Lithologic oil and gas reservoir resource evaluation method

Abstract

The invention provides a lithologic oil and gas reservoir resource evaluation method. The lithologic oil and gas reservoir resource evaluation method comprises the steps of collecting actual drilling data of oil and gas reservoir parameters of all single wells in an evaluation area of a lithologic oil and gas reservoir as discrete data; determining oil and gas reservoir forming geological knowledge of the evaluation area; drawing a contour map of oil and gas reservoir parameters based on oil and gas reservoir forming geological knowledge and discrete data; based on the discrete data and the contour map, establishing a data body of the oil and gas reservoir parameter value of any point in the evaluation area; determining a resource area abundance formula of the lithologic oil and gas reservoir according to a formula (1); establishing a data volume of the resource area abundance of any point in the evaluation region; approximating any point in the evaluation area as a differential area dS, and determining the resource quantity q of any point in the evaluation area according to a formula (2); and calculating the resource quantity of the lithologic oil and gas reservoir according to the formula (2) and the formula (3). The lithologic oil and gas reservoir resource evaluation method solves the problem that the evaluation result of the lithologic oil and gas reservoir resource evaluation method in the prior art is greatly deviated from the geological reality.

Description

Technical Field

[0001] The present invention relates to the field of oil and gas exploration, and in particular to a method for evaluating lithologic oil and gas reservoir resources. Background Art

[0002] The increasingly complex oil and gas exploration situation in my country requires that oil and gas resource evaluation should not only calculate the total amount of oil and gas resources, but also clarify the amount of oil and gas resources in any area (ecological protection area, mining right area, administrative area, exploration and production area, etc.). This requires an oil and gas resource evaluation method that can make a quantitative evaluation of the distribution of oil and gas resources on the plane. Among the existing oil and gas resource evaluation methods, few can make a quantitative evaluation of the distribution of oil and gas resources on the plane. Among them, only the small-surface volume method is based on the evaluation of lithological oil and gas reservoirs. However, the calculation process of the small-surface volume method lacks geological knowledge constraints, and there is no reasonable and clear definition of the "0" value boundary. At the same time, the heterogeneity of the oil and gas reservoir inside the small-surface method is ignored. In addition, the data mutation at the junction of the small-surface element does not conform to the actual geological laws. These deficiencies lead to certain defects in the precision of the resource evaluation results of the small-surface volume method.

[0003] That is to say, the existing lithologic oil and gas reservoir resource evaluation method has the problem that the evaluation results deviate greatly from the actual geology. Summary of the invention

[0004] The main purpose of the present invention is to provide a lithologic oil and gas reservoir resource evaluation method to solve the problem that the evaluation results of the lithologic oil and gas reservoir resource evaluation method in the prior art have a large deviation from the actual geology.

[0005] In order to achieve the above-mentioned object, the present invention provides a lithologic oil and gas reservoir resource evaluation method, comprising: step S10: collecting the actual drilling data of the oil and gas reservoir parameters of all single wells in the evaluation area of ​​the lithologic oil and gas reservoir, and taking the actual drilling data as discrete data; step S20: determining the geological knowledge of oil and gas accumulation in the evaluation area; step S30: drawing a contour map of the oil and gas reservoir parameters based on the geological knowledge of oil and gas accumulation and the discrete data; step S40: establishing a data body of the oil and gas reservoir parameter values ​​at any point in the evaluation area based on the discrete data and the contour map; step S50: determining the resource area abundance formula of the lithologic oil and gas reservoir according to formula (1),

[0006] Q=θ×S formula (1);

[0007] Step S60: Based on the data body of reservoir parameter values ​​and the resource area abundance formula, establish a data body of resource area abundance at any point in the evaluation area; Step S70: Approximate any point in the evaluation area as a differential area dS, and determine the resource amount q at any point in the evaluation area according to formula (2).

[0008] q=θ×dS formula (2);

[0009] Step S80: Calculate the resource volume of the lithologic oil and gas reservoir according to formula (2) and formula (3).

[0010]

[0011] Wherein, Q is the resource volume of lithologic oil and gas reservoir; θ is the resource area abundance of lithologic oil and gas reservoir; S is the resource-bearing area of ​​lithologic oil and gas reservoir; q is the resource volume of any point in the evaluation area; s1 is the area value of the first differential area in the evaluation area; s n is the area value of the nth differential area in the evaluation area, n→∞.

