Oil extraction method and device and storage medium

Abstract

The embodiment of the invention provides an oil extraction method and device and a storage medium, and the method comprises the following steps: S1, obtaining oil extraction data of a to-be-extracted oil well, the oil extraction data at least comprising an oil well production gas-oil ratio, an oil reservoir original gas-oil ratio, an oil reservoir formation pressure, a pseudo-bubble point pressure, an oil well oil production, a peak yield and a proportion of foam in an oil sample; s2, an oil well with the poor foam oil development effect is screened out according to the oil extraction data; s3, carrying out oil extraction actions on the oil well according to the oil extraction data, wherein the oil extraction actions comprise gas injection, soaking and pumping back; and S4, gas injection, soaking and pump-back are repeated in sequence till the oil well reaches the cold production limit yield, and the gas injection amount in gas injection is increased along with increase of the oil production turns. By means of the method, the yield of the cold production stage is increased, and effective treatment of low-yield wells and long-stop wells is achieved.

Description

Technical Field

[0001] The present invention relates to the technical field of oil production, and in particular to an oil production method, device and storage medium. Background Art

[0002] Foamy oil is a gas-containing crude oil, in which the gas phase is dispersed in the oil phase in the form of tiny bubbles. This special state makes the foamy oil highly fluid and has a high yield. In existing oil production, the dissolved gas in the foamy oil reservoir is released from the oil phase only when the formation pressure of the foamy oil reservoir drops below the bubble point pressure. Initially, the gas phase exists in the form of tiny bubbles. As time goes by and the pressure drops, the bubbles formed at different locations continue to grow and gradually gather to form a continuous gas phase.

[0003] However, as the pressure near the oil well decreases (to the pseudo-bubble point pressure), the crude oil gradually forms a free phase after degassing, the foam oil effect decreases, the oil phase viscosity increases, the oil well production decreases, and the production gas-oil ratio increases, affecting the normal production of the oil well. Summary of the invention

[0004] The purpose of the embodiments of the present invention is to provide an oil production method, device and storage medium, which improves the production in the cold production stage and realizes the effective management of low-production wells and long-stopped wells.

[0005] In order to achieve the above object, an embodiment of the present invention provides an oil recovery method, which comprises the following steps:

[0006] S1: Obtaining oil production data of the oil well to be produced, wherein the oil production data at least includes the gas-oil ratio of the oil well production, the original gas-oil ratio of the oil reservoir, the formation pressure of the oil reservoir, the pseudo-bubble point pressure, the oil production of the oil well, the peak production, and the proportion of foam in the oil sample;

[0007] S2: screening oil wells with poor foam oil development effects according to the oil production data;

[0008] S3: performing oil production actions on the oil well according to the oil production data, wherein the oil production actions include gas injection, well shut-down and pumping back;

[0009] S4: Repeating gas injection, well shut-down and pumping in sequence until the oil well reaches the cold production limit output, wherein the gas injection volume increases with the increase of oil production rounds.

[0010] Optionally, screening oil wells with poor foam oil development effects according to the oil production data includes:

[0011] When the oil well production gas-oil ratio> the original gas-oil ratio of the oil reservoir*10, and the reservoir formation pressure<the pseudo-bubble point pressure, and the oil well oil production<*20% of the peak production, and the foam proportion in the oil sample<the foam proportion threshold, then the oil well is an oil well with poor foam oil development effect.

[0012] Optionally, the method further includes:

[0013] If the adjacent wells of the oil well have not reached the cold production limit, the oil well and the adjacent wells are subjected to combined gas injection and huff-and-puff;

[0014] The combined gas injection and huff-and-puff method allows the production of oil from multiple oil wells to be performed synchronously.

[0015] Optionally, the gas injection volume is:

[0016]

[0017] Where r is the throughput radius,

[0018] L is the production length of the horizontal well section,

[0019] h is the thickness of the oil layer,

[0020] is the porosity of the oil layer,

[0021] S o is the oil saturation,

[0022] R is the volume of gas dissolved in unit volume of crude oil under formation conditions,

[0023] ρ is the surface density of gas,

[0024] A is the increase in gas injection volume, and n is the number of oil production rounds.

[0025] Optionally, the gas injection volume is increased by 5%-30%.

[0026] Optionally, the row spacing of horizontal wells in the reservoir is twice the throughput radius.

[0027] Optionally, the maximum rounds of gas injection throughput are 6, and the throughput radius under the maximum rounds is the maximum throughput radius.

[0028] Optionally, the duration of soaking is related to the nature of the injected gas, the injection volume, the nature of the crude oil, the formation temperature and the formation pressure.

[0029] Optionally, during the gas injection process, the gas injection pressure is lower than the fracture pressure of the formation in which the oil well is located.

[0030] Optionally, during the pumping process, the liquid production rate is 1.0%-4.0% of the controlled reserves of a single well.

