Deep fluid diversion agent suitable for hypersalinity stratum and preparation method of deep fluid diversion agent

Abstract

The invention discloses an in-depth fluid diversion agent suitable for a hypersalinity stratum, and the in-depth fluid diversion agent comprises the following components in percentage by mass: 1.0-2.0% of composite silicate, 8-12% of white oil, 4-6% of a surfactant and 0.02-1.8% of a high-molecular polymer, and the sum of the mass percentages of the components is 100%. The invention further discloses a preparation method of the deep fluid diversion agent suitable for the hypersalinity stratum. The problems that an existing inorganic profile control and flooding agent is high in reaction speed, the process is not easy to control, the strength of a generated product is not enough, meanwhile, waves are expanded only through plugging, and the range of improving the recovery efficiency is limited are solved.

Description

Technical Field

[0001] The invention belongs to the technical field of petroleum extraction, and in particular relates to a deep liquid flow diverting agent suitable for high-mineralization strata, and also relates to a preparation method of the deep liquid flow diverting agent suitable for high-mineralization strata. Background Art

[0002] At present, more than 80% of my country's oil fields are developed by water drive, of which more than 80% are old oil fields with high water content. Therefore, improving the water drive efficiency of old oil fields is an important guarantee for the sustainable development of the oil industry, and deep liquid flow diversion technology is one of the most effective methods to achieve this goal. For high-mineralization oil reservoirs, existing cement and inorganic particle plugging agents (such as Benyuan inorganic gel diverter) can better meet the requirements of high mineralization, but after injection into the formation, the resistance is large and the action distance is limited, and it cannot play a role in the deep formation; the existing organic plugging agents (such as cross-linked polymer gel) are easy to curl polymer molecules in a high-mineralization environment, making cross-linking reactions difficult to occur, and the effect is not good. Therefore, it is very necessary to find a diverter that can play a role under high-mineralization conditions and achieve deep oil reservoir adjustment and drive.

[0003] As for deep flow diverting agents, no ready-made solution technology has been found so far, only similar technologies.

[0004] (1) Patent: A deep flow control and diversion method (application number CN102797442A, application date 20110527), which controls the precipitation reaction process in the porous medium of the formation by adjusting the precipitation ion content in the injected water and / or adding anti-scaling agents to change the thermodynamic conditions of the reaction, so as to generate precipitation in a predetermined area deep in the formation and achieve the purpose of deep flow diversion. The advantage of this method is that it is simple to operate, the water injection process remains unchanged, and only the composition of the injected water needs to be adjusted; the problem is that it only relies on reducing the permeability of the reservoir to achieve deep flow diversion, and the extent of improving the recovery rate is limited.

[0005] (2) Patent: A displacement agent suitable for high-temperature and high-salinity oil reservoirs and its preparation method (application number CN115044356A, application date 20220812), which uses cations injected into water with high mineralization to generate nano-micron particles, and gradually aggregates during migration to the deep formation to form micron-sized precipitation particles, thereby gradually blocking water from passing through and realizing deep liquid flow diversion. The problem is that the inorganic reaction speed is fast, and the aggregation of nano-micron particles in the reservoir is difficult to control. At the same time, relying solely on plugging to expand the impact and improve the recovery rate is limited.

[0006] (3) Patent: An emulsion-type adaptive plugging agent suitable for high-mineralization formations and its preparation method (application number CN105385428A, application date 20150703). The displacement agent is an oil-in-silicic acid nanoemulsion, which not only has the performance of emulsion itself in profile control and water plugging, but also has the performance of inorganic salt reaction to produce chemical plugging, thus achieving secondary plugging. The existing problem is that the precipitate particle size generated by the reaction of water glass with calcium and magnesium ions in the formation is too small and not strong enough to plug large pores. Summary of the invention

[0007] The first purpose of the present invention is to provide a deep flow diverting agent suitable for high-mineralization formations, which solves the problems of fast reaction speed and difficult process control of existing inorganic displacement agents, and the limited range of wave volume expansion and recovery rate improvement by relying solely on plugging.

