CN112682015B

CN112682015B - Chemical flooding multi-medium injection flow quantity regulation method

Info

Publication number: CN112682015B
Application number: CN202011593257.4A
Authority: CN
Inventors: 刘义刚; 张志熊; 陈征; 张乐; 蓝飞; 王威; 徐元德; 张晓冉
Original assignee: China National Offshore Oil Corp CNOOC; CNOOC China Ltd Tianjin Branch
Current assignee: China National Offshore Oil Corp CNOOC; CNOOC China Ltd Tianjin Branch
Priority date: 2020-12-29
Filing date: 2020-12-29
Publication date: 2022-11-18
Anticipated expiration: 2040-12-29
Also published as: CN112682015A

Abstract

The invention provides a chemical flooding multi-medium injection flow measuring and adjusting method, which comprises the steps of setting a pipe column to each layer section to be detected of an injection well; sending the tool string of the measuring and adjusting instrument into the well; a measuring and adjusting instrument tool string is put on the small oil pipe central channel injection allocation device, a water nozzle of the small oil pipe central channel injection allocation device is adjusted to a proper opening degree, the position of the small oil pipe central channel injection allocation device is monitored on the ground, and the actual injection flow of the polymer solution in the well of the small oil pipe central channel is monitored until the injection flow of the polymer solution reaches 85-115% of the injection amount; lowering a measuring and adjusting instrument string to the position of the large and small oil pipe annular channel injection allocation device, and adjusting the water nozzle of the large and small oil pipe annular channel injection allocation device to a target opening; designing a wellhead pressure injection water solution according to the large and small oil pipe annulus channels until the injection total amount of the large and small oil pipe annulus channels water solution meets the requirement of the injection total amount of the large and small oil pipe annulus channels water solution; the method can meet the multi-medium testing and adjusting requirement that the maximum separated injection layer number is six layers.

Description

Chemical flooding multi-medium injection flow quantity regulation method

Technical Field

The invention belongs to the technical field of chemical flooding of offshore oil fields, and particularly relates to a chemical flooding multi-medium injection flow measurement and adjustment method.

Background

With the efficient and continuous development of oil fields, the contradiction between layers and in layers is increasingly prominent, and chemical flooding gradually becomes an important measure for improving the recovery ratio of the oil fields. Because the number of injection wells is relatively small, the offshore oil field mostly adopts a ground multi-tube injection process to carry out the injection of aqueous solution and polymer solution, the process can directly adjust the injection amount of each layer on the ground, the measurement and adjustment are simple, but the maximum injection layer number is only 3 layers because of the limitation of the size of a shaft. In order to meet the requirements of multi-layer segment water injection and polymerization dual-medium injection, a multi-medium multi-layer segment injection process is developed in the past, and the maximum injection layer number can reach 6 layers. Although the multi-medium multi-layer segment separate injection process still adopts a concentric multi-pipe column, the injection medium is not injected in a single layer any more, so that the measurement and the adjustment cannot be carried out by adopting a ground direct measurement and adjustment mode, and a new measurement and adjustment method needs to be developed to realize the flow measurement and the adjustment of the multi-medium multi-layer segment separate injection process.

Disclosure of Invention

The invention aims to provide a chemical flooding multi-medium injection flow measurement and regulation method to solve the technical problem of an oilfield multi-medium multi-layer segment separate injection process.

In order to achieve the purpose, the specific technical scheme of the chemical flooding multi-medium injection flow regulation method is as follows:

a chemical flooding multi-medium injection flow quantity regulation method comprises the following steps:

firstly, running a pipe column into each layer section to be detected of an injection well; firstly, a large oil pipe string provided with a small oil pipe central channel injection allocation device and a large oil pipe annular channel injection allocation device is put in, and then the small oil pipe string is put in the large oil pipe string, so that two overflowing channels are formed; the two flow-through channels are annular channels formed between a small oil pipe central channel and large and small oil pipes; wherein the small and medium oil pipe central passage injection allocation device is responsible for injecting polymer solution into the injection layer section, and the large and small oil pipe annular passage injection allocation device is responsible for injecting aqueous solution into the injection layer section;

secondly, assembling a measuring and adjusting instrument tool string, hanging the measuring and adjusting instrument tool string on a cable, lowering the cable in a central channel of the small oil pipe, and sending the measuring and adjusting instrument tool string into a well;

thirdly, after a measuring and adjusting instrument tool string is put down to the bottom of the small oil pipe central passage positioned in the bottommost layer, the measuring and adjusting instrument tool string is lifted to the position of a first small oil pipe central passage injection allocation device positioned in the bottommost layer, the measuring and adjusting instrument tool string is positioned on the first small oil pipe central passage injection allocation device positioned in the bottommost layer, a water nozzle of the first small oil pipe central passage injection allocation device positioned in the bottommost layer is adjusted to a proper opening degree, the actual injection flow of the polymer solution under the small oil pipe central passage at the position of the first small oil pipe central passage injection allocation device positioned in the bottommost layer is monitored on a ground control terminal until the injection flow of the polymer solution of the small oil pipe central passage in the layer reaches 85-115% of the injection amount;

fourthly, lifting the testing and adjusting instrument tool string to the position of the next small oil pipe central channel injection allocation device above the previous testing interval, positioning the testing and adjusting instrument tool string on the next small oil pipe central channel injection allocation device, adjusting the water nozzle of the next small oil pipe central channel injection allocation device to a proper opening degree, and monitoring the actual injection flow of the polymer solution of the underground small oil pipe central channel at the position of the next small oil pipe central channel injection allocation device on a ground control terminal until the injection flow of the polymer solution of the small oil pipe central channel of the interval reaches 85-115% of the injection amount;

fifthly, repeating the fourth step until the injection flow of the polymer solution flow of the small oil pipe central passage of the layer section where all the small oil pipe central passage injection distributors are located reaches 85-115% of the injection amount; if the water nozzle of the central channel injection allocation device of a small oil pipe is adjusted to the maximum opening degree, the injection flow of the polymer solution flow of the central channel of the small oil pipe of the interval where the water nozzle is located still cannot reach 85-115% of the injection amount, increasing the injection pressure of the wellhead of the central channel of the small oil pipe, and repeating the third step to the fifth step until the injection flow of the polymer solution of the central channel of the small oil pipe of the interval where all the central channel injection allocation devices of the small oil pipe are located reaches 85-115% of the injection amount;

sixthly, after the flow of the polymer solution in the central channel of the small oil pipe of the layer section where the central channel injection allocation device of each small oil pipe is located is measured and adjusted, a measuring and adjusting instrument string is put to the bottom of the central channel of the small oil pipe of the bottommost layer section, the flow of the polymer solution in the central channel of the small oil pipe of the layer section where the central channel injection allocation device of each small oil pipe is located is repeatedly measured from bottom to top under the condition that the opening degree of a water nozzle of the central channel injection allocation device of each small oil pipe is kept, and the test flow, the test temperature and the temperature of the polymer solution injected into a well mouth of the central channel of the small oil pipe of each layer section are recorded under the condition that the flow of the polymer solution in the central channel of the small oil pipe of the layer section where the central channel injection allocation device of all small oil pipes is located reaches 85-115% of the injection allocation amount; under the condition that the flow of the polymer solution in the central channel of the small oil pipe of the interval where the central channel injection allocation device of a certain small oil pipe is located cannot reach 85-115% of the injection allocation amount, repeating the third step to the sixth step until the flow of the polymer solution in the central channel of the small oil pipe of the interval where the central channel injection allocation device of all the small oil pipes is located reaches 85-115% of the injection allocation amount;

step seven, placing a testing and adjusting instrument tool string to the position of a first large and small oil pipe annular passage injection allocation device positioned at the bottommost layer, positioning the testing and adjusting instrument tool string on the first large and small oil pipe annular passage injection allocation device positioned at the bottommost layer, taking the bottommost layer as a first test layer section, adjusting a water nozzle of the first large and small oil pipe annular passage injection allocation device positioned at the bottommost layer to a target opening degree, and adjusting the water nozzle to be opened to the maximum opening degree when a first test layering indicating curve is tested and adjusted each time;

eighthly, lifting the testing and adjusting instrument tool string to the position of the next large and small oil pipe annulus channel injection allocation device above the previous test interval, and adjusting the water nozzle of the next large and small oil pipe annulus channel injection allocation device to be closed;

step nine, repeating the step eight until the water nozzles of the annular channel injection allocation device of the oil pipes with all the layer sections are closed;

step ten, pumping aqueous solution into the annular channels of the large and small oil pipes according to the pressure value of the maximum allowable point of the well, taking 5 pressures by a depressurization method, testing the interval layering indication curve of the test interval, wherein the span between adjacent pressure points is required to be more than 0.5MPa, and each point is tested for 30min;

