CN112816359B - Device and method for determining solid deposition amount of crude oil in solid-phase deposition oil reservoir - Google Patents

Abstract

The invention relates to a device for determining the solid deposition amount of crude oil in a solid-phase deposition oil reservoir, which comprises an ultrahigh pressure reaction kettle, a high pressure intermediate container A, a high pressure intermediate container B, a sampler or a sample preparation device and a high pressure filter, wherein the ultrahigh pressure reaction kettle is provided with an upper end surface sealing cover and a lower end surface sealing cover; the sampler or the sample preparation device is connected with the ultrahigh pressure reaction kettle; the high-pressure intermediate container A is respectively connected with a fluid channel of the upper end surface sealing cover of the reaction kettle and the inlet end of the high-pressure filter; the inlet end of the high-pressure filter is connected with the ultrahigh-pressure reaction kettle through a fluid channel of the lower end face sealing cover, and the outlet end of the high-pressure filter is connected with the high-pressure intermediate container B. The device can realize crude oil sample transfer under the reservoir condition of an oil reservoir, and the solid phase deposition amount in the crude oil is measured by pressure maintaining filtration under different temperatures and pressures. The invention has accurate test result and provides important basic parameters for recognizing the solid phase deposition characteristic of the shaft and effectively removing solids.

Description

A device and method for determining the amount of solids deposited in crude oil in a solid-phase sedimentary reservoir

technical field

The invention relates to an experimental system and method for determining the solid phase amount of crude oil deposits in solid phase sedimentary oil reservoirs in the field of oil and gas field exploration and development.

Background technique

The main components of formation crude oil include low-carbon light hydrocarbons, paraffins, gums and asphaltenes. Under reservoir conditions, asphaltenes, paraffins and light hydrocarbons are in a phase equilibrium condition. As crude oil is produced, the reservoir pressure will decrease. At the same time, during the flow of crude oil from the bottom of the well to the wellhead, the pressure and temperature will gradually decrease, which will lead to The initial phase equilibrium condition of crude oil is destroyed, so that the heavy components originally dissolved in crude oil, such as asphalt, paraffin, etc., may be deposited and adsorbed in the pores and wellbore, resulting in blockage of the pore throat of the oil layer, poor crude oil flow ability, and oil well sealing. . This hazard is particularly serious in high temperature, high pressure and ultra-high pressure reservoirs. For example, a reservoir with a reservoir temperature of 130 °C and a reservoir pressure of 134 MPa was recently discovered in the southern margin of Xinjiang Oilfield. During the development and evaluation process, the wellbore had serious solid phase deposition under ultra-high pressure conditions. Regular well cleaning operations. Therefore, it is very important to further effectively and quantitatively determine the amount of crude oil solid deposits in the wellbore during the exploration and evaluation stage, which is very important for the later blockage removal and cleanup.

Chinese patents "a kind of oil high pressure filter" (CN201721642818.9), "a kind of crude oil high pressure filter" (CN201821286792.3), "a kind of filter separation device and its use method" (CN202010199140.1), although it can be quantitative Determine the amount of solid phase deposition in crude oil, but it is a conventional filtration method under normal temperature and low pressure conditions; "a vertical steam-heated crude oil high-pressure filter" (CN201410742847.7) Although the idea of steam heating is proposed, but its heating Temperature is limited and filtration is also measured at atmospheric pressure.

SUMMARY OF THE INVENTION

The object of the present invention is to provide a device for determining the solid content of crude oil deposited in solid-phase deposition oil reservoirs, which is reliable in principle, simple and convenient to operate, and can realize the transfer of crude oil samples under the conditions of oil reservoirs, and can filter and measure crude oil under different temperatures and pressures. The amount of solid deposition in crude oil.

Another object of the present invention is to provide a method for determining the amount of solids deposited in crude oil in a solid deposition reservoir by using the above-mentioned device. The test process of the method is controllable and the test results are accurate, so as to understand the wellbore solid deposition characteristics of the actual reservoir and effectively remove it. Solid, providing important fundamental parameters.

In order to achieve the above technical purpose, the present invention adopts the following technical solutions.