[0031] In another aspect, the present invention provides an oil recovery device, comprising:

[0032] An acquisition module is used to acquire oil production data of the oil well to be produced, wherein the oil production data at least includes the gas-oil ratio of the oil well production, the original gas-oil ratio of the oil reservoir, the formation pressure of the oil reservoir, the pseudo-bubble point pressure, the oil production of the oil well, the peak production, and the proportion of foam in the oil sample;

[0033] A screening module, used for screening oil wells with poor foam oil development effects according to the oil production data;

[0034] An oil production module, used for performing oil production actions on the oil well according to the oil production data, wherein the oil production actions include gas injection, well soaking and pumping back;

[0035] The gas injection, well soaking and pumping are repeated in sequence until the oil well reaches the cold production limit production, and the gas injection volume in the gas injection increases with the increase of oil production rounds.

[0036] Optionally, screening oil wells with poor foam oil development effects according to the oil production data includes:

[0037] When the oil well production gas-oil ratio> the original gas-oil ratio of the oil reservoir*10, and the reservoir formation pressure<the pseudo-bubble point pressure, and the oil well oil production<*20% of the peak production, and the foam proportion in the oil sample<the foam proportion threshold, then the oil well is an oil well with poor foam oil development effect.

[0038] Optionally, the oil production module is further used to perform combined gas injection huff-and-puff on the oil well and the adjacent well if the adjacent well of the oil well has not reached the cold production limit production;

[0039] The combined gas injection and huff-and-puff method allows the production of oil from multiple oil wells to be performed synchronously.

[0040] Optionally, the gas injection volume is:

[0041]

[0042] Where r is the throughput radius,

[0043] L is the production length of the horizontal well section,

[0044] h is the oil layer thickness,

[0045] is the porosity of the oil layer,

[0046] S o is the oil saturation,

[0047] R is the volume of gas dissolved in unit volume of crude oil under formation conditions,

[0048] ρ is the surface density of gas,

[0049] A is the increase in gas injection volume, and n is the number of oil production rounds.

[0050] Optionally, the gas injection volume is increased by 5%-30%.

[0051] Optionally, the row spacing of horizontal wells in the reservoir is twice the throughput radius.

[0052] Optionally, the maximum rounds of gas injection throughput are 6, and the throughput radius under the maximum rounds is the maximum throughput radius.

[0053] Optionally, the duration of soaking is related to the nature of the injected gas, the injection volume, the nature of the crude oil, the formation temperature and the formation pressure.

[0054] Optionally, during the gas injection process, the gas injection pressure is lower than the fracture pressure of the formation in which the oil well is located.

[0055] Optionally, during the pumping process, the liquid production rate is 1.0%-4.0% of the controlled reserves of a single well.

[0056] On the other hand, the present invention further provides a machine-readable storage medium, on which instructions are stored, and the instructions are used to enable a machine to execute the above-mentioned oil production method.

[0057] The present invention provides an oil production method comprising the following steps: S1: obtaining oil production data of an oil well to be produced, wherein the oil production data at least includes the oil well production gas-oil ratio, the reservoir original gas-oil ratio, the reservoir formation pressure, the pseudo-bubble point pressure, the oil production of the oil well, the peak production, and the proportion of foam in the oil sample; S2: screening the oil well with poor foam oil development effect according to the oil production data; S3: performing oil production actions on the oil well according to the oil production data, wherein the oil production actions include gas injection, well soaking and pumping back; S4: repeating gas injection, well soaking and pumping back in sequence until the oil well reaches the cold production limit production, and the gas injection amount in the gas injection increases with the increase of the oil production rounds. The present invention achieves the reduction of the viscosity of the crude oil after degassing, increases the formation pressure, and reduces the interfacial tension of the crude oil by screening the oil well with poor foam oil development effect and determining the timing of gas injection, thereby extending the cold production life cycle of the foam oil by forming similar foam oil, continuing to exert the foam oil production capacity, improving the production in the cold production stage, and achieving effective treatment of low-yield wells and long-stopped wells.

[0058] Other features and advantages of the embodiments of the present invention will be described in detail in the subsequent detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] The accompanying drawings are used to provide a further understanding of the embodiments of the present invention and constitute a part of the specification. Together with the following specific implementations, they are used to explain the embodiments of the present invention, but do not constitute a limitation on the embodiments of the present invention. In the accompanying drawings:

[0060] Figure 1 It is a schematic flow diagram of an oil recovery method of the present invention;

[0061] Figure 2 It is a schematic plan view of the vertical well gas injection coverage of the present invention;

[0062] Figure 3 It is a schematic plan view of the gas injection coverage of a horizontal well of the present invention;

[0063] Figure 4 This is a preferred diagram of the horizontal well gas injection sweep radius of the present invention;

[0064] Figure 5 This is a diagram showing the optimal time for gas injection and well shut-in of a horizontal well according to the present invention;

[0065] Figure 6 This is a diagram showing the optimal gas injection and liquid production rate for a horizontal well according to the present invention;

[0066] Figure 7 This is a preferred diagram of the gas injection increment of the horizontal well according to the present invention compared with the previous gas injection. DETAILED DESCRIPTION

[0067] The specific implementation of the embodiment of the present invention is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described here is only used to illustrate and explain the embodiment of the present invention, and is not used to limit the embodiment of the present invention.