[0012] Furthermore, the resource of the lithologic oil and gas reservoir is petroleum, and the oil and gas reservoir parameters include effective reservoir thickness, effective reservoir porosity, oil saturation, crude oil density, and oil volume coefficient.

[0013] Further, step S50 includes: establishing a resource area abundance formula of oil, namely formula (5), according to formula (4),

[0014] Q 油 =0.01×H×φ×S O ×ρ÷B×S 油 Formula (4);

[0015] From formula (1) and formula (4), we can get:

[0016] θ 油 =0.01×H×φ×S O ×ρ÷B formula (5);

[0017] Among them, Q 油 is the amount of oil resources, in units of 10 4 t; H is the average effective thickness of the reservoir, in m; φ is the average effective porosity of the reservoir, in %; S o is the average oil saturation, in %; ρ is the oil density, in t / m 3 ; B is the oil volume coefficient, dimensionless; S 油 is the oil-bearing area of ​​the lithologic reservoir, in km 2 θ 油 is the resource area abundance of oil, in units of 10 4 t / km 2 .

[0018] Furthermore, the resource of the lithologic oil and gas reservoir is natural gas, and the oil and gas reservoir parameters include effective thickness of the gas reservoir reservoir, effective porosity of the gas reservoir reservoir, gas saturation, temperature in the middle of the gas reservoir, pressure in the middle of the gas reservoir, and natural gas deviation coefficient.

[0019] Further, step S50 includes: establishing a natural gas resource area abundance formula, namely, formula (7), according to formula (6),

[0020]

[0021] From formula (1) and formula (6), we can get:

[0022]

[0023] Among them, Q 气 is the amount of natural gas resources, in units of 10 8 m 3 ; H is the average effective thickness of the reservoir, in m; φ is the average effective porosity of the reservoir, in %; S q is the average gas saturation, in %; T SC is the surface standard temperature, in °C; P is the pressure in the middle of the gas reservoir, in MPa; T is the temperature in the middle of the gas reservoir, in °C; P SC is the surface standard pressure, in MPa; Z is the natural gas deviation coefficient, dimensionless; S 气 is the gas-bearing area of ​​the lithologic gas reservoir, in km 2 θ 气 is the resource area abundance of natural gas, in units of 10 8 m 3 / km 2 .

[0024] Further, step S40 includes: taking discrete data and contour maps as known data; estimating the values ​​of oil and gas reservoir parameters at any point in the evaluation area based on the known data; and establishing a data body of the values ​​of oil and gas reservoir parameters at any point in the evaluation area based on the values ​​of oil and gas reservoir parameters at any point in the evaluation area.

[0025] Furthermore, in the process of estimating the value of the oil and gas reservoir parameter at any point in the evaluation area based on known data, it includes: estimating the value of the oil and gas reservoir parameter at any point in the evaluation area using the Kriging interpolation method.

[0026] Further, step S80 includes: ds in formula (2) is tended to infinitesimal, and formula (8) is equivalently obtained,

[0027] q=θ Formula (8);

[0028] According to formula (8) and formula (9), we get formula (3):

[0029]

[0030] Wherein, Q is the resource volume of lithologic oil and gas reservoir; θ is the resource area abundance of lithologic oil and gas reservoir; S is the resource-bearing area of ​​lithologic oil and gas reservoir; q is the resource volume of any point in the evaluation area; s1 is the area value of the first differential area in the evaluation area; s n is the area value of the nth differential area in the evaluation area, n→∞.

[0031] By applying the technical solution of the present invention, the lithologic oil and gas reservoir resource evaluation method comprises: step S10: collecting the actual drilling data of the oil and gas reservoir parameters of all single wells in the evaluation area of ​​the lithologic oil and gas reservoir, and taking the actual drilling data as discrete data; step S20: determining the geological knowledge of oil and gas reservoir formation in the evaluation area; step S30: drawing the contour map of the oil and gas reservoir parameters based on the geological knowledge of oil and gas reservoir formation and the discrete data; step S40: establishing a data body of the oil and gas reservoir parameter values ​​at any point in the evaluation area based on the discrete data and the contour map; step S50: determining the resource area abundance formula of the lithologic oil and gas reservoir according to formula (1),

[0032] Q=θ×S formula (1);

[0033] Step S60: Based on the data body of reservoir parameter values ​​and the resource area abundance formula, establish a data body of resource area abundance at any point in the evaluation area; Step S70: Approximate any point in the evaluation area as a differential area dS, and determine the resource amount q at any point in the evaluation area according to formula (2).

