A method and device for evaluating the control potential of water drive multilayer sandstone oilfield oil wells

Abstract

The present application relates to the technical field of oil exploration and development, and particularly relates to a water drive multilayer sandstone oilfield well lifting control potential evaluation method and device, the method comprising: determining whether well or layer remaining geological reserves and remaining reserves quality exceed corresponding block average value, if both exceed, it is class one, if both do not exceed, it is class three; determining whether well or layer water content and liquid production rate are lower than corresponding block average value, if both are lower than, it is class one, if both are not lower than, it is class three, otherwise, it is class two; if both two class division results are class one, it is preferential liquid lifting, if both are class three, it is preferential liquid control, if one is class one and the other is class two or class three, or both are class two, it is suboptimal liquid lifting, if one is class three and the other is class two, it is suboptimal liquid control. The present application avoids the drawbacks of single method evaluation, further improves the reliability and accuracy of single well lifting control measures, and provides an important evaluation means for continuously improving development effect and improving recovery rate of oilfields in the later development stage.

Description

Technical Field

[0001] This invention relates to the field of petroleum exploration and development technology, and in particular to a method and apparatus for evaluating the uplift potential of oil wells in water-driven multi-layered sandstone oilfields. Background Technology

[0002] Water injection is the main extraction method in my country's oilfields. Most of my country's oilfields have entered the high and ultra-high water-cut stage, and are in the late development stage, accounting for over 80% of geological reserves and crude oil production. The core of improving development efficiency and increasing recovery rate in water-driven multi-layered sandstone oilfields is controlling the extraction rate of high water-cut wells and increasing the extraction rate of low water-cut wells. Generally, the potential for well extraction and control is determined based on two dynamic indicators: water cut and flowing pressure. Wells with low water cut and high flowing pressure are subjected to fluid extraction, while wells with high water cut and low flowing pressure are subjected to fluid control. In other cases, stable fluid production is maintained. Because this method is simple, direct, and easy to implement, it is widely used in actual field operations. However, its shortcomings lie in not considering the impact of static indicators, especially reserves, and the influence of individual layers. Especially for multi-layered sandstone oilfields entering the high and ultra-high water-cut stage, relying solely on these two dynamic indicators for adjustment often leads to adverse effects. Fluid extraction causes a rapid increase in water cut and a decrease in oil production, while fluid control further accelerates the decline in fluid and oil production, resulting in a large number of inefficient and ineffective wells. Therefore, there is an urgent need to establish an evaluation method to determine the lifting and control potential of oil wells in the later stages of water-drive multi-layered sandstone oilfield development, so as to more accurately determine the direction of lifting and control adjustment of oil wells. Summary of the Invention

[0003] This invention proposes a method and apparatus for evaluating the lifting potential of oil wells in water-driven multi-layered sandstone oilfields. This addresses the problem that existing methods for evaluating the lifting potential of oil wells only consider water cut and flowing pressure, without taking into account the influence of static indicators and single-layer effects. This leads to a rapid increase in water cut, a decrease in oil production, and an excessively rapid decline in both fluid production and oil production, resulting in a large number of inefficient and ineffective wells.

[0004] According to one aspect of the present invention, a method for evaluating the uplift potential of oil wells in water-drive multi-layered sandstone oilfields is provided, comprising:

[0005] Obtain the remaining geological reserves, remaining reserve quality, water cut, and fluid production rate of a single well and single layer in the target block;

[0006] The target well or target layer is classified into the first category, including: determining whether the remaining geological reserves and the quality of the remaining reserves of the target well or target layer exceed the average value of the corresponding block. If both exceed the average value, it is classified into the first category; if neither exceeds the average value, it is classified into the third category; otherwise, it is classified into the second category.

[0007] The target well or target layer is classified into a second category, which includes: determining whether the water cut and fluid production rate of the target well or target layer are lower than the corresponding block average. If both are lower, it is classified as Category 1; if both are not lower, it is classified as Category 3; otherwise, it is classified as Category 2.

[0008] If both the first and second category classification results are of the same category, then the target well or target layer is a well or layer with priority in fluid extraction potential. If both are of the same category, then it is a well or layer with priority in fluid control potential. If one is of the same category and the other is of the same category or the same category, or both are of the same category, then it is a well or layer with secondary potential for fluid extraction. If one is of the same category and the other is of the same category, then it is a well or layer with secondary potential for fluid control.

[0009] Preferably, before obtaining the remaining geological reserves of a single well and a single layer in the target block, the remaining geological reserves of a single well and a single layer are determined, and the method includes:

[0010] Obtain the geological reserves of the block;

[0011] Based on the geological reserves of the block, determine the geological reserves of a single well and a single layer;

[0012] Based on the geological reserves of a single well and a single layer, determine the remaining geological reserves of the single well and a single layer.

[0013] Preferably, before obtaining the geological reserves of the block, the method for determining the geological reserves of the block includes:

[0014] If the relative permeability curve of the block can be obtained, the geological reserves N of the block can be determined using equation (1-1) or (1-2);

[0015]

[0016] In the formula: A1 and B1 are the coefficients of the Type A water drive curve, which are dimensionless; A2 and B2 are the coefficients of the Type C water drive curve, which are dimensionless; a1, b1, a2, and b2 are coefficients obtained by fitting the relative permeability curve, which are dimensionless.

[0017] Preferably, a1, b1, a2, and b2 in equations (1-1) and (1-2) are determined by fitting the following equations (2-1) and (2-2);

[0018]

[0019] In the formula: R represents the degree of geological reserve extraction; f w It contains water.

[0020] Preferably, if a type C water drive curve cannot be obtained, the geological reserves N of the block are determined using equation (3-1) or (3-2);

[0021] N = C / B1 (3-1);

[0022] Where, C = 2(n w +n o ) / E d ln10 (3-2);

[0023] In the formula: B1 is the slope of the type A water drive curve, which is dimensionless; n o n w Oil phase and water phase indices, dimensionless; E d The value is the oil displacement efficiency, expressed as a percentage; N represents the geological reserves.

[0024] Preferably, in formula (3-2), the oil phase index n o Water phase index n w The results are obtained by fitting the relative permeability curve using the following equations (4-1) and (4-2);

[0025]

[0026] in:

[0027] Where: n o For oil phase index, f; n w For the aqueous phase index, f; S wi For bound water saturation, f; S or For residual oil saturation, f; K rw (where f is the relative permeability of the aqueous phase; K is the relative permeability of the aqueous phase) ro (where f is the relative permeability of the oil phase; K is the relative permeability of the oil phase) rw (S or ) represents the relative permeability of the residual oil to the aqueous phase at saturation, f; K ro (S wi f represents the relative permeability of the oil phase at bound water saturation; S represents the relative permeability of the oil phase at the bound water saturation level. w f; S represents the average water saturation. wd f represents the normalized water saturation.

[0028] Preferably, if oil displacement efficiency cannot be obtained, the geological reserves of the block are determined using equation (5-1);

[0029] N = 7.5422 / B1 0.969 (5-1);

[0030] In the formula: N is the geological reserves, 10 4 t; B1 is the slope of the type A water drive curve, dimensionless.