To determine the amount of solid deposition in high temperature and high pressure crude oil, a representative crude oil sample is required first. For oil reservoirs where solid deposition has occurred in the wellbore during the exploration and evaluation stage, since the temperature and pressure of the reservoir are basically unchanged at this stage, solid precipitation will not occur in the reservoir rock, and the fluid in the wellbore will decrease due to the temperature and pressure. , it becomes the place where solid deposition occurs, but it is difficult to determine the specific amount of solid deposited in the wellbore. At this time, sampling from the wellhead or separator according to the conventional method, and then measuring the amount of solid deposition of crude oil in the laboratory with mutual formation crude oil is no longer sufficient. representative.

In order to accurately evaluate the solid deposition amount of crude oil in this type of reservoir under different temperature and pressure conditions in the laboratory, it is best to carry out bottom-hole pressure-holding sampling of crude oil in the reservoir evaluation stage and early stage of development, and transport it to the experiment under heat preservation and pressure. Relevant experiments were carried out in the room. If the reservoir temperature and pressure are too high or for other reasons, bottom hole holding sampling cannot be performed, the associated gas, degassed oil, and sedimentary solids recovered from the tubing can be retrieved from the field separator in the laboratory. The formation crude oil is obtained by inter-matching under high temperature and high pressure conditions, and then the solid phase deposition amount is measured under high temperature and high pressure conditions.

A device for determining the solid amount of crude oil deposited in a solid-phase deposition oil reservoir includes a high-pressure sample preparation device, an ultra-high-pressure reaction kettle, a high-pressure intermediate container, a heat-preserving and pressure-holding sampler, a high-pressure filter, a valve, and a high-low temperature test chamber. A movable piston is arranged in the ultra-high pressure reaction kettle to divide it into a crude oil sample chamber and a hydraulic oil chamber. There is a fluid channel on one side wall of the sample chamber of the cavity, and there are also fluid channels on the end caps at both ends. The contact surface between the sealing piston at one end of the sample chamber of the ultra-high pressure reactor and the fluid is designed as a concave spherical surface, which facilitates the accumulation of solids deposited in the crude oil at the outlet. The high-pressure filter contains a metal filter screen with high temperature resistant nano-filter paper on the metal filter screen. One end of the high-pressure filter is connected to the outlet of the end cover of the sample chamber of the ultra-high pressure reactor, and the other end is connected to the high-pressure intermediate container. A movable piston is also provided in the high-pressure intermediate vessel. The high and low temperature test chamber provides a high temperature environment for the entire experimental system.

Preferably, the volume of the inner cavity of the reactor contained between the fluid channel on one side wall of the sample chamber of the ultra-high pressure reactor and the end cap at the nearest end is 20-30 mL.

Preferably, the pore size of the high temperature resistant nano filter paper is not more than 100 nanometers.

The method for determining the amount of solids deposited in crude oil in a solid-phase deposition oil reservoir using the above-mentioned device includes the following steps in sequence:

(1) Obtain the crude oil sample from the bottom of the wellbore of the field reservoir by the method of holding pressure sampling, and transfer the sample to the sampler; or configure the crude oil sample in the sampler;

The process of configuring crude oil samples in the sample matcher is as follows: according to the gas-oil ratio produced on site, the associated gas, degassed crude oil and sedimentary solids are added to the high-pressure sample matcher, and the pressure of the sample matcher is set to the target oil reservoir storage. The layer pressure and temperature are set to the target reservoir temperature, and the mixture is stirred for at least 24 hours to allow the fluid to undergo sufficient material exchange.

(2) The ultra-high pressure reaction kettle is in an upright state, keeping the sample chamber on top, and using a displacement pump to push the pistons of the high-pressure intermediate container A, the high-pressure intermediate container B and the reaction kettle to the uppermost end to remove air; The piston is pushed to the position below the fluid channel on the side of the sample chamber, and then the pressure of the hydraulic oil in the reaction kettle is raised to the pressure of the target oil reservoir, and the volume V ₁ (mL) of helium in the sample chamber at this time is recorded;

(3) Inject helium gas into the end of the high-pressure intermediate container A and the high-pressure intermediate container B that does not contain hydraulic oil, pressurize the helium gas in the high-pressure intermediate container A to the target reservoir pressure, and install it in the high-pressure filter High temperature resistant nano filter paper, the quality of filter paper is m ₁ (g);

