Gel profile control agent and application thereof

Abstract

The invention relates to a gel profile control agent and application thereof, the gel profile control agent is prepared from the following raw material components: oil sludge scum with set solid phase content, polyacrylamide and a cross-linking agent, and the ionic property of the polyacrylamide is anion or zwitterionic; wherein the oil sludge scum has a set solid phase content, and the content of the oil sludge scum is 20-40 wt%. Through interaction among the oil sludge scum, the polyacrylamide and the cross-linking agent, the technical problem that the existing oil sludge scum is difficult to effectively utilize is solved.

Description

Technical Field

[0001] The present application relates to the technical field of oilfield chemistry, and in particular to a gel profile control agent and application thereof. Background Art

[0002] During the development of oil fields, a large amount of sludge scum is produced. The sludge scum wastewater has a high mineralization degree and contains a large amount of benzene, phenols and other substances. If it comes into direct contact with soil, water bodies, etc., it will cause serious pollution and cannot be discharged directly. At the same time, the cost of harmless treatment of oily sludge is relatively high, which has put tremendous pressure on oil field development and environmental protection.

[0003] Therefore, there is an urgent need to improve the effective utilization of existing oil sludge and scum to achieve normal operation of crude oil production. Summary of the invention

[0004] The present application provides a gel profile control agent and application thereof, so as to solve the technical problem that existing oil sludge scum is difficult to effectively utilize.

[0005] In a first aspect, the present application provides a gel profile control agent, wherein the raw material components of the gel profile control agent include:

[0006] Oil sludge with a set solid content, polyacrylamide and a cross-linking agent, wherein the ionic property of the polyacrylamide is anionic or zwitterionic; wherein,

[0007] The oil sludge scum has a set solid content, and the content of the oil sludge scum is 20% by weight to 40% by weight.

[0008] Optionally, the content of the oil sludge scum is 20 wt % to 30 wt %.

[0009] Optionally, the solid content is set to 10% to 20% by weight.

[0010] Optionally, the median size of the solid phase particles of the oil sludge scum is 40 μm to 50 μm.

[0011] Optionally, the permeability is (100×10 -3 μm 2 )~(2000×10 -3 μm 2 )'s reservoir profile adjustment and production increase measures, and crude oil dehydration at the joint station.

[0012] Optionally, the content of the polyacrylamide is 0.2 wt % to 0.35 wt %.

[0013] Optionally, the cross-linking agent includes one of the following: an organic chromium cross-linking agent and a water-soluble phenolic resin.

[0014] Optionally, the content of the cross-linking agent is 0.16 wt % to 0.28 wt %.

[0015] Optionally, the viscosity of the gel profile control agent is 2600 mPa·s to 9000 mPa·s.

[0016] In a second aspect, the present application provides an application of the gel profile control agent described in any embodiment of the first aspect in water injection well flooding.

[0017] The above technical solution provided by the embodiment of the present application has the following advantages compared with the prior art:

[0018] The gel profile control agent provided in the embodiment of the present application uses oil sludge scum as the main agent, which has adsorption and accumulation effects, replaces granular plugging agents, and improves plugging efficiency. At the same time, oil sludge scum with a set solid content is used to ensure the gel viscosity of the profile control agent, so that the sludge is suspended and dispersed, and has good fluidity and plugging properties; the -NH2 group in the polyacrylamide is hydrogen-bonded with the -OH group on the surface of the oil sludge scum particles, so that the oil sludge particles are flocculated and aggregated, and the oil sludge scum can be dispersed and suspended in the solution, thereby improving the fluidity of the profile control agent; at the same time, the ionic characteristics of polyacrylamide are anionic or amphoteric, and some amide groups are negatively charged. Under the electrostatic repulsion, the polymer can be fully stretched, the adsorption bridging effect can be fully exerted, and the COO of polyacrylamide is utilized. - The anion reacts chemically with the cross-linking agent to form a gel profile control agent with a stable structure. In summary, the technical problem that the existing oil sludge sludge is difficult to effectively utilize is solved through the interaction between the oil sludge sludge, polyacrylamide and the cross-linking agent. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0020] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0021] Figure 1 A viscosity change curve of different raw material components of a gel profile control agent provided in an embodiment of the present application;

[0022] Figure 2 This is an apparent diagram of a gel profile control agent provided in an embodiment of the present application;

[0023] Figure 3This is a production curve diagram of the Ci 20-139 well group before and after slag profile adjustment provided in the embodiment of the present application. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0025] Various embodiments of the present application may be presented in the form of a range; it should be understood that the description in the form of a range is only for convenience and brevity, and should not be understood as a rigid limitation on the scope of the present application; therefore, the range description should be considered to have specifically disclosed all possible sub-ranges and single numerical values ​​within the range. For example, the range description from 1 to 6 should be considered to have specifically disclosed sub-ranges, such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., as well as single numbers within the range, such as 1, 2, 3, 4, 5 and 6, which apply regardless of the range. In addition, whenever a numerical range is indicated herein, it is meant to include any cited number (fractional or integer) within the indicated range.