and step eleven, after the test of the layering indication curve is finished, lowering the testing and adjusting instrument string to the position of the oil pipe annulus passage injection allocation device with the size of the previous test layer section, adjusting the water nozzle of the oil pipe annulus passage injection allocation device with the size of the test layer section to the closed position, lifting the testing and adjusting instrument string to the position of the next oil pipe annulus passage injection allocation device with the size above the previous test layer section, and adjusting the water nozzle of the next oil pipe annulus passage injection allocation device with the size to the target opening degree. Repeating the eighth step to the tenth step until the test of the layered indication curve of the layer section where all the oil pipe annulus passage injection distributors are located is completed;

step ten, reading the minimum injection pressure of the wellhead of the large and small oil pipe annulus channels, which meets the water solution injection allocation quantity of the large and small oil pipe annulus channels of the intervals under the target opening of the water nozzles of the large and small oil pipe annulus channels of the intervals according to the layering indication curve of each interval where the large and small oil pipe annulus channels are located, and taking the maximum value as the designed wellhead injection pressure of the large and small oil pipe annulus channels;

thirteenth, taking the difference value between the designed wellhead injection pressure of the large and small oil pipe annulus channels and the minimum wellhead injection pressure of the large and small oil pipe annulus channels meeting the water solution injection amount of the large and small oil pipe annulus channels of each layer section under the target opening of the water nozzles of the large and small oil pipe annulus channels as the throttling pressure difference required by the large and small oil pipe annulus channels of each layer section;

fourteenth, using a 1-meter-length shaft as a micro element section, using the temperature of an injected aqueous solution at a wellhead of a large and small oil pipe annulus passage and the designed wellhead pressure of the large and small oil pipe annulus passage as the upper end temperature of the large and small oil pipe annulus passage of the micro element section and the upper end pressure of the large and small oil pipe annulus passage of the micro element section, estimating the lower end temperature of the large and small oil pipe annulus passage of the micro element section and the lower end pressure of the large and small oil pipe annulus passage of the micro element section according to experience, using the average value of the upper end temperature of the large and small oil pipe annulus passage of the micro element section and the lower end temperature of the large and small oil pipe annulus passage of the micro element section as the average temperature of the large and small oil pipe annulus passage of the micro element section, and using the average value of the upper end pressure of the large and small oil pipe annulus passage of the micro element section and the lower end pressure of the large and small oil pipe annulus passage of the micro element section as the average pressure of the large and small oil pipe annulus passage of the micro element section;

fifteenth, according to the small oil pipe central channel test temperature of the layer section where each small oil pipe central channel injection allocator is located obtained through the test of the sixth step, interpolating and calculating the temperature of the polymer solution in the small oil pipe central channel of the micro-element section;

sixthly, calculating the heat transfer quantity between the polymer solution in the central passage of the small oil pipe and the aqueous solution in the annular passages of the large oil pipe and the small oil pipe according to the temperature of the polymer solution in the central passage of the small oil pipe in the micro-element section and the average temperature of the annular passages of the large oil pipe and the small oil pipe in the micro-element section;

seventhly, calculating the heat transfer quantity between the aqueous solution in the annular passages of the large and small oil pipes and the ground according to the difference between the average temperature of the annular passages of the large and small oil pipes of the micro element section and the temperature of the deep stratum where the micro element section is located;

eighteen, calculating to obtain the calculation temperature of the lower end of the annular channel of the oil pipe with the micro-element section and the large oil pipe according to the heat transfer quantity calculation results of the sixteenth step and the seventeenth step;

nineteenth step, comparing the calculated temperature of the lower end of the annular passage of the oil pipe with the size of the infinitesimal section obtained by calculation in the eighteenth step with the estimated temperature of the lower end of the annular passage of the oil pipe with the size of the infinitesimal section in the fourteenth step, and when the relative error is less than 5%, taking the calculated temperature of the lower end of the annular passage of the oil pipe with the size of the infinitesimal section as the actual temperature of the lower end of the annular passage of the oil pipe with the size of the infinitesimal section; when the relative error is more than 5%, the calculated temperature of the lower end of the micro element section large and small oil pipe annular passage is used as a new estimated temperature of the lower end of the micro element section large and small oil pipe annular passage, and the fourteenth step to the nineteenth step are repeated until the relative error is less than 5%;

twentieth, calculating the average value of the upper end temperature of the annular channel of the oil pipe with the large and small infinitesimal sections and the actual temperature of the lower end of the annular channel of the oil pipe with the large and small infinitesimal sections by adopting a calculation method which is the same as the average temperature of the annular channel of the oil pipe with the large and small infinitesimal sections in the fourteenth step, and taking the average value as the actual average temperature of the annular channel of the oil pipe with the large and small infinitesimal sections; then calculating the pressure change and the friction loss of the micro-element section large and small oil pipe annulus channel aqueous solution at the temperature according to the layer section aqueous solution injection amount of each large and small oil pipe annulus channel injection allocation device;

twenty, according to the calculation result of the twentieth step, calculating the pressure calculated by the lower end of the annular channel of the oil pipe with the micro element section; comparing the calculated pressure of the lower end of the annular channel of the oil pipe with the size of the micro element section estimated in the fourteenth step, and when the relative error is less than 5%, taking the calculated pressure of the lower end of the annular channel of the oil pipe with the size of the micro element section as the actual pressure of the lower end of the annular channel of the oil pipe with the size of the micro element section; when the relative error is more than 5%, the calculated pressure at the lower end of the micro-element section large and small oil pipe annular channel is used as a new estimated pressure at the lower end of the micro-element section large and small oil pipe annular channel, and the twentieth step to the twentieth step are repeated until the relative error between the calculated pressure at the lower end of the micro-element section large and small oil pipe annular channel and the estimated pressure at the lower end of the micro-element section large and small oil pipe annular channel is less than 5%;

a twenty-second step, taking the actual temperature of the lower end of the annular passage of the micro-element section large and small oil pipes obtained by calculation in the nineteenth step as the temperature of the upper end of the annular passage of the next micro-element section large and small oil pipes, and taking the actual pressure of the lower end of the annular passage of the micro-element section large and small oil pipes obtained by calculation in the twenty-first step as the pressure of the upper end of the annular passage of the next micro-element section large and small oil pipes; repeating the fourteenth step to the twentieth step until the calculation is carried out to the bottom of the well, and obtaining the total friction loss of the injected aqueous solution flowing from the well head to the layer section where the oil pipe annulus channel injectors of different sizes are located;

twenty-third step, making difference between the throttling pressure difference required by the large and small oil pipe annulus channel injection allocation devices of each layer section obtained by the thirteenth step and the total friction loss of the injected aqueous solution flowing from the well head to the layer section where the large and small oil pipe annulus channel injection allocation devices are located obtained by the twenty-second step, and obtaining the throttling pressure difference required by the large and small oil pipe annulus channel injection allocation devices of each layer section under the condition of considering the friction loss by calculation;

the twenty-fourth step, checking a nozzle loss curve chart of the large and small oil pipe annulus passage injection allocation machines obtained through related tests, obtaining the target opening degree of the large and small oil pipe annulus passage injection allocation machines required by the layer section where the large and small oil pipe annulus passage injection allocation machines are located when the layer section reaches the water solution injection allocation amount according to a check chart of the throttling pressure difference required by the large and small oil pipe annulus passage injection allocation machines of each layer section under the condition of considering the friction loss, and when the throttling pressure difference required by the large and small oil pipe annulus passage injection allocation machines under the condition of considering the friction loss of a certain layer section is a negative value, the target opening degree of the large and small oil pipe annulus passage injection allocation machines of the layer section is 100%;

a twenty-fifth step, lowering the measuring and adjusting instrument tool string to the position of the first large and small oil pipe annular channel injection allocator positioned at the bottommost layer, positioning the measuring and adjusting instrument tool string on the first large and small oil pipe annular channel injection allocator positioned at the bottommost layer, and adjusting a water nozzle of the first large and small oil pipe annular channel injection allocator positioned at the bottommost layer to a target opening degree;

lifting the measuring and adjusting instrument tool string to the position of a next large and small oil pipe annulus passage injection allocation device above the previous large and small oil pipe annulus passage injection allocation device water nozzle layer section, positioning the measuring and adjusting instrument tool string on the next large and small oil pipe annulus passage injection allocation device, and adjusting the water nozzle of the next large and small oil pipe annulus passage injection allocation device to a target opening degree;

twenty-seventh step, repeating the twenty-sixth step until the water nozzles of the oil pipe annulus channel injection allocation device in all the layer sections are adjusted to the target opening;

the twenty-eighth step: the water injection is recovered according to the total water injection amount of the large and small oil pipe annulus channels when the total water injection amount of the large and small oil pipe annulus channels reaches 85-115% of the total water injection amount of the large and small oil pipe annulus channels; and when the injection total amount of the aqueous solution of the large and small oil pipe annulus channels cannot reach 85-115% of the injection allocation total amount of the aqueous solution of the large and small oil pipe annulus channels, increasing or reducing the wellhead injection pressure of the large and small oil pipe annulus channels, taking the adjusted wellhead injection pressure of the large and small oil pipe annulus channels as the new design wellhead injection pressure of the large and small oil pipe annulus channels, and repeating the seventh step to the twenty-eighth step until the injection total amount of the aqueous solution of the large and small oil pipe annulus channels reaches 85-115% of the injection allocation total amount of the aqueous solution of the large and small oil pipe annulus channels.