[0068] Figure 1 It is a schematic flow diagram of an oil recovery method of the present invention, such as Figure 1 As shown, step S1 is to obtain the oil production data of the oil well to be produced, and the oil production data at least includes the gas-oil ratio of the oil well production, the original gas-oil ratio of the oil reservoir, the formation pressure of the oil reservoir, the pseudo-bubble point pressure, the oil production of the oil well, the peak production, and the proportion of foam in the oil sample. The oil reservoir is a foam oil reservoir.

[0069] Specifically, the oil well to be produced is generally a long-stopped oil well. The oil production data of the long-stopped oil well, such as the oil well production gas-oil ratio, the original gas-oil ratio of the reservoir, the reservoir formation pressure, the pseudo-bubble point pressure, the oil well production, the peak production, and the proportion of foam in the oil sample, are obtained.

[0070] According to a specific implementation method, the preliminary data of the oil field are searched to determine the value of the original gas-oil ratio of the crude oil in the block; the value of the production gas-oil ratio of the oil well is determined by the volume of gas and crude oil produced by the oil well in a period of time before gas injection; the ratio of the current production gas-oil ratio and the original gas-oil ratio of the oil well to be produced before gas injection is calculated, and the ratio of the production gas-oil ratio and the original gas-oil ratio before the shutdown of the shutdown well is determined according to the same method. The pseudo-bubble point pressure and reservoir formation pressure of the oil field crude oil are determined by the preliminary data, and the pseudo-bubble point pressure and reservoir formation pressure are compared to determine the relationship between the two. The peak oil production of the oil well is the oil production (generally cubic meters / day) during the production period (at least 2 months) when the oil well has a higher production, and the oil production of the oil well is the average oil production in a period of time before gas injection (at least 15 days). Specifically, the original gas-oil ratio is also called the original dissolved gas-oil ratio, which refers to the amount of natural gas dissolved in a unit volume or weight of crude oil under the original formation conditions. The oil formation pressure refers to the formation pressure of a certain period after the oil reservoir is put into development.

[0071] The bubble point pressure is the pressure at which the first bubble appears when the liquid mixture begins to vaporize by gradually reducing the system pressure under constant temperature. Heavy oil cold production technology is a development technology that uses the effect of foam oil to produce heavy oil reservoirs. The pressure range of foam generation is from the bubble point pressure to the pseudo-bubble point pressure. The pseudo-bubble point pressure is used to describe the depletion-type production of heavy oil reservoirs, and describes the characteristics of foam oil fluids based on conventional indoor pressure, volume, and temperature data. When the formation pressure is lower than the thermodynamic equilibrium bubble point pressure, the dissolved gas in the crude oil will precipitate in the form of diffused gas to form a free-moving gas phase until the pressure is lowered, that is, the pseudo-bubble point pressure. Below the pseudo-bubble point pressure, part of the diffused gas will become free gas. As the pressure decreases, the gas diffused in the crude oil will decrease until it all becomes free gas. With the deepening of cold production of foam oil reservoirs, the formation pressure is further reduced (lower than the pseudo-bubble point pressure), the dissolved gas gradually escapes into a continuous phase, the advantages of foam oil are exhausted, the gas-oil ratio of oil well production increases, the oil production decreases, and even the oil well is shut down.

[0072] Step S2 is to screen the oil wells with poor foam oil development effect according to the oil production data. The oil wells with poor foam oil development effect are oil wells with low cold production output, high production gas-oil ratio or stopped production oil wells.

[0073] Specifically, the oil wells with poor foam oil development effect are screened according to the oil production data, including: when the oil well production gas-oil ratio> the original gas-oil ratio of the oil reservoir*10, and the reservoir formation pressure<the pseudo-bubble point pressure, and the oil well oil production<*20% of the peak production, and the foam proportion in the oil sample<the foam proportion threshold, then the oil well is an oil well with poor foam oil development effect. When the foam oil well production gas-oil ratio rises to more than 10 times the original gas-oil ratio, the formation pressure is lower than the pseudo-bubble point pressure, the oil well oil production is lower than 20% of the peak production, and the foam proportion in the oil sample is significantly reduced, it can be determined that the production effect of the foam oil well has significantly deteriorated, and gas injection is required to extend the foam oil cold production life cycle to improve the foam oil cold production development.

[0074] Step S3 is to perform oil production actions on the oil well according to the oil production data, and the oil production actions include gas injection, well shut-down and pumping back.

[0075] Specifically, the gas injection amount is:

[0076]

[0077] Among them, r is the throughput radius, L is the horizontal well section production length, h is the oil layer thickness, is the porosity of the oil layer, So is the oil saturation, R is the volume of gas dissolved in a unit volume of crude oil under formation conditions, ρ is the surface density of gas, A is the amplitude of the increase in gas injection volume, and n is the number of oil production rounds. Preferably, the amplitude of the increase in gas injection volume is 5%-30%. The oil production data is related to the average oil saturation of the oil well control range. Preferably, the row spacing of the horizontal wells in the oil reservoir is twice the throughput radius. The maximum number of gas injection throughput rounds is 6, and the throughput radius under the maximum round is the maximum throughput radius.