[0034] q=θ×dS formula (2);

[0035] Step S80: Calculate the resource volume of the lithologic oil and gas reservoir according to formula (2) and formula (3).

[0036]

[0037] Wherein, Q is the resource volume of lithologic oil and gas reservoir; θ is the resource area abundance of lithologic oil and gas reservoir; S is the resource-bearing area of ​​lithologic oil and gas reservoir; q is the resource volume of any point in the evaluation area; s1 is the area value of the first differential area in the evaluation area; s n is the area value of the nth differential area in the evaluation area, n→∞.

[0038] By collecting the actual drilling data of the reservoir parameters of all single wells in the evaluation area of ​​the lithologic oil and gas reservoir as discrete data through step S10, the exploration status of the lithologic oil and gas reservoir to be evaluated can be mastered, and a basis is provided for estimating the values ​​of the reservoir parameters at any point in the evaluation area. By determining the geological knowledge of oil and gas accumulation in the evaluation area through step S20, and drawing the contour map of the reservoir parameters through step S30, it is conducive to combining the exploration status and geological knowledge to more finely evaluate the resource distribution. At the same time, the effective reservoir boundary is clarified in combination with the geological knowledge, that is, the "0" value boundary is reasonably and clearly defined, reducing the deviation from the actual geology. By step S40, a data body of the reservoir parameter values ​​at any point in the evaluation area will be established, fully considering the heterogeneity and continuity of each parameter on the plane, and further providing a rich data basis for estimating the resource volume at any point in the evaluation area. Through step S50 and step S60, the data provided by the above steps can be used to estimate the data body of the resource area abundance of any point in the evaluation area, and then using steps S70 and step S80, according to the thinking of calculus, any point in the evaluation area can be approximated as a differential area ds, and the resource area abundance of any point in the evaluation area can be equivalent to the resource amount of the point, that is, a quantitative evaluation is made on the distribution of the resource amount of the evaluation area on the plane, and then the total amount of oil and gas resources in the evaluation area can be obtained by performing integral calculation. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0040] Figure 1 A flow chart showing a method for evaluating lithologic oil and gas reservoir resources according to an optional embodiment of the present invention; and

[0041] Figure 2 The present invention shows the current situation of tight sandstone gas exploration in the first embodiment of the present invention;

[0042] Figure 3 Shows Figure 2 Contour map of effective sand body thickness in;

[0043] Figure 4 Shows Figure 2 The effective porosity contour map in ;

[0044] Figure 5 Shows Figure 2 Gas saturation contour map in ;

[0045] Figure 6 Shows Figure 2 Temperature contour map of the middle part of the gas reservoir;

[0046] Figure 7Shows Figure 2 The pressure contour map of the middle part of the gas reservoir in ;

[0047] Figure 8 Shows Figure 2 Contour map of natural gas deviation coefficient in;

[0048] Fig. 9 Shows Figure 2 Schematic diagram of the differential data volume of effective sand body thickness;

[0049] Fig.10 Shows Figure 2 Schematic diagram of effective porosity differential data volume in ;

[0050] Fig.11 Shows Figure 2 Schematic diagram of the differential data volume of gas saturation in ;

[0051] Fig.12 Shows Figure 2 Schematic diagram of temperature differential data volume in the middle of the gas reservoir;

[0052] Fig.13 Shows Figure 2 Schematic diagram of differential pressure data volume in the middle of the gas reservoir;

[0053] Fig.14 Shows Figure 2 Schematic diagram of the natural gas differential coefficient differential data volume;

[0054] Fig.15 Shows Figure 2 Schematic diagram of the data body showing the values ​​of the area abundance of natural gas resources in . DETAILED DESCRIPTION

[0055] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0056] It should be noted that, unless otherwise specified, all technical and scientific terms used in this application have the same meanings as commonly understood by ordinary technicians in the technical field to which this application belongs.