In the above method for adjusting injection flow rate of chemical flooding multi-media, wherein,

and the thirteenth step, taking the difference value between the designed wellhead injection pressure of the large and small oil pipe annulus channels and the minimum injection pressure of the wellhead of the large and small oil pipe annulus channels meeting the water solution injection quantity of the large and small oil pipe annulus channels of each layer section under the target opening of the water nozzle of the large and small oil pipe annulus channels as the throttling pressure difference required by the large and small oil pipe annulus channels of each layer section according to the formula (1):

P _throttling ＝P _{Well head} -P _{Injection of} (1)

In the formula, P _Throttling The throttling pressure difference required by the annular channel injection allocation device of the oil pipe with large and small intervals is obtained; p _{Well head} Designing wellhead injection pressure for large and small oil pipe annulus channels; p _{Injection into} The minimum injection pressure of the wellhead of the large and small oil pipe annulus channels meeting the water solution injection amount of the large and small oil pipe annulus channels of the interval under the target opening degree of the water nozzle of the large and small oil pipe annulus channel injection allocation device is set for the interval;

the fourteenth step, using a 1-meter long shaft as a micro element section, using the temperature of an aqueous solution injected into a wellhead of a large and small oil pipe annulus passage and the designed wellhead pressure of the large and small oil pipe annulus passage as the upper end temperature of the large and small oil pipe annulus passage of the micro element section and the upper end pressure of the large and small oil pipe annulus passage, estimating the lower end temperature of the large and small oil pipe annulus passage of the micro element section and the lower end pressure of the large and small oil pipe annulus passage of the micro element section according to experience, using the average value of the upper end temperature of the large and small oil pipe annulus passage of the micro element section and the lower end temperature of the large and small oil pipe annulus passage of the micro element section as the average temperature of the large and small oil pipe annulus passage of the micro element section, and using the average value of the upper end pressure of the large and small oil pipe annulus passage of the micro element section and the lower end pressure of the large and small oil pipe annulus passage of the micro element section as the average pressure of the large and small oil pipe annulus passage of the micro element section according to the formulas (2) and (3);

in the formula (I), the compound is shown in the specification,

the average temperature of the annular channel of the oil pipe with the micro-element section is obtained; t is a unit of _up The temperature of the upper end of the annular channel of the oil pipe with the micro-element section is measured; t is _down The temperature of the lower end of the annular channel of the oil pipe with the micro-element section is measured;

is micro-element segment large and small oilAverage pressure of the pipe annular channel; p is _up The pressure at the upper end of the annular channel of the oil pipe with the micro-element section is measured; p _down The pressure at the lower end of the annular channel of the oil pipe with the micro-element section is obtained;

the fifteenth step, according to the test temperature of the small oil pipe central channel of the layer section where each small oil pipe central channel injection allocator is located, which is obtained by the test of the sixth step, the temperature of the polymer solution in the small oil pipe central channel of the micro-element section is calculated by interpolation, which is according to a formula (4);

in the formula, T _{Micro element} The temperature of the polymer solution in the central channel of the micro-element section small oil pipe is measured; t is _{Well head} Injecting polymer solution temperature for the wellhead; h _{Micro element} The depth of the infinitesimal section; t is a unit of _{Interval section} Testing the temperature of the polymer solution at the position of the central channel injection distributor of the small oil pipe at the lower part of the infinitesimal closest to the infinitesimal section; h _{Interval section} The position depth of the injector of the central channel of the small oil pipe, which is the lower part of the micro element and is closest to the micro element section, is determined;

sixthly, calculating the heat transfer quantity between the polymer solution in the small oil pipe central channel and the aqueous solution in the large and small oil pipe annular channels according to the temperature of the polymer solution in the small oil pipe central channel and the average temperature of the micro-element large and small oil pipe annular channels, wherein the heat transfer quantity is calculated according to a formula (5);

E _p ＝ρ _p Q _p λ(T _p -T _w ) (5)

in the formula, E _p The heat transfer quantity between the polymer solution in the central passage of the small oil pipe and the aqueous solution in the annular passage of the large oil pipe and the small oil pipe is obtained; ρ is a unit of a gradient _p Injecting the polymer solution into the central channel of the micro-element section small oil pipe according to the density; q _p Injecting the flow of polymer solution into the central channel of the micro-element section small oil pipe; lambda is the heat conductivity coefficient of the small oil pipe; t is a unit of _p Injecting polymer solution into the central channel of the micro-element section small oil pipe; t is _w The temperature of injecting aqueous solution into the annular channel of the oil pipe with the micro-element section;

seventeenth step, calculating the heat transfer quantity between the aqueous solution in the annular channels of the large and small oil pipes and the ground layer according to the difference value between the average temperature of the annular channels of the large and small oil pipes of the micro element section and the temperature of the stratum at the depth of the micro element section, wherein the formula (6) is used;

E _w ＝Kρ _w Q _w (T _w -T _e ) (6)

in the formula, E _w The heat transfer quantity between the aqueous solution in the annular channel of the large and small oil pipes and the ground is obtained; k is the heat transfer coefficient between the injected aqueous solution in the annular channel of the oil pipe with the micro-element section and the ground; rho _w The density of water solution injected into the annular channel of the micro-element section large and small oil pipes; q _w Injecting the flow of aqueous solution into the annular channel of the oil pipe with the micro-element section; t is _e Is the formation temperature at the infinitesimal stage location;

eighteen, calculating the lower end calculation temperature of the annular channel of the oil pipe with the large and small micro-element sections according to the heat transfer quantity calculation results of the sixteenth step and the seventeenth step, wherein the calculation temperature is obtained according to a formula (7);

in the formula, T _w The temperature of the lower end of the annular channel of the oil pipe with the large and small infinitesimal sections is obtained through calculation; g is gravity acceleration; dl is the length of the infinitesimal segment; c _w Is the specific heat capacity of water;

the twentieth step is to calculate the average value of the upper end temperature of the annular channel of the oil pipe with the large and small infinitesimal sections and the actual temperature of the lower end of the annular channel of the oil pipe with the large and small infinitesimal sections by adopting a calculation method which is the same as the average temperature of the annular channel of the oil pipe with the large and small infinitesimal sections in the fourteenth step, and take the average value as the actual average temperature of the annular channel of the oil pipe with the large and small infinitesimal sections; then according to the water solution injection amount of the layer section where the oil pipe annulus passage injection allocation device of each size is located, calculating the pressure change and the friction loss of the water solution of the oil pipe annulus passages of the micro-element section at the temperature according to the formulas (8) and (9);

ΔP＝(ρ _w g+τ _f )·dl (8)

P _f ＝τ _f ·dl (9)

in the formula,. DELTA.P is the variation of the water solution pressure of the micro-element section large and small oil pipe annular channel; tau. _f Is the frictional loss velocity; p _f The friction loss in the infinitesimal section is obtained;

the twenty-first step, calculating the pressure calculated by the lower end of the annular channel of the oil pipe with the large and small infinitesimal sections according to the calculation result of the twentieth step; comparing the calculated pressure of the lower end of the annular channel of the oil pipe with the size of the micro element section estimated in the fourteenth step, and when the relative error is less than 5%, taking the calculated pressure of the lower end of the annular channel of the oil pipe with the size of the micro element section as the actual pressure of the lower end of the annular channel of the oil pipe with the size of the micro element section; when the relative error is more than 5%, the calculated pressure at the lower end of the micro element section large and small oil pipe annular channel is used as a new estimated pressure at the lower end of the micro element section large and small oil pipe annular channel, and the twentieth step to the twentieth step are repeated until the relative error between the calculated pressure at the lower end of the micro element section large and small oil pipe annular channel and the estimated pressure at the lower end of the micro element section large and small oil pipe annular channel is less than 5%, according to a formula (10);

P' _down ＝P _up +ΔP (10)

of formula (II) to (III)' _down Calculating the pressure of the lower end of the annular passage of the micro-element section large and small oil pipes;

the twenty-second step is to take the actual temperature of the lower end of the annular channel of the oil pipe with the micro-element section size obtained by the calculation in the nineteenth step as the temperature of the upper end of the annular channel of the oil pipe with the micro-element section size of the next calculation, and take the actual pressure of the lower end of the annular channel of the oil pipe with the micro-element section size obtained by the calculation in the twenty-first step as the pressure of the upper end of the annular channel of the oil pipe with the micro-element section size of the next calculation; repeating the fourteenth step to the twentieth step until the calculation is carried out to the bottom of the well, so as to obtain the total friction loss of the layer section where the injected aqueous solution flows to the tubing annulus channel injection allocation device of each size from the well head, wherein the total friction loss is according to a formula (11);

