CN114109324A - Method and device for determining well shut-in time - Google Patents
Method and device for determining well shut-in time Download PDFInfo
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- CN114109324A CN114109324A CN202010885632.6A CN202010885632A CN114109324A CN 114109324 A CN114109324 A CN 114109324A CN 202010885632 A CN202010885632 A CN 202010885632A CN 114109324 A CN114109324 A CN 114109324A
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Abstract
The application discloses a method and a device for determining well closing time, and belongs to the technical field of oil exploitation. The method comprises the following steps: determining a reference shut-in time based on the amount of carbon dioxide injected into the sand-filled pipe; calculating the dissolving and diffusing flux of the carbon dioxide according to the reference shut-in time and the sectional area of the sand filling pipe; determining a target sweep radius of carbon dioxide in the oil well according to relevant parameters of the oil well and the amount of carbon dioxide injected into the oil well; and calculating the target shut-in time of the oil well based on the dissolving and diffusing flux of the carbon dioxide and the target swept radius. Based on the actual condition of the oil well, the amount of carbon dioxide injected into the oil well and the reference shut-in time, a reasonable target shut-in time is determined, the carbon dioxide injected into the oil well in the target shut-in time can fully react with crude oil in the oil well, so that the carbon dioxide can fully expand, reduce the viscosity, extract and evaporate, the throughput effect of the carbon dioxide in the oil well can be improved, the oil well can be extruded, and the oil yield of the oil well is improved.
Description
Technical Field
The embodiment of the application relates to the technical field of oil exploitation, in particular to a method and a device for determining well closing time.
Background
In oil production, the production of oil from a well is typically enhanced by the use of production techniques in which carbon dioxide is injected into the well. After carbon dioxide is injected into the oil well, the oil well needs to be closed for a period of time, so that carbon dioxide molecules are dissolved in crude oil through diffusion mass transfer, and the effects of expansion, viscosity reduction, extraction and evaporation are achieved, namely the oil yield of the oil well is improved through the huff and puff of the carbon dioxide. Therefore, the length of the shut-in time directly affects the throughput effect of carbon dioxide, and thus the oil production of the oil well.
Too short a shut-in time may result in insufficient contact between the injected carbon dioxide and the crude oil, resulting in poor carbon dioxide throughput and consequently lower oil production in the field. The well shut-in time is too long, so that the injected carbon dioxide can be diffused to the deep part and the boundary of the oil well, the elastic driving energy of the carbon dioxide of the stratum around the oil well is reduced, and the oil production of the oil well is influenced. Therefore, a method for determining the closing time is needed to reasonably control the closing time, so as to improve the carbon dioxide throughput effect and the oil yield of the oil well.
Disclosure of Invention
The embodiment of the application provides a method and a device for determining the well closing time, which can be used for solving the problem of low oil yield of an oil well in the related art. The technical scheme is as follows:
in one aspect, an embodiment of the present application provides a method for determining a well shut-in time, where the method includes:
determining a reference shut-in time based on the amount of carbon dioxide injected into the sand-filled pipe;
calculating the dissolving and diffusing flux of the carbon dioxide according to the reference shut-in time and the sectional area of the sand-filled pipe;
determining a target sweep radius of carbon dioxide in the oil well according to relevant parameters of the oil well and the amount of carbon dioxide injected into the oil well;
and calculating the target shut-in time of the oil well based on the dissolving and diffusing flux of the carbon dioxide and the target swept radius.
In one possible implementation, the calculating the dissolution diffusion flux of the carbon dioxide according to the reference shut-in time and the cross-sectional area of the sand-packed pipe includes:
calculating the dissolving and diffusing flux of the carbon dioxide according to the reference shut-in time and the sectional area of the sand-filling pipe and the following formula
Wherein, the
And B, the amount of the carbon dioxide injected into the sand filling pipe is shown, A is the sectional area of the sand filling pipe, and t is the reference shut-in time.
In one possible implementation, the determining a target sweep radius of carbon dioxide in the oil well according to the relevant parameters of the oil well and the amount of carbon dioxide injected into the oil well includes:
calculating a first sweep radius of the carbon dioxide in the well based on the relevant parameters of the well, the amount of carbon dioxide injected into the well, and the formation crude oil density when the carbon dioxide injected into the well is not dissolved in the crude oil in the well;
calculating a second sweep radius of the carbon dioxide in the well based on the relevant parameters of the well, the amount of carbon dioxide injected into the well, and the solubility of the carbon dioxide in the formation crude oil when the carbon dioxide injected into the well is fully dissolved in the crude oil in the well;
determining a target sweep radius of the carbon dioxide in the oil well based on the first sweep radius and the second sweep radius.
In one possible implementation, the calculating a first sweep radius of the carbon dioxide in the well based on the relevant parameters of the well, the amount of carbon dioxide injected into the well, and the formation crude oil density when the carbon dioxide injected into the well is not dissolved in the crude oil in the well comprises:
when the carbon dioxide injected into the oil well is not dissolved in the crude oil in the oil well, based on relevant parameters of the oil well, the amount of the carbon dioxide injected into the oil well and the density of the crude oil in the stratum, calculating a first sweep radius R of the carbon dioxide in the oil well according to the following formula1：
Wherein, the
The amount of carbon dioxide injected into the oil well, the pi is a circumferential rate, the h is a thickness of an oil layer of the oil well, the
For porosity, said SoTo oil saturation, said
Is the formation crude oil density.
