A method for determining the distribution of remaining oil in a rigid water drive reservoir and an oil production method

Abstract

The present invention belongs to the technical field of rigid water drive oil reservoirs, and specifically relates to a method for determining the distribution of residual oil in a rigid water drive oil reservoir and an oil production method. Obtain the edge water volume of the rigid water drive oil reservoir, and determine whether the edge water volume is greater than the edge water volume set value: if the edge water volume is greater than the edge water volume threshold, it is determined that there is residual oil on the plane of the rigid water drive oil reservoir; and the larger the edge water volume, the more residual oil is distributed on the plane. Through research and simulation analysis, the present invention finds that the factors affecting the distribution of residual oil include the edge water volume. By comparing the edge water volume with the edge water volume threshold, it can be determined that there is residual oil on the plane of the rigid water drive oil reservoir when the edge water volume is greater than the edge water volume threshold. Then, according to the size of the edge water volume, the amount of residual oil distribution on the plane is determined to determine whether it is worth exploiting, thereby purposefully exploiting the residual oil and improving the reserve utilization rate and ultimate recovery rate of the rigid water drive oil reservoir.

Description

Technical Field

[0001] The invention belongs to the technical field of rigid water drive oil reservoirs, and in particular relates to a method for determining the distribution of remaining oil in a rigid water drive oil reservoir and an oil production method. Background Art

[0002] In the process of oil development, generally only about 30% of the total underground reserves can be extracted, which means that a large amount of oil still remains underground. The formation and distribution of residual oil is a difficult problem in the current oil industry and one of the core technologies of oil field development.

[0003] Commonly used methods for studying the distribution of remaining oil include production logging and neural network technology. It is found that factors affecting the distribution of remaining oil include interlayers within the layer, changes in sedimentary structures, etc. For rigid water-driven reservoirs, they have the characteristics of single oil-bearing strata, thin oil layer thickness, small reserves, strong edge water energy, high porosity and high permeability. Due to their special reservoir characteristics, the water content rises rapidly during the development process. After years of development, the output has shown a trend of significant decrease after a short period of stable production. These factors are no longer applicable, which will lead to unclear distribution characteristics of the remaining oil and inability to effectively exploit the remaining oil. Summary of the invention

[0004] The present invention provides a method for determining the distribution of residual oil in a rigid water drive oil reservoir and an oil production method, which are used to solve the problem in the prior art that the unclear distribution characteristics of the residual oil lead to the inability to effectively produce oil.

[0005] In order to solve the above technical problems, the technical solution of the present invention includes:

[0006] The present invention provides a method for determining the remaining oil distribution in a rigid water drive reservoir, comprising the following steps:

[0007] Get the edge water volume of the rigid water drive reservoir and determine whether the edge water volume is greater than the set edge water volume value:

[0008] If the edge water volume is greater than the edge water volume threshold, it is determined that there is residual oil on the plane of the rigid water drive reservoir; and the larger the edge water volume, the more the residual oil distribution on the plane.

[0009] The beneficial effect of the above technical solution is as follows: the present invention has found through research and simulation analysis that the factors affecting the distribution of residual oil include edge water volume. By comparing the edge water volume with the edge water volume threshold, it can be determined that there is residual oil on the plane of the rigid water drive oil reservoir when the edge water volume is greater than the edge water volume threshold. Then, according to the size of the edge water volume, the amount of residual oil distribution on the plane is determined to determine whether it is worth exploiting, so as to purposefully exploit the residual oil and improve the reserve utilization rate and ultimate recovery rate of the rigid water drive oil reservoir.

[0010] Furthermore, after determining that there is residual oil on the plane of the rigid water drive reservoir, the production rate of the rigid water drive reservoir is further obtained to determine the distribution amount of the residual oil on the plane. The greater the production rate, the greater the distribution amount of the residual oil on the plane. The edge water volume is combined with the production rate to determine the distribution amount of the residual oil, so as to more accurately determine the distribution amount of the residual oil.

[0011] Furthermore, the remaining oil is distributed in the high part and flank of the sand body of the oil reservoir. By determining the distribution position of the remaining oil, the remaining oil can be exploited purposefully.