P _{friction resistance} ＝P _f1 +P _f2 +…+P _fn (11)

In the formula, P _{Friction resistance} The total friction loss of the interval where the injector is positioned for injecting the aqueous solution to flow from the well head to the annular channel of the large and small oil pipes; p is _fn In the nth infinitesimal segmentThe friction loss of (2), wherein the maximum value of n is the depth of the position where the large and small oil pipe annular channel injection allocation device is located;

the twenty-third step, the throttling pressure difference required by the large and small oil pipe annulus channel injection allocation devices of each layer section obtained by the thirteenth step is differed from the total friction loss of the layer section where the injection aqueous solution obtained by the twenty-second step flows from the well head to the large and small oil pipe annulus channel injection allocation devices, the throttling pressure difference required by the large and small oil pipe annulus channel injection allocation devices of each layer section under the condition of considering the friction loss is obtained by calculation according to a formula (12);

P' _throttling ＝P _Throttling -P _{Friction resistance} (12)

Of formula (II) to (III)' _Throttling The throttling pressure difference required by the tubing annulus channel injection allocation device for the size of each layer section under the condition of considering the friction loss.

In the chemical flooding multi-medium injection flow measuring and adjusting method, the large and small oil pipe annular channel injection allocation device and the small oil pipe central channel injection allocation device are patented in another application. The invention of the patent application of the large and small oil pipe annular channel injection allocation device is named as a chemical flooding multi-medium bridge type channel injection allocation device with the application number of 2020115774617; the invention discloses a chemical flooding multi-medium central channel type injection allocation device, which is applied to the small oil pipe central channel injection allocation device and has the application number of 2020115773084.

The chemical flooding multi-medium injection flow quantity adjusting method has the following advantages: according to the method, the small oil pipe central passage injection allocation device is matched with the large oil pipe annular passage injection allocation device and the small oil pipe annular passage injection allocation device, so that flow measurement and adjustment under the condition that the polymer solution and the aqueous solution are respectively injected into the small oil pipe central passage and the large oil pipe annular passage can be realized. The prior art can only meet the multi-medium testing and adjusting requirement that the maximum number of the separated injection layers is three, and the chemical-flooding multi-medium injection flow testing and adjusting method can meet the multi-medium testing and adjusting requirement that the maximum number of the separated injection layers is six.

Drawings

Fig. 1 is a schematic view of an embodiment of a chemical flooding multi-media injection flow regulation method according to the present invention.

Fig. 2 is a large and small oil pipe annulus channel layered indication curve diagram in the embodiment of the chemical flooding multi-medium injection flow measurement and adjustment method.

Fig. 3 is a graph of nozzle loss of a large and small oil pipe annulus channel injection distributor in an embodiment of the chemical flooding multi-medium injection flow measurement and adjustment method of the invention.

The notation in the figure is: 1, sleeving a sleeve; 2, sand control top packer; 3, a high-quality sieve tube; 4, sand control interlayer packer; 5, a sand prevention interlayer packer; 6, sand control interlayer packer; 7, setting a sand packer; 8, artificial well bottom; 9, a ground control terminal; 10 a cable; 11 measuring and adjusting an instrument tool string; 12 large oil pipe at the upper part of the sand prevention section; 13 small oil pipe at the upper part of the sand prevention section; 14 small oil pipe central passage; 15-size oil pipe annulus channel; 16 positioning the sealing tool; 17, a small oil pipe of a sand prevention section; 18 a second size tubing annulus passageway injection distributor; 19 large oil pipes of sand prevention sections; 20 interlayer isolation tools; 21 a second small oil pipe central passage injection distributor; 22 an interlayer isolation tool; 23 a first size tubing annulus passageway injection distributor; 24-layer isolation tool; 25 first small oil pipe central passage injection distributor; 26 small plug; 27 large plug;

a a first oil layer, B a second oil layer, C a third oil layer and D a fourth oil layer.

Detailed Description

In order to better understand the purpose, structure and function of the present invention, a chemical flooding multi-media injection flow rate adjusting method of the present invention is further described in detail below with reference to the accompanying drawings.

As shown in fig. 1, the method for adjusting the injection flow of the chemical flooding multimedia is applicable to a concentric double-pipe injection string, wherein the concentric double-pipe injection string comprises an outer sand control string and an inner injection string; the external sand control pipe column consists of a casing pipe 1, a sand control top packer 2, a high-quality sieve pipe 3, a plurality of interlayer packers for subsection sand control, a sand setting packer 7 and an artificial well bottom 8; an internal injection pipe column is arranged in the external sand control pipe column;

in this embodiment, four oil layers are injected as an example. The flow measurement and regulation under the condition that different fluids are respectively injected into the small oil pipe central passage 14 and the large and small oil pipe annular passages 15 can be realized by matching with the first small oil pipe central passage injection distributor 25, the second small oil pipe central passage injection distributor 21, the first large and small oil pipe annular passage injection distributors 23 and the second large and small oil pipe annular passage injection distributors 18.

The first oil layer A and the third oil layer C are respectively put into the second large and small oil pipe annular channel injection distributor 18 and the first large and small oil pipe annular channel injection distributor 23 to be responsible for injecting aqueous solution; and the second oil layer B and the fourth oil layer D are put into a second small oil pipe central channel injection distributor 21 and a first small oil pipe central channel injection distributor 25 to be responsible for injecting polymer solution.

Concentric double-barrelled injection string contains little oil pipe tubular column and big oil pipe tubular column, and big oil pipe tubular column is gone into earlier when the tubular column is gone down, goes into little oil pipe tubular column again in big oil pipe tubular column to form two and overflow the passageway, do respectively: a small tubing central passage 14 and a large and small tubing annulus passage 15. The small oil pipe central passage 14 is respectively communicated with a water nozzle of a second small oil pipe central passage injection distributor 21 and a first small oil pipe central passage injection distributor 25 at the interval of injecting the polymer solution and is responsible for injecting the polymer solution into the injection interval; the large and small oil pipe annulus channels 15 are respectively communicated with the water nozzles of the second large and small oil pipe annulus channel injection distributor 18 and the first large and small oil pipe annulus channel injection distributor 23 at the water solution injection interval and are responsible for injecting water solution into the water solution injection interval.

The flow measuring and adjusting method under the condition that the polymer solution and the aqueous solution are respectively injected into the small oil pipe central passage 14 and the large oil pipe annular passage 15 comprises the following specific steps:

the first step is as follows: assembling a measuring and adjusting instrument tool string 11, hanging the measuring and adjusting instrument tool string 11 on a cable 10, lowering the cable 10 in a small oil pipe central passage 14, and sending the measuring and adjusting instrument tool string 11 into a well.

The second step is that: after the testing and adjusting instrument tool string 11 is lowered to the bottom of the small oil pipe central channel located in the fourth oil layer D, the testing and adjusting instrument tool string 11 is lifted to the position of a first small oil pipe central channel injection allocation device 25 located in the fourth oil layer D, the testing and adjusting instrument tool string 11 is positioned on the first small oil pipe central channel injection allocation device 25, a water nozzle of the first small oil pipe central channel injection allocation device 25 is adjusted to be 50% of opening, and the position of the first small oil pipe central channel injection allocation device 25 in the underground mode is monitored on a ground control terminal 9, the actual injection flow of the polymer solution in the underground small oil pipe central channel is 120m ³ D is the injection amount of 100m ³ 120% of/d, which exceeds the qualified range of 85% to 115%, so that the water nozzle opening of the first small oil pipe central passage injection allocation device 25 is adjusted to be smaller to 40%, and the actual injection flow of the polymer solution in the small oil pipe central passage at the position of the first small oil pipe central passage injection allocation device 25 in the well, which is monitored on the ground control terminal 9, is 105m ³ D is the dispensing quantity of 100m ³ 105% of the/d, and is qualified in the qualified range of 85% to 115% in testing and adjusting.

The third step: lifting the testing and adjusting instrument tool string 11 to the position of a second small oil pipe central channel injection allocation device 21 positioned on a second oil layer B above a fourth oil layer D of a previous test layer section, positioning the testing and adjusting instrument tool string 11 on the second small oil pipe central channel injection allocation device 21, adjusting a water nozzle of the second small oil pipe central channel injection allocation device 21 to 40% opening, and monitoring the position of the second small oil pipe central channel injection allocation device 21 in the well on a ground control terminal 9, wherein the actual injection flow of polymer solution in the central channel of the well is 150m ³ D is the injection amount of 160m ³ 94% of the/d, and the qualified range of 85% to 115%, the testing and the adjustment are qualified.