[0026] In the present application, in the absence of any contrary description, the directional words used, such as "upper" and "lower", are specifically the directions of the drawings in the accompanying drawings. In addition, in the description of the present specification, the terms "including", "comprising", etc. refer to "including but not limited to". In this article, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that there is any such actual relationship or order between these entities or operations. In this article, "and / or" describes the association relationship of the associated objects, indicating that there may be three relationships, for example, A and / or B, which can represent: A exists alone, A and B exist at the same time, and B exists alone. Wherein A, B can be singular or plural. In this article, "at least one" refers to one or more, and "plural" refers to two or more. "At least one", "at least one of the following" or similar expressions refer to any combination of these items, including any combination of singular or plural items. For example, "at least one of a, b, or c", or "at least one of a, b and c", can both mean: a, b, c, ab (i.e. a and b), ac, bc or abc, where a, b, c can be single or plural, respectively.

[0027] Unless otherwise specified, various raw materials, reagents, instruments and equipment used in this application can be purchased from the market or prepared by existing methods.

[0028] In the first aspect, the present application provides a gel profile control agent, see Figure 2 The surface diagram of the gel profile control agent shown is black and viscous with strong fluidity. The raw material components of the gel profile control agent include:

[0029] Oil sludge with a set solid content, polyacrylamide and a cross-linking agent, wherein the ionic property of the polyacrylamide is anionic or zwitterionic; wherein,

[0030] The oil sludge scum has a set solid content, and the content of the oil sludge scum is 20% by weight to 40% by weight.

[0031] In some embodiments, the oil sludge scum has a content of 20 wt % to 30 wt %.

[0032] In the embodiments of the present application, oil sludge slag is used as the main agent, which has adsorption and accumulation effects, replaces the granular plugging agent, and improves the plugging efficiency. A gel-type profile control agent using slag as a proppant is configured to replace the granular plugging agent with "slag", which further improves the plugging efficiency, can save the cost of oil sludge slag treatment, and reduce the cost of profile control agents. This profile control agent can effectively reduce the pore throat radius of the high permeability layer, play the role of plugging the high permeability layer of the formation, and at the same time achieve increased production and efficiency, and help the efficient secondary development of high-permeability blocks in old oil fields.

[0033] At the same time, oil sludge scum with a set solid content is selected to ensure the gel viscosity of the profile control agent, so that the sludge is suspended and dispersed, and has good fluidity and plugging properties; the -NH2 group in polyacrylamide is hydrogen-bonded with the -OH group on the surface of the oil sludge sludge particles to flocculate the oil sludge particles, and the oil sludge sludge can be dispersed and suspended in the solution, thereby improving the fluidity of the profile control agent. At the same time, the ionic characteristics of polyacrylamide are anionic or amphoteric, and some amide groups are negatively charged. Under electrostatic repulsion, the polymer can be fully extended, and the adsorption bridging effect can be fully exerted, and the COO of polyacrylamide can be used to - The anions react chemically with the crosslinking agent to form a gel profile modifier with a stable structure.

[0034] When using anionic or amphoteric polyacrylamide, each link of the polyacrylamide contains an amide group (-CONH2). Due to the hydrogen bonding between amide groups, linear molecules often cannot fully stretch out, resulting in a weakened bridging effect. However, in anionic or amphoteric polyacrylamide, some amide groups carry negative charges. Under electrostatic repulsion, the polymer can fully stretch out, and the adsorption bridging effect can be fully exerted.

[0035] In the embodiment of the present application, the content of the sludge scum is controlled to ensure the fluidity, plugging property and gelling viscosity of the profile control agent, and to treat the sludge to the greatest extent to solve the environmental hazards; if the content of the sludge scum is too high, it will cause the profile control agent to have poor fluidity and poor dispersibility to a certain extent, and it will be impossible to prepare a stable gel; if the content of the sludge scum is too low, it will reduce the plugging performance of the profile control agent to a certain extent, and it will not be able to treat the excess sludge to the greatest extent. Specifically, the content of the sludge scum can be 20% by weight, 22% by weight, 24% by weight, 26% by weight, 28% by weight, 30% by weight, 32% by weight, 34% by weight, 36% by weight, 38% by weight, 40% by weight, etc. Preferably, the content of the sludge scum can be 20% by weight, 22% by weight, 24% by weight, 26% by weight, 28% by weight, 30% by weight, etc.

[0036] In some embodiments, the set solid content is 10 wt % to 20 wt %.