[0012] Furthermore, the method further includes the steps of obtaining the permeability rhythm of the rigid water drive oil reservoir in the longitudinal direction to determine whether there is residual oil in the rigid water drive oil reservoir in the longitudinal direction: determining the breakthrough coefficient according to the permeability rhythm of the rigid water drive oil reservoir in the longitudinal direction; judging whether the breakthrough coefficient is greater than the breakthrough coefficient threshold: if the breakthrough coefficient is greater than or equal to the breakthrough coefficient threshold, it is determined that there is residual oil in the longitudinal direction of the rigid water drive oil reservoir. The breakthrough coefficient is determined by the permeability rhythm, so as to determine whether there is residual oil in the longitudinal direction, so as to determine whether it is worth continuing to exploit.

[0013] Furthermore, the edge water volume threshold is 50 times the oil zone volume.

[0014] The present invention also provides an oil production method for a rigid water drive oil reservoir, comprising the following steps:

[0015] Obtain the edge water volume of the rigid water drive oil reservoir, and determine the remaining oil distribution amount of the rigid water drive oil reservoir on the plane according to the edge water volume: if the edge water volume is greater than the edge water volume set value, it is determined that there is remaining oil on the plane of the rigid water drive oil reservoir, and the remaining oil is distributed in the high part and flank of the sand body of the oil reservoir, and the larger the edge water volume, the more the remaining oil distribution amount on the plane;

[0016] According to the remaining oil distribution position and the remaining oil distribution amount of the rigid water drive oil reservoir on the plane, the well pattern is adjusted to carry out the remaining oil production.

[0017] The beneficial effect of the above technical solution is as follows: after research and simulation analysis, the present invention finds that the factors affecting the distribution of residual oil include the edge water volume. By comparing the edge water volume with the edge water volume threshold, it can be determined that there is residual oil on the plane of the rigid water drive oil reservoir when the edge water volume is greater than the edge water volume threshold. Then, according to the size of the edge water volume, the amount of residual oil distribution on the plane and the distribution position of the residual oil are determined to determine whether it is worth exploiting, thereby purposefully exploiting the residual oil and improving the reserve utilization rate and ultimate recovery rate of the rigid water drive oil reservoir.

[0018] Furthermore, after determining that there is residual oil on the plane of the rigid water drive reservoir, the liquid production rate of the rigid water drive reservoir is further obtained, and the greater the liquid production rate, the greater the residual oil distribution on the plane. The edge water volume is combined with the liquid production rate to determine the distribution of the residual oil, and the distribution of the residual oil is determined more accurately.

[0019] Furthermore, the method further includes the steps of obtaining the change of the permeability in the longitudinal direction of the rigid water drive oil reservoir to determine whether there is residual oil in the longitudinal direction of the rigid water drive oil reservoir: determining the breakthrough coefficient according to the change of the permeability in the longitudinal direction of the rigid water drive oil reservoir; judging whether the breakthrough coefficient is greater than the breakthrough coefficient threshold: if the breakthrough coefficient is greater than the breakthrough coefficient threshold, it is determined that there is residual oil in the longitudinal direction of the rigid water drive oil reservoir. The breakthrough coefficient is determined by the permeability rhythm, so as to determine whether there is residual oil in the longitudinal direction, so as to determine whether it is worth continuing to exploit.

[0020] Furthermore, the edge water volume threshold is 50 times the oil zone volume. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a flow chart of an embodiment of a method for determining the distribution of remaining oil in a rigid water drive reservoir according to the present invention;

[0022] Figure 2 is a flow chart of an embodiment of a rigid water drive reservoir oil production method of the present invention;

[0023] Figure 3-1 It is the streamline diagram of the present invention with a liquid collection speed of 4% and 1 times the water body;

[0024] Figure 3-2 It is the streamline diagram of the water body with a liquid collection speed of 4% and 20 times of the present invention;

[0025] Figure 3-3 It is the streamline diagram of the water body with a liquid collection speed of 4% and 50 times of the present invention;

[0026] Figure 3-4 It is the streamline diagram of the water body when the liquid collection speed is 4% and 100 times of the present invention;