The fourth step: and after the polymer solution flow rate of the layer section where the second small oil pipe central passage injection allocation device 21 and the first small oil pipe central passage injection allocation device 25 are located is measured and adjusted, the small oil pipe central passage polymer solution flow rate measurement and adjustment of the layer section where all the small oil pipe central passage injection allocation devices are located is finished, and the fifth step is carried out.

The fifth step: the injection amount of the polymer solution of the second small oil pipe central passage injection distributor 21 and the first small oil pipe central passage injection distributor 25 meets the injection distribution requirement, so that the sixth step can be carried out without increasing the injection pressure of a well head.

And a sixth step: after the flow of the polymer solution in the central channel of the small oil pipe of the section where the second small oil pipe central channel injection allocation device 21 and the first small oil pipe central channel injection allocation device 25 are located is measured and adjusted, a measuring and adjusting instrument string 11 is put down to the bottom of the central channel of the small oil pipe of the fourth oil layer D, and the actual injection flow of the polymer solution in the central channel of the small oil pipe at the position of the small oil pipe central channel injection allocation device 25 is remeasured from bottom to top to be 98m under the condition that the opening degree of a water nozzle of the central channel injection allocation device of each layer of the small oil pipe is not changed ³ D is the injection amount of 100m ³ D of98 percent, the actual injection flow of the polymer solution in the central passage of the small oil pipe at the position of the central passage injection distributor 25 of the first small oil pipe is 155m ³ D is the injection amount of 160m ³ And the flow rate of the polymer solution injected into the small oil pipe central channels of the layer section where the second small oil pipe central channel injection allocation device 21 and the first small oil pipe central channel injection allocation device 25 are positioned reaches 85-115% of the injection rate, and the measurement and the adjustment of the flow rate of the polymer solution in the small oil pipe central channels of the layer section where all the small oil pipe central channel injection allocation devices are positioned are finished. Recording the injection flow of the small oil pipe central passage polymer solution of the second oil layer B of the layer section where the second small oil pipe central passage injection distributor 21 is positioned and the fourth oil layer D of the layer section where the first small oil pipe central passage injection distributor 25 is positioned as 98m ³ /d、155m ³ D is calculated as the ratio of the total weight of the composition. Recording the test temperatures of polymer solution injected into the small oil pipe central channels of the second oil layer B of the layer section where the second small oil pipe central channel injection distributor 21 is located and the fourth oil layer D of the layer section where the first small oil pipe central channel injection distributor 25 is located as 38 ℃ and 37.8 ℃ respectively.

The seventh step: and (3) lowering the testing and adjusting instrument tool string 11 to the position of the first-size oil pipe annular channel injection allocation device 23 located in the third oil layer C, positioning the testing and adjusting instrument tool string 11 on the first-size oil pipe annular channel injection allocation device 23, and adjusting the water nozzle of the first-size oil pipe annular channel injection allocation device 23 to be fully opened.

Eighth step: and lifting the testing and adjusting instrument string 11 to the position of the second-size oil pipe annulus channel injection allocation device 18 of the first oil layer A positioned at the upper part of the third oil layer C, positioning the testing and adjusting instrument string 11 on the second-size oil pipe annulus channel injection allocation device 18, and adjusting the water nozzle of the second-size oil pipe annulus channel injection allocation device 18 to be closed.

The ninth step: pumping aqueous solution into the annular channel 15 of the large and small oil pipes according to the maximum allowable pressure value of the well, taking 5 pressure points respectively at 10MPa, 8MPa, 6MPa, 4MPa and 2MPa by a depressurization method, testing the layering indicating curve of the third oil layer C, and testing each point for 30min.

The tenth step: after the test of the layered indication curve of the third oil layer C is finished, the testing and adjusting instrument string 11 is lowered to the position of the first-size oil pipe annular channel injection allocation device 23 located in the third oil layer C, the testing and adjusting instrument string 11 is located on the first-size oil pipe annular channel injection allocation device 23, and the water nozzle of the first-size oil pipe annular channel injection allocation device 23 is adjusted to be fully closed.

The eleventh step: and lifting the testing and adjusting instrument tool string 11 to the position of the second-size oil pipe annular passage injection allocator 18 positioned in the first oil layer A, positioning the testing and adjusting instrument tool string 11 on the second-size oil pipe annular passage injection allocator 18, and adjusting the water nozzle of the second-size oil pipe annular passage injection allocator 18 to be fully opened.

The twelfth step: pumping aqueous solution into the annular channel 15 of the large and small oil pipes according to the maximum allowable pressure value of the well, taking 5 pressure points respectively at 10MPa, 8MPa, 6MPa, 4MPa and 2MPa by a depressurization method, testing the layering indicating curve of the first oil layer A, and testing each point for 30min.

And a thirteenth step of: according to the layered indication curve of the A-size oil pipe annulus passage of the first oil layer, reading 105m of the injection allocation quantity of the A-size oil pipe annulus passage of the second oil layer when the 18 water nozzles of the injection allocation device of the A-size oil pipe annulus passage are in the fully open state as shown in figure 2 ³ D, the minimum injection pressure of the wellhead of the annular channel of the large and small oil pipes is 8.4MPa; according to the layered indicating curve of the large and small oil pipe annulus channels 15 of the third oil layer C, as shown in FIG. 2, the injection allocation quantity of 120m meeting the requirement of the large and small oil pipe annulus channel layer section under the condition that the water nozzles of the first large and small oil pipe annulus channel injection allocator 23 are fully opened is read ³ And d, taking the maximum value of 8.4MPa in the minimum injection pressures of the annular channel wellheads of the large and small oil pipes of the first oil layer A and the third oil layer C as the designed wellhead injection pressure of the annular channel of the large and small oil pipes.

The fourteenth step is that: by using the formula (1), the designed wellhead injection pressure of the large and small oil pipe annulus channels is calculated to be 8.4MPa, and the injection quantity of the large and small oil pipe annulus channel layer section is 105m under the condition that the 18 water nozzles of the second large and small oil pipe annulus channel injection allocation device are fully opened ³ The difference value between the minimum injection pressure of 8.4MPa of the wellhead of the large and small oil pipe annular channel is 0MPa, and the minimum injection pressure is used as the throttling pressure difference required by the second large and small oil pipe annular channel injection allocator 18. By using the formula (1), calculating to obtain the designed wellhead injection pressure of the large and small oil pipe annulus channels of 8.4MPa and the injection amount of 120m meeting the requirement of the large and small oil pipe annulus channel layer section under the condition that the water nozzle of the first large and small oil pipe annulus channel injection allocator 23 is fully opened ³ D the difference value between the minimum injection pressure of 8MPa of the wellhead of the large and small oil pipe annular passage is 0.4MPa, which is used as the throttling pressure difference required by the first large and small oil pipe annular passage injection allocation device 23,

P _throttling ＝P _{Well head} -P _{Injection of} Formula (1)

In the formula, P _Throttling The throttling pressure difference required by the annular channel injection allocation device of the oil pipe with large and small intervals is obtained; p _{Well head} Designing wellhead injection pressure for large and small oil pipe annulus channels; p _{Injection of} And (3) satisfying the minimum injection pressure of the wellhead of the large and small oil pipe annulus channels of the water solution injection amount of the large and small oil pipe annulus channels of the interval under the target opening degree of the water nozzle of the injector for the large and small oil pipe annulus channels of the interval.

The fifteenth step: the method is characterized in that a shaft with the length of 1m is used as a infinitesimal section, the temperature of water solution injected into a wellhead of an annular passage of a large oil pipe and a small oil pipe and the pressure of the designed wellhead of the annular passage of the large oil pipe and the small oil pipe are 8.4MPa and are used as the temperature of the upper end of the annular passage of the large oil pipe and the small oil pipe and the pressure of the upper end of the annular passage of the small oil pipe of the infinitesimal section and the pressure of the lower end of the annular passage of the large oil pipe and the small oil pipe of the infinitesimal section, the temperature of the lower end of the annular passage of the large oil pipe and the small oil pipe of the infinitesimal section is estimated to be 41 ℃ according to experience, and the pressure of the lower end of the annular passage of the large oil pipe of the small oil pipe of the infinitesimal section and the pressure of the annular passage of the small oil pipe is 8.42MPa, and the average temperature of the annular passage of the large oil pipe of the small oil pipe of the infinitesimal section is calculated by using a formula (2) and is 40.5 ℃ and is used as the average temperature of the annular passage of the large oil pipe of the infinitesimal section. The average value of the pressure at the upper end of the micro element section large and small oil pipe annular passage and the pressure at the lower end of the micro element section large and small oil pipe annular passage is calculated by using a formula (3) and is 8.41MPa as the average pressure of the micro element section large and small oil pipe annular passage,

in the formula (I), the compound is shown in the specification,

is a littleAverage temperature of annular channels of oil pipes with large and small sections; t is _up The temperature of the upper end of the annular channel of the oil pipe with the micro-element section is measured; t is _down The temperature of the lower end of the annular channel of the oil pipe with the micro-element section is measured;

average pressure of annular channels of oil pipes with the micro-element sections; p _up The pressure at the upper end of the annular channel of the oil pipe with the micro-element section is measured; p _down The pressure at the lower end of the annular channel of the oil pipe with the micro-element section is obtained.