[0057] In the present invention, unless otherwise specified, the directional words used, such as "up, down, top, bottom", usually refer to the directions shown in the drawings, or to the components themselves in the vertical, perpendicular or gravity directions; similarly, for ease of understanding and description, "inside and outside" refer to the inside and outside relative to the outline of each component itself, but the above-mentioned directional words are not used to limit the present invention.

[0058] In order to solve the problem that the evaluation results of the lithologic oil and gas reservoir resource evaluation method in the prior art have a large deviation from the actual geology, the present invention provides a lithologic oil and gas reservoir resource evaluation method.

[0059] like Figures 1 to 15 As shown, the lithologic oil and gas reservoir resource evaluation method comprises: step S10: collecting the actual drilling data of the oil and gas reservoir parameters of all single wells in the evaluation area of ​​the lithologic oil and gas reservoir, and taking the actual drilling data as discrete data; step S20: determining the geological knowledge of oil and gas accumulation in the evaluation area; step S30: drawing the contour map of the oil and gas reservoir parameters based on the geological knowledge of oil and gas accumulation and the discrete data; step S40: establishing a data body of the oil and gas reservoir parameter values ​​at any point in the evaluation area based on the discrete data and the contour map; step S50: determining the resource area abundance formula of the lithologic oil and gas reservoir according to formula (1),

[0060] Q=θ×S formula (1);

[0061] Step S60: Based on the data body of reservoir parameter values ​​and the resource area abundance formula, establish a data body of resource area abundance at any point in the evaluation area; Step S70: Approximate any point in the evaluation area as a differential area dS, and determine the resource amount q at any point in the evaluation area according to formula (2).

[0062] q=θ×dS formula (2);

[0063] Step S80: Calculate the resource volume of the lithologic oil and gas reservoir according to formula (2) and formula (3).

[0064]

[0065] Wherein, Q is the resource volume of lithologic oil and gas reservoir; θ is the resource area abundance of lithologic oil and gas reservoir; S is the resource-bearing area of ​​lithologic oil and gas reservoir; q is the resource volume of any point in the evaluation area; s1 is the area value of the first differential area in the evaluation area; s n is the area value of the nth differential area in the evaluation area, n→∞.

[0066] By collecting the actual drilling data of the reservoir parameters of all single wells in the evaluation area of ​​the lithologic oil and gas reservoir as discrete data through step S10, the exploration status of the lithologic oil and gas reservoir to be evaluated can be grasped, and a basis is provided for estimating the values ​​of the reservoir parameters at any point in the evaluation area. By determining the geological knowledge of oil and gas accumulation in the evaluation area through step S20, and drawing the contour map of the reservoir parameters through step S30, it is conducive to combining the exploration status and geological knowledge to more finely evaluate the resource distribution. At the same time, the effective reservoir boundary is clarified in combination with the geological knowledge, that is, the "0" value boundary is reasonably and clearly defined to reduce the deviation from the actual geology. By establishing a data body of the reservoir parameter values ​​at any point in the evaluation area through step S40, the heterogeneity and continuity of each parameter on the plane are fully considered, and a rich data basis is further provided for estimating the resource volume at any point in the evaluation area. Through step S50 and step S60, the data provided by the above steps can be used to estimate the data body of the resource area abundance of any point in the evaluation area, and then using steps S70 and step S80, according to the thinking of calculus, any point in the evaluation area can be approximated as a differential area ds, and the resource area abundance of any point in the evaluation area can be equivalent to the resource amount of the point, that is, a quantitative evaluation is made on the distribution of the resource amount of the evaluation area on the plane, and then the total amount of oil and gas resources in the evaluation area can be obtained by performing integral calculation.

[0067] This application adds geological constraints to the lithologic oil and gas reservoir resource evaluation method, fully considers the heterogeneity and continuity of lithologic oil and gas reservoir parameters on the plane, achieves the purpose of quantitatively evaluating the amount of oil and gas resources and their planar distribution characteristics, and can also accurately split the amount of oil and gas resources and their planar distribution characteristics in any area of ​​the evaluation area, which can meet the needs of more refined resource evaluation work.