(4) Open the high and low temperature test chamber, and set the temperature as the target reservoir temperature;

(5) Open the fluid channel on the side of the sample chamber, slowly transfer the crude oil in the sampler or the sample dispenser into the ultra-high pressure reactor, and open the fluid channel of the upper end cover of the ultra-high pressure reactor. Since the density of crude oil is much greater than that of helium Gas density, the helium gas injected in advance in the reaction kettle is displaced into the high-pressure intermediate vessel A by crude oil;

(6) Rotate the ultra-high pressure reactor so that the sample chamber faces downward, and depressurize the crude oil in the ultra-high pressure reactor to the set pressure, that is, the pressure corresponding to the plugged section in the wellbore of the oil reservoir, and keep the pressure constant for at least 10 hours to let the heavy components in the crude oil. Adequate aggregation and deposition;

(7) Slowly open the valve between the outlet end of the high-pressure filter and the high-pressure intermediate container B, let the helium gas in the intermediate container B enter the high-pressure filter, and the pressure of the helium gas in the high-pressure filter and the intermediate container B is lower than that of the ultra-high pressure reactor Pressure 0.1-0.3MPa;

(8) Open the valve between the inlet end of the high pressure filter and the cover fluid channel on the lower end face of the ultra-high pressure reactor, and the crude oil in the ultra-high pressure reactor will pass through the high-pressure filter to the high-pressure intermediate container B under the action of the pressure difference, until the ultra-high pressure reactor All crude oil in the autoclave is released;

(9) Open the valve between the inlet end of the high-pressure filter and the high-pressure intermediate container A, let helium flush the crude oil remaining in the high-pressure filter into the intermediate container B, release the pressure slowly, and take out the filter paper in the high-pressure filter, Weigh m ₂ (g) after drying;

单位为g/ml，重复步骤(2)-(9)，得到不同设定温度和压力下井筒中不同位置原油的固相沉积量。(10) Calculate the solid mass deposited in unit crude oil at the set temperature and pressure as

The unit is g/ml, and steps (2)-(9) are repeated to obtain the solid deposition amount of crude oil at different positions in the wellbore under different set temperatures and pressures.

Preferably, during the experiment, the pressure difference between the inlet and outlet of the high-pressure filter is controlled to be no greater than 0.3 MPa, so as to ensure that the pressure during the filtration process has little effect on the sedimentation amount in the crude oil.

Preferably, the crude oil sample adopts the sample obtained by the pressure-holding sampling method at the bottom of the wellbore of the on-site oil reservoir.

Compared with the prior art, the present invention has the following advantages:

It can meet the determination of solid phase deposition in oil samples under different temperature and pressure conditions. There are not many samples used each time. After taking a downhole sample or preparing a sample, multiple tests under different conditions can be completed; crude oil sample transfer and filtration The process ensures that the pressure of the oil sample remains unchanged, and after filtration, the remaining crude oil in the high-pressure filter is purged with helium under high pressure, which ensures the accuracy of the test results of solid phase deposition; the application prospect is broad.

Description of drawings

Fig. 1 is a schematic structural diagram of a device for determining the solid amount of crude oil deposited in a solid deposition reservoir.

In Figure 1: 1, 2, 3 - displacement pump; 4 - sampler or sampler; 5 - high pressure intermediate vessel A; 6 - high pressure intermediate vessel B; 7 - ultra-high pressure reactor; 8, 9, 10, 11, 12, 13 - valve; 14, 15 - three-way valve; 16 - sample chamber; 17 - hydraulic oil; 18 - crude oil sample; 19 - movable piston; 20 - high pressure filter; 21 - helium gas; 22 - Hexagon bolts; 23-reaction kettle piston; 24, 25-combination sealing ring; 26, 27- upper and lower end face covers; 28- high and low temperature test chamber; 29- high pressure chamber; 30, 31 sealing piston; 32- fluid Channel; 33-hydraulic oil chamber; 34-heating jacket.

Detailed ways

The present invention is further described below according to the accompanying drawings and examples, so as to facilitate the understanding of the present invention by those skilled in the art. However, it should be clear that the present invention is not limited to the scope of the specific embodiments. For those skilled in the art, as long as various changes are within the spirit and scope of the present invention defined and determined by the appended claims, they are protected within the scope of the present invention. List.