[0031] Preferably, the method for determining the geological reserves of a single well and a single layer based on the geological reserves of the block includes:

[0032] The geological reserves of the block are divided into single wells and single layers to obtain single-layer geological reserves;

[0033] The geological reserves of a single well are determined based on the geological reserves of the single layer obtained from the splitting.

[0034] Preferably, the method for dividing the geological reserves of the block into single wells and single layers includes:

[0035] Using equation (6), the geological reserves of a single layer are determined;

[0036] N ix =r ix N t (6);

[0037] Where: N t For the geological reserves of the block, 10 4 t; N ix For the geological reserves of the i-th well and the x-th layer in the block, 10 4 t;r ix is the splitting coefficient for a single well and a single layer, dimensionless.

[0038] Preferably, in equation (6), the splitting coefficient r ix Calculated using equation (7);

[0039]

[0040] In the formula: b ix Let x be the single reservoir coefficient of the x-th layer in the i-th well, 10 4 t / (m·km 2 );h ix Let x be the effective thickness of the x-th layer in the i-th well, in m.

[0041] Preferably, the method for determining the remaining geological reserves of a single well and single layer based on the geological reserves of the single well and single layer includes:

[0042] Obtain the cumulative oil production of a single well in the block;

[0043] The remaining geological reserves of a single well are determined based on its geological reserves and cumulative oil production.

[0044] The cumulative oil production is divided into individual layers, and the remaining geological reserves of each layer are determined based on the cumulative oil production of the individual layers obtained after division.

[0045] Preferably, the method for determining the remaining geological reserves of a single well based on its geological reserves and cumulative oil production includes:

[0046] The remaining geological reserves of a single well are determined using equation (8);

[0047] N Ri =N i -N pi (8);

[0048] Where: N Ri For the remaining geological reserves of the i-th well, 10 4 t; N pi For the cumulative oil production of the i-th well, 10 4 t; N i For single-well geological reserves, 10 4 t.

[0049] Preferably, the method for dividing the cumulative oil production into a single layer includes:

[0050] The cumulative oil production of a single layer is determined using equation (9);

[0051] N pix =r jx ×N pi (9);

[0052] Where: N pix For the cumulative oil production of the i-th well in the x-th layer, 10 4 t;r jx N is the splitting coefficient, dimensionless; pi For the cumulative oil production of the i-th well, 10 4 t.

[0053] Preferably, the splitting coefficient r in equation (9) jx It is calculated using equation (10) or (11);

[0054]

[0055] Where: R is the total recovery rate of the coring well, %; R i The recovery rate (%) of the i-th layer in the core well; N ix For the geological reserves of the i-th well and the x-th layer in the block, 10 4 t;

[0056]

[0057] In the formula: k ix Let mD be the permeability of the x-th layer in the i-th well; h be the permeability of the x-th layer in the i-th well. ix Let x be the effective thickness of the x-th layer in the i-th well, in meters.

[0058] Preferably, the method for determining the remaining geological reserves of a single layer based on the cumulative oil production obtained after splitting the layer includes:

[0059] The remaining geological reserves of a single layer can be calculated using equation (12);

[0060] N Rix =N ix -N pix(12);

[0061] Where: N Rix For the remaining geological reserves of the x-th layer in the i-th well, 10 4 t; N ix For the geological reserves of the i-th well and the x-th layer in the block, 10 4 t; N pix For the cumulative oil production of the i-th well in the x-th layer, 10 4 t.

[0062] Preferably, before obtaining the remaining reserve quality of the target block, the method for determining the remaining reserve quality includes:

[0063] The quality of the remaining reserves is determined using equation (13);

[0064] G Rix =N Rih / N Ri (13);

[0065] In the formula: G Ri The remaining reserves quality of the i-th well is %, %; N Rih For the remaining geological reserves of the oil layer with an effective thickness ≥ 1m in the i-th well, 10 4 t.

[0066] Preferably, before obtaining the water-bearing content of a single well and a single layer in the target block, the method for determining the water-bearing content of the single layer includes:

[0067] The water content of the single layer is calculated using formula (14) based on the water content of the single well.

[0068]

[0069] In the formula: f iw The water content of the i-th well is %, %; Q lix The production rate of the x-th layer in the i-th well as measured by the production profile is 10. 4 t; Q li For the production rate of the i-th well, 10 4 t;f iwx The water cut of the x-th layer in the i-th well, as measured in the production profile, is %.

[0070] Preferably, the method for determining the fluid collection rate before obtaining the fluid collection rate of the target block includes:

[0071] The single-well fluid production rate is determined using equation (15);

[0072] v i =Q li / N i (15);

[0073] In the formula: v i Q is the fluid production rate of the i-th well, %; li For the production rate of the i-th well, 10 4 t; N i For single-well geological reserves, 10 4 t;

[0074] The single-layer liquid collection rate is determined using equation (16);

[0075] v ix =Q lix / N ix (16);

[0076] In the formula: v ix The fluid production rate (%) of the x-th layer in the i-th well; N ix For the geological reserves of the i-th well and the x-th layer in the block, 10 4 t; Q lix The production volume of the x-th layer in the i-th well is measured for the production profile.

[0077] Preferably, if both the first category classification result and the second category classification result are of category two, then the target well or target layer is a stable fluid well or layer.

[0078] According to one aspect of the present invention, a device for evaluating the uplift potential of wells in water-drive multi-layered sandstone oilfields is provided, comprising:

[0079] The acquisition unit is used to acquire the remaining geological reserves, remaining reserve quality, water cut, and fluid production rate of a single well and single layer in the target block.

[0080] The first category division unit is used to classify the target well or target layer into the first category, including: determining whether the remaining geological reserves and the quality of the remaining reserves of the target well or target layer exceed the average value of the corresponding block. If both exceed, it is classified as Category 1; if neither exceeds, it is classified as Category 3; otherwise, it is classified as Category 2.

[0081] The second category division unit is used to classify the target well or target layer into a second category, including: determining whether the water cut and fluid production rate of the target well or target layer are lower than the corresponding block average. If both are lower, it is classified as Category I; if both are not lower, it is classified as Category III; otherwise, it is classified as Category II.

[0082] The comprehensive evaluation unit is used to determine the target well or layer as having priority in fluid extraction potential if both the first and second category classification results are of the same category; if both are of the same category, it is a priority in fluid control potential; if one is of the same category and the other is of the same category or the same category, or both are of the same category, it is a suboptimal well or layer in terms of fluid extraction potential; and if one is of the same category and the other is of the same category, it is a suboptimal well or layer in terms of fluid control potential.