Sixteenth step: according to the test of the sixth step, the test temperature of the small oil pipe central passage 14 of the second oil layer B of the layer section where the small oil pipe central passage injection allocation device 21 is located and the test temperature of the small oil pipe central passage 14 of the fourth oil layer D of the layer section where the small oil pipe central passage injection allocation device 25 is located are 38 ℃ and 37.8 ℃, the temperature of the polymer solution in the micro-element section small oil pipe central passage is interpolated and calculated to be 45 ℃ by using a formula (4),

in the formula, T _{Micro element} The temperature of the polymer solution in the central channel of the micro-element section small oil pipe is measured; t is _{Well head} The temperature at which the polymer solution is injected into the wellhead; h _{Micro element} The depth of the infinitesimal section; t is _{Layer segment} Testing the temperature of the polymer solution in the layer section of the injector of the central passage of the small oil pipe closest to the lower part of the micro element; h _{Layer segment} The depth of the layer section where the injector of the central passage of the small oil pipe on the lower part of the micro element is located.

Seventeenth step: according to the temperature of the polymer solution injected into the central channel 14 of the small oil pipe of the micro-element section being 45 ℃ and the average temperature of the annular channels of the large oil pipe and the small oil pipe of the micro-element section being 40.5 ℃, the formula (5) is utilized to calculate the heat transfer quantity between the polymer solution in the central channel 14 of the small oil pipe and the aqueous solution in the annular channels 15 of the large oil pipe and the small oil pipe being 600 joules,

E _p ＝ρ _p Q _p λ(T _p -T _w ) Formula (5)

In the formula, E _p Is a polymer solution in the central passage of the small oil pipe and the annular passage of the large oil pipe and the small oil pipeHeat transfer capacity between aqueous solutions; rho _p Injecting the density of the polymer solution into the central channel of the micro-element section small oil pipe; q _p Injecting the flow of polymer solution into the central channel of the micro-element section small oil pipe; lambda is the heat conductivity coefficient of the small oil pipe; t is a unit of _p Injecting polymer solution into the central channel of the micro-element section small oil pipe; t is _w The temperature of water solution injected into the annular channel of the micro-element section large and small oil pipes.

And eighteenth step: according to the difference value of 25 ℃ between the average temperature of the annular channel of the oil pipes with the large and the small micro-element sections and the temperature of the stratum with the depth of the micro-element sections, the heat transfer quantity between the aqueous solution in the annular channel of the oil pipes with the large and the small micro-element sections and the stratum is 1200 joules by utilizing the formula (6),

E _w ＝Kρ _w Q _w (T _w -T _e ) Formula (6)

In the formula, E _w The heat transfer quantity between the aqueous solution in the annular channel of the large and small oil pipes and the ground is obtained; k is the heat transfer coefficient between the injected aqueous solution in the annular channel of the oil pipe with the micro-element section and the ground; rho _w The density of water solution injected into the annular channel of the micro-element section large and small oil pipes; q _w Injecting the flow of aqueous solution into the annular channel of the oil pipe with the micro-element section; t is _e The formation temperature at the micro-segment location.

The nineteenth step: according to the heat transfer quantity calculation results of the seventeenth step and the eighteenth step, the calculation temperature of the lower end of the annular channel of the oil pipe with the large and the small infinitesimal sections is 40.1 ℃ by using the formula (7),

in the formula, T _w Calculating the temperature of the lower end of the annular passage of the micro-element section large and small oil pipes obtained by calculation; g is the acceleration of gravity; dl is the length of the infinitesimal segment; c _w Is the specific heat capacity of water.

The twentieth step: comparing the calculated temperature of the lower end of the annular channel of the micro-element section large and small oil pipe obtained by the nineteenth step with the estimated temperature of the lower end of the annular channel of the micro-element section large and small oil pipe obtained by the fifteenth step of 41 ℃, wherein the relative error is 2 percent, the error is less than 5 percent, and the error requirement is met, so that the calculated temperature of the lower end of the annular channel of the micro-element section large and small oil pipe obtained by calculation is 40.1 ℃ as the actual temperature of the lower end of the annular channel of the micro-element section large and small oil pipe.

The twenty-first step: and (3) according to the actual temperature of the lower end of the annular channel of the oil pipe with the large and small infinitesimal sections obtained by the calculation in the twentieth step and the temperature of the upper end of the annular channel of the oil pipe with the large and small infinitesimal sections in the fifteenth step, recalculating the actual average temperature of the annular channel of the oil pipe with the large and small infinitesimal sections to be 40.05 ℃ by using the formula (1). Then calculating the variation of the pressure of the aqueous solution of the annular channel of the micro-element section large and small oil pipe at the average temperature of 40.05 ℃ to be 0.01MPa according to a formula (8), calculating the friction loss of the aqueous solution of the annular channel of the micro-element section large and small oil pipe to be 0.001MPa according to a formula (9),

ΔP＝(ρ _w g+τ _f ) Dl formula (8)

P _f ＝τ _f Dl formula (9)

In the formula, delta P is the variation of the pressure of the aqueous solution in the annular channel of the micro-element section large and small oil pipes; tau. _f Is the friction loss speed; p _f Is the friction loss in the infinitesimal section.

A twenty-second step: and (4) according to the calculation result of the twenty-first step, calculating the lower end calculation pressure of the annular channel of the micro element section large and small oil pipe by using a formula (10) to be 8.41MPa. Comparing the calculated pressure 8.41MPa at the lower end of the annular passage of the micro-element section large and small oil pipes with the pressure 8.42MPa at the lower end of the annular passage of the micro-element section large and small oil pipes estimated in the fifteenth step, wherein the relative error is 0.1 percent and less than 5 percent, and the error requirement is met, so that the calculated pressure 8.41MPa at the lower end of the annular passage of the micro-element section large and small oil pipes obtained by calculation is used as the actual pressure at the lower end of the annular passage of the micro-element section large and small oil pipes,

P' _down ＝P _up + delta P type (10)

Of formula (II) to (III)' _down The pressure of the lower end of the annular channel of the oil pipe with the micro-element section is obtained through calculation.

A twenty-third step: taking the actual temperature of the lower end of the annular channel of the oil pipe with the large and small infinitesimal sections obtained by the calculation in the twentieth step as the temperature of the upper end of the annular channel of the oil pipe with the large and small infinitesimal sections next, taking the actual pressure of the lower end of the annular channel of the oil pipe with the large and small infinitesimal sections obtained by the calculation in the twenty-second step as the pressure of the upper end of the annular channel of the oil pipe with the large and small infinitesimal sections next, repeating the fifteenth step to the twenty-second step until the bottom is calculated, calculating by using a formula (11) to obtain the total friction loss of the injected aqueous solution flowing from the wellhead to the injector 18 of the annular channel of the oil pipe with the large and small second size until the bottom is calculated, and obtaining the total friction loss of the injected aqueous solution flowing from the wellhead to the injector 23 of the annular channel of the oil pipe with the large and small size as 0.13MPa,

P _{friction resistance} ＝P _f1 +P _f2 +…+P _fn Formula (11)

In the formula, P _{Friction resistance} The total friction loss of the interval where the injector is positioned for injecting the aqueous solution to flow from the well head to the large and small oil pipe annulus channels is reduced; p _fn The friction loss in the nth infinitesimal section is shown, wherein the maximum value of n is the depth of the position of the large and small oil pipe annular channel injection allocation device.

And a twenty-fourth step: by using a formula (12), making a difference between the throttling pressure difference 0MPa required by the second large and small oil pipe annular channel injection allocator 18 obtained by the fourteenth step and the total frictional resistance loss 0.13MPa of the injected aqueous solution flowing from the wellhead to the second large and small oil pipe annular channel injection allocator 18 obtained by the twenty-third step, and calculating to obtain the throttling pressure difference-0.13 MPa required by the second large and small oil pipe annular channel injection allocator 18 under the condition of considering the frictional resistance loss; by using a formula (12), the difference is made between 0.4MPa of the throttling pressure difference required by the first large and small oil pipe annular channel injection allocation device 23 obtained by the fourteenth step and 0.15MPa of the total frictional resistance loss of the injected aqueous solution flowing from the wellhead to the first large and small oil pipe annular channel injection allocation device 23 obtained by the twenty-third step, the throttling pressure difference required by the first large and small oil pipe annular channel injection allocation device 23 under the condition of considering the frictional resistance loss is obtained by calculation and is 0.25MPa,

P' _throttling ＝P _Throttling -P _{Friction resistance} Formula (12)

Of formula (II) to (III)' _Throttling The throttling pressure difference required by the oil pipe annulus channel injection allocation device for each layer section is considered under the condition of friction loss; p _Throttling The throttling pressure difference, P, required by the annular channel injection allocation device of the oil pipe with large and small intervals _{Friction resistance} The total friction loss of the interval where the injector is positioned for injecting the water solution to flow from the wellhead to the tubing annulus channel is reduced.