[0078] According to a specific implementation method, the amount of gas injection is determined by the thickness of the oil layer encountered by the oil well to be produced, the porosity of the oil layer, the sweep radius and the solubility of the gas in the crude oil. The oil production data is related to the solubility of the oil. Usually, the sweep range of a vertical well can be considered as a circle, such as Figure 2 As shown in Figure 2, the gas injection range of a horizontal well is similar to an ellipse (rectangle + two semicircles), as shown in Figure 2. Figure 3As shown. The injected gas should be appropriate. Too much injection will cause the gas to be unable to dissolve in the affected crude oil, causing difficulties and waste in the later pumping. Too little injection will result in the failure to achieve the desired effect of pressurization, viscosity reduction, and improved oil recovery efficiency. The inventors have found that after the gas was injected, the formation pressure at the bottom of the oil well within the affected radius increased by 0.5MPa, the crude oil viscosity decreased by 50%-80%, and the formation driving force and crude oil fluidity were significantly enhanced. The amount of cold production liquid is related to the reservoir pressure and the degree of crude oil degassing, and is related to the dissolution of gas in crude oil after the later gas injection and the length of the well soaking time. The length of the well soaking time is related to the nature of the gas injection, the injection amount, the crude oil properties, the formation temperature and the formation pressure. For example, the greater the gas injection amount within a certain range, the longer the well soaking time. During the gas injection process, the gas injection pressure is lower than the fracture pressure of the formation in which the oil well is located.

[0079] Step S4 is to repeat gas injection, well shut-down and pumping in sequence until the oil well reaches the cold production limit production, and the gas injection volume in the gas injection increases with the increase of oil production rounds.

[0080] According to a specific implementation method, when the first round throughput radius is 30-110m, the oil well stage production effect is that as the injection volume increases, the oil production of the oil well increases, but the oil change rate decreases. When the throughput radius is 50m, the oil change rate decreases slowly. Therefore, the preferred first round throughput radius of this application is 50m. Figure 4 shown.

[0081] The soaking time is generally based on the time when the injected gas is fully dissolved in the crude oil and can be utilized. Figure 5 As shown in the figure, if the soaking time is too short, the gas will be directly recovered without dissolving, which will cause waste; if the soaking time is too long, it will lead to low production rate of the oil well, affecting the production within a certain period of time, and may also cause the injected gas to be far away from the bottom of the well, causing waste. The inventors have found that as the soaking time increases, the gas oil exchange rate decreases, so the preferred soaking time is 10 days.

[0082] Among them, the liquid production rate can reflect the extent of the gas drainage effect in the formation. Figure 6 As shown in the figure, when the total discharge volume of the cycle is equal, a too high discharge speed will cause the pressure near the bottom of the well to drop too quickly, and the viscosity of the crude oil will increase, which is not conducive to the flow of crude oil. A too low discharge volume will result in a low single well production, and the purpose of increasing production cannot be achieved. Therefore, the liquid production speed of this application is 1.0%-4.0%. After the liquid production speed reaches 2.0%, the oil change rate decreases faster, and at this time, a higher single well production can be guaranteed. Therefore, the preferred liquid production speed of this application is 2.0%.

[0083] The gas injection volume in the gas injection increases with the increase in the number of oil production rounds. Specifically, according to the need to increase the radius of the gas injection, the gas injection volume is increased by a certain proportion compared with the previous time. According to the on-site production effect, if the gas injection volume is too large, it will not be able to be recovered in time during the withdrawal, and if the gas injection volume is too small, it will lead to the inability to exert the reservoir capacity, affecting the overall production increase effect. Preferably, during the withdrawal process, the liquid production rate is 1.0%-4.0% of the single well controlled reserves. The single well controlled reserves are the geological reserves within the flow range of the single well controlled fluid. It can be calculated based on the results data obtained from the oil test using the formation test data processing and interpretation method.

[0084] The inventors have found that the production effect is best when the gas injection volume is increased by 5%-30% compared with the first round, and as the increment becomes larger, the oil production of the second round gradually increases. When the gas injection volume increases by 20%, the oil change rate decreases slowly. Therefore, the new gas injection volume of the present application is increased by 20% compared with the previous one. Figure 7 shown.

[0085] Moreover, as the number of gas injection rounds increases, the oil saturation at the bottom of the well decreases, and the periodic oil production decreases to the limit of cold production. The preferred maximum round of gas injection throughput in this application is 6 rounds, at which time the limit radius of gas injection throughput is obtained. By determining the limit radius of gas injection throughput, it can be preliminarily determined that the optimal row spacing of horizontal wells in foam oil reservoirs should be twice the throughput radius. According to the current status of horizontal well development in foam oil reservoirs, the adaptability of early well spacing is determined, and the adjustment of well spacing in the later well network is guided to achieve economic and efficient development of foam oil. The row spacing is the distance between the water well row and the oil well row.

[0086] The oil production method of the present application also includes: if the adjacent wells of the oil well have not reached the cold production limit, then the oil well and the adjacent wells are subjected to combined gas injection and huff; the combined gas injection and huff are performed synchronously for the oil production actions of multiple oil wells. Specifically, the combined gas injection and huff include: if the adjacent oil wells all reach the time when gas injection is required to extend the life cycle of foam oil cold production, the adjacent oil wells should be gas injected and opened for oil production at the same time, so as to avoid the injected gas from flowing into the adjacent wells that are recovering, thereby causing waste of injected gas and affecting the production of the adjacent wells.