[0068] Specifically, oil and gas accumulation geology includes various geological conditions that affect oil and gas accumulation, such as sedimentary characteristics, reservoir characteristics, and oil and gas reservoir types, which are conducive to determining the effective reservoir boundary in combination with geological knowledge, that is, to reasonably and clearly define the "0" value boundary.

[0069] Specifically, step S40 includes: taking the discrete data and the contour map as known data; estimating the value of the reservoir parameter at any point in the evaluation area according to the known data; establishing a data body of the reservoir parameter value at any point in the evaluation area according to the reservoir parameter value at any point in the evaluation area. On this basis, according to the thinking of calculus, any point in the evaluation area is approximated as a differential area ds, then the value y of each parameter at any point can be regarded as a function that changes continuously with the corresponding ds, and the functional relationship y=f(ds) can be established.

[0070] Specifically, in the process of estimating the value of the reservoir parameters at any point in the evaluation area based on known data, it includes: using the Kriging interpolation method to estimate the value of the reservoir parameters at any point in the evaluation area. The Kriging interpolation method can be used to estimate the value of the reservoir parameters at any point in the evaluation area, and the known data can be combined to fully consider the heterogeneity and continuity of the lithologic reservoir parameters on the plane, so that the geological parameter values ​​are more in line with the geological reality.

[0071] Specifically, step S80 includes: ds in formula (2) tends to be infinitesimal, and equivalently obtains formula (8),

[0072] q=θ Formula (8);

[0073] According to formula (8) and formula (9), we get formula (3):

[0074]

[0075] Wherein, Q is the resource volume of lithologic oil and gas reservoir; θ is the resource area abundance of lithologic oil and gas reservoir; S is the resource-bearing area of ​​lithologic oil and gas reservoir; q is the resource volume of any point in the evaluation area; s1 is the area value of the first differential area in the evaluation area; s n is the area value of the nth differential area in the evaluation area, n→∞.

[0076] According to the thinking of calculus, any point in the evaluation area is approximated as the differential area ds, and the resource area abundance of any point in the evaluation area is equivalent to the resource amount of the point. That is, a quantitative evaluation is made on the distribution of the resource amount of the evaluation area on the plane. After further integral calculation, the total amount of oil and gas resources in the evaluation area can be obtained, thereby achieving the purpose of quantitative evaluation of the oil and gas resources and their planar distribution characteristics. The oil and gas resources and their planar distribution characteristics in any area of ​​the evaluation area can also be accurately split, which can meet the needs of more refined resource evaluation work.

[0077] The following will provide a more detailed explanation based on the different classifications of lithologic oil and gas reservoir resources.

[0078] Optionally, the resource of the lithologic oil and gas reservoir is petroleum, and the oil and gas reservoir parameters include effective reservoir thickness, effective reservoir porosity, oil saturation, crude oil density, and oil volume coefficient.

[0079] Specifically, step S50 includes: establishing the resource area abundance formula of oil according to formula (4), that is, formula (5),

[0080] Q 油 =0.01×H×φ×S O ×ρ÷B×S 油 Formula (4);

[0081] From formula (1) and formula (4), we can get:

[0082] θ 油 =0.01×H×φ×S O ×ρ÷B formula (5);

[0083] Among them, Q 油 is the amount of oil resources, in units of 10 4 t; H is the average effective thickness of the reservoir, in m; φ is the average effective porosity of the reservoir, in %; S o is the average oil saturation, in %; ρ is the oil density, in t / m 3 ; B is the oil volume coefficient, dimensionless; S 油 is the oil-bearing area of ​​the lithologic reservoir, in km 2 θ 油 is the resource area abundance of oil, in units of 10 4 t / km 2 .

[0084] It should be noted that formula (4) is obtained by transforming the oil volume formula, namely formula (10).

[0085] Q 油 =0.01×S×H×φ×S O ×ρ÷B formula (10).

[0086] It should be noted that when calculating the amount of oil resources, formula (12) can be obtained from formula (3).

