阅读说明：本技术 一种源储侧接型油气藏油气充注能力的定量评价方法 (Quantitative evaluation method for oil-gas filling capacity of source-storage-side-connected oil-gas reservoir ) 是由 吕雪莹 徐建根 蒋有录 刘景东 于 2021-09-07 设计创作，主要内容包括：本发明公开了一种源储侧接型油气藏油气充注能力的定量评价方法,属于油气勘探技术领域。其技术方案包括选取代表砂层样品,通过储集层岩石热解实验,得到储集层含油气性ST值；计算油气充注动力P-(0)与油气充注阻力P-(c),计算所述油气充注动力与所述油气充注阻力的差值ΔP；分析储集层含油气性ST值与所述ΔP之间的关系,确定油气发生有效充注的临界值ΔP-(min)；当ΔP＞ΔP-(min)时,判断油气方可发生有效充注,且ΔP越大,油气充注能力越强；当ΔP≤ΔP-(min)时,判断油气无法发生有效充注。本发明应用于油气勘探方面,解决了现有“源控论”不能准确判断油气是否能够发生充注、不能定量评价油气充注能力的技术问题,具有能够对油气充注能力进行定量评价,评价准确性高,且适用范围广泛的特点。(The invention discloses a quantitative evaluation method for oil-gas filling capacity of a source-storage side-connected oil-gas reservoir, and belongs to the technical field of oil-gas exploration. Selecting a representative sand layer sample, and obtaining an oil-gas containing ST value of a reservoir through a reservoir rock pyrolysis experiment; calculating oil gas filling power P 0 With oil-gas filling resistance P c Calculating the difference value delta P between the oil-gas charging power and the oil-gas charging resistance; analyzing the relation between the reservoir oil-gas property ST value and the delta P, and determining the critical value delta P of the effective charge of oil gas min (ii) a When Δ P > Δ P min Judging that effective filling can be carried out on oil gas, wherein the larger the delta P is, the stronger the oil gas filling capacity is; when Δ P is less than or equal to Δ P min And judging that the oil gas cannot be effectively filled. The method is applied to the aspect of oil-gas exploration, solves the technical problems that whether oil-gas can be filled or not cannot be accurately judged by the conventional source control theory, and the oil-gas filling capacity cannot be quantitatively evaluated, and has the advantages of capability of quantitatively evaluating the oil-gas filling capacity, high evaluation accuracy and capability of quantitatively evaluating the oil-gas filling capacityWide application range.)

1. A quantitative evaluation method for oil-gas filling capacity of a source-storage-side type oil-gas reservoir is characterized by comprising the following steps:

selecting a representative sand layer sample, and obtaining an oil-gas containing ST value of a reservoir through a reservoir rock pyrolysis experiment;

calculating oil gas filling power P₀With oil-gas filling resistance P_cCalculating the difference value delta P between the oil-gas charging power and the oil-gas charging resistance;

analyzing the relation between the reservoir oil-gas property ST value and the delta P, and determining the critical value delta P of the effective charge of oil gas_min；

When Δ P > Δ P_minJudging that effective filling can be carried out on oil gas, wherein the larger the delta P is, the stronger the oil gas filling capacity is; when Δ P is less than or equal to Δ P_minAnd judging that the oil gas cannot be effectively filled.

2. The method for quantitatively evaluating the hydrocarbon filling capacity of the source-reservoir-side-type hydrocarbon reservoir according to claim 1, is characterized by comprising the following steps of:

determining the oil-gas-containing ST value in each sample sand layer by taking a plurality of reservoir sand layers of a single well as the sample sand layers according to the pyrolysis data or the logging interpretation data of the rock;

determining overpressure characteristics of the target hydrocarbon reservoir in butt joint with the hydrocarbon source rock stratum according to formation test data and logging data, and calculating oil gas filling power P₀；

According to the pore throat parameter of the reservoir layer of the target oil-gas reservoir and by combining the interfacial tension and wetting angle parameters, the oil-gas filling resistance P is calculated_c；