[0037] In the embodiment of the present application, the solid content of the sludge scum is controlled to ensure the viscosity of the profile control agent, so that the scum is suspended and dispersed, and has good fluidity and plugging properties. If the solid content is too high, it will affect the viscosity of the profile control agent to a certain extent, causing uneven suspension of the scum, and scum precipitation may occur; if the solid content is too low, it will reduce the plugging effect of the profile control agent to a certain extent, and it will not be able to effectively plug the high permeability layer of the formation. Specifically, the set solid content can be 10 weight%, 11 weight%, 12 weight%, 13 weight%, 14 weight%, 15 weight%, 16 weight%, 17 weight%, 18 weight%, 19 weight%, 20 weight%, etc.

[0038] In some embodiments, the median size of the solid particles of the oil sludge scum is 40 μm to 50 μm.

[0039] In the embodiment of the present application, the median particle size of the solid phase particles of the oil sludge scum is controlled so that the ratio of the sludge particle size to the reservoir pore throat is matched. Under the formation conditions, the mud and oil in the emulsified suspension in the profile control agent are separated, the colloid and asphaltene in the formation are adsorbed, and the sedimentation is carried out in the large pores, so as to achieve the purpose of plugging the high permeability layer. If the median particle size is too high, the plugging strength of the profile control agent will be too large to a certain extent, and the fluidity of the profile control agent will be deteriorated, which may cause the injection failure; if the median particle size is too low, the plugging effect of the profile control agent will be deteriorated to a certain extent. Specifically, the median particle size of the solid phase particles of the oil sludge scum can be 40μm, 41μm, 42μm, 43μm, 44μm, 45μm, 46μm, 47μm, 48μm, 49μm, 50μm, etc.

[0040] In some embodiments, the permeability is (100×10 -3 μm 2)~(2000×10 -3 μm 2 )'s reservoir profile adjustment and production increase measures, and crude oil dehydration at the joint station.

[0041] In the embodiment of the present application, the above-mentioned oil sludge scum may be generated from: a permeability of (100×10 -3 μm 2 )~(2000×10 -3 μm 2 ) in the reservoir profile control and production increase measures, or in the crude oil dehydration of the joint station. The oil sludge scum is prepared into a gel-type profile control agent. It is used for the profile control of oil field water injection wells. The water plugging and oil displacement effect of the profile control agent prepared by it is further enhanced. The gel viscosity can be ≥5000mPa·s. Compared with conventional gel profile control agents, it has stronger plugging ability and stability, meets the needs of profile control and production increase of medium and high permeability oil reservoirs, and realizes the reuse of scum to reduce environmental pollution.

[0042] In some embodiments, the content of the polyacrylamide is 0.2 wt % to 0.35 wt %.

[0043] In the embodiments of the present application, the content of polyacrylamide is controlled to prepare a stable gel with good gel viscosity and good plugging performance; if the content of the polyacrylamide is too high, to a certain extent, the gel viscosity will be too large, the fluidity of the profile control agent will be poor, and the cost will be too high; if the content of the polyacrylamide is too low, to a certain extent, the profile control agent will not gel, and the effect of water plugging and profile control will not be achieved. Specifically, the content of the polyacrylamide can be 0.2 weight%, 0.22 weight%, 0.24 weight%, 0.26 weight%, 0.28 weight%, 0.30 weight%, 0.32 weight%, 0.34 weight%, 0.35 weight%, etc.

[0044] In some embodiments, the cross-linking agent includes one of the following: an organic chromium cross-linking agent and a water-soluble phenolic resin.

[0045] In some embodiments, the content of the cross-linking agent is 0.16 wt % to 0.28 wt %.

[0046] In some embodiments, the cross-linking agent includes one of the following: an organic chromium cross-linking agent and a water-soluble phenolic resin.

[0047] In the examples of this application, the COO of polyacrylamide -The anion reacts chemically with the organic chromium crosslinking agent or the water-soluble phenolic resin to form a crosslinked body; the organic chromium crosslinking agent or the water-soluble phenolic resin is selected as the crosslinking agent, and after the polyacrylamide and the crosslinking agent are mixed, they can react effectively to form a gel with good fluidity and good stability; among them, the chromium crosslinking agent has a low initial viscosity, better fluidity, a small pressure increase, and is easy to flow to the deep formation, so the organic chromium crosslinking agent is preferably used. Specifically, the reaction mechanism between the oil sludge scum, polyacrylamide and the organic chromium crosslinking agent is as follows:

[0048] (1) Organic chromium dissociates into trivalent chromium ions

[0049]

[0050] (2) Trivalent chromium ions undergo hydration reaction

[0051]

[0052]

[0053] (3) Hydroxyl bridge effect: Hydroxyl bridge means that a hydroxyl group in the coordination compound forms a bond with two or more central atoms at the same time. In simple terms, it acts like a bridge to connect the two parts and improve the stability of the gel profile control agent.