In one possible implementation, the calculating a second sweep radius of the carbon dioxide in the oil well based on the relevant parameters of the oil well, the amount of carbon dioxide injected into the oil well, and the solubility of the carbon dioxide in the formation crude oil when the carbon dioxide injected into the oil well is completely dissolved in the crude oil in the oil well comprises:
when the carbon dioxide injected into the oil well is totally dissolved in the crude oil in the oil well, based on relevant parameters of the oil well, the amount of the carbon dioxide injected into the oil well and the solubility of the carbon dioxide in the crude oil in the formation, a second sweep radius R of the carbon dioxide in the oil well is calculated according to the following formula2：
Wherein, the
The amount of carbon dioxide injected into the oil well, the pi is a circumferential rate, the h is a thickness of an oil layer of the oil well, the
For porosity, said SoTo oil saturation, said
Is the solubility of the carbon dioxide in the crude oil of the formation.
In one possible implementation, the calculating a target shut-in time of the oil well based on the dissolution diffusion flux of the carbon dioxide and the target sweep radius includes:
determining the amount of carbon dioxide injected into the well and the associated parameters of the well;
calculating a target shut-in time for the well based on the dissolved diffusion flux of carbon dioxide, the target sweep radius, the amount of carbon dioxide injected into the well, and the relevant parameters of the well.
In one possible implementation, the calculating a target shut-in time for the oil well based on the dissolved diffusion flux of the carbon dioxide, the target sweep radius, the amount of carbon dioxide injected into the oil well, and the related parameters of the oil well comprises:
calculating a target shut-in time t of the oil well according to the following formula based on the dissolved diffusion flux of the carbon dioxide, the target sweep radius, the amount of the carbon dioxide injected into the oil well, and the parameters of the oil wellfield：
Wherein, the
The amount of carbon dioxide injected into the oil well, the pi is a circumferential rate, the R is the target swept radius, the h is the reservoir thickness of the oil well, the
The flux of dissolved diffusion of carbon dioxide.
In another aspect, an embodiment of the present application provides a device for determining a shut-in time, where the device includes:
the first determination module is used for determining reference shut-in time based on the amount of carbon dioxide injected into the sand-filled pipe;
the first calculation module is used for calculating the dissolving and diffusing flux of the carbon dioxide according to the reference shut-in time and the sectional area of the sand filling pipe;
the second determination module is used for determining the target sweep radius of the carbon dioxide in the oil well according to the relevant parameters of the oil well and the amount of the carbon dioxide injected into the oil well;
and the second calculation module is used for calculating the target shut-in time of the oil well based on the dissolving diffusion flux of the carbon dioxide and the target swept radius.
In a possible implementation manner, the first calculation module is used for calculating the carbon dioxide according to the following formula according to the reference shut-in time and the sectional area of the sand filling pipeFlux of dissolution diffusion
Wherein, the
And B, the amount of the carbon dioxide injected into the sand filling pipe is shown, A is the sectional area of the sand filling pipe, and t is the reference shut-in time.
In one possible implementation, the second determination module is configured to calculate a first sweep radius of the carbon dioxide in the oil well based on the relevant parameters of the oil well, the amount of the carbon dioxide injected into the oil well, and the formation crude oil density when the carbon dioxide injected into the oil well is not dissolved in the crude oil in the oil well;
calculating a second sweep radius of the carbon dioxide in the well based on the relevant parameters of the well, the amount of carbon dioxide injected into the well, and the solubility of the carbon dioxide in the formation crude oil when the carbon dioxide injected into the well is fully dissolved in the crude oil in the well;
determining a target sweep radius of the carbon dioxide in the oil well based on the first sweep radius and the second sweep radius.
In a possible implementation, the second determination module is configured to calculate a first sweep radius R of the carbon dioxide in the oil well according to the following formula based on the relevant parameters of the oil well, the amount of the carbon dioxide injected into the oil well and the formation crude oil density when the carbon dioxide injected into the oil well is not dissolved in the crude oil in the oil well1：
Wherein, the
The amount of carbon dioxide injected into the oil well, the pi is a circumferential rate, the h is a thickness of an oil layer of the oil well, the
For porosity, said SoTo oil saturation, said
Is the formation crude oil density.
In a possible implementation, the second determining module is configured to calculate a second sweep radius R of the carbon dioxide in the oil well according to the following formula based on the relevant parameters of the oil well, the amount of the carbon dioxide injected into the oil well and the solubility of the carbon dioxide in the crude oil in the formation when the carbon dioxide injected into the oil well is completely dissolved in the crude oil in the oil well2：
Wherein, the
The amount of carbon dioxide injected into the oil well, the pi is a circumferential rate, the h is a thickness of an oil layer of the oil well, the
For porosity, said SoTo oil saturation, said
Is the solubility of the carbon dioxide in the crude oil of the formation.
In a possible implementation, the second calculation module is configured to determine the amount of carbon dioxide injected into the oil well and the related parameters of the oil well; calculating a target shut-in time for the well based on the dissolved diffusion flux of carbon dioxide, the target sweep radius, the amount of carbon dioxide injected into the well, and the relevant parameters of the well.