[0087]

[0088] Optionally, the resource of the lithologic oil and gas reservoir is natural gas, and the oil and gas reservoir parameters include effective thickness of the gas reservoir reservoir, effective porosity of the gas reservoir reservoir, gas saturation, middle temperature of the gas reservoir, middle pressure of the gas reservoir, and natural gas deviation coefficient.

[0089] Specifically, step S50 includes: establishing a natural gas resource area abundance formula, namely, formula (7), according to formula (6),

[0090]

[0091] From formula (1) and formula (6), we can get:

[0092]

[0093] Among them, Q 气 is the amount of natural gas resources, in units of 10 8 m 3 ; H is the average effective thickness of the reservoir, in m; φ is the average effective porosity of the reservoir, in %; S qis the average gas saturation, in %; T SC is the surface standard temperature, in °C; P is the pressure in the middle of the gas reservoir, in MPa; T is the temperature in the middle of the gas reservoir, in °C; P SC is the surface standard pressure, in MPa; Z is the natural gas deviation coefficient, dimensionless; S 气 is the gas-bearing area of ​​the lithologic gas reservoir, in km 2 θ 气 is the resource area abundance of natural gas, in units of 10 8 m 3 / km 2 .

[0094] It should be noted that formula (6) is obtained by transforming the natural gas volume formula, namely formula (11).

[0095]

[0096] It should be noted that when calculating the amount of natural gas resources, formula (13) can be obtained from formula (3).

[0097]

[0098] Embodiment 1

[0099] like Figures 1 to 15 As shown in the figure, this example selects a dense sandstone lithology gas reservoir evaluation area, which covers an area of ​​6822 square kilometers. The area has a natural gas reserve area of ​​3995 square kilometers, accounting for 58.56% of the evaluation area, and the exploration degree is relatively high. The area has a third-level natural gas reserve of 203.1 billion cubic meters, and the reserve area abundance is 0.51×10 8 m 3 / km 2 ,like Figure 2 This embodiment specifically carries out the evaluation of natural gas resources according to the implementation steps of the present invention.

[0100] Specifically, the actual drilling data of the effective thickness of the gas reservoir, effective reservoir porosity, gas saturation, temperature in the middle of the gas reservoir, pressure in the middle of the gas reservoir, and natural gas deviation coefficient of 138 exploration wells in the area were counted as discrete data, and the statistical data of the evaluation parameters are shown in Table 1. The geological understanding of natural gas accumulation in the area is clarified as follows: the sedimentary phase of the river delta front is developed, mainly including two sedimentary microphases: underwater distributary channel and inter-distributary bay. The effective reservoir for natural gas accumulation is the underwater distributary channel sand body distributed continuously from north to south, and the gas reservoir type is a tight sandstone lithologic gas reservoir. The boundary of the evaluation area was determined. Figure 2 The rectangular area shown.

[0101] parameter Number of data Value range Effective sand body thickness (m) 138 0-30.4 Reservoir effective porosity (%) 38 3.86-11.5 Gas saturation (%) 34 38-100 Temperature in the middle of gas reservoir (℃) 138 116.92-119.33 Gas reservoir center pressure (MPa) 138 31-31.83 Natural gas deviation coefficient 135 0.981-1.001

[0102] Table 1

[0103] Specifically, based on the above geological knowledge and combined with the effective reservoir thickness data of the actual drilling, the effective reservoir boundary is determined (i.e. the "0" value boundary is reasonably and clearly defined). On this basis, contour maps of the effective reservoir thickness, effective reservoir porosity, gas saturation, central temperature of the gas reservoir, central pressure of the gas reservoir, and natural gas deviation coefficient of the evaluation area are drawn, such as Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7 , Figure 8 As shown. Take the discrete data and contour data of each parameter as known data.

[0104] Specifically, based on the above known data, the Kriging interpolation method is used to estimate the values ​​of the effective thickness of the gas reservoir, the effective porosity of the reservoir, the gas saturation, the middle temperature of the gas reservoir, the middle pressure of the gas reservoir, and the natural gas deviation coefficient at any unknown point in the evaluation area, and then the values ​​of the effective thickness of the gas reservoir, the effective porosity of the reservoir, the gas saturation, the middle temperature of the gas reservoir, the middle pressure of the gas reservoir, and the natural gas deviation coefficient at all arbitrary points in the evaluation area are obtained, thereby establishing the data body of the effective thickness of the gas reservoir, the effective porosity of the reservoir, the gas saturation, the middle temperature of the gas reservoir, the middle pressure of the gas reservoir, and the natural gas deviation coefficient at any point in the evaluation area, such as Fig. 9 , Fig.10 , Fig.11 , Fig.12 , Fig.13 , Fig.14 As shown, the heterogeneity and continuity of various parameters on the plane are fully considered.