[0087] The present invention provides an oil production method comprising the following steps: S1: obtaining oil production data of an oil well to be produced, wherein the oil production data at least includes the oil well production gas-oil ratio, the reservoir original gas-oil ratio, the reservoir formation pressure, the pseudo-bubble point pressure, the oil production of the oil well, the peak production, and the proportion of foam in the oil sample; S2: screening the oil well with poor foam oil development effect according to the oil production data; S3: performing oil production actions on the oil well according to the oil production data, wherein the oil production actions include gas injection, well soaking and pumping back; S4: repeating gas injection, well soaking and pumping back in sequence until the oil well reaches the cold production limit production, and the gas injection amount in the gas injection increases with the increase of the oil production rounds. The present invention achieves the reduction of the viscosity of the crude oil after degassing, increases the formation pressure, and reduces the interfacial tension of the crude oil by screening the oil well with poor foam oil development effect and determining the timing of gas injection, thereby extending the cold production life cycle of the foam oil by forming similar foam oil, continuing to exert the foam oil production capacity, improving the production in the cold production stage, and achieving effective treatment of low-yield wells and long-stopped wells.

[0088] The present invention also provides an oil production device, which includes: an acquisition module, used to acquire oil production data of the oil well to be produced, the oil production data at least including the oil well production gas-oil ratio, the original gas-oil ratio of the oil reservoir, the oil reservoir formation pressure, the pseudo-bubble point pressure, the oil production of the oil well, the peak production, and the proportion of foam in the oil sample; a screening module, used to screen the oil wells with poor foam oil development effect according to the oil production data; an oil production module, used to perform oil production actions on the oil wells according to the oil production data, the oil production actions including gas injection, well shut-in and pumping back; gas injection, well shut-in and pumping back are repeated in sequence until the oil well reaches the cold production limit production, and the gas injection amount in the gas injection increases with the increase of oil production rounds.

[0089] The bubble point pressure is the pressure at which the first bubble appears when the liquid mixture begins to vaporize by gradually reducing the system pressure under constant temperature. Heavy oil cold production technology is a development technology that uses the effect of foam oil to produce heavy oil reservoirs. The pressure range of foam generation is from the bubble point pressure to the pseudo-bubble point pressure. The pseudo-bubble point pressure is used to describe the depletion-type production of heavy oil reservoirs, and describes the characteristics of foam oil fluids based on conventional indoor pressure, volume, and temperature data. When the formation pressure is lower than the thermodynamic equilibrium bubble point pressure, the dissolved gas in the crude oil will precipitate in the form of diffused gas to form a free-moving gas phase until the pressure is lowered, that is, the pseudo-bubble point pressure. Below the pseudo-bubble point pressure, part of the diffused gas will become free gas. As the pressure decreases, the gas diffused in the crude oil will decrease until it all becomes free gas. With the deepening of cold production of foam oil reservoirs, the formation pressure is further reduced (lower than the pseudo-bubble point pressure), the dissolved gas gradually escapes into a continuous phase, the advantages of foam oil are exhausted, the gas-oil ratio of oil well production increases, the oil production decreases, and even the oil well is shut down.

[0090] The method of screening the oil wells with poor foam oil development effect according to the oil production data includes: when the production gas-oil ratio of the oil well> the original gas-oil ratio of the oil reservoir*10, and the formation pressure of the oil reservoir<the pseudo-bubble point pressure, and the oil production of the oil well<*20% of the peak production, and the foam proportion in the oil sample<the foam proportion threshold, then the oil well is an oil well with poor foam oil development effect.

[0091] The gas injection volume is:

[0092]

[0093] Among them, r is the throughput radius, L is the horizontal well section production length, h is the oil layer thickness, is the porosity of the oil layer, So is the oil saturation, R is the volume of gas dissolved in a unit volume of crude oil under formation conditions, ρ is the surface density of gas, A is the increase in gas injection volume, and n is the number of oil production rounds. Preferably, the increase in gas injection volume is 5%-30%.

[0094] According to a specific implementation method, the amount of gas injection is related to the thickness of the oil layer encountered by the oil well to be produced, the porosity of the oil layer, the swept radius and the solubility of the gas in the crude oil. Usually, the swept range of a vertical well can be considered as a circle; while the swept range of a horizontal well gas injection is similar to an ellipse (rectangle + two semicircles). The injected gas should be appropriate. Too much injection will cause the gas to be unable to dissolve in the affected crude oil, causing difficulties and waste in the later pumping. Too little injection will result in the inability to achieve the desired effect of pressurization, viscosity reduction, and improvement of oil recovery efficiency. The inventors have found that after the gas is injected, the formation pressure at the bottom of the oil well within the swept radius increased by 0.5MPa, the crude oil viscosity decreased by 50%-80%, and the formation driving force and crude oil fluidity were significantly enhanced.

[0095] The oil production module is also used to perform combined gas injection and huffing on the oil well and the adjacent wells if the adjacent wells of the oil well have not reached the cold production limit production; the combined gas injection and huffing is a synchronous oil production action of multiple oil wells.