[0027] Figure 4-1 It is a streamline diagram of the present invention in which the edge water volume is 100 times the oil zone volume and the liquid production rate is 4%;

[0028] Figure 4-2 It is a streamline diagram of the present invention in which the edge water volume is 100 times the oil zone volume and the liquid production rate is 6%;

[0029] Figure 4-3 It is a streamline diagram of the present invention in which the edge water volume is 100 times the oil zone volume and the liquid production rate is 8%;

[0030] Figure 4-4It is a streamline diagram of the present invention in which the edge water volume is 100 times the oil zone volume and the liquid production rate is 10%;

[0031] Figure 5 It is a relationship diagram between the water volume and the oil drainage radius of a single well at a high position of the present invention;

[0032] Figure 6 It is the sand body streamline model of the XX well of the present invention;

[0033] Figure 7-1 It is a diagram of the pressure variation pattern of the closed boundary reservoir of the present invention;

[0034] Figure 7-2 It is a pressure variation pattern diagram of a constant pressure boundary reservoir of the present invention;

[0035] Figure 8-1 It is the pressure field diagram of the point dam model of the present invention when the water body has 100 times the liquid extraction rate of 6% and 95% water content;

[0036] Figure 8-2 It is the residual oil distribution diagram of the point-sand-bar model of the present invention when the water body has 100 times the 6% liquid production rate and 95% water content;

[0037] Fig. 9 It is the logging interpretation curve diagram of XXX well in XX oil field of the present invention.

[0038] Figure 10-1 It is the oil saturation distribution map in 2026 of the present invention (first grid layer);

[0039] Figure 10-2 It is the oil saturation distribution map in 2026 of the present invention (second layer grid);

[0040] Figure 10-3 It is the oil saturation distribution map in 2026 of the present invention (third grid layer);

[0041] Figure 10-4 It is the oil saturation distribution map in 2026 of the present invention (the fourth grid layer);

[0042] Figure 10-5 This is the oil saturation distribution map in 2026 (fifth grid layer) of the present invention. DETAILED DESCRIPTION

[0043] The present invention aims at rigid water drive reservoirs and determines the remaining oil distribution of the reservoir based on three factors: edge water volume, liquid production rate and permeability rhythm. According to the characteristics of this type of reservoir, a numerical simulation method combining typical theoretical models and practical models is used to analyze how to select the three most influential factors from many factors, and how these three factors specifically affect the remaining oil distribution.

[0044] The specific process of analysis using numerical simulation method is as follows:

[0045] For the distribution of remaining oil in rigid water drive reservoirs, simulation and analysis are performed in both the horizontal and vertical directions to determine the factors that affect the horizontal and vertical remaining oil distributions, and how each factor affects the remaining oil distribution. The specific analysis process includes:

[0046] 1) Through the combination of geological knowledge and dynamic analysis, the reservoir characteristics of rigid water-driven thin oil reservoirs are analyzed, and the factors affecting the horizontal / vertical remaining oil distribution are analyzed;

[0047] 2) Based on the factors affecting the horizontal / vertical remaining oil distribution, a typical streamline model is first established based on the geological model and the streamline numerical simulation model. Then, based on the typical streamline model, the streamline field characteristics of the typical model are described. Finally, a numerical simulation study of the actual streamline field is carried out for the actual reservoir to verify the research results of the typical theoretical model. The following is an explanation.

[0048] 1. Reservoir characteristics

[0049] The thin oil reservoir of XX Oilfield is a typical rigid water-driven high-permeability thin oil reservoir. It has the characteristics of single oil-bearing stratum, thin oil layer thickness, small reserves, strong edge water energy, high porosity and high permeability. Its structure belongs to the secondary structural unit of the western uplift of Junggar Basin. The oil-bearing layer N1S1Ⅱ2 has a simple structure. The formation is generally a monocline structure with a nearly east-west trend and a dip angle of 2°. The reservoir lithology is mainly gray-brown and gray gravel-bearing fine sandstone, with quartz as the main component and feldspar as the second. It is mud-cemented and loosely cemented, with an average porosity of 28.8% and a permeability of 0.704μm2. The reservoir conditions are good and it belongs to a high-porosity and high-permeability reservoir. The sedimentary characteristics are typical meandering river deposits. The sand body morphology has the characteristics of "convex on the top and flat on the bottom". The sand body changes rapidly on the plane. The sand body is small in scale and the reserves are only 42×10 4 t, the oil-bearing height is only 26m; the oil-bearing stratum is single, and the average effective thickness of the oil layer is 3.2m; the edge water energy is strong, and the volume of the external water body is more than 100 times larger. The oil well has strong self-flowing ability in the initial stage after production, and the daily oil production is relatively high, with the highest daily oil production of 37t / d and the average daily production of 29.9t / d. In the six years of production, the block pressure has been maintained at above 95%.