In a possible implementation manner, the second calculation module is configured to calculate the target shut-in time t of the oil well according to the following formula based on the dissolution diffusion flux of the carbon dioxide, the target sweep radius, the amount of carbon dioxide injected into the oil well, and the parameters of the oil wellfield：
Wherein, the
The amount of carbon dioxide injected into the oil well, the pi is a circumferential rate, the R is the target swept radius, the h is the reservoir thickness of the oil well, the
The flux of dissolved diffusion of carbon dioxide.
The technical scheme provided by the embodiment of the application at least has the following beneficial effects:
the technical scheme that this application embodiment provided adopts the sand-packed pipe to simulate the oil well scene, based on the carbon dioxide volume of injecting into the sand-packed pipe, confirm the dissolution diffusion flux of a reference shut-in time and carbon dioxide, thereby according to the dissolution diffusion flux of carbon dioxide, the actual conditions of oil well and the carbon dioxide volume of injecting into the oil well, determine a reasonable target shut-in time, carbon dioxide and the crude oil in the oil well can fully react in this target shut-in time, make carbon dioxide can fully expand, the viscosity reduction, extract the evaporation, thereby improve the throughput effect of carbon dioxide in the oil well, and then carry out reasonable and abundant extrusion to the oil well, further improve the oil production volume of oil well.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.
FIG. 1 is a flow chart of a method for determining shut-in time according to an embodiment of the present disclosure;
FIG. 2 is a graph of the change of pressure in a sand pack pipe based on the change of time according to an embodiment of the application;
fig. 3 is a schematic structural diagram of a device for determining a shut-in time according to an embodiment of the present application.
Detailed Description
To make the objects, technical solutions and advantages of the present application more clear, embodiments of the present application will be described in further detail below with reference to the accompanying drawings.
The embodiment of the application provides a method for determining well closing time, and the method can be applied to electronic equipment or a server. The electronic device is any electronic product capable of performing man-machine interaction with a user through one or more modes of a keyboard, a touch pad, a touch screen, a remote controller, voice interaction or handwriting equipment and the like. Examples of the PC include a PC (Personal computer), a mobile phone, a smart phone, a PDA (Personal Digital Assistant), a wearable device, a palm PC (pocket PC), and a tablet PC. The server is a server, or a server cluster formed by a plurality of servers, or at least one of a cloud computing platform and a virtualization center, which is not limited in the embodiment of the present application.
Those skilled in the art should appreciate that the above-described electronic devices and servers are merely examples, and that other existing or future electronic devices or servers may be suitable for use in the present application and are also included within the scope of the present application and are hereby incorporated by reference.
The embodiment provides a method for determining a well closing time, and an implementation subject of the method for determining the well closing time is taken as an example to be explained. Referring to fig. 1, the method includes the following steps 101 to 104.
In step 101, a reference shut-in time is determined based on the amount of carbon dioxide injected into the sand pack.
In one possible implementation, a sand pack pipe is used to simulate the actual well scenario, thereby determining the reference shut-in time. The sand-filling pipe is a stainless steel type pipeline, technicians fill the sand-filling pipe with sand, crude oil and water, and inject a certain amount of carbon dioxide into the sand-filling pipe, wherein the carbon dioxide can react with the crude oil in the sand-filling pipe. As the time for the reaction of the carbon dioxide injected into the sand pack and the crude oil in the sand pack varies, the pressure value in the sand pack also varies. And recording the time change numerical value and the pressure value change numerical value in the sand filling pipe in real time, and inputting the time change numerical value and the pressure value change numerical value in the sand filling pipe into the electronic equipment. The electronic equipment generates a graph based on the time change value and the pressure value in the sand filling pipe, wherein the graph is the graph based on the time change value and the pressure value in the sand filling pipe.
Based on the graph, a reference shut-in time may be determined in the following manner.
And the first mode is to calculate the slope of the curve graph at each time and determine the reference shut-in time based on the slope at each time.
And calculating the slope of the curve graph at each time, and when the slope is zero, determining the corresponding time as the reference well closing time. Namely, the time when the pressure value in the sand filling pipe reaches the inflection point is determined in the curve chart, and the corresponding time at the inflection point is determined as the reference shut-in time.
And secondly, when the pressure value in the sand filling pipe does not change along with the change of time any more, or the change range of the pressure value in the sand filling pipe along with the change of time is within a target threshold value, determining the time as the reference shut-in time.
The value of the target threshold value can be set based on the setting, or different target threshold values can be determined according to different amounts of carbon dioxide injected into the sand-packed pipe, and the value of the target threshold value is not limited in the embodiment of the application. For example, the value of the target threshold is 0.1, or the value of the target threshold is 1.0.
It should be noted that any one of the above manners may be selected to determine the reference shut-in time, which is not limited in the embodiment of the present application.
Fig. 2 is a graph showing a change of pressure in a sand pack pipe based on a change of time according to an embodiment of the present application, in fig. 2, after a certain amount of carbon dioxide is input into the sand pack pipe, crude oil in the sand pack pipe reacts with the injected carbon dioxide, and the pressure in the sand pack pipe slowly decreases with increasing time. When the time reaches 24h (hours), the pressure value in the sand filling pipe is found not to be changed basically, or the change range of the pressure value in the sand filling pipe is within the target threshold value, so that the reference shut-in time is determined to be 24 hours.