[0096] Specifically, the combined gas injection and huff-and-puff includes: if adjacent oil wells all reach the time when gas injection is required to extend the life cycle of foam oil cold production, the adjacent oil wells should be injected with gas and opened for oil production at the same time, so as to avoid the injected gas from flowing along the high-permeability channel to the adjacent well that is recovering, thereby causing waste of injected gas, affecting the production of adjacent wells, and causing the current well to fail to meet the expected gas injection requirements, and also affecting the production effect of the current well.

[0097] In the cold production process of foam oil wells, due to the effect of foam oil, the stage production is high, but as the production continues, some wells have a long production time, the formation deficit near the bottom of the well is large, and the pressure is reduced (lower than the pseudo-bubble point pressure), and the bubbles originally dispersed in the oil phase will gradually escape to form free gas in a free state. After degassing, the viscosity of crude oil increases, the fluidity of crude oil deteriorates, the production of oil wells will decrease, and some oil wells will even be shut down due to excessively high production gas-oil ratios, which leads to a deterioration in the overall production effect of the oil wells. The present application selectively injects gas into the oil well, which can expand the crude oil to increase the formation pressure, improve the oil displacement efficiency, reduce the viscosity of crude oil, form the effect of dissolved gas drive, and even form secondary foam, and continue to apply the foam oil mechanism to play a role in increasing production and resuming production.

[0098] According to a specific implementation method, the injected gas enters the bottom of the well and gradually dissolves in the crude oil after contacting with the crude oil. The length of the dissolution time is related to the gas properties, the gas injection amount, the crude oil properties, and the temperature and pressure of the formation. During this dissolution process, the oil well will be closed, that is, the well soaking time is related to the nature of the gas injection, the injection amount, the crude oil properties, the formation temperature and the formation pressure. After a period of well soaking, when the gas and the crude oil are fully dissolved (the bottom hole pressure is relatively stable), the oil well can be organized to be pumped back at a certain liquid production rate in a timely manner, so that the oil well production should be improved to a certain extent compared with before the gas injection, and the production of the shut-down well will also increase significantly compared with before the shutdown; after a period of production, the oil well production gradually decreases (generally not higher than before the gas injection), the oil well can be shut down and the next round of gas injection can be carried out, and the gas injection volume is increased by a certain proportion compared with the previous time; repeat the gas injection, well soaking, and pumping until the oil well reaches the cold production limit production. This method achieves the extension of the life cycle of foam oil cold production and improves the effect of cold production stage development.

[0099] The soaking time is generally based on the injected gas being fully dissolved in the crude oil and being utilized. If the soaking time is too short, the gas will be directly recovered without being dissolved, which will cause waste; if the soaking time is too long, it will lead to low production rate of the oil well, affecting the production within a certain period of time, and may also cause the injected gas to be far away from the bottom of the well and cause waste. The inventors have found that as the soaking time increases, the gas oil exchange rate becomes lower, so the preferred soaking time is 10 days.

[0100] Among them, the speed of liquid production can reflect the magnitude of the gas's drainage effect in the formation. When the total liquid discharge volume in a period is equal, a too high liquid discharge speed will cause the pressure near the bottom of the well to drop too quickly, and the viscosity of the crude oil will increase, which is not conducive to the flow of crude oil. Too low a liquid discharge volume will result in low production of a single well, and the purpose of increasing production cannot be achieved. Therefore, the liquid production speed of this application is 1.0%-4.0%. After the liquid production speed reaches 2.0%, the oil change rate decreases faster, and at this time, a higher production of a single well can be guaranteed. Therefore, the preferred liquid production speed of this application is 2.0%.

[0101] The gas injection volume in the gas injection increases with the increase in the number of oil production rounds. Specifically, according to the need to increase the radius of the gas injection, the gas injection volume is increased by a certain proportion compared with the previous time. According to the on-site production effect, if the gas injection volume is too large, it will not be able to be recovered in time during the withdrawal, and if the gas injection volume is too small, it will lead to the inability to exert the reservoir capacity, affecting the overall production increase effect. The inventors have found that the production effect is best when the gas injection volume is increased by 5%-30% compared with the first round, and as the increment becomes larger, the oil production of the second round gradually increases. When the gas injection volume increases by 20%, the oil change rate decreases slowly. Therefore, the new gas injection volume of this application is increased by 20% compared with the previous time.

[0102] Moreover, as the number of gas injection rounds increases, the oil saturation at the bottom of the well decreases, and the periodic oil production decreases to the cold production limit. The preferred maximum number of gas injection throughput rounds in this application is 6 rounds, at which time the gas injection throughput limit radius is obtained. By determining the gas injection throughput limit radius, it can be preliminarily determined that the optimal row spacing of horizontal wells in foam oil reservoirs should be twice the throughput radius. According to the current status of horizontal well development in foam oil reservoirs, the adaptability of the early well spacing is determined, and the adjustment of the well spacing in the later well network is guided to achieve economic and effective development of foam oil.