[0083] The present invention has at least the following beneficial effects:

[0084] A method and apparatus for evaluating the lifting potential of wells in water-driven multi-layered sandstone oilfields have been developed. This method addresses the shortcomings of previous methods by adding reserve parameters such as remaining geological reserves and remaining reserve quality, thus overcoming the lack of static indicators. Furthermore, the introduction of fluid production rate makes the method more consistent with the characteristics of oilfields in the later stages of development. The combination of static and dynamic indicators to determine well layers with lifting potential ensures the accuracy of the evaluation, avoids the drawbacks of relying on a single method, and further improves the reliability and accuracy of single-well lifting measures. This provides an important evaluation tool for continuously improving development effects and enhancing recovery rates in oilfields in the later stages of development. Attached Figure Description

[0085] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present invention and, together with the specification, serve to explain the technical solutions of the present invention.

[0086] Figure 1 A flowchart illustrating the method for evaluating the uplift potential of water-driven multi-layered sandstone oilfields according to an embodiment of the present invention is shown.

[0087] Figure 2 This diagram illustrates the principle of a first category classification according to an embodiment of the present invention;

[0088] Figure 3 This diagram illustrates the principle of the second category classification according to an embodiment of the present invention;

[0089] Figure 4 This diagram shows the classification results of oil well reserves in the South Eighth Zone according to an embodiment of the present invention.

[0090] Figure 5 This diagram illustrates the classification results of development indicators in the eight southern districts according to an embodiment of the present invention.

[0091] Figure 6 This diagram illustrates the distribution of the well network of priority fluid extraction wells in the South Eighth District according to an embodiment of the present invention.

[0092] Figure 7 The diagram shows the distribution of the priority fluid control wells in the South Eighth District according to an embodiment of the present invention. Detailed Implementation

[0093] Various exemplary embodiments, features, and aspects of the present invention will now be described in detail with reference to the accompanying drawings. The same reference numerals in the drawings denote elements that have the same or similar functions. Although various aspects of the embodiments are shown in the drawings, they are not necessarily drawn to scale unless specifically indicated otherwise.

[0094] The term “exemplary” as used herein means “serving as an example, embodiment, or illustration.” Any embodiment illustrated herein as “exemplary” is not necessarily to be construed as superior to or better than other embodiments.

[0095] In this document, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent three cases: A alone, A and B simultaneously, and B alone. Furthermore, the term "at least one" in this document means any combination of at least two of any one or more elements. For example, including at least one of A, B, and C can mean including any one or more elements selected from the set consisting of A, B, and C.

[0096] Furthermore, to better illustrate the present invention, numerous specific details are set forth in the following detailed embodiments. Those skilled in the art will understand that the present invention can be practiced without certain specific details. In some instances, methods, means, elements, and circuits well known to those skilled in the art have not been described in detail in order to highlight the spirit of the invention.

[0097] Figure 1 A flowchart illustrating the method for evaluating the uplift potential of water-driven multi-layered sandstone oilfields according to an embodiment of the present invention is shown. Figure 2 This diagram illustrates the principle of a first category classification according to an embodiment of the present invention; Figure 3 This diagram illustrates the principle of the second category classification according to an embodiment of the present invention; Figure 4 This diagram shows the classification results of oil well reserves in the South Eighth Zone according to an embodiment of the present invention. Figure 5 This diagram illustrates the classification results of development indicators in the eight southern districts according to an embodiment of the present invention. Figure 6 This diagram illustrates the distribution of the well network of priority fluid extraction wells in the South Eighth District according to an embodiment of the present invention. Figure 7 A well network distribution diagram of priority fluid control wells in the South Eighth District according to an embodiment of the present invention is shown. Figure 1-7As shown, a method for evaluating the uplift potential of water-driven multi-layer sandstone oilfield wells includes: Step S01: Obtaining the remaining geological reserves, remaining reserve quality, water cut, and fluid production rate of a single well and single layer in the target block; Step S02: Classifying the target well or target layer into a first category, including: determining whether the remaining geological reserves and remaining reserve quality of the target well or target layer exceed the corresponding block average. If both exceed, it is classified as Category I; if neither exceeds, it is classified as Category III; otherwise, it is classified as Category II; Step S03: Classifying the target well or target layer into a second category, including: determining whether the remaining geological reserves and remaining reserve quality of the target well or target layer exceed the corresponding block average. If the water cut and fluid production rate of the target well or target layer are lower than the average value of the corresponding block, then it is classified as Category I; if both are not lower, then it is classified as Category III; otherwise, it is classified as Category II. Step S04: If the first category classification result and the second category classification result are both Category I, then the target well or target layer is a priority fluid production potential well or layer; if both are Category III, then it is a priority fluid control potential well or layer; if one is Category I and the other is Category II or III, then it is a secondary priority fluid production potential well or layer; if one is Category III and the other is Category II, then it is a secondary priority fluid control potential well or layer.

[0098] The method for evaluating the uplift potential of water-driven multi-layered sandstone oilfield wells provided in this embodiment of the invention specifically includes the following steps:

[0099] Step S01: Obtain the remaining geological reserves, remaining reserve quality, water cut, and fluid production rate of a single well and single layer in the target block.

[0100] In this invention, before obtaining the remaining geological reserves of a single well and a single layer in a target block, the remaining geological reserves of a single well and a single layer are determined. The method includes: obtaining the geological reserves of the block; determining the geological reserves of a single well and a single layer based on the geological reserves of the block; and determining the remaining geological reserves of a single well and a single layer based on the geological reserves of the single well and a single layer.

[0101] In this invention, the method for determining the geological reserves of a block before obtaining the geological reserves of the block includes: if a relative permeability curve of the block can be obtained, then the geological reserves N of the block are determined using formula (1-1) or (1-2).

[0102]

[0103] In the formula: A1 and B1 are the coefficients of the Type A water drive curve, which are dimensionless; A2 and B2 are the coefficients of the Type C water drive curve, which are dimensionless; a1, b1, a2, and b2 are coefficients obtained by fitting the relative permeability curve, which are dimensionless.

[0104] In this embodiment of the invention, the most important static indicators for evaluating the lifting potential of a single well and a single layer are geological reserves and remaining geological reserves, which are the foundation and core of oilfield development. The geological reserves of a single well and a single layer can be obtained by dividing the geological reserves of a block (development unit). The geological reserves of a developed oilfield block (development unit) can be calculated using dynamic methods.

[0105] The method for determining the geological reserves of a block using formulas (1-1) and (1-2) is a combination of theoretical and practical methods, specifically the method of using relative permeability curves and water drive curves. Formula (1-1) requires obtaining the coefficients of the type A water drive curve for the work area, while formula (1-2) requires obtaining the coefficients of the type C water drive curve. The appropriate formula is selected for calculation based on the type of parameters that are actually available.

[0106] In this invention, a1, b1, a2, and b2 in equations (1-1) and (1-2) are determined by fitting the following equations (2-1) and (2-2);

[0107]

[0108] In the formula: R represents the degree of geological reserve extraction; f w It contains water.