[0050] 2. Factors affecting residual oil distribution

[0051] Residual oil refers to the crude oil that has not been produced and remains in the underground reservoir during the development of the oil field. It is negatively correlated with the oil field recovery rate. The higher the recovery rate, the less residual oil, and vice versa. However, the generation of residual oil is often caused by heterogeneity, mainly including reservoir heterogeneity and production heterogeneity. Among them, reservoir heterogeneity includes structural, reservoir and fluid heterogeneity, which are internal control factors of residual oil distribution, that is, internal factors. Production heterogeneity is mainly the heterogeneity of reservoir production conditions caused by injection and production conditions such as stratum combination, well network layout, perforation position, injection and production correspondence, injection and production intensity, which is an external control factor of residual oil distribution, that is, external factors.

[0052] The characteristics of the oil reservoir in this area are different from other light oil reservoirs in that it has strong edge water and small scale. According to the reservoir characteristics and development practices of this type of oil reservoir, five factors are screened out, which are mainly controlled by the planar physical property difference, crude oil viscosity, permeability rhythm, well network control degree and liquid production rate.

[0053] 3. Simulation analysis of plane residual oil distribution

[0054] The main factors affecting the distribution of remaining oil on the plane include reservoir conditions, mainly including plane physical property differences, fluid viscosity differences, well network control degree, and liquid production rate. Due to the differences in plane physical properties, fluid viscosity differences, well network control degree (main part) and liquid production rate in a single reservoir, the development effect is affected to a certain extent, and in the main part of the sand body, the results of the influence can ultimately be reflected by the waterline advancement during the development process. Based on the years of development experience of the small sand body of thin oil in XX Oilfield, uniform waterline advancement is the key factor to ensure the development effect of each thin oil reservoir in XX Oilfield. The uniform waterline can ensure that the appropriate adjustment of each well row at a reasonable liquid production rate can maintain stable production, and the uniform waterline can effectively displace the inter-well reserves to ensure a higher reserve utilization rate and ultimately obtain a higher recovery rate. On the contrary, if the waterline is not uniformly advanced, the reserve utilization between wells will deteriorate, making it difficult to achieve a higher recovery rate.

[0055] In order to study the distribution characteristics of remaining oil in the study area, a typical streamline model was first established based on the geological model and streamline numerical simulation model. The plane grid accuracy of the geological model is 10m×10m, the vertical grid accuracy is 1m, the total number of grids is 100×100×4, the formation dip angle is 4 degrees, the porosity is 35%, and the permeability is 1800×10 -3 μm 2 At 140m from the boundary, the sand body gradually becomes thinner to 0.5m, and the permeability gradually decreases to 600×10 -3 μm 2 .

[0056] The study area has sufficient edge water energy and belongs to a rigid water drive reservoir. The size of the edge water has an important influence on the oil-water distribution. In order to study the influence of edge water energy on streamline characteristics, in this streamline numerical simulation, the water body of the typical model is set as a grid and numerical type, the liquid production rate is 4%, and the edge water volume is 1, 20, 50, 100, and 200 times the volume of the oil zone for calculation and comparative analysis. Figure 3-1 to Figure 3-4 From the comparison of the streamline diagrams, the greater the edge water energy is, the more unfavorable it is for oil leakage from the top of the sand body above the production well.

[0057] In order to study the influence of oil production speed on streamline characteristics, in this streamline numerical simulation, the water body is set as a grid and numerical type, the edge water size is 100 times the volume of the oil zone, and the production speed of 4%, 6%, 8%, and 10% are calculated and analyzed respectively. Figure 4-1 to Figure 4-4 From the comparison of the streamline diagrams, the greater the liquid production velocity, the more unfavorable it is for oil leakage from the top of the sand body above the production well.