In step 102, the dissolving diffusion flux of the carbon dioxide is calculated according to the reference shut-in time and the sectional area of the sand-packed pipe.
In a possible implementation manner, the sand filling pipe is generally a cylindrical pipe, the cross section of the sand filling pipe is circular, and before the cross section of the sand filling pipe is determined, the radius of the sand filling pipe needs to be determined. The technical personnel in the art determine the radius of the sand filling pipe through a manual measurement mode, and input the radius of the sand filling pipe into the electronic equipment, namely the electronic equipment obtains the radius of the sand filling pipe. Or the electronic device obtains the number of the sand pack, where the number is a production number of the sand pack, or another number that can uniquely identify the sand pack, which is not limited in this embodiment of the present application. The electronic equipment determines the radius of the sand filling pipe according to the serial number of the sand filling pipe, namely the radius of the sand filling pipe acquired by the electronic equipment. After the radius of the sand pack pipe is determined, the sectional area a of the sand pack pipe is calculated according to the following sectional area calculation formula (1).
A＝π*r2 (1)
In the above formula (1), the unit of the cross-sectional area A is m2(square meter); pi is the circumference ratio, and the value is 3.14; r is the radius of the sand-filled pipe in m (meters).
Illustratively, the radius of the sand-packed pipe is 3.825cm (cm), and the cross-sectional area of the sand-packed pipe is calculated according to the above formula (1), yielding a-3.14 × 0.38252That is, the cross-sectional area of the sand-packed pipe is 0.4594 square meters.
The sand-filled pipe may be a pipe of another shape, and when the sand-filled pipe is a pipe of another shape, the sectional area of the sand-filled pipe is calculated according to a corresponding area calculation formula. In the embodiment of the present application, only the formula (1) is given as an example, where the shape of the sand pack pipe is cylindrical, the cross section is circular, and the formula for calculating the cross section area is circular.
In a possible implementation manner, according to the amount of carbon dioxide injected into the sand-packed pipe, the sectional area of the sand-packed pipe determined in the step and the reference shut-in time determined in the step 101, the following formula (2) is used for calculation to obtain the dissolving and diffusing flux of the carbon dioxide
In the above-mentioned formula (2),
has the unit of t/m2A day;
the unit is ton of carbon dioxide injected into the sand filling pipe; a is the sectional area of the sand filling pipe, and the unit is square meter; and t is reference shut-in time in days.
Illustratively, the amount of carbon dioxide injected into the sand pack as determined by one skilled in the art is 1.3 x 10-5t (ton), section of sand-filled pipeThe area is 0.4594 square meters, and the reference shut-in time is 24 hours, namely one day. Based on the formula (2), obtaining
That is, the dissolving and diffusing flux of the carbon dioxide is 0.00283t/m2The day is.
It should be noted that, the values in the above calculation formula of the dissolving diffusion flux of carbon dioxide are merely examples of the embodiments of the present application, and are not intended to limit the present application.
In step 103, a target sweep radius of carbon dioxide in the well is determined based on the relevant parameters of the well and the amount of carbon dioxide injected into the well.
Wherein the relevant parameters of the oil well comprise the thickness of the oil layer of the oil well, the porosity of the oil well and the oil saturation. The related parameters of different oil wells are different, and the parameters obtained by measurement in the oil well exploration of technical personnel are calculated to obtain the related parameters of the oil wells. The oil layer thickness of the oil well is measured by descending a logging instrument to an oil layer section, and the accurate oil layer thickness can be obtained through computer processing according to a measured logging curve. The porosity of an oil well is an important parameter for evaluating the storage function of the oil well and describing the physical properties of a stratum, and the porosity is the ratio of the void volume of the stratum to the total volume of rocks. And inputting the physical parameters into an empirical formula according to the physical parameters such as the acoustic velocity, the density and the like of the oil well measured by the logging instrument, so as to obtain the porosity of the oil well. The oil saturation is the percentage of the oil volume in the effective pore space of the oil layer to the effective pore space volume of the rock, and can be determined by any determination mode of a direct core measurement method, a capillary pressure curve calculation method and a logging interpretation method.
In a possible implementation manner, the storage space of the electronic device stores the relevant parameters of each oil well, and the storage space of the electronic device is divided into a plurality of target storage spaces, wherein each target storage space is used for storing the relevant parameters of one oil well. In order to facilitate the subsequent extraction of the relevant parameters of the oil wells, a number can be added to each target storage space, and the number is consistent with the number corresponding to the oil well stored in the target storage space. And when the technician wants to determine the target closing time of the target oil well, the electronic equipment determines the oil well number of the target oil well, acquires a target storage space corresponding to the relevant parameters of the oil well according to the oil well number of the target oil well, and extracts the relevant parameters of the target oil well from the target storage space.
In one possible implementation, determining the amount of carbon dioxide injected into the well by the technician, inputting the value of the amount of carbon dioxide into the electronic device, and determining the target sweep radius of carbon dioxide in the well by the electronic device based on the determined relevant parameters of the well and the amount of carbon dioxide injected into the well includes steps 1031 to 1033, described below.
Step 1031, when the carbon dioxide injected into the oil well is not dissolved in the crude oil in the oil well, calculating a first sweep radius of the carbon dioxide in the oil well based on relevant parameters of the oil well, the amount of the carbon dioxide injected into the oil well and the density of the crude oil in the stratum.