Judging whether each sample sand layer can be effectively filled according to the oil-gas-containing ST value, taking the sample sand layer which can be effectively filled with oil gas, and filling power P corresponding to the oil gas₀And a filling resistance P_cThe minimum value of the difference value delta P is used as the critical value delta P of the effective charge of the oil gas_min；

If the difference value of the oil gas filling power and the filling resistance of the unknown reservoir sand layer is larger than the critical value delta P_minIf the difference between the oil gas filling power and the filling resistance of the unknown reservoir sand layer is less than or equal to the critical value delta P_minThen the unknown reservoir sand layer cannot be effectively filled.

3. The method for quantitatively evaluating the hydrocarbon filling capacity of a source-storage-side-type hydrocarbon reservoir according to claim 2, wherein the hydrocarbon filling power P₀By calculating the formation pressure P of the source-reservoir contact middle hydrocarbon source rock₁Source-reservoir contact intermediate reservoir formation pressure P₂The difference of (a) is obtained.

4. The method for quantitatively evaluating the hydrocarbon filling capacity of a source-reservoir-side-type hydrocarbon reservoir according to claim 2, wherein the hydrocarbon filling resistance P is_cCalculated by the following formula:

sigma is interfacial tension, mN/m; r is the mean throat radius, μm; theta is the wetting angle.

5. The method for quantitatively evaluating the oil-gas filling capacity of a source-storage-side-type oil-gas reservoir according to claim 4, wherein the interfacial tension is oil-water interfacial tension or gas-water interfacial tension, and the oil-water interfacial tension is calculated by the following formula:

σ_oil-water＝-0.0001765*T+0.02844，R²＝0.9992

The gas-water interfacial tension is calculated by the following formula:

σ_gas-water＝-17.586339*T+51.639344*P+416.562842，R²＝0.9590

T is the formation temperature, DEG C; p is the formation pressure, MPa.

6. The method for quantitatively evaluating the hydrocarbon filling capacity of the source-reservoir-side-connected hydrocarbon reservoir according to claim 4, wherein the wetting angle of a reservoir layer which does not undergo hydrocarbon filling at an early stage is 0 degrees, and the wetting angle of a reservoir layer which does undergo hydrocarbon filling at an early stage is measured by a contact angle measuring instrument.

7. The method for quantitatively evaluating the hydrocarbon filling capacity of a source-reservoir-side-hung type hydrocarbon reservoir according to claim 4, wherein the average throat radius is obtained by nuclear magnetic resonance or high-pressure mercury intrusion test.

Technical Field

The invention belongs to the technical field of oil-gas exploration, and particularly relates to a quantitative evaluation method for oil-gas filling capacity of a source-storage-side-connected oil-gas reservoir.

Background

Hydrocarbon charging mechanisms concern the dynamic process of hydrocarbons from "source" to "reservoir" involving a number of hydrocarbon reservoir elements, such as source rocks, reservoirs, and hydrocarbon conduits. The geological conditions of the oil-gas-containing basin in the east of China are complex, multiple sets of hydrocarbon source rocks develop, the fracture is complex, the reservoir heterogeneity is strong, and oil-gas transportation channels are complex and diverse, so that a plurality of difficulties exist in the research of oil-gas filling mechanism. Over decades of exploration and development, "source control theory" has been widely accepted and applied to exploration practice. The source is generally considered as a key factor of oil and gas accumulation, as long as effective hydrocarbon source rocks are developed and an oil and gas transmission and guide channel exists, oil and gas have accumulation conditions, but the influence of the composition and the coupling of oil and gas filling movement and resistance on the oil and gas filling capacity is usually ignored in the theory, quantitative evaluation cannot be carried out on the oil and gas filling capacity, and the condition of inaccurate evaluation results exists.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to solve the technical problem that whether oil gas can be filled or not cannot be accurately judged due to the fact that the influence of the composition and the coupling of oil gas filling movement and resistance on the oil gas filling capacity is neglected in the conventional source control theory, and provides the quantitative evaluation method for the oil gas filling capacity of the source storage side type oil gas reservoir, which has the advantages of capability of quantitatively evaluating the oil gas filling capacity, high evaluation accuracy and wide application range.