[0008] The second object of the present invention is to provide a method for preparing a deep liquid flow diverting agent suitable for high-mineralization formations.

[0009] The first technical solution adopted by the present invention is: a deep liquid flow diverting agent suitable for high-mineralization strata, which is composed of the following components in mass percentage: 1.0% to 2.0% composite silicate, 8% to 12% white oil, 4% to 6% surfactant, 0.02% to 1.8% high molecular polymer, and the sum of the mass percentages of the above components is 100%.

[0010] The first technical solution adopted by the present invention is also characterized in that:

[0011] Preferably, a deep liquid flow diverting agent suitable for high-mineralization formations is composed of the following components in mass percentage: 1.2% to 1.8% composite silicate, 8% to 12% white oil, 4% to 6% surfactant, and 0.02% to 1.8% high molecular polymer, and the sum of the mass percentages of the above components is 100%.

[0012] Preferably, a deep liquid flow diverting agent suitable for high-mineralization formations is composed of the following components in mass percentage: 1.0% to 2.0% composite silicate, 8% to 12% white oil, 4% to 6% surfactant, and 0.04% to 0.08% high molecular polymer, and the sum of the mass percentages of the above components is 100%.

[0013] Preferably, a deep liquid flow diverting agent suitable for high-mineralization formations is composed of the following components in mass percentage: 1.2% to 1.8% composite silicate, 8% to 12% white oil, 4% to 6% surfactant, and 0.04% to 0.08% high molecular polymer, and the sum of the mass percentages of the above components is 100%.

[0014] Preferably, the composite silicate is Na2 O·mSiO 2 , the water glass modulus m is 2.5~3.5.

[0015] Preferably, the surfactant is a mixture of Tween 80 and betaine, wherein the mass percentage of Tween 80 is 80% to 90%, and the mass percentage of betaine is 10% to 20%.

[0016] Preferably, the surfactant is a mixture of Tween 80 and betaine, wherein the mass percentage of Tween 80 is 82% to 86%, and the mass percentage of betaine is 14% to 18%.

[0017] Preferably, the high molecular weight polymer is polyacrylamide.

[0018] The second technical solution adopted by the present invention is: a method for preparing a deep flow diverting agent suitable for high-mineralization formations, which is specifically implemented according to the following steps:

[0019] The composite silicate, white oil, surfactant and high molecular polymer are added into water in sequence according to the proportion, and the mixture is shaken at a frequency of 60-80 times / min for 30 minutes to obtain a uniform emulsion.

[0020] The beneficial effects of the present invention are:

[0021] (1) The present invention utilizes the rich metal cations in the high-mineralization reservoir to react with the composite silicate in situ to generate scale ions, which are gradually adsorbed on the rock skeleton to form an inorganic gel coating. The subsequent water flow is diverted by "coating diameter reduction" to achieve deep liquid flow diversion.

[0022] (2) The present invention aggregates inorganic microgels through the flocculation adsorption bridging effect of high molecular polymers to form larger-scale inorganic microgel-organic polymer composite gel particles. Such composite gel particles can adapt to different levels of dominant channels and disrupt the fixed streamline field.

[0023] (3) The present invention protects the composite silicate by adding an emulsion formed by a surfactant. After being demulsified by shear and high mineralization deep in the formation, it reacts with divalent cations in the formation to form a precipitate, thereby achieving entry into the deep reservoir.

[0024] (4) The present invention can improve the oil washing efficiency while expanding the swept volume by compounding composite silicates, surfactants and high molecular polymers, thereby greatly improving the recovery rate. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with embodiments.

[0026] The invention discloses a deep liquid flow diverting agent suitable for high-mineralization strata, which is composed of the following components by mass percentage: 1.0% to 2.0% of composite silicate, white oil, surfactant, 0.02% to 1.8% of high molecular polymer, and the sum of the mass percentages of the above components is 100%.