In one possible implementation, the density of the formation crude oil is in the range of 0.75, 0.95 per cubic meter of crude oil mass under standard conditions (20 degrees, 0.1 mpa), the density of the formation crude oil is heavy crude oil with the density of 0.9,1.0, and the density of the formation crude oil is light crude oil with the density of less than 0.9. And randomly determining a value in the value range as the value of the density of the formation crude oil based on the value range of the density of the formation crude oil, or determining a value as the value of the density of the formation crude oil based on experience.
In one possible implementation, when the carbon dioxide injected into the well is not dissolved in the crude oil in the well, a first sweep radius R of the carbon dioxide in the well is calculated according to the following equation (3) based on the relevant parameters of the well, the amount of carbon dioxide injected into the well, and the formation crude oil density1：
In the above-mentioned formula (3),
the amount of carbon dioxide injected into the oil well is expressed in tons; pi is the circumference ratio, and the value is 3.14; h is the oil layer thickness of the oil well, and the unit is meter;
is porosity; soIs the oil saturation;
is the formation crude oil density in tons/cubic meter.
Illustratively, the amount of carbon dioxide injected into the well is 100 tons, the reservoir thickness is 10 meters, the porosity is 0.15, the oil saturation is 0.55, and the formation crude oil density is 0.8 tons/cubic meter. Substituting the value into the formula (3) to obtain: 100 ═ 3.14 × R1 210 x 0.15 x 0.55 x 0.8, the first swept radius was calculated to be 7.0 meters.
It should be noted that the values of the relevant parameters of the oil well and the formation crude oil density are only examples, and when the oil well is actually exploited, the calculation is performed based on the actual condition of the oil well.
Step 1032, when the carbon dioxide injected into the oil well is completely dissolved in the crude oil in the oil well, calculating a second sweep radius of the carbon dioxide in the oil well based on relevant parameters of the oil well, the amount of the carbon dioxide injected into the oil well and the solubility of the carbon dioxide in the crude oil in the stratum.
In one possible implementation, the solubility of carbon dioxide in the crude formation oil is related to the temperature and pressure of the well, the higher the temperature of the well, the lower the solubility of carbon dioxide in the crude formation oil; the higher the gas pressure of the well, the greater the solubility of carbon dioxide in the crude oil in the formation. The electronic device stores a table of the corresponding relation between the solubility of the carbon dioxide in the crude oil in the formation and the temperature and the gas pressure, and determines the solubility of the carbon dioxide in the crude oil in the oil well according to the temperature and the gas pressure of the oil well in the table.
Oxidation of hydrocarbons in injection wellsWhen all the carbon is dissolved in the crude oil in the oil well, the second sweep radius R of the carbon dioxide in the oil well is calculated according to the following formula (4) based on the relevant parameters of the oil well, the amount of carbon dioxide injected into the oil well and the solubility of the carbon dioxide in the crude oil at the bottom layer2：
In the above-mentioned formula (4),
the amount of carbon dioxide injected into the oil well is expressed in tons; pi is the circumference ratio, and the value is 3.14; h is the oil layer thickness of the oil well, and the unit is meter;
is porosity, SoIn order to obtain the degree of saturation of the oil,
is the solubility of carbon dioxide in crude oil in the formation and has the unit of ton/cubic meter.
Illustratively, the amount of carbon dioxide injected into the well is 100 tons, the reservoir thickness is 10 meters, the porosity is 0.15, the oil saturation is 0.55, and the formation crude oil density is 0.177 tons/cubic meter. Substituting the values into the formula (4) to obtain: 100 ═ 3.14 × R2 210 x 0.15 x 0.55 x 0.177, the second swept radius was calculated to be 14.8 meters.
The solubility of carbon dioxide in crude oil in the formation may be other values, which are not limited in the examples of the present application.
Step 1033, determining a target sweep radius of the carbon dioxide in the oil well based on the first sweep radius and the second sweep radius.
In a possible implementation manner, since the first swept radius obtained in step 1031 is smaller and the second swept radius obtained in step 1032 is larger, in practical applications, the target swept radius should be between the first swept radius and the second swept radius and closer to the second swept radius. Therefore, based on the obtained first and second swept radii, the value range of the target swept radius is determined to be [7.0, 14.8 ]. And randomly determining a numerical value in the value range as a target swept radius. For example, the target sweep radius is determined to be 10 meters, or alternatively, the target sweep radius is determined to be 14.8 meters.
In step 104, a target shut-in time for the well is calculated based on the dissolution diffusion flux of carbon dioxide and the target sweep radius.
In one possible implementation, calculating the target shut-in time of the oil well based on the dissolution diffusion flux of the carbon dioxide and the target swept radius includes the following steps 1041 to 1042.
Step 1041, determining the amount of carbon dioxide injected into the well and the associated parameters of the well.
The amount of carbon dioxide injected into the well is determined by the technician, and the amount of carbon dioxide injected into the well matches the amount of carbon dioxide injected into the well when the target sweep radius is determined, for example, 100 tons. The relevant parameters of the wells determined in this step are also identical to the relevant parameters of the wells determined in the above step 103, and the electronic device may extract the relevant parameters of the wells based on the number of the wells.