[0103] The present application also proposes a specific embodiment, specifically: a certain oil reservoir is a heavy oil reservoir, and the oil well production shows the characteristics of foam oil. Among them, the oil reservoir is buried at a depth of 800m, the average thickness of the oil layer is 22m, the work area is a pure oil reservoir, and the original gas-oil ratio of the oil reservoir is 15 cubic meters. The oil reservoir is developed by horizontal well cold production. The peak production of the horizontal well is 122 tons / day. After 11 years of production, the production before suspension dropped to 23.4 tons / day. The production gas-oil ratio is 21.7 times the original gas-oil ratio, and the cold production effect is poor.

[0104] After being shut down for two years, gas was injected into the well to resume production. The radius of the first cycle was calculated to be about 50m. Then, gas was injected and the well was shut down for 10 days before production was resumed. Under the condition of controlling the liquid production rate at 2.5%, the initial daily oil production reached 95 tons. The well was shut down when the production dropped to the production before the shutdown. The second gas injection volume was increased by 20% on the basis of the first one, and production continued. The gas injection production could be cyclically performed for 6 rounds, and the production in the cyclic gas injection stage accounted for more than 40% of the previous foam oil cold production. This embodiment shows that the method for extending the life cycle of foam oil cold production of the present invention effectively extends the cold production stage of foam oil wells.

[0105] The oil production method of the present invention, when the foam oil cold production effect of the oil well becomes poor or has been shut down, injects a certain amount of gas into the oil well, allowing the gas to contact with crude oil for a certain period of time and dissolve into the crude oil, so that the crude oil expands and thereby increases the formation pressure, reduces the viscosity of the formation crude oil, reduces the crude oil interfacial tension, and reduces the residual oil saturation, thereby increasing the oil recovery efficiency, increasing the oil well recovery output, extending the foam oil cold production time, and improving the effect of cold production development.

[0106] On the other hand, the present invention also provides an electronic device, comprising: at least one processor; a memory connected to the at least one processor; wherein the memory stores instructions that can be executed by the at least one processor, and the at least one processor implements the above-mentioned oil production method by executing the instructions stored in the memory.

[0107] The processor includes a kernel, which retrieves the corresponding program unit from the memory. One or more kernels can be set, and the production in the cold production stage is increased by adjusting the kernel parameters, thereby achieving effective treatment of low-yield wells and long-stopped wells.

[0108] The memory may include non-permanent memory in a computer-readable medium, random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM, and the memory includes at least one memory chip.

[0109] An embodiment of the present invention provides a storage medium on which a program is stored. When the program is executed by a processor, the oil production method is implemented.

[0110] An embodiment of the present invention provides a processor, which is used to run a program, wherein the oil production method is executed when the program is run.

[0111] The embodiment of the present invention provides a device, which includes a processor, a memory, and a program stored in the memory and executable on the processor. When the processor executes the program, the following steps are implemented: (method claim steps, sole right + subordinate right). The device in this article can be a server, a PC, a PAD, a mobile phone, etc.

[0112] The present application also provides a computer program product, which, when executed on a data processing device, is suitable for executing a program initialized with the following method steps: obtaining oil production data of the oil well to be produced, the oil production data at least including the oil well production gas-oil ratio, the original gas-oil ratio of the oil reservoir, the oil reservoir formation pressure, the pseudo-bubble point pressure, the oil production of the oil well, the peak production, and the proportion of foam in the oil sample; screening oil wells with poor foam oil development effect according to the oil production data; performing oil production actions on the oil wells according to the oil production data, the oil production actions including gas injection, well shut-in and pumping back; repeating the gas injection, well shut-in and pumping back in sequence until the oil well reaches the cold production limit production, and the gas injection amount in the gas injection increases with the increase in the number of oil production cycles. The method of screening oil wells with poor foam oil development effects according to the oil production data includes: when the oil well production gas-oil ratio> the original gas-oil ratio of the oil reservoir*10, and the reservoir formation pressure<the pseudo-bubble point pressure, and the oil well production<*20% of the peak production, and the foam proportion in the oil sample<the foam proportion threshold, then the oil well is an oil well with poor foam oil development effects. The method also includes: if the adjacent wells of the oil well have not reached the cold production limit production, then the oil well and the adjacent wells are subjected to combined gas injection and huff-and-puff; the combined gas injection and huff-and-puff are performed synchronously for the oil production actions of multiple oil wells.

[0113] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that include computer-usable program code.

[0114] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0115] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0116] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0117] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0118] The memory may include non-permanent memory in a computer-readable medium, random access memory (RAM) and / or non-volatile memory in the form of read-only memory (ROM) or flash RAM. The memory is an example of a computer-readable medium.

[0119] Computer readable media include permanent and non-permanent, removable and non-removable media that can be implemented by any method or technology to store information. Information can be computer readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disk read-only memory (CD-ROM), digital versatile disk (DVD) or other optical storage, magnetic cassettes, magnetic tape magnetic disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer readable media does not include temporary computer readable media (transitory media), such as modulated data signals and carrier waves.

[0120] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0121] The above are only embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included within the scope of the claims of the present application.