In order to solve the technical problem, the technical scheme adopted by the invention is as follows:

the invention provides a quantitative evaluation method for oil-gas filling capacity of a source-storage-side type oil-gas reservoir, which comprises the following steps:

selecting a representative sand layer sample, and obtaining an oil-gas containing ST value of a reservoir through a reservoir rock pyrolysis experiment;

calculating oil gas filling power P₀With oil-gas filling resistance P_cCalculating the difference value delta P between the oil-gas charging power and the oil-gas charging resistance;

analyzing the relation between the reservoir oil-gas property ST value and the delta P, and determining the critical value delta P of the effective charge of oil gas_min；

When Δ P > Δ P_minJudging that effective filling can be carried out on oil gas, wherein the larger the delta P is, the stronger the oil gas filling capacity is; when Δ P is less than or equal to Δ P_minAnd judging that the oil gas cannot be effectively filled.

Preferably, the method specifically comprises the following steps:

determining the oil-gas-containing ST value in each sample sand layer by taking a plurality of reservoir sand layers of a single well as the sample sand layers according to the pyrolysis data or the logging interpretation data of the rock;

determining overpressure characteristics of the target hydrocarbon reservoir in butt joint with the hydrocarbon source rock stratum according to formation test data and logging data, and calculating oil gas filling power P₀；

According to the pore throat parameter of the reservoir layer of the target oil-gas reservoir and by combining the interfacial tension and wetting angle parameters, the oil-gas filling resistance P is calculated_c；

Judging whether each sample sand layer can be effectively filled according to the oil-gas-containing ST value, taking the sample sand layer which can be effectively filled with oil gas, and filling power P corresponding to the oil gas₀And a filling resistance P_cThe minimum value of the difference value delta P is used as the critical value delta P of the effective charge of the oil gas_min；

If the difference value of the oil gas filling power and the filling resistance of the unknown reservoir sand layer is larger than the critical value delta P_minIf the difference between the oil gas filling power and the filling resistance of the unknown reservoir sand layer is less than or equal to the critical value delta P_minThen the unknown reservoir sand layer cannot be effectively filled.

Preferably, the hydrocarbon charging power P₀By calculating the formation pressure P of the source-reservoir contact middle hydrocarbon source rock₁Source-reservoir contact intermediate reservoir formation pressure P₂The difference of (a) is obtained.

Preferably, the hydrocarbon charge resistance P_cCalculated by the following formula:

sigma is interfacial tension, mN/m; r is the mean throat radius, μm; theta is the wetting angle.

Preferably, the interfacial tension is oil-water interfacial tension or gas-water interfacial tension, and the oil-water interfacial tension is calculated by the following formula:

σ_oil-water＝-0.0001765*T+0.02844，R²＝0.9992 (2)

The gas-water interfacial tension is calculated by the following formula:

σ_gas-water＝-17.586339*T+51.639344*P+416.562842，R²＝0.9590 (3)

T is the formation temperature, DEG C; p is the formation pressure, MPa.

Preferably, the wetting angle for an early hydrocarbon-unfilled reservoir is taken to be 0 °, and the wetting angle for an early hydrocarbon-filled reservoir is measured by a contact angle measuring instrument.

Preferably, the average throat radius is obtained by nuclear magnetic resonance or high pressure mercury intrusion tests.

Compared with the prior art, the invention has the beneficial effects that:

the invention provides a quantitative evaluation method for oil-gas filling capacity of a source-storage side type oil-gas reservoir, which has the characteristics of capability of quantitatively evaluating the oil-gas filling capacity, high evaluation accuracy and wide application range.

Drawings

FIG. 1 is a schematic diagram of lateral hydrocarbon filling along a fault according to an embodiment of the present invention.