The relevant parameters of the oil well used in this step are the thickness of the oil layer of the oil well, and the electronic device can extract the thickness of the oil layer of the oil well from the relevant parameters of the oil well only, so that the situation that all the relevant parameters of the oil well are extracted, but some relevant parameters are not used can be avoided.
Illustratively, the amount of carbon dioxide injected into the well is 100 tons and the reservoir thickness of the well is 10 meters in the relevant parameters of the well.
And 1042, calculating the target shut-in time of the oil well based on the dissolving and diffusing flux of the carbon dioxide, the target swept radius, the amount of the carbon dioxide injected into the oil well and relevant parameters of the oil well.
In a possible implementation mode, a reasonable target shut-in time is determined based on the dissolving diffusion flux of the carbon dioxide, the target swept radius, relevant parameters of the oil well and the amount of the carbon dioxide injected into the oil well, so that crude oil in the oil well and the carbon dioxide injected into the oil well can fully react within the target shut-in time, the oil well is fully squeezed, and the oil yield of the oil well is more.
In one possible implementation, the target shut-in time t of the oil well is calculated according to the following formula (5) based on the dissolved diffusion flux of carbon dioxide, the target sweep radius, the amount of carbon dioxide injected into the oil well, and the related parameters of the oil wellfield：
In the above-mentioned formula (5),
the amount of carbon dioxide injected into the oil well is expressed in tons; pi is the circumference ratio, and the value is 3.14; r is the target swept radius in meters; h is the oil layer thickness of the oil well, and the unit is meter;
the flux of dissolved and diffused carbon dioxide is expressed in tons/square meter/day.
Illustratively, the amount of carbon dioxide injected into the well is 100 tons, the reservoir thickness is 10 meters, the target sweep radius is 14.8 meters, and the carbon dioxide dissolution and diffusion flux is 0.00283 tons/m/day. Calculating the target shut-in time according to the formula (5) as
I.e. the target shut-in time is 38 days.
When the amount of carbon dioxide injected into the oil well is 200 tons, the first swept radius of the carbon dioxide in the oil well is 9.8 meters according to the above formula (3), and the second swept radius of the carbon dioxide in the oil well is 20.8 meters according to the above formula (4), that is, the value range of the target swept radius is [9.8,20.8 ]. And (4) determining the second sweep radius as a target sweep radius, and calculating the target well closing time according to the formula (5) to be 54 days.
When the amount of carbon dioxide injected into the oil well is 300 tons, the first swept radius of the carbon dioxide in the oil well is 12 meters according to the above formula (3), and the second swept radius of the carbon dioxide in the oil well is 25.6 meters according to the above formula (4), that is, the value range of the target swept radius is [12,25.6 ]. And determining the second sweep radius as a target sweep radius, and calculating according to the formula (5) to obtain the target shut-in time of 65 days.
When the amount of carbon dioxide injected into the oil well changes, the target shut-in time of the oil well also changes accordingly. Therefore, after the amount of carbon dioxide injected into the oil well is determined, the value range of the target sweep radius is determined according to the amount of carbon dioxide injected into the oil well, and a numerical value in the value range is randomly determined to be the target sweep radius. And calculating the target shut-in time of the oil well according to the target sweep radius, the amount of carbon dioxide injected into the oil well, the thickness of an oil layer of the oil well and the dissolving and diffusing flux of the carbon dioxide.
To sum up, this application embodiment adopts the sand-packed pipe to simulate the oil well scene, based on the carbon dioxide volume of injecting into the sand-packed pipe, confirm a reference shut-in time and the dissolving diffusion flux of carbon dioxide, thereby according to the dissolving diffusion flux of carbon dioxide, the actual conditions of oil well and the carbon dioxide volume of injecting into the oil well, determine a reasonable target shut-in time, carbon dioxide and the crude oil in the oil well can fully react in this target shut-in time, make carbon dioxide can fully expand, the viscosity reduction, extract the evaporation, thereby improve the throughput effect of carbon dioxide in the oil well, and then carry out reasonable and abundant extrusion to the oil well, further improve the oil production volume of oil well.
Based on the same inventive concept, the present embodiment further provides a device for determining a shut-in time, as shown in fig. 3, the device includes:
a first determination module 301, configured to determine a reference shut-in time based on an amount of carbon dioxide injected into a sand-packed pipe;
a first calculating module 302, configured to calculate a dissolution diffusion flux of the carbon dioxide according to the reference shut-in time and a cross-sectional area of the sand-packed pipe;
a second determining module 303, configured to determine a target sweep radius of carbon dioxide in the oil well according to the relevant parameters of the oil well and the amount of carbon dioxide injected into the oil well;
a second calculating module 304, configured to calculate a target shut-in time of the oil well based on the dissolution diffusion flux of the carbon dioxide and the target sweep radius.
In a possible implementation manner, the first calculation module 302 is used for calculating the dissolving diffusion flux of the carbon dioxide according to the following formula according to the reference shut-in time and the cross-sectional area of the sand-filling pipe
Wherein, the
The amount of carbon dioxide injected into the sand-filled pipe is A, the cross-sectional area of the sand-filled pipe is A, and t is the reference shut-in time.
