capacity and stronger sealing performance.

The inflection point where the conductance coefficient drops to the lowest in the surrounding rock area is determined as the outer boundary of the fault fracture zone, and the distance from the outer boundary to the fault core is determined as the conduction distance (Fig. 2). As shown in Figure 2, section 1 has the largest conduction distance, and the lateral sealing of the fault fracture zone is poor.

On the fault fracture zone and its surrounding unified conduction path, the conductance coefficient decreases with the increase of the distance from the drilling to the fault core. Through the correlation analysis of the well-correlated conductance coefficient and the distance from the drilling to the fault core, it can be obtained The slope of the decrease of the conductance coefficient (Figure 2), and calculate the conduction attenuation coefficient of different sections. As shown in Figure 2, it can be seen that the conduction attenuation coefficient of section 2 is large, indicating that the conductance along the fault core to the outside weakens rapidly, and the sealing property increases rapidly. The fault fragmentation zone in Section 1 has a wide width, a larger conductance coefficient over a larger distance, and a higher degree of opening. In and around different sections, local abnormally low values may appear, indicating that this area is a local closed area; if local abnormally high values appear, it may indicate local oil and gas accumulation and high-speed passages.

Through the conduction coefficient, conduction distance and conduction attenuation coefficient, the oil and gas conduction capacity of different sections and different fault plates of the same carbonate fault fracture zone are compared, so as to judge the relative sealing of the fault fracture zone.

Example 3 Evaluation of the Sealability of Different Carbonate Fault Fracture Zones in an Ordovician Carbonate Area in the Tarim Basin

In another Ordovician carbonate rock block in the Tarim Basin, through the quantitative analysis of gas-oil ratio in different fault zones, the conduction coefficient, conduction distance, and conduction attenuation coefficient were obtained, so as to carry out different fault fractures of carbonate rocks Quantitative analysis of the oil and gas transport capacity of the fault zone to determine the relative size of the fault fracture zone sealing. details as follows:

(1) Selection of fault zone:

On the basis of seismic structure interpretation and mapping, finely interpret the selected fault zones F1, F2, and F3, and determine the distribution of different fault fracture zones.

(2) Fluid parameter statistics:

On different carbonate rock fault zones, fluid parameters such as gas-oil ratio, crude oil density, and drying coefficient of oil and gas wells/reservoirs were counted along the fractured carbonate rock fault zones.

(3) Selection of parameters:

Through comparative analysis of parameters such as oil, gas, water and other fluid properties and geochemical components, parameters that effectively reflect fluid migration are selected. Comparative analysis shows that the effect of gas-oil ratio is better.

(4) Obtain the conductance coefficient:

For different fault fracture zones of carbonate rocks, the gas-oil ratio is normalized with a unified standard to obtain the transport coefficient.

Among them, the gas-oil ratio on the F1 fault fracture zone is high, mainly condensate gas, and the transport coefficient is obviously larger, indicating that the fault fracture zone has a stronger transport capacity, and the sealing property of the fault fracture zone is worse. On the other hand, the gas-oil ratio in the F2 and F3 fault fracture zones is low, mainly normal crude oil, and the transport coefficient is obviously low.

(5) Obtain the conduction distance:

In the study area, determine the inflection point at which the conductance coefficient of the drilling target layer drops to the lowest in the surrounding rock area, and divide it into the outer boundary of fault fracture zone conduction, and the vertical distance from the outer boundary to the fault core is determined as the conduction distance (Ml) .

(6) Obtain the conduction attenuation coefficient:

According to the change of the conductance coefficient with the conduction distance, the background value of the conductance coefficient is determined. Take the correlation analysis between the conductance coefficient above the background value and the distance from the drilling to the fault core to obtain the descending slope of the conductance coefficient with high correlation, and normalize the absolute value of the slope, and the obtained value is the conductance attenuation Coefficient (Ma).

On the F2 and F3 fault fracture zones, the conduction attenuation coefficients are low and have similar values, indicating that the difference in fluid properties is small and the fault fracture zones are strongly sealed. The conductance coefficient attenuation is obvious in the F1 fault fracture zone, which has a good conduction effect, but the sealing performance is relatively poor.

(7) Evaluation of fault sealing:

Statistical analysis of the conductance coefficient shows that F2 and F3 have low values of conductance coefficient and small difference, lack of natural gas filling in the later stage, and are local closed areas. The gas-oil ratio of the F1 fault fracture zone is high, the transport coefficient is high, the transport attenuation coefficient is large, and the fault fracture zone has good opening and connectivity.