[0058] The oil drainage radius of the high part under different water volume sizes is statistically analyzed. As the external water volume increases, the oil drainage radius of the high part decreases rapidly. When the water volume is greater than 50 times, the remaining oil is enriched in the high part and flank of the sand body, and the oil drainage radius of the high part decreases only to a limited extent, and the oil drainage radius is about 30-40m. Figure 5 shown.

[0059] 5. Analysis and verification of plane residual oil distribution

[0060] A numerical simulation study of streamline field was carried out for XXX well in XX oil field. Figure 6 As shown in the figure, based on the analysis of the streamline field distribution characteristics, it is believed that under the current well pattern and working system, there is an incomplete reserve utilization phenomenon in the high parts and flanks of the sand bodies in this area, which is consistent with the results of typical model research.

[0061] The study believes that the sand body in the northern part of the study area pinches out and is a closed boundary; there is edge water in the southern part, which is a rigid water drive through natural energy evaluation and a constant pressure boundary, and the internal pressure of the reservoir is maintained at a high level. The seepage field formed by vertical well development is somewhat different from the conventional closed boundary and constant pressure boundary. From the pressure field diagram and streamline field diagram of the typical model, it can be seen that the pressure drop in the high part of a single well is limited, the degree of oil utilization in the high part is limited, the residual oil is enriched, and the main supply direction of the fluid is the edge water drive direction. Therefore, residual oil is formed in the high part and flanks of the sand body, such as Figure 7-1 , Figure 7-2 , Figure 8-1 and Figure 8-2 shown.

[0062] VI. Simulation Analysis of Vertical Residual Oil Distribution

[0063] Since there is no interlayer in the vertical distribution of remaining oil in the study area, the main influencing factor of its heterogeneity is the permeability rhythm. The typical XXX well in the XX oil field was selected as the research object. The permeability does not change much from bottom to top in the vertical direction. The natural gamma curve can present a smooth box shape, and the acoustic time difference and resistivity logging curves present a slight sawtooth shape. The minimum vertical permeability is 0.0373μm 2 , Maximum permeability 1.4783μm 2 , average permeability 0.7183μm 2 , the calculated breakthrough coefficient is 2.1, which belongs to the weak inhomogeneous rhythm, such as Fig. 9 shown.

[0064] For weakly homogeneous reservoirs, since there is no coring data in the study area, geological modeling and numerical simulation methods are used to study the vertical distribution of remaining oil, such as Figure 10-1 to Figure 10-5 shown.

[0065] According to the results of numerical simulation, under the current production conditions, the saturation values ​​of the five grid layers from top to bottom at the flooded well Chun 22-1 well point are 24.8%, 24.2%, 23.9%, 23.6% and 23.1% respectively until 2026. This indicates that this type of weakly heterogeneous sand body is uniformly water-driven vertically, with a sweep coefficient of 100%, and basically no residual oil potential distribution in the vertical direction.

[0066] In addition, it should be noted that the reservoir geological model and typical geological model were established using Schlumberger's Petrel software. The reservoir numerical simulation and streamline simulation used Schlumberger's ECLIPSE software E100 simulator and FrontSIM simulator. The simulator input data consists of three parts: geological model (structural data, porosity, permeability, net-to-gross ratio distribution, etc.), rock and fluid property model (oil, gas and water high-pressure physical properties, relative permeability curve, capillary pressure curve, rock compressibility, etc.) and production model (completion data, oil, gas and water production, etc.).

[0067] Based on the above research results, a method for determining the remaining oil distribution in a rigid water drive oil reservoir and an oil production method in a rigid water drive oil reservoir of the present invention can be realized.

[0068] The two methods are further described in detail below in conjunction with the accompanying drawings and embodiments.