See Figure 1.

A device for determining the solid amount of crude oil deposited in a solid-phase deposition reservoir, comprising an ultra-high pressure reactor 7, a high-pressure intermediate vessel A5, a high-pressure intermediate vessel B6, a sampler or a sample dispenser 4, and a high-pressure filter 20, the high-pressure intermediate vessel A5. The high-pressure intermediate vessel B6 and the ultra-high-pressure reactor 7 are located in the high and low temperature test chamber 28 .

The ultra-high pressure reaction kettle 7 has upper and lower end face covers 26, 27. The upper and lower end face covers are fixed to the high pressure chamber 29 by hexagonal bolts 22 to form a high pressure reaction kettle body, and the kettle body is divided into samples by the reaction kettle piston 23 Chamber 16 and hydraulic oil chamber 33, there are sealing pistons 30, 31 between the sample chamber, the hydraulic oil chamber and the end face cover, and a combined sealing ring 24, 25 is arranged between the sealing piston and the inner wall of the kettle, on the side and upper, The lower end face covers are provided with fluid passages 32 .

The sampler or sample dispenser 4 contains a crude oil sample 18, is covered with a heating jacket 34, and is connected to the ultra-high pressure reactor 7 through a fluid channel on the side of the sample chamber.

Both the high-pressure intermediate container A5 and the high-pressure intermediate container B6 have movable pistons 19, and the lower space of the movable pistons is equipped with hydraulic oil 17. Connect the fluid channel and the inlet end of the high pressure filter on the upper end of the ultra-high pressure reactor; the inlet end of the high pressure filter 20 is also connected with the ultra-high pressure reactor through the fluid channel of the lower end cap, and the outlet end is connected with the high-pressure intermediate container One end of B that does not contain hydraulic oil, the high-pressure intermediate container A5 and the ultra-high pressure reactor 7 are connected to the displacement pump 2 through the three-way valve 14, and the sampler or sample dispenser 4 and the high-pressure intermediate container B6 are respectively connected to the displacement pump 1, 3.

The contact surface between the sealing piston and the fluid between the sample chamber and the end face cover is designed as a concave spherical shape.

The high-pressure filter contains a metal filter screen, and the metal filter screen is provided with a high temperature resistant nano filter paper, and the pore size of the high temperature resistant nano filter paper is not more than 100 nanometers.

Example 1

Determination of solid phase deposition during the depressurization process of crude oil in a high temperature and ultra-high pressure reservoir:

(1) Obtain high-pressure formation crude oil sample 18 from the bottom of the reservoir (reservoir temperature is 134° C., reservoir pressure 133MPa) with a heat-preserving and pressure-holding sampler 4 and transport the sample to the laboratory under heat preservation and pressure;

(2) The ultra-high pressure reaction kettle is in an upright state, keeping the sample chamber on top, first use the high-pressure displacement pump to push the two high-pressure intermediate containers A5, the high-pressure intermediate containers B6 and the pistons 19 and 23 of the reaction kettle to the maximum The upper end is emptied, and then the piston 23 of the ultra-high pressure reactor is pushed to the position below the side fluid channel 32 with helium, and then the right end valve of the three-way valve 14 is opened, and the ultra-high pressure reactor 7 is replaced by the high-pressure displacement pump 2. Press the pressure to 133MPa (make sure that the moving piston is below the fluid channel position on the side of the cavity), record the total volume of high-pressure helium gas in the ultra-high pressure reactor of 30mL, and close the right end valve of the three-way valve 14;

(3) Inject a certain amount of helium gas 21 into the high-pressure intermediate containers A5 and B6 (excluding the hydraulic oil end), open the left end valve of the three-way valve 14, and use the high-pressure displacement pump 1 to add helium gas in the high-pressure intermediate container A5. The pressure is 133MPa, and the high temperature resistant nano filter paper is installed in the high pressure filter 20, and the quality of the filter paper is 0.2571g;