Claims

1. A method for oil recovery, characterized in that: The method comprises the following steps: S1: Obtaining oil production data of the oil well to be produced, wherein the oil production data at least includes the gas-oil ratio of the oil well production, the original gas-oil ratio of the oil reservoir, the formation pressure of the oil reservoir, the pseudo-bubble point pressure, the oil production of the oil well, the peak production, and the proportion of foam in the oil sample; S2: screening oil wells with poor foam oil development effects according to the oil production data; S3: performing oil production actions on the oil well according to the oil production data, wherein the oil production actions include gas injection, well shut-down and pumping back; S4: Repeating gas injection, well shut-down and pumping in sequence until the oil well reaches the cold production limit output, wherein the gas injection volume increases with the increase of oil production rounds.

2. The method according to claim 1, characterized in that The step of screening oil wells with poor foam oil development effects according to the oil production data comprises: When the oil well production gas-oil ratio> the original gas-oil ratio of the oil reservoir*10, and the reservoir formation pressure<the pseudo-bubble point pressure, and the oil well oil production<*20% of the peak production, and the foam proportion in the oil sample<the foam proportion threshold, then the oil well is an oil well with poor foam oil development effect.

3. The method according to claim 1, characterized in that The method further includes: If the adjacent wells of the oil well have not reached the cold production limit, a combined gas injection and huff-and-puff method is performed on the oil well and the adjacent wells; the combined gas injection and huff-and-puff method is a method for synchronously performing oil production actions of multiple oil wells.

4. The method according to claim 1, characterized in that The gas injection volume is: Where r is the throughput radius, L is the production length of the horizontal well section, h is the oil layer thickness, is the porosity of the oil layer, S o is the oil saturation, R is the volume of gas dissolved in unit volume of crude oil under formation conditions, ρ is the surface density of gas, A is the increase in gas injection volume, and n is the number of oil production rounds.

5. The method according to claim 4, characterized in that The increase range of the gas injection amount is 5%-30%.

6. The method according to claim 1, characterized in that The row spacing of horizontal wells in the reservoir is twice the throughput radius.

7. The method according to claim 1, characterized in that The maximum number of gas injection throughput rounds is 6, and the throughput radius under the maximum number of rounds is the maximum throughput radius.

8. The method according to claim 1, characterized in that The duration of soaking is related to the nature and amount of gas injection, the nature of crude oil, the formation temperature and the formation pressure.

9. The method according to claim 1, characterized in that: During the gas injection process, the injection pressure is lower than the fracture pressure of the formation where the oil well is located.

10. The method according to claim 1, characterized in that During the pumping process, the liquid production rate is 1.0%-4.0% of the controlled reserves of a single well.

11. An oil production device, characterized in that: The device includes: An acquisition module is used to acquire oil production data of the oil well to be produced, wherein the oil production data at least includes the gas-oil ratio of the oil well production, the original gas-oil ratio of the oil reservoir, the formation pressure of the oil reservoir, the pseudo-bubble point pressure, the oil production of the oil well, the peak production, and the proportion of foam in the oil sample; A screening module, used for screening oil wells with poor foam oil development effects according to the oil production data; An oil production module, used for performing oil production actions on the oil well according to the oil production data, wherein the oil production actions include gas injection, well soaking and pumping back; The gas injection, well soaking and pumping are repeated in sequence until the oil well reaches the cold production limit production, and the gas injection volume in the gas injection increases with the increase of oil production rounds.

12. The device according to claim 11, characterized in that The step of screening oil wells with poor foam oil development effects according to the oil production data comprises: When the oil well production gas-oil ratio> the original gas-oil ratio of the oil reservoir*10, and the reservoir formation pressure<the pseudo-bubble point pressure, and the oil well oil production<*20% of the peak production, and the foam proportion in the oil sample<the foam proportion threshold, then the oil well is an oil well with poor foam oil development effect.

13. The device according to claim 11, characterized in that The oil production module is also used to perform combined gas injection huff and puff on the oil well and the adjacent well if the adjacent well of the oil well has not reached the cold production limit production; The combined gas injection and huff-and-puff method allows the production of oil from multiple oil wells to be performed synchronously.

14. The device according to claim 11, characterized in that The gas injection volume is: Where r is the throughput radius, L is the production length of the horizontal well section, h is the oil layer thickness, is the porosity of the oil layer, So is the oil saturation, R is the volume of gas dissolved in unit volume of crude oil under formation conditions, ρ is the surface density of gas, A is the increase in gas injection volume, and n is the number of oil production rounds.

15. The device according to claim 14, characterized in that The increase range of the gas injection amount is 5%-30%.

16. The device according to claim 11, characterized in that The row spacing of horizontal wells in the reservoir is twice the throughput radius.

17. The device according to claim 11, characterized in that The maximum number of gas injection throughput rounds is 6, and the throughput radius under the maximum number of rounds is the maximum throughput radius.

18. The device according to claim 11, characterized in that The duration of soaking is related to the nature and amount of gas injection, the nature of crude oil, the formation temperature and the formation pressure.

19. The device according to claim 11, characterized in that During the gas injection process, the injection pressure is lower than the fracture pressure of the formation where the oil well is located.

20. The device according to claim 11, characterized in that During the pumping process, the liquid production rate is 1.0%-4.0% of the controlled reserves of a single well.

21. A machine-readable storage medium having instructions stored thereon, the instructions being used to enable a machine to execute the oil production method as claimed in any one of claims 1 to 10.

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