In one possible implementation, the second determining module 303 is configured to calculate a first sweep radius of the carbon dioxide in the oil well based on the relevant parameters of the oil well, the amount of the carbon dioxide injected into the oil well, and the formation crude oil density when the carbon dioxide injected into the oil well is not dissolved in the crude oil in the oil well;
calculating a second sweep radius of the carbon dioxide in the well based on the relevant parameters of the well, the amount of carbon dioxide injected into the well, and the solubility of the carbon dioxide in the formation crude oil when the carbon dioxide injected into the well is completely dissolved in the crude oil in the well;
determining a target sweep radius of the carbon dioxide in the oil well based on the first sweep radius and the second sweep radius.
In a possible implementation, the second determining module 303 is configured to calculate a first sweep radius R of the carbon dioxide in the oil well according to the following formula based on the relevant parameters of the oil well, the amount of the carbon dioxide injected into the oil well and the formation crude oil density when the carbon dioxide injected into the oil well is not dissolved in the crude oil in the oil well1：
Wherein, the
Is the amount of carbon dioxide injected into the well, pi is the circumferential ratio, h is the reservoir thickness of the well, h is the oil reservoir thickness
Is porosity, the SoTo an oil saturation degree, the
Is the formation crude oil density.
In a possible implementation, the second determining module 303 is configured to calculate a second sweep radius R of the carbon dioxide in the oil well according to the following formula based on the relevant parameters of the oil well, the amount of the carbon dioxide injected into the oil well, and the solubility of the carbon dioxide in the crude oil in the formation when the carbon dioxide injected into the oil well is completely dissolved in the crude oil in the oil well2：
Wherein, the
Is the amount of carbon dioxide injected into the well, pi is the circumferential rate, and h is the oil of the wellLayer thickness of
Is porosity, the SoTo an oil saturation degree, the
Is the solubility of the carbon dioxide in the crude oil in the formation.
In one possible implementation, the second calculation module 304 is configured to determine the amount of carbon dioxide injected into the well and the related parameters of the well; and calculating the target shut-in time of the oil well based on the dissolving and diffusing flux of the carbon dioxide, the target sweep radius, the amount of the carbon dioxide injected into the oil well and relevant parameters of the oil well.
In a possible implementation manner, the second calculation module is used for calculating the target shut-in time t of the oil well according to the following formula based on the dissolving and diffusing flux of the carbon dioxide, the target sweep radius, the carbon dioxide amount injected into the oil well and the parameters of the oil wellfield：
Wherein, the
The amount of carbon dioxide injected into the well, the pi is the circumferential ratio, the R is the target swept radius, the h is the reservoir thickness of the well, the
The flux of dissolved diffusion of carbon dioxide.
To sum up, this application embodiment adopts the sand-packed pipe to simulate the oil well scene, based on the carbon dioxide volume of injecting into the sand-packed pipe, confirm a reference shut-in time and the dissolving diffusion flux of carbon dioxide, thereby according to the dissolving diffusion flux of carbon dioxide, the actual conditions of oil well and the carbon dioxide volume of injecting into the oil well, determine a reasonable target shut-in time, carbon dioxide and the crude oil in the oil well can fully react in this target shut-in time, make carbon dioxide can fully expand, the viscosity reduction, extract the evaporation, thereby improve the throughput effect of carbon dioxide in the oil well, and then carry out reasonable and abundant extrusion to the oil well, further improve the oil production volume of oil well.
It should be noted that, when the device provided in the foregoing embodiment implements the functions thereof, only the division of the functional modules is illustrated, and in practical applications, the functions may be distributed by different functional modules according to needs, that is, the internal structure of the device may be divided into different functional modules to implement all or part of the functions described above. In addition, the apparatus and method embodiments provided by the above embodiments belong to the same concept, and specific implementation processes thereof are described in the method embodiments for details, which are not described herein again.
All the above optional technical solutions may be combined arbitrarily to form the optional embodiments of the present disclosure, and are not described herein again.
In an exemplary embodiment, a computer-readable storage medium is also provided, in which at least one instruction is stored, and when executed by a processor of an electronic device, the at least one instruction implements any one of the methods for determining a shut-in time described above.
It will be understood by those skilled in the art that all or part of the steps for implementing the above embodiments may be implemented by hardware, or may be implemented by a program instructing relevant hardware, and the program may be stored in a computer-readable storage medium, and the above-mentioned storage medium may be a read-only memory, a magnetic disk or an optical disk, etc.
The above description is only exemplary of the present application and should not be taken as limiting the present application, as any modification, equivalent replacement, or improvement made within the spirit and principle of the present application should be included in the protection scope of the present application.
Claims (10)
1. A method of determining shut-in time, the method comprising:
determining a reference shut-in time based on the amount of carbon dioxide injected into the sand-filled pipe;
calculating the dissolving and diffusing flux of the carbon dioxide according to the reference shut-in time and the sectional area of the sand-filled pipe;
determining a target sweep radius of carbon dioxide in the oil well according to relevant parameters of the oil well and the amount of carbon dioxide injected into the oil well;
and calculating the target shut-in time of the oil well based on the dissolving and diffusing flux of the carbon dioxide and the target swept radius.
2. The method of claim 1, wherein calculating the dissolution diffusion flux of the carbon dioxide based on the reference shut-in time and the cross-sectional area of the sand-pack pipe comprises:
calculating the dissolving and diffusing flux of the carbon dioxide according to the reference shut-in time and the sectional area of the sand-filling pipe and the following formula
Wherein, the
And B, the amount of the carbon dioxide injected into the sand filling pipe is shown, A is the sectional area of the sand filling pipe, and t is the reference shut-in time.