(4) open the high and low temperature test box 28 to heat the ultra-high pressure reactor 7, the high pressure filter 20 and the high pressure intermediate containers A5 and B6, set the temperature to 134°C, and open the valve 11, the left end of the three-way valve 14 and the left end of the heating process. The right end valve and valve 13 are used to replace the pumps 2 and 3 with high pressure to ensure that the pressure in the ultra-high pressure reactor 7 and the high-pressure intermediate containers A and B remain unchanged;

(5) When the temperature in the high and low temperature test chamber 28 is stable for more than 10 hours, close the right end valve of the three-way valve 14, open the valve 9, valve 8, the right end valve and valve 10 of the three-way valve 15, and set the high pressure displacement pump 1. In the pump mode at a constant speed of 10ml/min, the high-pressure displacement pump 2 is set in the pump mode at a constant speed of 10ml/min. Since the density of crude oil is much greater than that of helium, the formation crude oil 18 in the thermal insulation and pressure-holding sampler 4 will rotate. into the ultra-high pressure reactor 7, and the helium gas 21 injected in advance in the ultra-high pressure reactor 7 is pushed back into the intermediate container 5A by the crude oil, so that the formation crude oil 18 completely replaces the helium gas 21 in the ultra-high pressure reactor 7, and finally turns The volume of the formation crude oil 18 in the ultra-high pressure reactor 7 is 30ml, and after the sample transfer is completed, the valves 8, 9, 10, and 11 are closed, the left end valve of the three-way valve 14 and the right end valve of the three-way valve 15;

(6) Rotate the ultra-high pressure reaction kettle to make the sample chamber face downward, depressurize the ultra-high pressure reaction kettle 7 to 65 MPa through the high-pressure displacement pump 2 (the fluid pressure at the site where the wellbore is blocked is about 65 MPa), and then keep the pressure constant for at least 10 hours, and let the crude oil Aggregation and deposition of medium and heavy components;

(7) slowly open valve 12, let helium enter high-pressure filter 20 in high-pressure intermediate container B6, ensure that the pressure in high-pressure filter 20 and high-pressure intermediate container B6 is 64.8MPa with high-pressure displacement pump 3;

(8) Open the left end valve of the three-way valve 15, the crude oil sample in the ultra-high pressure reactor 7 reaches the high-pressure intermediate container B through the high-pressure filter under the action of the pressure difference, until all the formation crude oil in the ultra-high pressure reactor is transferred to the high pressure in intermediate container B;

(9) Open the right end valve of the three-way valve 15, the valve 10 allows the high-pressure helium gas to flush the crude oil remaining in the high-pressure filter 20 into the intermediate container B6, slowly release the pressure, and take out the filter paper in the high-pressure filter 20 After drying Weighing mass 0.5871g;

单位为g/ml，求得134℃时，储层原油从133MPa降低至65MPa时原油固相沉积量为0.011g/ml；(10) According to the formula

The unit is g/ml, and the solid deposition amount of crude oil is 0.011g/ml when the crude oil in the reservoir decreases from 133MPa to 65MPa at 134℃;

(11) Cleaning the experimental device, repeating the steps (2)-(10) to set other experimental temperatures and pressures to obtain the solid phase deposition characteristics of the target crude oil under different conditions.

The present invention is not limited to the above-described embodiments, and various modifications can be made to the present invention for those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims (3)