[0109] In this embodiment of the invention, the coefficients a1 and b1 in the above formulas (1-1) and (1-2) are obtained by fitting the relative permeability curve of the work area using formula (2-1); the coefficients a2 and b2 are obtained by fitting the relative permeability curve of the work area using formula (2-1). Substituting the fitted a1 and b1 into formula (1-1) or the fitted a2 and b2 into formula (1-2), and combining the coefficients of the type A water drive curve or the type C water drive curve, the geological reserves N of the block are calculated.

[0110] In this invention, if the type C water drive curve cannot be obtained, the geological reserves N of the block are determined using formula (3-1) or (3-2);

[0111] N = C / B1 (3-1);

[0112] Where, C = 2(n w +n o ) / E d ln10 (3-2);

[0113] In the formula: B1 is the slope of the type A water drive curve, which is dimensionless; n o n w Oil phase and water phase indices, dimensionless; E d The value is the oil displacement efficiency, expressed as a percentage; N represents the geological reserves.

[0114] In this embodiment of the invention, the method for obtaining geological reserves using equation (3-1) is the oil-water phase index method. When a large number of parameters are available, equation (1-1) or (1-2) is preferred for calculating geological reserves. If corresponding parameters are lacking, such as the type C water drive curve and / or the recovery degree of geological reserves and / or water content, but the oil displacement efficiency can be obtained and the oil and water phase indices can be obtained by fitting the relative permeability curve, then equation (3-1) can be used to calculate the geological reserves.

[0115] In this invention, the oil phase index n in formula (3-2) o Water phase index n w The results are obtained by fitting the relative permeability curve using the following equations (4-1) and (4-2);

[0116]

[0117] in:

[0118] Where: n o For oil phase index, f; n w For the aqueous phase index, f; S wi For bound water saturation, f; S or For residual oil saturation, f; K rw (where f is the relative permeability of the aqueous phase; K is the relative permeability of the aqueous phase) ro (where f is the relative permeability of the oil phase; K is the relative permeability of the oil phase) rw (S or ) represents the relative permeability of the residual oil to the aqueous phase at saturation, f; K ro (S wi f represents the relative permeability of the oil phase at bound water saturation; S represents the relative permeability of the oil phase at the bound water saturation level. w f; S represents the average water saturation. wd f represents the normalized water saturation.

[0119] In this embodiment of the invention, the bound water saturation, residual oil saturation, and the relative permeability of the water phase and oil phase determined according to the relative permeability curve are substituted into equations (4-1) and (4-2) to obtain the oil phase index and water phase index. Then, the fitted oil phase index and water phase index are substituted into equation (3-2) to calculate the corresponding parameter C, and C is substituted into equation (3-1) to calculate the geological reserves.

[0120] In this invention, if oil displacement efficiency cannot be obtained, the geological reserves of the block are determined using formula (5-1).

[0121] N = 7.5422 / B1 0.969 (5-1);

[0122] In the formula: N is the geological reserves, 10 4t; B1 is the slope of the type A water drive curve, dimensionless.

[0123] In this embodiment of the invention, the method for obtaining geological reserves by formula (5-1) is the classical statistical method, wherein formula (5-1) is an improved formula of the following formula (5-2).

[0124] N = 7.5 / B1(5-2).

[0125] If parameters such as relative permeability curves are available, equation (1-1) or (1-2) is preferred for calculating geological reserves. If parameters such as the degree of geological reserve extraction and water content are lacking, equation (3-1) is preferred for calculating geological reserves. If relative permeability curves are lacking, equation (5-1) is used to calculate geological reserves.

[0126] In this invention, the method for determining the geological reserves of a single well and a single layer based on the geological reserves of the block includes: dividing the geological reserves of the block into single wells and single layers to obtain single-layer geological reserves; and determining the geological reserves of a single well based on the single-layer geological reserves obtained from the division.

[0127] In this invention, the method of dividing the geological reserves of the block into a single well and a single layer includes: using formula (6) to determine the geological reserves of a single layer;

[0128] N ix =r ix N t (6);

[0129] Where: N t For the geological reserves of the block, 10 4 t; N ix For the geological reserves of the i-th well and the x-th layer in the block, 10 4 t;r ix is the splitting coefficient for a single well and a single layer, dimensionless.

[0130] In this invention, the splitting coefficient r in equation (6) ix Calculated using equation (7);

[0131]

[0132] In the formula: b ix Let x be the single reservoir coefficient of the x-th layer in the i-th well, 10 4 t / (m·km 2 );h ix Let x be the effective thickness of the x-th layer in the i-th well, in m.

[0133] In this embodiment of the invention, after determining the geological reserves N of the block obtained above, it is necessary to first divide the geological reserves of the block into single wells and single layers to determine the geological reserves of a single well or single layer.

[0134] The average thickness and single-reservoir coefficient of a single well in the block can be extracted, and based on this, the geological reserves of the block can be divided into single wells and single layers using formula (6).

[0135] Obtain the single-layer geological reserves N ix Then, the geological reserves of a single well are the sum of the calculated geological reserves of a single layer in that well, that is, the geological reserves of a single well are calculated according to formula (6-1).

[0136] N i =∑N ix (6-1);

[0137] Where: N i For the geological reserves of the i-th well, 10 4 t; N ix This represents the geological reserves of the x-th layer in the i-th well of the block.

[0138] In this invention, the method for determining the remaining geological reserves of a single well and a single layer based on the geological reserves of the single well and a single layer includes: obtaining the cumulative oil production of a single well in a block; determining the remaining geological reserves of a single well based on the geological reserves of the single well and the cumulative oil production; dividing the cumulative oil production into single layers; and determining the remaining geological reserves of a single layer based on the cumulative oil production of the single layer obtained after the division.

[0139] In this invention, the method for determining the remaining geological reserves of a single well based on the single well geological reserves and cumulative oil production includes: determining the remaining geological reserves of a single well using formula (8);

[0140] N Ri =N i -N pi (8);

[0141] Where: N Ri For the remaining geological reserves of the i-th well, 10 4 t; N pi For the cumulative oil production of the i-th well, 10 4 t; N i For single-well geological reserves, 10 4 t.

[0142] In this embodiment of the invention, the remaining geological reserves N of a single well Ri That is, the single-well geological reserves N calculated according to the above formula (6-1). i The difference between the cumulative oil production of the well and the cumulative oil production of the well is given by equation (8).

[0143] In this invention, the method of dividing the cumulative oil production into a single layer includes: determining the cumulative oil production of a single layer using formula (9);

[0144] Npix =r jx ×N pi (9);

[0145] Where: N pix For the cumulative oil production of the i-th well in the x-th layer, 10 4 t;r jx N is the splitting coefficient, dimensionless; pi For the cumulative oil production of the i-th well, 10 4 t.

[0146] In this invention, the splitting coefficient r in equation (9) jx It is calculated using equation (10) or (11);

[0147]

[0148] Where: R is the total recovery rate of the coring well, %; R i The recovery rate (%) of the i-th layer in the core well; N ix For the geological reserves of the i-th well and the x-th layer in the block, 10 4 t;

[0149]

[0150] In the formula: k ix Let mD be the permeability of the x-th layer in the i-th well; h be the permeability of the x-th layer in the i-th well. ix Let x be the effective thickness of the x-th layer in the i-th well, in meters.