[0027] Preferably, the deep liquid flow diverting agent suitable for high-mineralization formations is composed of the following components by mass percentage: 1.2% to 1.8% composite silicate, white oil, surfactant, 0.02% to 1.8% high molecular polymer, and the sum of the mass percentages of the above components is 100%.

[0028] Preferably, the deep liquid flow diverting agent suitable for high-mineralization formations is composed of the following components in mass percentage: 1.0% to 2.0% composite silicate, white oil, surfactant, 0.04% to 0.08% high molecular polymer, and the sum of the mass percentages of the above components is 100%.

[0029] Preferably, the deep flow diverting agent suitable for high-mineralization formations is composed of the following components by mass percentage: 1.2% to 1.8% composite silicate, white oil, surfactant, 0.04% to 0.08% high molecular polymer, and the sum of the mass percentages of the above components is 100%.

[0030] Preferably, the composite silicate is Na 2 O·mSiO 2 , the water glass modulus m is 2.5~3.5.

[0031] Preferably, the surfactant is a mixture of Tween 80 and betaine, wherein the mass percentage of Tween 80 is 80% to 90%, and the mass percentage of betaine is 10% to 20%.

[0032] Preferably, the surfactant is a mixture of Tween 80 and betaine, wherein the mass percentage of Tween 80 (T80) is 82% to 86%, and the mass percentage of betaine is 14% to 18%.

[0033] The present invention also discloses a method for preparing a deep liquid flow diverting agent suitable for high-mineralization formations, which is specifically implemented according to the following steps:

[0034] The composite silicate, white oil, surfactant and high molecular polymer are added into water in sequence according to the proportion, and the mixture is shaken at a frequency of 60-80 times / min for 30 minutes to obtain a uniform emulsion.

[0035] The deep liquid flow diverter of the present invention is adjusted and driven in the reservoir in the form of an emulsion, thereby improving the oil washing efficiency. After the emulsion is demulsified due to shear and high mineralization in the deep formation, the composite silicate in the system and the calcium and magnesium ions in the reservoir form inorganic microgels through cross-linking reactions. At the same time, the high molecular polymer aggregates the inorganic microgels through flocculation adsorption bridge action to form larger-scale inorganic microgel-organic polymer composite gel particles. Such composite gel particles can adapt to dominant channels of different levels and disrupt the fixed streamline field. At the same time, a large number of microgels can regulate the seepage capacity of channels of different levels through multifunctional synergistic blocking effects such as increasing the specific surface area in the channel, flowing through the curvature, and aggregating pore throat plugging, thereby achieving the expansion of the swept volume in the high mineralization formation while improving the oil washing efficiency, thereby greatly improving the recovery rate.

[0036] After the emulsion breaks, the inorganic silicate reacts with the divalent metal cations in the reservoir to form inorganic microgels. The principle is as follows:

[0037] Ca 2+ +Na 2 O·mSiO 2 →CaO·mSiO 2 ↓+2Na +

[0038] Mg 2+ +Na 2 O·mSiO 2 →MgO·mSiO 2 ↓+2Na +

[0039] Example 1

[0040] It is a deep flow diversion agent suitable for high-mineralization formations. It is composed of composite silicate, white oil, surfactant and high molecular polymer, among which the silicate is Na 2 O·mSiO 2 , mass percentage is 1.5%, and the water glass modulus m is 3.0; the surfactant is a mixture of Tween 80 (T80) and betaine, with a mass percentage of 5%, of which the mass percentage of Tween 80 (T80) is 85%, and the mass percentage of betaine is 15%. White oil is added to the surfactant to form an emulsion, and the mass percentage of white oil is 10%; the high molecular polymer is polyacrylamide (HPAM), with a mass percentage of 0.06%.

[0041] Preparation method:

[0042] The composite silicate, surfactant and high molecular polymer are added into water in sequence according to the proportion, and the mixture is shaken at a frequency of 60 times / min for 30 minutes to obtain a uniform emulsion.