3. The method of claim 1, wherein determining a target sweep radius of carbon dioxide in the well based on the well related parameters and an amount of carbon dioxide injected into the well comprises:
calculating a first sweep radius of the carbon dioxide in the well based on the relevant parameters of the well, the amount of carbon dioxide injected into the well, and the formation crude oil density when the carbon dioxide injected into the well is not dissolved in the crude oil in the well;
calculating a second sweep radius of the carbon dioxide in the well based on the relevant parameters of the well, the amount of carbon dioxide injected into the well, and the solubility of the carbon dioxide in the formation crude oil when the carbon dioxide injected into the well is fully dissolved in the crude oil in the well;
determining a target sweep radius of the carbon dioxide in the oil well based on the first sweep radius and the second sweep radius.
4. The method of claim 3, wherein calculating a first sweep radius of the carbon dioxide in the well based on the relevant parameters of the well, the amount of carbon dioxide injected into the well, and the formation crude oil density while the carbon dioxide injected into the well is not dissolved in the crude oil in the well comprises:
when the carbon dioxide injected into the oil well is not dissolved in the crude oil in the oil well, based on relevant parameters of the oil well, the amount of the carbon dioxide injected into the oil well and the density of the crude oil in the stratum, calculating a first sweep radius R of the carbon dioxide in the oil well according to the following formula1：
Wherein, the
The amount of carbon dioxide injected into the oil well, the pi is a circumferential rate, the h is a thickness of an oil layer of the oil well, the
For porosity, said SoTo oil saturation, said
Is the formation crude oil density.
5. The method of claim 3, wherein calculating a second sweep radius of the carbon dioxide in the well based on the relevant parameters of the well, the amount of carbon dioxide injected into the well, and the solubility of the carbon dioxide in the formation crude oil when the carbon dioxide injected into the well is fully dissolved in the crude oil in the well comprises:
when the carbon dioxide injected into the oil well is totally dissolved in the crude oil in the oil well, based on relevant parameters of the oil well, the amount of the carbon dioxide injected into the oil well and the solubility of the carbon dioxide in the crude oil in the formation, a second sweep radius R of the carbon dioxide in the oil well is calculated according to the following formula2：
Wherein, the
The amount of carbon dioxide injected into the oil well, the pi is a circumferential rate, the h is a thickness of an oil layer of the oil well, the
For porosity, said SoTo oil saturation, said
Is the solubility of the carbon dioxide in the crude oil of the formation.
6. The method of any one of claims 1-5, wherein calculating the target shut-in time for the oil well based on the dissolution diffusion flux of carbon dioxide and the target sweep radius comprises:
determining the amount of carbon dioxide injected into the well and the associated parameters of the well;
calculating a target shut-in time for the well based on the dissolved diffusion flux of carbon dioxide, the target sweep radius, the amount of carbon dioxide injected into the well, and the relevant parameters of the well.
7. The method of claim 6, wherein calculating a target shut-in time for the well based on the dissolved diffusion flux of carbon dioxide, the target sweep radius, the amount of carbon dioxide injected into the well, and the relevant parameters of the well comprises:
calculating a target shut-in time t of the oil well according to the following formula based on the dissolved diffusion flux of the carbon dioxide, the target sweep radius, the amount of the carbon dioxide injected into the oil well, and the parameters of the oil wellfield：
Wherein, the
The amount of carbon dioxide injected into the oil well, the pi is a circumferential rate, the R is the target swept radius, the h is the reservoir thickness of the oil well, the
The flux of dissolved diffusion of carbon dioxide.
8. An apparatus for determining shut-in time, the apparatus comprising:
the first determination module is used for determining reference shut-in time based on the amount of carbon dioxide injected into the sand-filled pipe;
the first calculation module is used for calculating the dissolving and diffusing flux of the carbon dioxide according to the reference shut-in time and the sectional area of the sand filling pipe;
the second determination module is used for determining the target sweep radius of the carbon dioxide in the oil well according to the relevant parameters of the oil well and the amount of the carbon dioxide injected into the oil well;
and the second calculation module is used for calculating the target shut-in time of the oil well based on the dissolving diffusion flux of the carbon dioxide and the target swept radius.
9. The apparatus of claim 8, wherein the first calculation module is configured to calculate the dissolution diffusion flux of the carbon dioxide according to the following formula according to the reference shut-in time and the cross-sectional area of the sand-pack pipe
Wherein, the
And B, the amount of the carbon dioxide injected into the sand filling pipe is shown, A is the sectional area of the sand filling pipe, and t is the reference shut-in time.
10. The apparatus of claim 8, wherein the second determining module is configured to calculate a first sweep radius of the carbon dioxide in the well based on the relevant parameters of the well, the amount of carbon dioxide injected into the well, and a formation crude oil density when the carbon dioxide injected into the well is not dissolved in the crude oil in the well;
calculating a second sweep radius of the carbon dioxide in the well based on the relevant parameters of the well, the amount of carbon dioxide injected into the well, and the solubility of the carbon dioxide in the formation crude oil when the carbon dioxide injected into the well is fully dissolved in the crude oil in the well;
determining a target sweep radius of the carbon dioxide in the oil well based on the first sweep radius and the second sweep radius.
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