[0069] Embodiment of the method for determining the distribution of remaining oil in a rigid water drive reservoir:

[0070] An embodiment of a method for determining the remaining oil distribution in a rigid water drive reservoir of the present invention is as follows: Figure 1 As shown:

[0071] First, the edge water volume of the rigid water drive oil reservoir is obtained to determine whether the edge water volume is greater than 50 times the oil zone volume: if the edge water volume is greater than 50 times the oil zone volume, it is determined that there is residual oil on the plane of the rigid water drive oil reservoir; if the edge water volume is less than or equal to 50 times the oil zone volume, it is determined that there is no residual oil on the plane of the rigid water drive oil reservoir.

[0072] Then, after determining that there is residual oil on the plane of the rigid water drive reservoir, the liquid production rate of the rigid water drive reservoir is further obtained, and the residual oil distribution on the plane of the rigid water drive reservoir is determined by combining the edge water volume and the oil production rate. Among them, the larger the edge water volume, the more residual oil distribution on the plane; the faster the liquid production rate, the more residual oil distribution on the plane.

[0073] Next, determine the plane remaining oil distribution position, that is, the sand body high part and flank of the rigid water drive reservoir. Combined with the remaining oil distribution on the plane, the remaining oil distribution on the plane of the rigid water drive reservoir is determined.

[0074] Secondly, obtain the permeability rhythm of the rigid water drive reservoir in the vertical direction and determine the breakthrough coefficient. Determine whether the breakthrough coefficient is greater than the breakthrough coefficient threshold: if the breakthrough coefficient is greater than or equal to the breakthrough coefficient threshold, it is determined that there is residual oil in the vertical direction of the rigid water drive reservoir; if the breakthrough coefficient is less than the breakthrough coefficient threshold, it is determined that there is no residual oil in the vertical direction of the rigid water drive reservoir. For a rigid water drive reservoir, if its breakthrough coefficient is less than the breakthrough coefficient threshold, there is no residual oil distribution in the vertical direction. This step determines the distribution of the residual oil in the vertical direction of the rigid water drive reservoir. Combined with the distribution of the residual oil on the plane of the rigid water drive reservoir determined in the above three steps, the distribution of the residual oil in the rigid water drive reservoir is determined.

[0075] Embodiment of the oil recovery method of rigid water drive oil reservoir:

[0076] An embodiment of an oil recovery method for a rigid water drive reservoir of the present invention is as follows: Figure 2 As shown:

[0077] First, the edge water volume of the rigid water drive oil reservoir is obtained to determine whether the edge water volume is greater than 50 times the oil zone volume: if the edge water volume is greater than 50 times the oil zone volume, it is determined that there is residual oil on the plane of the rigid water drive oil reservoir; if the edge water volume is less than or equal to 50 times the oil zone volume, it is determined that there is no residual oil on the plane of the rigid water drive oil reservoir.

[0078] Then, after determining that there is residual oil on the plane of the rigid water drive reservoir, the liquid production rate of the rigid water drive reservoir is further obtained, and the residual oil distribution on the plane of the rigid water drive reservoir is determined by combining the edge water volume and the oil production rate. Among them, the larger the edge water volume, the more residual oil distribution on the plane; the faster the liquid production rate, the more residual oil distribution on the plane.

[0079] Next, determine the plane remaining oil distribution position, that is, the sand body high part and flank. Combined with the plane remaining oil distribution, the plane remaining oil distribution of the rigid water drive reservoir is determined.

[0080] Secondly, obtain the permeability rhythm of the rigid water drive reservoir in the vertical direction and determine the breakthrough coefficient. Determine whether the breakthrough coefficient is greater than the breakthrough coefficient threshold: if the breakthrough coefficient is greater than or equal to the breakthrough coefficient threshold, it is determined that there is residual oil in the vertical direction of the rigid water drive reservoir; if the breakthrough coefficient is less than the breakthrough coefficient threshold, it is determined that there is no residual oil in the vertical direction of the rigid water drive reservoir. For a rigid water drive reservoir, if its breakthrough coefficient is less than the breakthrough coefficient threshold, there is no residual oil distribution in the vertical direction. This step determines the distribution of the residual oil in the vertical direction of the rigid water drive reservoir. Combined with the distribution of the residual oil on the plane of the rigid water drive reservoir determined in the above three steps, the distribution of the residual oil in the rigid water drive reservoir is determined.