[0151] In this embodiment of the invention, the remaining geological reserves of a single well and a single layer are first divided into the single layer using equation (9) to obtain the cumulative oil production N of the single layer. pix .

[0152] Single-well single-layer cumulative oil production splitting coefficient r jx The calculation method can be selected in the order of equations (10) and (11). If there is a lot of core well data and the production degree parameters can be obtained, the core well data can be selected first, i.e., equation (10) is used to calculate the splitting coefficient; if there is no core well data or there is little data, the formation coefficient method can be used to determine it, i.e., equation (11).

[0153] In this invention, the method for determining the remaining geological reserves of a single layer based on the cumulative oil production of the single layer obtained after splitting includes: calculating the remaining geological reserves of the single layer using formula (12);

[0154] N Rix =N ix -N pix (12);

[0155] Where: NRix For the remaining geological reserves of the x-th layer in the i-th well, 10 4 t; N ix For the geological reserves of the i-th well and the x-th layer in the block, 10 4 t; N pix For the cumulative oil production of the i-th well in the x-th layer, 10 4 t.

[0156] In this embodiment of the invention, the single-layer geological reserves N are calculated according to the above formula (6). ix And the cumulative oil production N of a single layer calculated according to equation (9) pix Substituting into equation (12), the remaining geological reserves N of a single layer are calculated. Rix .

[0157] In this invention, before obtaining the remaining reserve quality of the target block, the remaining reserve quality is determined, and the method includes: determining the remaining reserve quality using formula (13).

[0158] G Rix =N Rih / N Ri (13);

[0159] In the formula: G Ri The remaining reserves quality of the i-th well is %, %; N Rih For the remaining geological reserves of the oil layer with an effective thickness ≥ 1m in the i-th well, 10 4 t.

[0160] In this embodiment of the invention, generally speaking, the greater the thickness of the oil layer, the better its physical properties, the greater its potential and the easier it is to mine. Therefore, the remaining reserve quality is defined as the proportion of the remaining reserves of the oil layer with an effective thickness ≥ 1m to the total well. The calculation method is shown in Equation (13).

[0161] In this invention, before obtaining the water content of a single well and a single layer in the target block, the water content of the single layer is determined. The method includes: calculating the water content of the single layer using formula (14) based on the water content of the single well.

[0162]

[0163] In the formula: f iw The water content of the i-th well is %, %; Q lix The production rate of the x-th layer in the i-th well as measured by the production profile is 10. 4 t; Q li For the production rate of the i-th well, 10 4 t;f iwx The water cut of the x-th layer in the i-th well, as measured in the production profile, is %.

[0164] In this embodiment of the invention, the most important dynamic indicators for evaluating the lifting potential of a single well and a single layer are water cut and fluid production rate. Water cut is a comprehensive indicator reflecting geological and development factors, and its importance is self-evident. Fluid production rate is a key parameter affecting development effectiveness, depending on factors such as reservoir seepage characteristics, well spacing, and production pressure differential. Existing methods only use the flowing pressure index, which is a single parameter and difficult to obtain accurately. Therefore, this invention uses the comprehensive indicator of fluid production rate to replace the original flowing pressure index, which better reflects the characteristics of multiple factors jointly affecting the oilfield in the later stages of development.

[0165] Water cut in a single well refers to the percentage by mass of water in the produced fluid. Considering the relative stability of the extraction of each layer in the later stages of multi-layer sandstone oilfield development, the oil layer can be considered to be composed of a series of relatively independent development units. The relationship between water cut in a single well and water cut in a single layer of a single well can be obtained, i.e., equation (14). In this equation, the water cut in a single well is known. Substituting it into equation (14), the corresponding water cut f in a single layer is calculated. iwx .

[0166] For determining the water cut of a single well or single layer where production profile data is lacking, a trial-and-error method can be used. Based on field experience statistics such as formation coefficients, the water cut and production ratio of a single well or single layer are predetermined. Then, the minimum difference between the actual water cut and the predetermined water cut is used as the constraint condition, i.e., min(f). iwp -f iw The water content of a single well and a single layer can be calculated by applying the following formula (14-1).

[0167] f iwp =∑r jxp ×f iwxp (14-1);

[0168] In the formula: f iwp Calculate the water cut (%) for the i-th well; r jxp To predetermine the production rate (%) of the x-th layer in the i-th well; f iwxp Given the water content of the x-th layer in the i-th well in advance, %.

[0169] In this invention, before obtaining the fluid production rate of the target block, the method for determining the fluid production rate includes: using formula (15) to determine the fluid production rate of the single well;

[0170] v i =Q li / N i (15);

[0171] In the formula: v i Q is the fluid production rate of the i-th well, %; li For the production rate of the i-th well, 10 4 t; N i For single-well geological reserves, 10 4t;

[0172] The single-layer liquid collection rate is determined using equation (16);

[0173] v ix =Q lix / N ix (16);

[0174] In the formula: v ix The fluid production rate (%) of the x-th layer in the i-th well; N ix For the geological reserves of the i-th well and the x-th layer in the block, 10 4 t; Q lix The production volume of the x-th layer in the i-th well is measured for the production profile.

[0175] In this embodiment of the invention, in order to unify the comparison and measurement standards, the fluid production rate index is adopted, which is a key parameter affecting the development effect and depends on factors such as reservoir seepage characteristics, well spacing and production pressure difference.

[0176] Fluid production rate v of a single well i The calculation method is shown in equation (15), where the fluid production rate v of a single well and a single layer is... ix The calculation method is shown in equation (16). The single-well geological reserves N calculated according to equation (6-1) are... i Substituting into equation (15) yields the single-well fluid production rate, and using equation (6) yields the single-layer geological reserves N. ix Substituting into equation (16), the single-layer liquid collection rate is calculated.

[0177] Step S02: Classify the target well or target layer into the first category, including: determining whether the remaining geological reserves and quality of the target well or target layer exceed the average value of the corresponding block. If both exceed, it is classified as Category I; if neither exceeds, it is classified as Category III; otherwise, it is classified as Category II.

[0178] In this embodiment of the invention, based on the four parameters of a single oil well obtained in step S01 above—namely, the remaining geological reserves of a single well layer, the quality of remaining reserves, the water cut of a single well layer, and the fluid production rate—it is first classified according to the reserve potential parameters, i.e., the first category. Specifically, the classification is based on two static parameters: remaining geological reserves and remaining reserve quality, with the classification standard being the block average.