Twenty-fifth step: looking up a nozzle loss curve chart of the large and small oil pipe annulus passage injection allocation device obtained through a related test as shown in fig. 3, and according to the throttle pressure difference 0.25MPa required by the first large and small oil pipe annulus passage injection allocation device 23 under the condition of considering the friction loss, looking up the chart to obtain that the third oil layer C of the layer section where the first large and small oil pipe annulus passage injection allocation device 23 is located reaches the water solution injection allocation amount 120m ³ The target opening of the large and small oil pipe annular channel injection allocation device required in the/d condition is 90%. The required throttling pressure difference of-0.13 MPa of the second large and small oil pipe annular passage injection allocation device 18 under the condition of considering the friction loss is a negative value, so that the target opening degree of the second large and small oil pipe annular passage injection allocation device 18 is 100 percent.

Twenty-sixth step: and (3) putting the testing and adjusting instrument string 11 to the position of the first-size oil pipe annular passage injection allocation device 23 positioned at the bottommost layer, positioning the testing and adjusting instrument string 11 on the first-size oil pipe annular passage injection allocation device 23 positioned at the bottommost layer, and adjusting the water nozzle of the first-size oil pipe annular passage injection allocation device 23 to the target opening degree of 90%.

Twenty-seventh step: and lifting the testing and adjusting instrument tool string 11 to the position of the second large and small oil pipe annulus channel injection allocation device 18 of the next large and small oil pipe annulus channel injection allocation device above the third oil layer C of the layer section where the first large and small oil pipe annulus channel injection allocation device 23 which is adjusted before is positioned, positioning the testing and adjusting instrument tool string 11 on the second large and small oil pipe annulus channel injection allocation device 18, and adjusting the water nozzle of the second large and small oil pipe annulus channel injection allocation device 18 to the target opening degree of 100%.

The twenty-eighth step: injecting water solution under the wellhead pressure of 8.4MPa according to the design of the large and small oil pipe annulus channels, wherein the total injection amount of the water solution in the large and small oil pipe annulus channels is 220m ³ D, achieving the total injection amount of the water solution in the annular channel of the large oil pipe and the small oil pipe of 225m ³ 97.8% of/d, in the range of 85% to 115% of the total amount of the aqueous solution injection in the large and small oil pipe annular channels, thus the water injection is recovered by taking 8.4MPa as the well head pressure.

The content that is not described in this embodiment is the prior art, and therefore, the description thereof is omitted.

It is to be understood that the present invention has been described with reference to certain embodiments, and that various changes in the features and embodiments, or equivalent substitutions may be made therein by those skilled in the art without departing from the spirit and scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.

Claims

1. A chemical flooding multi-medium injection flow regulation method is characterized by comprising the following steps:

thirdly, after the testing and adjusting instrument tool string is placed at the bottom of the small oil pipe central passage positioned in the bottommost layer section, the testing and adjusting instrument tool string is lifted to the position of the first small oil pipe central passage injection allocation device positioned in the bottommost layer section, the testing and adjusting instrument tool string is positioned on the first small oil pipe central passage injection allocation device positioned in the bottommost layer section, a water nozzle of the first small oil pipe central passage injection allocation device positioned in the bottommost layer section is adjusted to be in a proper opening degree, and the actual injection flow of the polymer solution under the small oil pipe central passage is monitored on a ground control terminal at the position of the first small oil pipe central passage injection allocation device positioned in the bottommost layer section until the injection flow of the polymer solution of the small oil pipe central passage in the layer section reaches 85-115% of the injection amount;

fourthly, lifting the testing and adjusting instrument tool string to the position of the next small oil pipe central passage injection allocation device above the previous testing interval, positioning the testing and adjusting instrument tool string on the next small oil pipe central passage injection allocation device, adjusting the water nozzle of the next small oil pipe central passage injection allocation device to a proper opening degree, and monitoring the actual injection flow of the polymer solution of the underground small oil pipe central passage at the position of the next small oil pipe central passage injection allocation device on a ground control terminal until the injection flow of the polymer solution of the small oil pipe central passage of the interval reaches 85-115% of the injection amount;

fifthly, repeating the fourth step until the injection flow of the polymer solution flow of the small oil pipe central passage of the layer section where all the small oil pipe central passage injection distributors are located reaches 85-115% of the injection amount; if the water nozzle of the central channel injection allocation device of a small oil pipe is adjusted to the maximum opening, the injection flow of the polymer solution flow of the central channel of the small oil pipe of the interval where the water nozzle is located still can not reach 85-115% of the injection allocation amount, increasing the injection pressure of the wellhead of the central channel of the small oil pipe, and repeating the third step to the fifth step until the injection flow of the polymer solution of the central channel of the small oil pipe of the interval where the central channel injection allocation device of the small oil pipe is located reaches 85-115% of the injection allocation amount;

sixthly, after the flow measurement and regulation of the polymer solution in the central passage of the small oil pipe of the section where the central passage injection allocation device of each small oil pipe is located is completed, a measurement and regulation instrument tool string is put to the bottom of the central passage of the small oil pipe of the bottommost layer section, the flow of the polymer solution in the central passage of the small oil pipe of the section where the central passage injection allocation device of each small oil pipe is located is repeatedly measured from bottom to top under the condition that the opening degree of a water nozzle of the central passage injection allocation device of each small oil pipe is kept, and the test flow, the test temperature and the temperature of the polymer solution injected into the central passage of the small oil pipe of each layer section are recorded under the condition that the flow of the polymer solution in the central passage of the small oil pipe of the section where the central passage injection allocation device of all small oil pipes is located reaches 85-115% of the injection allocation amount; under the condition that the flow rate of the polymer solution of the central passage of the small oil pipe of the interval where the central passage injection allocation device of the small oil pipe is located cannot reach 85-115% of the injection allocation amount, repeating the third step to the sixth step until the flow rates of the polymer solution of the central passages of the small oil pipes of the intervals where the central passage injection allocation device of the small oil pipe is located reach 85-115% of the injection allocation amount;

ninth, repeating the eighth step until all water nozzles of the annular channel injection allocation device of the oil pipes with the sizes of all the layer sections are closed;

pumping aqueous solution into the annular channels of the large and small oil pipes according to the pressure value of the maximum allowable point of the well, taking 5 pressures by a depressurization method, and testing the layer interval layering indication curve of the test layer interval, wherein the span between adjacent pressure points is required to be more than 0.5MPa, and each point is tested for 30min;

step ten, after the test of the layering indication curve is finished, lowering the testing and adjusting instrument tool string to the position of the oil pipe annulus passage injection allocation device with the size of the previous test layer section, adjusting the water nozzle of the oil pipe annulus passage injection allocation device with the size of the test layer section to be closed, lifting the testing and adjusting instrument tool string to the position of the next oil pipe annulus passage injection allocation device with the size above the previous test layer section, and adjusting the water nozzle of the next oil pipe annulus passage injection allocation device with the size to be in a target opening degree; repeating the eighth step to the tenth step until the test of the layered indication curve of the layer section where all the oil pipe annulus passage injection distributors are located is completed;

step ten, reading the minimum injection pressure of the wellhead of the large and small oil pipe annulus channels, which meets the injection quantity of the aqueous solution of the large and small oil pipe annulus channels of the layer section under the target opening degree of the water nozzles of the large and small oil pipe annulus channels according to the layering indication curve of each layer section where the large and small oil pipe annulus channels are located, and taking the maximum value as the injection pressure of the design wellhead of the large and small oil pipe annulus channels;

fifteenth, interpolating and calculating the temperature of the polymer solution in the central channel of the micro-element section small oil pipe according to the test temperature of the central channel of the small oil pipe of the layer section where each small oil pipe central channel injection allocator is located, which is obtained by the test of the sixth step;

twentieth, calculating the average value of the upper end temperature of the annular channel of the micro element section large and small oil pipes and the actual temperature of the lower end of the annular channel of the micro element section large and small oil pipes by adopting a calculation method which is the same as the average temperature of the annular channel of the micro element section large and small oil pipes in the fourteenth step, and taking the average value as the actual average temperature of the annular channel of the micro element section large and small oil pipes; then calculating the pressure change and the friction loss of the micro-element section large and small oil pipe annulus channel aqueous solution at the temperature according to the layer section aqueous solution injection amount of each large and small oil pipe annulus channel injection allocation device;