Detailed Description

The technical solutions in the embodiments of the present invention will be fully described in detail below with reference to the accompanying drawings. It is obvious that the described embodiments are only some specific embodiments, not all embodiments, of the general technical solution of the present invention. All other embodiments, which can be derived by a person skilled in the art from the general idea of the invention, fall within the scope of protection of the invention.

The invention provides a quantitative evaluation method for oil-gas filling capacity of a source-storage-side type oil-gas reservoir, which comprises the following steps:

selecting a representative sand layer sample, and obtaining an oil-gas containing ST value of a reservoir through a reservoir rock pyrolysis experiment;

calculating oil gas filling power P₀With oil-gas filling resistance P_cCalculating the difference value delta P between the oil-gas charging power and the oil-gas charging resistance;

analyzing the relation between the reservoir oil-gas property ST value and the delta P, and determining the critical value delta P of the effective charge of oil gas_min；

When Δ P > Δ P_minJudging that effective filling can be carried out on oil gas, wherein the larger the delta P is, the stronger the oil gas filling capacity is; when Δ P is less than or equal to Δ P_minAnd judging that the oil gas cannot be effectively filled.

The evaluation method provided by the technical scheme comprehensively considers the influence of the composition and the coupling of the oil-gas filling movement and resistance on the oil-gas filling capacity, can quantitatively evaluate the oil-gas filling capacity, and has high evaluation accuracy and wide application range. The method specifically comprises the following steps: determining the oil-gas-containing condition in each sample sand layer by taking a plurality of reservoir sand layers of a certain single well as the sample sand layers according to the pyrolysis data or the well logging interpretation data of the rock; determining overpressure characteristics of a target oil-gas reservoir in butt joint with a hydrocarbon source rock stratum according to formation testing data and logging data, and calculating oil-gas filling power; calculating oil-gas filling resistance according to pore throat parameters of a reservoir layer of a target oil-gas reservoir and by combining interfacial tension and wetting angle parameters; judging whether each sample sand layer can be effectively filled according to the oil-gas containing condition, and taking the minimum value of the difference value between the oil-gas filling power and the filling resistance in the sample sand layer which can be effectively filled with the oil gas as a critical value; if the difference value between the oil gas filling power and the filling resistance of the unknown reservoir sand layer is larger than the critical value, the unknown reservoir sand layer can be effectively filled, otherwise, the unknown reservoir sand layer cannot be effectively filled.

It should be noted that the source of oil and gas, the conductance channel, the filling dynamic resistance, the accumulation time and the filling process are the main research contents of the oil and gas filling mechanism, and the filling dynamic resistance is the core of the filling mechanism. However, the source control theory is widely accepted and applied to exploration practice, the source is generally considered to be a key factor of oil and gas reservoir formation, oil and gas can be filled as long as effective hydrocarbon source rocks are developed and an oil and gas transmission and guide channel exists, and the influence of the oil and gas filling movement and resistance composition and coupling on the oil and gas filling capacity is usually ignored. After oil gas is generated, the oil gas is driven by power such as hydrocarbon generation pressurization, buoyancy and diffusion, the resistance such as reservoir stratum pressure, capillary force and viscous force is overcome, and the oil gas can be filled from the hydrocarbon source rock to the reservoir stratum only when the filling power is larger than the resistance. The quantitative evaluation of oil gas filling ability is always the key and difficult point of oil gas filling research, but the predecessor research often only concerns whether oil gas can take place to fill, thinks that filling power is greater than filling resistance, and oil gas alright can take place to fill, and considers reservoir stratum rerum natura, tectonic position etc. to the influence of oil gas filling more, thinks that reservoir stratum rerum natura is good, oil gas filling ability is strong, but has ignored filling power, the influence of wettability etc. to oil gas filling. The method further analyzes the coupling relation of the oil-gas filling power and the oil-gas filling resistance on the basis of quantitative characterization of the oil-gas filling power and the oil-gas filling resistance, analyzes the oil-gas content of the reservoir through a reservoir rock pyrolysis experiment, establishes the quantitative relation between the difference value of the oil-gas filling power and the oil-gas filling resistance and the oil-gas content of the reservoir on the basis, further determines the critical difference value of the oil-gas filling power and the oil-gas filling resistance for effective oil-gas filling, can judge whether oil-gas filling can occur in other sand layers by utilizing the critical difference value, and quantitatively evaluates the oil-gas filling capacity.