[0179] like Figure 2As shown, if the remaining geological reserves of a single well or layer corresponding to a target well or layer are greater than the average remaining geological reserves of the block, and the quality of the remaining reserves is greater than the average quality of the remaining reserves of the block, then the first category classification result for the target well or layer is Class I, i.e., a potential well for priority fluid extraction. If the remaining geological reserves of a single well or layer corresponding to a target well or layer are greater than the average remaining geological reserves of the block, and the quality of the remaining reserves is less than the average quality of the remaining reserves of the block, or if the remaining geological reserves of a single well or layer corresponding to a target well or layer are less than the average remaining geological reserves of the block, and the quality of the remaining reserves is greater than the average quality of the remaining reserves of the block, then the first category classification result for the target well or layer is Class II, i.e., maintaining the current production status. If the remaining geological reserves of a single well or layer corresponding to a target well or layer are less than the average remaining geological reserves of the block, and the quality of the remaining reserves is less than the average quality of the remaining reserves of the block, then the first category classification result for the target well or layer is Class III, i.e., a potential well for priority fluid control.

[0180] Step S03: Classify the target well or target layer into a second category, including: determining whether the water cut and fluid production rate of the target well or target layer are lower than the corresponding block average. If both are lower, it is classified as Category 1; if both are not lower, it is classified as Category 3; otherwise, it is classified as Category 2.

[0181] In this embodiment of the invention, after the static parameters are classified, they are further categorized according to the dynamic parameters, i.e., the second category classification. Specifically, the classification is based on two indicators: water content and liquid extraction rate.

[0182] like Figure 3 As shown, if the water cut of a single well or layer corresponding to the target well or layer is less than the average water cut of the block, and the fluid production rate is less than the average fluid production rate of the block, then the second category classification result for the target well or layer is Category I, i.e., a potential well for priority fluid production. If the water cut of a single well or layer corresponding to the target well or layer is greater than the average water cut of the block, and the fluid production rate is less than the average fluid production rate of the block, or if the water cut of a single well or layer corresponding to the target well or layer is less than the average water cut of the block, and the fluid production rate is greater than the average fluid production rate of the block, then the second category classification result for the target well or layer is Category II, i.e., maintaining the current production status (stable fluid production). If the water cut of a single well or layer corresponding to the target well or layer is greater than the average water cut of the block, and the fluid production rate is greater than the average fluid production rate of the block, then the second category classification result for the target well or layer is Category III, i.e., a potential well for priority fluid control.

[0183] Step S04: If both the first category classification result and the second category classification result are of the same category, then the target well or target layer is a well or layer with priority in fluid extraction potential. If both are of the same category, then it is a well or layer with priority in fluid control potential. If one is of the same category and the other is of the same category or the same category, or both are of the same category, then it is a well or layer with secondary fluid extraction potential. If one is of the same category and the other is of the same category, then it is a well or layer with secondary fluid control potential.

[0184] In this embodiment of the invention, the two classification results are combined to obtain the final classification result of the extraction and control potential, i.e., the comprehensive evaluation result. Specifically: if the first category classification result and the second category classification result corresponding to the target well or target layer are both of the same type, then the final classification of the target well or target layer is Class I, i.e., a well or layer with priority in fluid extraction potential. If the first category classification result corresponding to the target well or target layer is Class I and the second category classification result is Class II or III, or the second category classification result is Class I and the first category classification result is Class II or III, or both the first and second category classification results are Class II, then the final classification of the target well or target layer is Class II, i.e., a well or layer with secondary potential for fluid extraction. If the first category classification result corresponding to the target well or target layer is Class II and the second category classification result is Class III, or the second category classification result is Class II and the first category classification result is Class III, i.e., a well or layer with secondary potential for fluid control, which should maintain its current production status. If both the first and second category classification results for the target well or target layer are Category III, then the final classification of the target well or target layer is Category IV, i.e., a potential well or layer for priority fluid control. The final classification results are shown in Table 1 below.

[0185] Table 1: Final Classification Results

[0186]

[0187]

[0188] In actual operation, priority is given to fluid extraction in Class I wells or formations, and / or fluid control in Class IV wells or formations. Class II and III wells or formations can maintain their current production status (stable fluid). When the block's production declines or the water cut rises above the corresponding threshold, fluid extraction can be carried out on the second-best wells or formations (Class II), and / or fluid control can be carried out on the second-best wells or formations (Class III).

[0189] In this embodiment of the invention, taking the target block as the South Eighth Block as an example, the remaining reserves of a single well and a single layer in the South Eighth Block are used to classify the adjustment potential of oil wells in the block according to the four parameters obtained in step S01, and the classification results of different well network reserve parameters in the South Eighth Block (first category classification results) and the development dynamic classification results (second category classification results) are obtained respectively. Finally, the two classification results are combined to obtain the distribution results of the lifting and control potential of the South Eighth Block.

[0190] like Figure 4 The image shows the classification results of the reserve indicators (parameters) in the Southern Eighth District. Figure 4 There are 96 Class I potential wells, mainly distributed in foundation and primary well networks; 80 Class II potential wells, distributed across all four well networks; and 102 Class III potential wells, mainly distributed in secondary and tertiary well networks. Figure 5 The following is a classification result of development indicators (dynamic) for the eight southern districts. Figure 5 There are 87 Class I potential wells, 121 Class II potential wells, and 70 Class III potential wells. All types of potential wells are distributed in the four sets of well networks.

[0191] The combined results of the two classifications yielded the final distribution of wells with potential for fluid extraction in the South Eighth District. Among these, 95 wells were prioritized for fluid extraction and adjustment, primarily distributed within the primary and foundational well networks. Figure 6 As shown; there are 90 priority wells for fluid control adjustment, mainly distributed in the secondary and tertiary well networks, such as... Figure 7 As shown.

[0192] By adjusting and controlling 393 wells in the South Eighth District according to the comprehensive evaluation results, including water injection, monitoring and adjustment, fracturing, and parameter adjustment, the fluid increase in the foundation and primary wells was 20.8%, the secondary wells remained basically stable, the tertiary wells controlled fluid at 24.5%, and the overall fluid increase was 3.4%. The water cut rise rate was controlled from 0.89% to 0.49%, and the decline rate was controlled from 6.5% to 3.9%, achieving very good adjustment results. At the same time, it effectively guided the water drive development adjustment work in the Lasa Xing Oilfield, reducing the water cut rise value from 0.22% to 0.11%, which is expected to increase recoverable reserves by 43.72 million tons, generating economic benefits of 4.71 billion yuan. Calculated based on a 3% contribution rate of scientific research results, it creates direct economic benefits of 140 million yuan.

[0193] It is understood that the various method embodiments mentioned above in this invention can be combined with each other to form combined embodiments without violating the principle and logic. Due to space limitations, this invention will not elaborate further.

[0194] The execution entity for the method of evaluating the lifting potential of wells in water-driven multi-layered sandstone oilfields can be a processing device for evaluating the lifting potential of wells in water-driven multi-layered sandstone oilfields. For example, the method can be executed by a terminal device, a server, or other processing equipment. The terminal device can be a user equipment (UE), mobile device, user terminal, terminal, cellular phone, cordless phone, personal digital assistant (PDA), handheld device, computing device, vehicle-mounted device, wearable device, etc. In some possible implementations, this method can be implemented by a processor calling computer-readable instructions stored in memory.