1. A method for determining the solid amount of crude oil deposited in a solid-phase deposition oil reservoir by using a device, the device comprising an ultra-high pressure reactor (7), a high-pressure intermediate vessel A (5), a high-pressure intermediate vessel B (6), a sampler or a sample dispenser (4), high pressure filter (20), described high pressure intermediate container A, high pressure intermediate container B, ultra-high pressure reactor are located in high and low temperature test chamber (28), and described ultra-high pressure reactor (7) has upper and lower The end face covers (26, 27), the upper and lower end face covers are fixed to the high pressure chamber (29) by hexagonal bolts to form a high pressure reaction kettle body, and the kettle body is divided into a sample chamber (16) and a hydraulic pressure chamber by the reaction kettle piston (23). The oil chamber (33) has sealing pistons (30, 31) between the sample chamber, the hydraulic oil chamber and the end face cover. A combined sealing ring is arranged between the sealing piston and the inner wall of the kettle, and the side and upper and lower end faces of the sample chamber are sealed. The cover is provided with a fluid channel (32); the sampler or the sample dispenser (4) contains a crude oil sample (18), and is covered with a heating jacket (34), and is connected to the ultra-high pressure reactor through the fluid channel on the side of the sample chamber; The high-pressure intermediate container A (5) and the high-pressure intermediate container B (6) have movable pistons (19), and the lower space of the movable pistons is equipped with hydraulic oil (17), and the high-pressure intermediate container A does not contain hydraulic pressure. One end of the oil is respectively connected to the fluid passage of the upper end face of the ultra-high pressure reactor and the inlet end of the high pressure filter through the three-way valve; the inlet end of the high pressure filter (20) is also connected to the fluid passage of the lower end face cap. The ultra-high pressure reaction kettle, the outlet end is connected to the end of the high-pressure intermediate container B that does not contain hydraulic oil, and the high-pressure intermediate container A, the ultra-high pressure reaction kettle, the sampler or sampler, and the high-pressure intermediate container B are all connected to the displacement pump. The following steps are included in sequence: (1) Obtain the crude oil sample from the bottom of the wellbore of the field reservoir by the method of holding pressure sampling, and transfer the sample to the sampler; or configure the crude oil sample in the sampler; (2) The ultra-high pressure reaction kettle is in an upright state, keeping the sample chamber on top, and using a displacement pump to push the pistons of the high-pressure intermediate container A, the high-pressure intermediate container B and the reaction kettle to the uppermost end to remove air; The kettle piston is pushed to the position below the fluid channel on the side of the sample chamber, the hydraulic oil pressure in the reaction kettle is raised to the pressure of the target oil reservoir, and the volume V ₁ of helium in the sample chamber at this time is recorded; (3) Inject helium gas into the end of the high-pressure intermediate container A and the high-pressure intermediate container B that does not contain hydraulic oil, pressurize the helium gas in the high-pressure intermediate container A to the target reservoir pressure, and install it in the high-pressure filter High temperature resistant nano filter paper, the quality of filter paper is m ₁ ; (4) Open the high and low temperature test chamber, and set the temperature as the target reservoir temperature; (5) Open the fluid channel on the side of the sample chamber, slowly transfer the crude oil in the sampler or the sample dispenser into the ultra-high pressure reactor, and open the fluid channel of the upper end cover of the ultra-high pressure reactor. Since the density of crude oil is much greater than that of helium Gas density, the helium gas injected in advance in the reaction kettle is displaced into the high-pressure intermediate vessel A by crude oil; (6) Rotate the ultra-high pressure reactor so that the sample chamber faces downward, and depressurize the crude oil in the ultra-high pressure reactor to the pressure corresponding to the blockage section of the wellbore, and keep the pressure constant for at least 10 hours, so that the heavy components in the crude oil are fully aggregated and deposited; (7) Slowly open the valve between the outlet end of the high-pressure filter and the high-pressure intermediate container B, let the helium gas in the intermediate container B enter the high-pressure filter, and the pressure of the helium gas in the high-pressure filter and the intermediate container B is lower than that of the ultra-high pressure reactor Pressure 0.1-0.3MPa; (8) open the valve between the inlet end of the high pressure filter and the lower end face of the ultra-high pressure reactor to cover the fluid channel, and the crude oil in the ultra-high pressure reactor reaches the high pressure intermediate container B through the high pressure filter under the action of the pressure difference; (9) Open the valve between the inlet end of the high-pressure filter and the high-pressure intermediate container A, let helium flush the crude oil remaining in the high-pressure filter into the intermediate container B, then slowly release the pressure, and take out the filter paper in the high-pressure filter , and weigh m ₂ after drying; (10) Calculate the solid mass deposited in unit crude oil at the set temperature and pressure as

Steps (2)-(9) are repeated to obtain the solid deposition amount of crude oil at different positions in the wellbore under different set temperatures and pressures. 2 . The method for determining the amount of solids deposited in crude oil in a solid-phase sedimentary reservoir according to claim 1 , wherein the pressure difference between the inlet and outlet of the high-pressure filter is controlled to be no greater than 0.3 MPa. 3 . 3 . The method of claim 1 , wherein the crude oil sample adopts a sample obtained by a pressure-holding sampling method at the bottom of a wellbore of an on-site oil reservoir. 4 .

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