[0105] Specifically, according to the data body of the values ​​of each of the above parameters at any point in the evaluation area, the data body of the area abundance value of natural gas resources at any point in the evaluation area can be obtained according to formula (7), such as Fig.15 As shown in the figure, the area abundance of natural gas resources at any point in the evaluation area is equivalent to the natural gas resources at that point, which means that a quantitative evaluation is made on the distribution of the natural gas resources in the evaluation area on the plane.

[0106] Specifically, according to the thinking of calculus, the data body of the area abundance of natural gas resources in the above evaluation area is integrated according to formula (13), and the total amount of natural gas resources in the evaluation area is 3187×10 8 m 3 , the resource area abundance is 0.47×10 8 m 3 / km 2 The evaluation results match the actual exploration level and the status of the third-level reserves in the evaluation area, and the evaluation results are within a reasonable range.

[0107] From the above description, it can be seen that the above embodiments of the present invention achieve the following technical effects:

[0108] 1. By collecting the actual drilling data of the reservoir parameters of all single wells in the evaluation area of ​​the lithologic reservoir as discrete data through step S10, the exploration status of the lithologic reservoir to be evaluated can be grasped, providing a basis for estimating the reservoir parameter values ​​at any point in the evaluation area.

[0109] 2. The geological understanding of oil and gas accumulation in the evaluation area is determined through step S20, and the contour map of oil and gas reservoir parameters is drawn through step S30, which is conducive to combining the exploration status and geological understanding to more accurately evaluate the resource distribution. At the same time, the effective reservoir boundary is clarified in combination with the geological understanding, that is, the "0" value boundary is reasonably and clearly defined to reduce the deviation from the actual geology.

[0110] 3. Step S40 will establish a data body of reservoir parameter values ​​at any point in the evaluation area, taking full account of the heterogeneity and continuity of each parameter on the plane, and further provide a rich data basis for estimating the resource volume at any point in the evaluation area.

[0111] 4. Through step S50 and step S60, the data provided by the above steps can be used to estimate the data body of the resource area abundance of any point in the evaluation area, so as to use steps S70 and step S80, according to the thinking of calculus, approximate any point in the evaluation area to the differential area ds, and equate the resource area abundance of any point in the evaluation area to the resource amount of the point, that is, a quantitative evaluation is made on the distribution of the resource amount of the evaluation area on the plane, and then the total amount of oil and gas resources in the evaluation area can be obtained by performing integral calculation.

[0112] Obviously, the above-described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0113] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0114] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein.

[0115] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for evaluating lithologic oil and gas reservoir resources, characterized in that: include: Step S10: collecting actual drilling data of oil and gas reservoir parameters of all single wells in the evaluation area of ​​lithologic oil and gas reservoirs, and using the actual drilling data as discrete data; Step S20: Determine the geological knowledge of oil and gas accumulation in the evaluation area; Step S30: based on the geological knowledge of oil and gas reservoir formation and the discrete data, draw a contour map of the oil and gas reservoir parameters; Step S40: establishing a data body of the oil and gas reservoir parameter values ​​at any point in the evaluation area based on the discrete data and the contour map; Step S50: Determine the resource area abundance formula of the lithologic oil and gas reservoir according to formula (1), Q=θ×S formula (1); Step S60: establishing a data body of resource area abundance at any point in the evaluation area according to the data body of the oil and gas reservoir parameter values ​​and the resource area abundance formula; Step S70: Approximate any point in the evaluation area as a differential area dS, and determine the resource quantity q of any point in the evaluation area according to formula (2). q=θ×dS formula (2); Step S80: Calculate the resource volume of the lithologic oil and gas reservoir according to the formula (2) and formula (3). Among them, Q is the resource volume of lithologic oil and gas reservoirs; θ is the resource area abundance of lithologic oil and gas reservoirs; S is the resource-bearing area of ​​lithologic oil and gas reservoirs; q is the resource volume at any point in the evaluation area; s1 is the area value of the first differential area in the evaluation area; s n is the area value of the nth differential area in the evaluation area, n→∞.