Comprehensive analysis shows (Fig. 3) that the fractured zone of the F1 fault has a high degree of opening and a weak seal, resulting in a large amount of natural gas invasion in the late stage, forming a condensate gas reservoir with a high gas-oil ratio on the basis of the early paleo-reservoir. On the other hand, the fractured zones of F2 and F3 faults have strong sealing and low opening degree, and the fractured zones of the faults in between have strong sealing properties. Due to the closure of the fault fracture zone, there is a lack of natural gas invasion from the late deep layer of the fault zone, and at the same time, the natural gas transported by the F1 fault fracture zone from the side has not yet arrived, forming a local oil reservoir area.

Due to the difference in sealing properties of different fault fracture zones, or different parts, layers, and fault plates of the same fault fracture zone, the differences in the late natural gas transport capacity have resulted in the complexity and complexity of oil and gas fluid properties in this area. diversity. On the basis of this method and its principles, it is easy to use different fluid properties or geochemical components for statistical analysis, improve and establish different identification models for fault fracture zone sealing, and guide the geological understanding and oil and gas exploration of such complex oil and gas reservoirs development practice.

Claims (4)

1. a kind of method of carbonate rock fault belt lateral seal evaluation, which is characterized in that be to be filled in early stage with petroleum Note, advanced stage in the HYDROCARBON-BEARING REGION of natural gas origin, or in the HYDROCARBON-BEARING REGION that oil gas fills simultaneously, pass through quantifying for fluid properties Analysis obtains transporting coefficient, transporting distance, transporting attenuation coefficient, to carry out different carbonate rock fault belts, or same The quantitative analysis of the petroleum conduction ability of one fault belt different parts, different fault walls, to sentence the envelope for knowing fault belt Closing property；

The preparation method of the transporting coefficient are as follows: on the carbonate rock fracture belt of oil-gas exploration and development, along carbonate rock tomography Crushed zone layering, subregion count oil/gas well/hiding fluid properties；For same block or same fracture belt, to fluidity Matter is normalized, and the numerical value after normalization is in 0~1 range；In early stage with oil charging, advanced stage with natural gas origin HYDROCARBON-BEARING REGION in, the difference of fluid properties parameter reflects the transporting capability of fault belt, and this kind of reflection fault belt is defeated The normalized parameter for leading performance is referred to as transporting coefficient；

The preparation method of the transporting distance are as follows: transporting coefficient, which is dropped to country rock area at minimum inflection point, is determined as fault disruption zone Outer boundary with transporting, the distance of outer boundary to tomographic nuclear are determined as transporting distance；

Fault belt and its around on unified transporting path, transporting coefficient is reduced with the increase away from tomographic nuclear distance； The preparation method of the transporting attenuation coefficient are as follows: the correlation analysis by transporting coefficient and drilling well away from tomographic nuclear distance can obtain Obtain the slope of transporting coefficient decline；The slope is bigger, shows that the transporting decaying of fault belt is faster, to the absolute value of the slope It is normalized, obtained numerical value is referred to as transporting attenuation coefficient.

2. the method for carbonate rock fault belt lateral seal evaluation according to claim 1, which is characterized in that including Following steps:

S1. it determines research area, is explained by seismotectonics at figure, determine the distribution of fracture belt；

S2. oil/gas well/hiding fluid properties are counted along the layering of carbonate rock fault belt two sides, subregion；

S3. it is directed to same block or same fracture belt, Selecting All Parameters are normalized, different well/hiding/areas are obtained The transporting coefficient of block；

S4. transporting coefficient with away from tomographic nuclear distance do correlation analysis, transporting coefficient drops to true at minimum inflection point to country rock area It is set to the outer boundary of fault belt transporting；

S5. the distance of transporting outer boundary to tomographic nuclear is determined as transporting distance；

S6. by the correlation analysis of transporting coefficient and drilling well away from tomographic nuclear distance, the slope of transporting coefficient decline is obtained, it is oblique to this The absolute value of rate is normalized, and obtained numerical value is transporting attenuation coefficient；

S7. the transporting system of different carbonate rock fault belts or same fracture belt different parts, different fault walls is compared Number, transporting distance, transporting attenuation coefficient, sentence the relative size for knowing the closure of fault belt.

3. to know carbonate rock disconnected sentencing for the method for carbonate rock fault belt lateral seal as claimed in claim 1 or 2 evaluation Application in terms of the closure of layer crushed zone.

4. application according to claim 3, which is characterized in that the carbonate rock fault belt refers to that heterogeneity is strong The heterogeneous compact clastic rock fault belt of strong carbonate rock fault belt or large size.