In a preferred embodiment, the hydrocarbon charging power P₀By calculating the formation pressure P of the source-reservoir contact middle hydrocarbon source rock₁Source-reservoir contact intermediate reservoir formation pressure P₂The difference of (a) is obtained. Filling model As shown in FIG. 1, after oil and gas are generated from the hydrocarbon source rock, the oil and gas are driven by the hydrocarbon source rock to generate hydrocarbon under pressurization (P)₁) Through the oil source fracture and the formation pressure (P) at the lower reservoir (point B)₂) And a pressure difference is formed, the filling resistance of oil and gas in the reservoir is overcome, and the lateral filling and the accumulation are carried out. In the aspect of oil gas filling power, for source-storage side-connected oil gas reservoirs, the oil gas has reservoir forming conditions as long as effective hydrocarbon source rocks are developed and an oil gas transportation and guiding channel exists, andthe residual pressure is often used as the main power of the oil-gas charge, but the source-storage pressure difference is the root power source of the oil-gas charge, but the pressure difference is difficult to calculate quantitatively. On the basis of the research on the formation pressure of the hydrocarbon source rock, the invention further combines the formation pressure characteristics of the reservoir layer to calculate the source-reservoir residual pressure difference of different sand layers as oil-gas filling power. Specifically, the formation pressures of the upper hydrocarbon source rock and the lower reservoir layer of the fault can be recovered based on the currently measured pressure data and well logging data to obtain the formation pressures of different depths of burial.

In a preferred embodiment, the hydrocarbon charge resistance P_cCalculated by the following formula:

sigma is interfacial tension, mN/m; r is the mean throat radius, μm; theta is the wetting angle. The resistance of oil and gas filling comprises various acting forces such as reservoir stratum pressure, capillary pressure, friction force, viscous force and the like, but the friction force, the viscous force and the like are very small and can be ignored. The capillary forces generated by the pore-throat structure are the primary resistance to hydrocarbon filling of a voided reservoir, and their magnitude depends on the oil (gas) -water interfacial tension, the reservoir wettability, and the pore-throat radius. In the actual research process, the influence of temperature and pressure changes on the wettability, interfacial tension and the like of the reservoir is often ignored. However, the actual oil and gas reservoir burial depth is relatively large, and the oil and gas filling resistance cannot be accurately calculated only by using empirical data to represent interfacial tension and wetting angle. On the basis of defining the pore throat radius characteristics of the reservoir, the method further combines the temperature and pressure characteristics of the reservoir to calculate the oil (gas) -water interfacial tension, fully considers the influence of wettability and more accurately calculates the oil-gas filling resistance. It should be noted that reservoir wettability is the tendency of reservoir fluids to adhere to the rock surface and is usually expressed by the wetting angle, i.e. the angle between the liquid-solid interface and the tangent of the liquid surface at the point of contact between the liquid and the solid. Under the condition of an original stratum, sedimentary rocks are formed in a water body environment, and the mineral composition is mostly silicates, so that underground rocks mostly have hydrophilic characteristics, and the wetting angle is regarded as 0 degree; in the later oil gas filling process, hydrocarbon molecules are attached to the surfaces of rock particles for a long time, so that the wettability of a reservoir layer can be changed, and the wetting angle is related to the oil gas enrichment degree and can be measured by a laboratory.

In a preferred embodiment, the interfacial tension is oil-water interfacial tension or gas-water interfacial tension, and the functional relationship between the oil (gas) -water interfacial tension and the temperature and the pressure is obtained according to the characteristics of the oil (gas) -water interfacial tension along with the change of the temperature and the pressure researched by Schwalter. The oil-water interfacial tension is calculated by the following formula:

σ_oil-water＝-0.0001765*T+0.02844，R²＝0.9992 (2)

The gas-water interfacial tension is calculated by the following formula:

σ_gas-water＝-17.586339*T+51.639344*P+416.562842，R²＝0.9590 (3)

T is the formation temperature, DEG C; p is the formation pressure, MPa.