twenty-second step, using the actual temperature of the lower end of the annular channel of the oil pipe with the micro-element section size obtained by the calculation in the nineteenth step as the temperature of the upper end of the annular channel of the oil pipe with the micro-element section size of the next calculation, and using the actual pressure of the lower end of the annular channel of the oil pipe with the micro-element section size obtained by the calculation in the twenty-first step as the pressure of the upper end of the annular channel of the oil pipe with the micro-element section size of the next calculation; repeating the fourteenth step to the twentieth step until the calculation is carried out to the bottom of the well, and obtaining the total friction loss of the injected aqueous solution flowing from the well head to the layer section where the oil pipe annulus channel injectors of different sizes are located;

twenty-sixth step, lifting the measuring and adjusting instrument tool string to the next large and small oil pipe annulus passage injection allocation device position above the previous large and small oil pipe annulus passage injection allocation device water nozzle layer section, positioning the measuring and adjusting instrument tool string on the next large and small oil pipe annulus passage injection allocation device, and adjusting the next large and small oil pipe annulus passage injection allocation device water nozzle to a target opening degree;

twenty-seventh step, repeating the twenty-sixth step until the opening degree of the water nozzles of the annular channel injection allocation devices of the oil pipes with the sizes of all the layer sections is adjusted to the target opening degree;

the twenty-eighth step: the water injection is recovered according to the total water injection amount of the large and small oil pipe annulus channels when the total water injection amount of the large and small oil pipe annulus channels reaches 85-115% of the total water injection amount of the large and small oil pipe annulus channels; and when the injection total amount of the aqueous solution of the large and small oil pipe annulus channels cannot reach 85-115% of the injection total amount of the aqueous solution of the large and small oil pipe annulus channels, increasing or decreasing the wellhead injection pressure of the large and small oil pipe annulus channels, taking the adjusted wellhead injection pressure of the large and small oil pipe annulus channels as the design wellhead injection pressure of the new large and small oil pipe annulus channels, and repeating the seventh step to the twenty-eighth step until the injection total amount of the aqueous solution of the large and small oil pipe annulus channels reaches 85-115% of the injection total amount of the aqueous solution of the large and small oil pipe annulus channels.

2. The chemical flooding multi-media injection flow regulating method according to claim 1,

and the thirteenth step, taking the difference between the injection pressure of the designed wellhead of the large and small oil pipe annulus channels and the minimum injection pressure of the wellhead of the large and small oil pipe annulus channels meeting the water solution injection quantity of the large and small oil pipe annulus channels of the intervals under the target opening of the water nozzles of the large and small oil pipe annulus channels of the intervals as the throttling pressure difference required by the large and small oil pipe annulus channels of the intervals according to the formula (1):

P _throttling ＝P _{Well head} -P _{Injection of} (1)

In the formula, P _Throttling The throttling pressure difference required by the annular channel injection allocation device of the oil pipe with the large and small layer sections is obtained; p _{Well head} Designing wellhead injection pressure for large and small oil pipe annulus passages; p _{Injection of} The minimum injection pressure of the wellhead of the large and small oil pipe annulus channels meeting the water solution injection amount of the large and small oil pipe annulus channels of the interval under the target opening degree of the water nozzle of the large and small oil pipe annulus channel injection allocation device is set for the interval;

the fourteenth step is to use a shaft with the length of 1 meter as a infinitesimal section, use the temperature of an injected aqueous solution at the wellhead of the annular passage of the large and small oil pipes and the pressure at the upper end of the annular passage of the large and small oil pipes as the temperature at the upper end of the annular passage of the large and small oil pipes and the pressure at the upper end of the annular passage of the large and small oil pipes, estimate the temperature at the lower end of the annular passage of the large and small oil pipes and the pressure at the lower end of the annular passage of the large and small oil pipes according to experience, use the average value of the temperature at the upper end of the annular passage of the large and small oil pipes and the temperature at the lower end of the annular passage of the large and small oil pipes as the average temperature of the annular passage of the large and small oil pipes, and use the average value of the pressure at the upper end of the annular passage of the large and small oil pipes and the pressure at the lower end of the annular passage of the large and small oil pipes as the average pressure of the annular passage of the large and small oil pipes according to the formulas (2) and (3);

in the formula (I), the compound is shown in the specification,

average pressure of annular channels of oil pipes with the micro-element sections; p _up The pressure at the upper end of the annular channel of the micro-element section large and small oil pipes; p _down The pressure at the lower end of the annular channel of the oil pipe with the micro-element section is obtained;

in the formula, T _{Micro element} The temperature of the polymer solution in the central channel of the micro-element section small oil pipe is measured; t is _{Well head} Injecting polymer solution temperature for the wellhead; h _{Micro element} The depth of the infinitesimal section; t is _{Layer segment} Testing the temperature of the polymer solution at the position of the central channel injection distributor of the small oil pipe at the lower part of the infinitesimal closest to the infinitesimal section; h _{Interval section} The position depth of the injector for the central channel of the small oil pipe at the lower part of the micro element, which is closest to the micro element section;

E _p ＝ρ _p Q _p λ(T _p -T _w ) (5)

in the formula, E _p The heat transfer quantity between the polymer solution in the central passage of the small oil pipe and the aqueous solution in the annular passage of the large oil pipe and the small oil pipe is obtained; rho _p Injecting the density of the polymer solution into the central channel of the micro-element section small oil pipe; q _p Injecting the flow of polymer solution into the central channel of the micro-element section small oil pipe; lambda is the heat conductivity coefficient of the small oil pipe; t is _p Injecting polymer solution into the central channel of the micro-element section small oil pipe; t is a unit of _w The temperature of injecting aqueous solution into the annular channel of the oil pipe with the micro-element section;

E _w ＝Kρ _w Q _w (T _w -T _e ) (6)

in the formula，E _w The heat transfer quantity between the aqueous solution in the annular channel of the large and small oil pipes and the ground is obtained; k is the heat transfer coefficient between the injected aqueous solution in the annular channel of the oil pipe with the micro-element section and the ground; rho _w The density of water solution injected into the annular channel of the micro-element section large and small oil pipes; q _w Injecting the flow of the aqueous solution into the annular channel of the micro-element section large and small oil pipes; t is _e The formation temperature at the infinitesimal section position;

ΔP＝(ρ _w g+τ _f )·dl (8)

P _f ＝τ _f ·dl (9)

in the formula, delta P is the variation of the pressure of the aqueous solution in the annular channel of the micro-element section large and small oil pipes; tau. _f Is the frictional loss velocity; p is _f The friction loss in the infinitesimal section is obtained;

the twenty-first step, calculating the pressure calculated by the lower end of the annular channel of the oil pipe with the large and small infinitesimal sections according to the calculation result of the twentieth step; comparing the calculated pressure of the lower end of the annular channel of the oil pipe with the size of the micro element section estimated in the fourteenth step, and when the relative error is less than 5%, taking the calculated pressure of the lower end of the annular channel of the oil pipe with the size of the micro element section as the actual pressure of the lower end of the annular channel of the oil pipe with the size of the micro element section; when the relative error is larger than 5%, the calculated pressure at the lower end of the micro element section large and small oil pipe annular channel is used as new estimated pressure at the lower end of the micro element section large and small oil pipe annular channel, and the twentieth step to the twentieth step are repeated until the relative error between the calculated pressure at the lower end of the micro element section large and small oil pipe annular channel and the estimated pressure at the lower end of the micro element section large and small oil pipe annular channel is smaller than 5%, according to a formula (10);

P′ _down ＝P _up +ΔP (10)

of formula (II) to (III)' _down Calculating the pressure of the lower end of the annular channel of the oil pipe with the large and small infinitesimal sections;

the twenty-second step is to take the actual temperature of the lower end of the annular channel of the oil pipe with the micro-element section size obtained by the calculation in the nineteenth step as the temperature of the upper end of the annular channel of the oil pipe with the micro-element section size of the next calculation, and take the actual pressure of the lower end of the annular channel of the oil pipe with the micro-element section size obtained by the calculation in the twenty-first step as the pressure of the upper end of the annular channel of the oil pipe with the micro-element section size of the next calculation; repeating the fourteenth step to the twentieth step until the calculation is carried out to the bottom of the well, and obtaining the total friction loss of the interval where the injection aqueous solution flows from the well head to the annular channel injection allocation device of each oil pipe with different sizes according to the formula (11);

P _{friction resistance} ＝P _f1 +P _f2 +…+P _fn (11)

In the formula, P _{Friction resistance} The total friction loss of the interval where the injector is positioned for injecting the aqueous solution to flow from the well head to the large and small oil pipe annulus channels is reduced; p _fn The friction loss in the nth infinitesimal section is shown, wherein the maximum value of n is the depth of the position of the large and small oil pipe annular channel injection allocation device;

P' _throttling ＝P _Throttling -P _{Friction resistance} (12)

Of formula (II) to (III)' _Throttling The throttling pressure difference is needed by the oil pipe annulus channel injection allocation device for each layer section under the condition of considering the friction loss.