[0043] Example 2

[0044] It is a deep flow diversion agent suitable for high-mineralization formations. It is composed of composite silicate, white oil, surfactant and high molecular polymer, among which the silicate is Na 2 O·mSiO 2 , mass percentage is 1.0%, and the water glass modulus m is 2.5; the surfactant is a mixture of Tween 80 (T80) and betaine, with a mass percentage of 4%, of which the mass percentage of Tween 80 (T80) is 80%, and the mass percentage of betaine is 10%. White oil is added to the surfactant to form an emulsion, and the mass percentage of white oil is 8%; the high molecular polymer is polyacrylamide (HPAM), with a mass percentage of 0.02%.

[0045] Preparation method:

[0046] The composite silicate, surfactant and high molecular polymer are added into water in sequence according to the proportion, and the mixture is shaken at a frequency of 70 times / min for 30 minutes to obtain a uniform emulsion.

[0047] Example 3

[0048] It is a deep flow diversion agent suitable for high-mineralization formations. It is composed of composite silicate, white oil, surfactant and high molecular polymer, among which the silicate is Na 2 O·mSiO 2 , mass percentage is 2.0%, and the water glass modulus m is 3.5; the surfactant is a mixture of Tween 80 (T80) and betaine, with a mass percentage of 6%, of which the mass percentage of Tween 80 (T80) is 90%, and the mass percentage of betaine is 20%. White oil is added to the surfactant to form an emulsion, and the mass percentage of white oil is 12%; the high molecular polymer is polyacrylamide (HPAM), with a mass percentage of 1.8%.

[0049] Preparation method:

[0050] The composite silicate, surfactant and high molecular polymer are added into water in sequence according to the proportion, and the mixture is shaken at a frequency of 70 times / min for 30 minutes to obtain a uniform emulsion.

[0051] Example 4

[0052] It is a deep flow diversion agent suitable for high-mineralization formations. It is composed of composite silicate, white oil, surfactant and high molecular polymer, among which the silicate is Na 2 O·mSiO 2, mass percentage is 1.2%, and the water glass modulus m is 2.5; the surfactant is a mixture of Tween 80 (T80) and betaine, with a mass percentage of 6%, of which the mass percentage of Tween 80 (T80) is 82%, and the mass percentage of betaine is 14%. White oil is added to the surfactant to form an emulsion, and the mass percentage of white oil is 12%; the high molecular polymer is polyacrylamide (HPAM), with a mass percentage of 0.04%.

[0053] Preparation method:

[0054] The composite silicate, surfactant and high molecular polymer are added into water in sequence according to the proportion, and the mixture is shaken at a frequency of 80 times / min for 30 minutes to obtain a uniform emulsion.

[0055] Example 5

[0056] It is a deep flow diversion agent suitable for high-mineralization formations. It is composed of composite silicate, white oil, surfactant and high molecular polymer, among which the silicate is Na 2 O·mSiO 2 , mass percentage is 1.8%, and the water glass modulus m is 3.0; the surfactant is a mixture of Tween 80 (T80) and betaine, with a mass percentage of 6%, of which the mass percentage of Tween 80 (T80) is 86%, and the mass percentage of betaine is 18%. White oil is added to the surfactant to form an emulsion, and the mass percentage of white oil is 12%; the high molecular polymer is polyacrylamide (HPAM), with a mass percentage of 0.08%.

[0057] Preparation method:

[0058] The composite silicate, surfactant and high molecular polymer are added into water in sequence according to the proportion, and the mixture is shaken at a frequency of 70 times / min for 30 minutes to obtain a uniform emulsion.