In a preferred embodiment, the average throat radius is obtained by nuclear magnetic resonance or high pressure mercury intrusion tests.

In order to more clearly and specifically describe the method for quantitatively evaluating the hydrocarbon filling capacity of the source reservoir-side type hydrocarbon reservoir provided by the embodiment of the invention, the following description is given with reference to specific embodiments.

Example 1

Taking a GG1601 single well as a Bohai Bay Wang guantun buried hill as a research area, and evaluating the buried hill at a Kondong fault which develops since ancient times, so that a rock box group reservoir layer on a lower disk of the fault is directly connected with a two-section hydrocarbon source rock on an upper disk of the fault in a side mode, and selecting a reservoir sand layer of a rock box group on a second-tier system of the well as an evaluation object.

(1) Taking 7 different reservoir sand layers of a GG1601 well two-cascade lower stone box group as sample sand layers, obtaining the formation pressure of a hole two-section hydrocarbon source rock and a lower stone box group reservoir sand layer according to formation test data and logging data, and further calculating oil gas filling power P₀(ii) a Obtaining formation temperature according to formation test dataCharacterized by calculating the oil-water interfacial tension sigma by using the formula (2)_Oil-waterThe average throat radius is obtained according to the nuclear magnetic resonance test, and because the oil gas is filled only in the late stage, the reservoir layer can be regarded as completely wet when the oil gas is filled, the wetting angle is 0 degrees, and then the oil gas filling resistance P is calculated by using the formula (1)_cThe results are shown in table 1; the difference value delta P between the oil-gas filling power and the oil-gas filling resistance corresponding to 7 sample sand layers is calculated by the method, and the result is shown in Table 1.

TABLE 1 GG1601 well 7 sample sand layer corresponding data statistics table

(2) Through reservoir rock pyrolysis experiment, obtain the oil and gas nature ST value of 7 reservoir sand beds, determine whether it can the side direction reposition of redundant personnel oil gas, the result is shown as table 1, and 7 reservoir sand beds homoenergetic take place effectively to fill and fill, and fill and have fine functional relation between difference delta P and the oil and gas nature ST of power and filling resistance:

ST＝305.7*ΔP-136.39，R²＝0.9054

from this, it was found that the critical Δ P value at which the hydrocarbon-containing ST was 0 was 0.4438 MPa.

When Δ P >0.4438MPa, effective charge of the oil and gas can occur, and otherwise, charge cannot be performed.

(3) With the G142 well middle level as the 2 reservoir sand layers of the rock setting box subgroup as unknown reservoir sand layers, the difference value Δ P between the hydrocarbon charge power and the hydrocarbon charge resistance is calculated by the method, and the result is shown in Table 2. Wherein, the Delta P of the No. 8 reservoir sand layer is more than 0.4438MPa, therefore, the evaluation result of the reservoir sand layer is that effective filling can occur; the Δ P for reservoir sand 9 was less than 0.4438MPa, and as a result, the reservoir sand was evaluated as failing to fill effectively.

Table 2G 142 well data and evaluation results corresponding to two unknown sandstone reservoirs

(4) And (5) result verification: according to the pyrolysis experimental data of the rock of the reservoir stratum of the G142 well, the oil-gas-containing ST value of the No. 8 reservoir sand layer is 8.2113mg/G rock, oil gas can be effectively filled, and the oil gas filling is consistent with the evaluation result; the oil-gas bearing ST value of No. 9 reservoir sand layer is 0, and oil gas can not be effectively filled, which is consistent with the evaluation result. Therefore, the quantitative evaluation method for the oil-gas filling capacity of the source-storage-side type oil-gas reservoir provided by the embodiment of the invention can be used for quantitatively evaluating the oil-gas filling capacity and has high evaluation accuracy.