2. The lithologic oil and gas reservoir resource evaluation method according to claim 1, characterized in that: The resource of the lithologic oil and gas reservoir is petroleum, and the oil and gas reservoir parameters include effective thickness of the reservoir, effective porosity of the reservoir, oil saturation, crude oil density, and oil volume coefficient.

3. The lithologic oil and gas reservoir resource evaluation method according to claim 2, characterized in that: The step S50 includes: establishing the resource area abundance formula of the oil according to formula (4), that is, formula (5), Q 油 = 0.01 x H x φ x S O ×ρ÷B×S 油 Formula (4): From the formula (1) and formula (4), we can get: θ 油 =0.01×H×φ×S O ×ρ÷B formula (5); Among them, Q 油 is the amount of oil resources, in units of 10 4 t; H is the average effective thickness of the reservoir, in m; φ is the average effective porosity of the reservoir, in %; S o is the average oil saturation, in %; ρ is the oil density, in t / m 3 ; B is the oil volume coefficient, dimensionless; S 油 is the oil-bearing area of ​​the lithologic reservoir, in km 2 θ 油 is the resource area abundance of oil, in units of 10 4 t / km 2 .

4. The lithologic oil and gas reservoir resource evaluation method according to claim 1, characterized in that: The resource of the lithologic oil and gas reservoir is natural gas, and the oil and gas reservoir parameters include effective thickness of the gas reservoir reservoir, effective porosity of the gas reservoir reservoir, gas saturation, temperature in the middle of the gas reservoir, pressure in the middle of the gas reservoir, and natural gas deviation coefficient.

5. The lithologic oil and gas reservoir resource evaluation method according to claim 4, characterized in that: The step S50 comprises: establishing the resource area abundance formula of the natural gas according to formula (6), namely formula (7), From the formula (1) and formula (6), we can get: Among them, Q 气 is the amount of natural gas resources, in units of 10 8 m 3 ; H is the average effective thickness of the reservoir, in m; φ is the average effective porosity of the reservoir, in %; S q is the average gas saturation, in %; T SC is the surface standard temperature, in °C; P is the pressure in the middle of the gas reservoir, in MPa; T is the temperature in the middle of the gas reservoir, in °C; P SC is the surface standard pressure, in MPa; Z is the natural gas deviation coefficient, dimensionless; S 气 is the gas-bearing area of ​​the lithologic gas reservoir, in km 2 θ 气 is the resource area abundance of natural gas, in units of 10 8 m 3 / km 2 .

6. The lithologic oil and gas reservoir resource evaluation method according to any one of claims 1 to 5, characterized in that: The step S40 comprises: Taking the discrete data and the contour map as known data; Based on the known data, estimating the value of the reservoir parameter at any point in the evaluation area; According to the values ​​of the oil and gas reservoir parameters at any point in the evaluation area, a data body of the values ​​of the oil and gas reservoir parameters at any point in the evaluation area is established.

7. The lithologic oil and gas reservoir resource evaluation method according to claim 6, characterized in that: The process of estimating the value of the oil and gas reservoir parameter at any point in the evaluation area based on the known data includes: estimating the value of the oil and gas reservoir parameter at any point in the evaluation area using the Kriging interpolation method.

8. The method for evaluating lithologic oil and gas reservoir resources according to any one of claims 1 to 5, characterized in that: The step S80 includes: When ds in formula (2) is reduced to infinity, we can get formula (8): q=θ Formula (8); According to Formula (8) and Formula (9), Formula (3) is obtained, Among them, Q is the resource volume of lithologic oil and gas reservoirs; θ is the resource area abundance of lithologic oil and gas reservoirs; S is the resource-bearing area of ​​lithologic oil and gas reservoirs; q is the resource volume at any point in the evaluation area; s1 is the area value of the first differential area in the evaluation area; s n is the area value of the nth differential area in the evaluation area, n→∞.

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