[0081] Finally, according to the plane distribution of the remaining oil in the rigid water drive reservoir (including the plane distribution amount and the plane distribution position of the remaining oil) and the vertical distribution of the remaining oil, the well pattern is adjusted to produce the remaining oil.

[0082] After obtaining the distribution of the remaining oil in the rigid water drive oil reservoir, the present invention determines whether to exploit and how to exploit according to the amount of the remaining oil, thereby improving the reserve utilization rate and the final recovery rate of the rigid water drive oil reservoir.

[0083] The oil production method of the rigid water drive reservoir of the present invention was applied to the development practice of the XXX oil reservoir, and in particular, a total of 68 high-efficiency adjustment wells were deployed for the XXX oil reservoir. As of the end of May 2019, a cumulative increase of 476,500 tons of oil was achieved, achieving good development results and greatly improving the reserve utilization rate and ultimate recovery rate of small sand bodies with strong edge water and thin oil.

Claims

1. A method for determining the remaining oil distribution in a rigid water drive reservoir, characterized in that: The steps include: Get the edge water volume of the rigid water drive reservoir and determine whether the edge water volume is greater than the edge water volume threshold: If the edge water volume is greater than the edge water volume threshold, it is determined that there is residual oil on the plane of the rigid water drive reservoir; and the larger the edge water volume, the more residual oil is distributed on the plane; The step of obtaining the permeability rhythm of the rigid water drive oil reservoir in the vertical direction to determine whether there is residual oil in the rigid water drive oil reservoir in the vertical direction is also included: According to the vertical permeability rhythm of the rigid water drive reservoir, the breakthrough coefficient is determined; Determine whether the advance coefficient is greater than the advance coefficient threshold: If the breakthrough coefficient is greater than or equal to the breakthrough coefficient threshold, it is determined that there is residual oil in the rigid water drive reservoir in the vertical direction.

2. The method for determining the remaining oil distribution in a rigid water drive reservoir according to claim 1, characterized in that: After determining that there is residual oil on the plane of the rigid water drive reservoir, the production rate of the rigid water drive reservoir is further obtained to determine the distribution amount of the residual oil on the plane. The greater the production rate, the greater the distribution amount of the residual oil on the plane.

3. The method for determining the remaining oil distribution in a rigid water drive reservoir according to claim 1, characterized in that: The remaining oil is distributed in the high parts and flanks of the sand body of the reservoir.

4. The method for determining the remaining oil distribution in a rigid water drive reservoir according to claim 1, characterized in that: The edge water volume threshold is 50 times the oil zone volume.

5. A method for producing oil from a rigid water drive reservoir, characterized in that: The steps include: Obtain the edge water volume of the rigid water drive oil reservoir, and determine the remaining oil distribution amount of the rigid water drive oil reservoir on the plane according to the edge water volume: if the edge water volume is greater than the edge water volume threshold, it is determined that there is remaining oil on the plane of the rigid water drive oil reservoir, and the remaining oil is distributed in the high part and flank of the sand body of the oil reservoir, and the larger the edge water volume, the more the remaining oil distribution amount on the plane; The step of obtaining the permeability rhythm of the rigid water drive oil reservoir in the vertical direction to determine whether there is residual oil in the rigid water drive oil reservoir in the vertical direction is also included: According to the vertical permeability rhythm of the rigid water drive reservoir, the breakthrough coefficient is determined; Determine whether the advance coefficient is greater than the advance coefficient threshold: If the breakthrough coefficient is greater than the breakthrough coefficient threshold, it is determined that there is residual oil in the vertical direction of the rigid water drive reservoir; According to the remaining oil distribution position and the remaining oil distribution amount of the rigid water drive oil reservoir on the plane, the well pattern is adjusted to carry out the remaining oil production.

6. The method for producing oil from a rigid water drive reservoir according to claim 5, characterized in that: After determining that there is residual oil on the plane of the rigid water drive reservoir, the production rate of the rigid water drive reservoir is further obtained, and the greater the production rate, the greater the amount of residual oil distributed on the plane.

7. The method for producing oil from a rigid water drive reservoir according to claim 5, characterized in that: The edge water volume threshold is 50 times the oil zone volume.

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