[0059] The effect of the diverter of the present invention is further described below through experimental data:

[0060] Injectability and plugging evaluation:

[0061] A sand-filled pipe was used to simulate the dominant channel (2-3D) of the reservoir. First, it was saturated with simulated formation water (the ion composition of the simulated formation water is shown in Table 1), and then the deep flow diverter in this implementation case was water-driven at a rate of 0.5 mL / min until the pressure difference at both ends of the sand-filled pipe remained stable. The water permeability was calculated to evaluate the injection capacity of the diverter. After the diverter was injected, it was left to stand in an oven (50°C) for 48 hours, and then subsequent water driving was carried out to evaluate its plugging performance. The experimental results are shown in Table 2, and the final plugging rate reached 95.87%.

[0062] Improved oil recovery capability evaluation:

[0063] A sand-filled pipe was used to simulate the dominant channel (2-3D) of the reservoir. First, the crude oil was saturated, and then the simulated formation water was used to drive the pipe to a water content of 98%. Then, the deep flow diverter in this implementation case was used to drive the pipe at a rate of 0.5 mL / min until the pressure difference at both ends of the sand-filled pipe remained stable. The water permeability was calculated. After the diverter was injected, the pipe was left to stand in an oven (50°C) for 48 hours, and then a subsequent water drive was performed to 98%. The experimental results are shown in Table 3, and the recovery factor was finally increased by 49.9%.

[0064] Table 1 Simulated formation water composition

[0065]

[0066]

[0067] Table 2 Diverter plugging injectivity and plugging performance evaluation test results

[0068]

[0069] Table 3 Diverter plugging and enhanced oil recovery test results

[0070]

Claims

1. A deep flow diverter suitable for high mineralization formations, characterized in that: The invention is composed of the following components by mass percentage: 1.0% to 2.0% of composite silicate, 8% to 12% of white oil, 4% to 6% of surfactant, and 0.02% to 1.8% of high molecular polymer. The sum of the mass percentages of the above components is 100%.

2. The deep liquid flow diverter suitable for high-mineralization formation according to claim 1, characterized in that: The invention is composed of the following components by mass percentage: 1.2% to 1.8% of composite silicate, 8% to 12% of white oil, 4% to 6% of surfactant, and 0.02% to 1.8% of high molecular polymer. The sum of the mass percentages of the above components is 100%.

3. The deep liquid flow diverting agent suitable for high-mineralization formations according to claim 1, characterized in that: The invention is composed of the following components by mass percentage: 1.0% to 2.0% of composite silicate, 8% to 12% of white oil, 4% to 6% of surfactant, and 0.04% to 0.08% of high molecular polymer. The sum of the mass percentages of the above components is 100%.

4. The deep liquid flow diverting agent suitable for high-mineralization formations according to claim 1, characterized in that: The invention is composed of the following components by mass percentage: 1.2% to 1.8% of composite silicate, 8% to 12% of white oil, 4% to 6% of surfactant, and 0.04% to 0.08% of high molecular polymer. The sum of the mass percentages of the above components is 100%.

5. The deep liquid flow diverting agent suitable for high-mineralization formations according to any one of claims 1 to 4, characterized in that: The composite silicate is Na2O·mSiO2, and the water glass modulus m is 2.5-3.

5.

6. The deep liquid flow diverting agent suitable for high-mineralization formations according to any one of claims 1 to 4, characterized in that: The surfactant is a mixture of Tween 80 and betaine, wherein the mass percentage of Tween 80 is 80% to 90% and the mass percentage of betaine is 10% to 20%.

7. The deep liquid flow diverting agent suitable for high-mineralization formations according to claim 6, characterized in that: The surfactant is a mixture of Tween 80 and betaine, wherein the mass percentage of Tween 80 is 82% to 86% and the mass percentage of betaine is 14% to 18%.

8. The deep liquid flow diverting agent suitable for high-mineralization formations according to any one of claims 1 to 4, characterized in that: The high molecular polymer is polyacrylamide.

9. A method for preparing a deep flow diverter suitable for high-mineralization formations, characterized in that: Follow the steps below to implement it: The composite silicate, white oil, surfactant and high molecular polymer are added into water in sequence according to the proportion, and the mixture is shaken at a frequency of 60-80 times / min for 30 minutes to obtain a uniform emulsion.

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