[0195] Those skilled in the art will understand that, in the above-described method of the specific implementation, the order in which each step is written does not imply a strict execution order and does not constitute any limitation on the implementation process. The specific execution order of each step should be determined by its function and possible internal logic.

[0196] This invention also proposes a device for evaluating the uplift potential of water-driven multilayer sandstone oilfield wells, comprising: an acquisition unit for acquiring the remaining geological reserves, remaining reserve quality, water cut, and fluid production rate of a single well and single layer in a target block; a first category division unit for classifying the target well or target layer into a first category, including determining whether the remaining geological reserves and remaining reserve quality of the target well or target layer exceed the corresponding block average; if both exceed, it is classified as Category I; if neither exceeds, it is classified as Category III; otherwise, it is classified as Category II; and a second category division unit for classifying the target well or target layer into a second category. This includes: determining whether the water cut and fluid production rate of the target well or target layer are lower than the corresponding block average; if both are lower, it is classified as Category 1; if both are not lower, it is classified as Category 3; otherwise, it is classified as Category 2; and a comprehensive evaluation unit, used to determine that if both the first and second category classification results are Category 1, the target well or target layer is a priority fluid production potential well or layer; if both are Category 3, it is a priority fluid control potential well or layer; if one is Category 1 and the other is Category 2 or Category 3, or both are Category 2, it is a secondary priority fluid production potential well or layer; and if one is Category 3 and the other is Category 2, it is a secondary priority fluid control potential well or layer.

[0197] In some embodiments, the functions or modules and units included in the apparatus provided by the present invention can be used to execute the methods described in the above method embodiments. The specific implementation can be referred to the description of the above method embodiments, and for the sake of brevity, it will not be repeated here.

[0198] The proposed method for determining lifting potential based on a combination of static and dynamic indicators achieves an organic integration of reserve baselines and dynamic realities, avoiding the drawbacks of relying solely on water cut and flowing pressure adjustments. This invention offers at least the following advantages: 1. It adds reserve parameters, addressing the lack of static indicators in the original method; 2. It optimizes dynamic indicators by replacing flowing pressure with fluid production rate, making it more consistent with the characteristics of late-stage oilfields; 3. The combination of static and dynamic indicators in determining lifting potential well layers ensures the accuracy of lifting potential evaluation. This invention further enhances the reliability and accuracy of single-well lifting measures, providing an important evaluation tool for continuously improving development effects and increasing recovery rates in late-stage oilfields.

[0199] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or technical improvements to the embodiments in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A method for evaluating the lifting and control potential of oil wells in water-drive multi-layered sandstone oilfields, characterized in that, include: Obtain the remaining geological reserves, remaining reserve quality, water cut, and fluid production rate of a single well and single layer in the target block; The target well or target layer is classified into the first category, including: determining whether the remaining geological reserves and the quality of the remaining reserves of the target well or target layer exceed the average value of the corresponding block. If both exceed the average value, it is classified into the first category; if neither exceeds the average value, it is classified into the third category; otherwise, it is classified into the second category. The target well or target layer is classified into a second category, which includes: determining whether the water cut and fluid production rate of the target well or target layer are lower than the corresponding block average. If both are lower, it is classified as Category 1; if both are not lower, it is classified as Category 3; otherwise, it is classified as Category 2. If both the first and second category classification results are of the same category, then the target well or target layer is a well or layer with priority in fluid extraction potential. If both are of the third category, then it is a well or layer with priority in fluid control potential. If one is of the first category and the other is of the second or third category, or both are of the second category, then it is a well or layer with secondary fluid extraction potential. If one is of the third category and the other is of the second category, then it is a well or layer with secondary fluid control potential.

2. The method for evaluating the uplift potential of wells in water-driven multi-layered sandstone oilfields according to claim 1, characterized in that, Before obtaining the remaining geological reserves of a single well and a single layer in the target block, the method for determining the remaining geological reserves of a single well and a single layer includes: Obtain the geological reserves of the block; Based on the geological reserves of the block, determine the geological reserves of a single well and a single layer; Based on the geological reserves of a single well and a single layer, determine the remaining geological reserves of the single well and a single layer.

3. The method for evaluating the uplift potential of wells in water-driven multi-layered sandstone oilfields according to claim 2, characterized in that, Determining the geological reserves of a block before acquiring the geological reserves of the block includes the following methods: If the relative permeability curve of the block can be obtained, the geological reserves N of the block can be determined using equation (1-1) or (1-2); In the formula: A1 and B1 are the coefficients of the Type A water drive curve, which are dimensionless; A2 and B2 are the coefficients of the Type C water drive curve, which are dimensionless; a1, b1, a2, and b2 are coefficients obtained by fitting the relative permeability curve, which are dimensionless.

4. The method for evaluating the uplift potential of wells in water-drive multi-layered sandstone oilfields according to claim 3, characterized in that: In equations (1-1) and (1-2), a1, b1, a2, and b2 are determined by fitting equations (2-1) and (2-2); In the formula: R represents the degree of geological reserve extraction; f w It contains water.

5. The method for evaluating the uplift potential of wells in water-drive multi-layered sandstone oilfields according to claim 3, characterized in that: If a type C water drive curve cannot be obtained, the geological reserves N of the block can be determined using equation (3-1) or (3-2). N = C / B1(3-1); Where, C = 2(n w +n o ) / E d ln10(3-2); In the formula: B1 is the slope of the type A water drive curve, which is dimensionless; n o n w Oil phase and water phase indices, dimensionless; E d The value is the oil displacement efficiency, expressed as a percentage; N represents the geological reserves.

6. The method for evaluating the uplift potential of wells in water-drive multi-layered sandstone oilfields according to claim 5, characterized in that: In the formula (3-2), the oil phase index n o Water phase index n w The results are obtained by fitting the relative permeability curve using the following equations (4-1) and (4-2); in: Where: n o For oil phase index, f; n w For the aqueous phase index, f; S wi For bound water saturation, f; S or For residual oil saturation, f; K rw f is the relative permeability of the aqueous phase; K ro f is the relative permeability of the oil phase; K rw (S or ) represents the relative permeability of the residual oil to the aqueous phase at saturation, f; K ro (S wi f represents the relative permeability of the oil phase at the bound water saturation level; S represents the relative permeability of the oil phase at the bound water saturation level. w f; S represents the average water saturation. wd f represents the normalized water saturation.

7. The method for evaluating the uplift potential of wells in water-driven multi-layered sandstone oilfields according to claim 5, characterized in that: If oil displacement efficiency cannot be obtained, the geological reserves of the block can be determined using equation (5-1). N=7.5422 / B1 0.969 (5-1); In the formula: N is the geological reserves, 10 4 t; B1 is the slope of the type A water drive curve, dimensionless.

8. The method for evaluating the uplift potential of wells in water-driven multi-layered sandstone oilfields according to claim 1, characterized in that, The method for determining the geological reserves of a single well and a single layer based on the geological reserves of the block includes: The geological reserves of the block are divided into single wells and single layers to obtain single-layer geological reserves; The geological reserves of a single well are determined based on the geological reserves of the single layer obtained from the splitting.

9. The method for evaluating the uplift potential of wells in water-driven multi-layered sandstone oilfields according to claim 8, characterized in that, The method for dividing the geological reserves of the block into single wells and single layers includes: Using equation (6), the geological reserves of a single layer are determined; N ix =r ix N t (6); Where: N t For the geological reserves of the block, 10 4 t; N ix For the geological reserves of the i-th well and the x-th layer in the block, 10 4 t;r ix is the splitting coefficient for a single well and a single layer, dimensionless.

10. The method for evaluating the uplift potential of wells in water-drive multi-layered sandstone oilfields according to claim 9, characterized in that: In equation (6), the splitting coefficient r ix Calculated using equation (7); In the formula: b ix Let x be the single reservoir coefficient of the x-th layer in the i-th well, 10 4 t / (m·km 2 );h ix Let x be the effective thickness of the x-th layer in the i-th well, in m.

11. The method for evaluating the uplift potential of oil wells in water-drive multi-layered sandstone oilfields according to claim 1, characterized in that, The method for determining the remaining geological reserves of a single well and a single layer based on the geological reserves of the single well and a single layer includes: Obtain the cumulative oil production of a single well in the block; The remaining geological reserves of a single well are determined based on its geological reserves and cumulative oil production. The cumulative oil production is divided into individual layers, and the remaining geological reserves of each layer are determined based on the cumulative oil production of the individual layers obtained after division.

12. The method for evaluating the uplift potential of wells in water-drive multi-layered sandstone oilfields according to claim 11, characterized in that, The method for determining the remaining geological reserves of a single well based on its geological reserves and cumulative oil production includes: The remaining geological reserves of a single well are determined using equation (8); N Ri =N i -N pi (8); Where: N Ri For the remaining geological reserves of the i-th well, 10 4 t; N pi For the cumulative oil production of the i-th well, 10 4 t; N i For single-well geological reserves, 10 4 t.

13. The method for evaluating the uplift potential of wells in water-drive multi-layered sandstone oilfields according to claim 11, characterized in that, The method for dividing the cumulative oil production into individual layers includes: The cumulative oil production of a single layer is determined using equation (9); N pix =r jx ×N pi (9); Where: N pix For the cumulative oil production of the i-th well in the x-th layer, 10 4 t;r jx N is the splitting coefficient, dimensionless; pi For the cumulative oil production of the i-th well, 10 4 t.

14. The method for evaluating the uplift potential of wells in water-drive multi-layered sandstone oilfields according to claim 13, characterized in that: The splitting coefficient r in equation (9) jx It is calculated using equation (10) or (11); Where: R is the total recovery rate of the coring well, %; R i The recovery rate (%) of the i-th layer in the core well; N ix For the geological reserves of the i-th well and the x-th layer in the block, 10 4 t; In the formula: k ix Let mD be the permeability of the x-th layer in the i-th well; h be the permeability of the x-th layer in the i-th well. ix Let x be the effective thickness of the x-th layer in the i-th well, in meters.

15. The method for evaluating the uplift potential of wells in water-drive multi-layered sandstone oilfields according to claim 11, characterized in that, The method for determining the remaining geological reserves of a single layer based on the cumulative oil production obtained after splitting the layer includes: The remaining geological reserves of a single layer can be calculated using equation (12); N Rix =N ix -N pix (12); Where: N Rix For the remaining geological reserves of the x-th layer in the i-th well, 10 4 t; N ix For the geological reserves of the i-th well and the x-th layer in the block, 10 4 t; N pix For the cumulative oil production of the i-th well in the x-th layer, 10 4 t.

16. The method for evaluating the uplift potential of wells in water-drive multi-layered sandstone oilfields according to claim 1, characterized in that, Before obtaining the remaining reserve quality of the target block, the method for determining the remaining reserve quality includes: The quality of the remaining reserves is determined using equation (13); G Rix =N Rih / N Ri (13); In the formula: G Ri The remaining reserves quality of the i-th well is expressed as %, %; N Rih For the remaining geological reserves of the oil layer with an effective thickness ≥ 1m in the i-th well, 10 4 t.

17. The method for evaluating the uplift potential of oil wells in water-drive multi-layered sandstone oilfields according to claim 1, characterized in that, Before obtaining the water-bearing content of a single well and a single layer in the target block, the method for determining the water-bearing content of the single layer includes: The water content of the single layer is calculated using formula (14) based on the water content of the single well. In the formula: f iw The water content of the i-th well is %, %; Q lix The production rate of the x-th layer in the i-th well as measured by the production profile is 10. 4 t; Q li Let i be the production rate of the i-th well, 10 4 t;f iwx The water cut of the x-th layer in the i-th well, as measured in the production profile, is %.

18. The method for evaluating the uplift potential of wells in water-drive multi-layered sandstone oilfields according to claim 1, characterized in that, Determining the fluid collection rate before acquiring the fluid collection rate of the target block includes the following methods: The single-well fluid production rate is determined using equation (15); v i =Q li / N i (15); In the formula: v i Q is the fluid production rate of the i-th well, %; li Let i be the production rate of the i-th well, 10 4 t; N i For single-well geological reserves, 10 4 t; The single-layer liquid collection rate is determined using equation (16); v ix =Q lix / N ix (16); In the formula: v ix The fluid production rate (%) of the x-th layer in the i-th well; N ix For the geological reserves of the i-th well and the x-th layer in the block, 10 4 t; Q lix The production volume of the x-th layer in the i-th well is measured for the production profile.

19. The method for evaluating the uplift potential of wells in water-drive multi-layered sandstone oilfields according to any one of claims 1-18, characterized in that: If both the first and second category classification results are classified as Category II, then the target well or target layer is a stable fluid well or layer.

20. A device for evaluating the lifting potential of oil wells in water-driven multi-layered sandstone oilfields, characterized in that, include: The acquisition unit is used to acquire the remaining geological reserves, remaining reserve quality, water cut, and fluid production rate of a single well and single layer in the target block. The first category division unit is used to classify the target well or target layer into the first category, including: determining whether the remaining geological reserves and the quality of the remaining reserves of the target well or target layer exceed the average value of the corresponding block. If both exceed, it is classified as Category 1; if neither exceeds, it is classified as Category 3; otherwise, it is classified as Category 2. The second category division unit is used to classify the target well or target layer into a second category, including: determining whether the water cut and fluid production rate of the target well or target layer are lower than the corresponding block average. If both are lower, it is classified as Category I; if both are not lower, it is classified as Category III; otherwise, it is classified as Category II. The comprehensive evaluation unit is used to determine the target well or layer as having priority in fluid extraction potential if both the first and second category classification results are of the same category; if both are of the same category, it is a priority in fluid control potential; if one is of the same category and the other is of the same category or the same category, or both are of the same category, it is a suboptimal well or layer in terms of fluid extraction potential; and if one is of the same category and the other is of the same category, it is a suboptimal well or layer in terms of fluid control potential.

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