[0054]

[0055] (4) Reaction of trivalent chromium ions with carboxyl groups of polyacrylamide

[0056]

[0057] (5) Suspension effect of scum and polyacrylamide

[0058]

[0059] The content of the cross-linking agent is controlled to prepare a gel with strong gelling and stability; if the content of the cross-linking agent is too high, the stability of the profile control agent will be reduced to a certain extent, the gel breaking time will be shortened, and the purpose of effective plugging will not be achieved; if the content of the cross-linking agent is too low, it will be difficult to form a gel to a certain extent, and the plugging effect of the profile control agent will be lost. Specifically, the content of the cross-linking agent can be 0.16 weight%, 0.17 weight%, 0.18 weight%, 0.19 weight%, 0.20 weight%, 0.21 weight%, 0.22 weight%, 0.23 weight%, 0.24 weight%, 0.25 weight%, 0.26 weight%, 0.27 weight%, 0.28 weight%, etc.

[0060] In some embodiments, the viscosity of the gel profile control agent is 2600 mPa·s to 9000 mPa·s.

[0061] In the embodiment of the present application, the formula of the above-mentioned gel profile control agent can achieve a viscosity of 2600mPa·s to 9000mPa·s. Specifically, the viscosity can be 2600mPa·s, 3000mPa·s, 4000mPa·s, 5000mPa·s, 6000mPa·s, 7000mPa·s, 8000mPa·s, 9000mPa·s, etc.

[0062] The preparation method of the above-mentioned gel profile control agent comprises: S1, preparing an oil sludge scum solution, and performing a first stirring to make the oil sludge scum fluid; S2, adding polyacrylamide dry powder to the above-mentioned oil sludge scum solution, and performing aging and dissolution, and then adding a cross-linking agent, and performing a second stirring to obtain a gel profile control agent.

[0063] In a second aspect, the present application provides an application of the gel profile control agent described in any embodiment of the first aspect in water injection well flooding.

[0064] In the embodiments of the present application, the gel profile control agent has good compatibility with the formation fluid, improves the plugging ability and stability of the profile control agent, realizes the effective utilization of oil sludge and alleviates environmental pressure. At the same time, it is applied to water injection well drive and profile control, with significant effects of increasing oil production and reducing water. It can effectively improve the vertical and planar contradictions of the oil layer and improve the water injection development effect of the block.

[0065] The gel profile control agent was applied in the Ci 20-139 well in the Ci 13 block. After the measures were taken, the corresponding oil wells increased oil production by 7.3 tons per day, the water content decreased by 5.1 percentage points, and the annual oil production increased by 2,432.2 tons. The cumulative injection of scum and sewage totaled 1,839.8 tons, saving 331,000 yuan in scum outsourcing treatment fees. Figure 3 The production curves of the slag profile control before and after the 20-139 well group are shown. According to SY / T 5588-2003 "Water Injection Well Profile Control Technology and Effect Evaluation" standard 10.1, the profile control is effective.

[0066] The present application will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are intended only to illustrate the present application and are not intended to limit the scope of the present application. The experimental methods for which specific conditions are not specified in the following examples are usually measured according to national standards. If there is no corresponding national standard, then the conditions recommended by the manufacturer are followed.

[0067] The present application embodiment provides a gel profile control agent, wherein the raw material components of the gel profile control agent include:

[0068] Oil sludge scum with a set solid content, polyacrylamide and a crosslinking agent, wherein the ionic property of the polyacrylamide is anionic or zwitterionic. Specifically, see the solid content and solid phase particle size median of the oil sludge scum shown in Table 1, and the raw material components of the oil sludge scum shown in Table 2.

[0069] Table 1 Solid content and median particle size of oil sludge scum

[0070]

[0071]

[0072] Table 2 Raw material components of oil sludge scum

[0073]

[0074]

[0075] The gel profile control agents of Examples 1 to 20 and Comparative Examples 1 to 4 were subjected to gel viscosity tests. See Table 3 for the test results.

[0076] Table 3 Gel viscosity test results of gel profile control agent

[0077]

[0078]

[0079] The plugging rates of the gel profile control agents of Examples 1 to 20 were tested. Please refer to Table 4 for the test results.

[0080] Table 4 Plugging rate of gel profile control agent

[0081] Serial number experiment Before blocking After blocking Blockage rate% Example 1 Core experiment 678 244 64 Example 5 Core experiment 678 420 38 Example 6 Core experiment 678 396 42 Example 7 Core experiment 678 382 44 Example 8 Core experiment 678 368 46 Example 9 Core experiment 678 312 54 Example 10 Core experiment 678 244 64 Embodiment 11 Core experiment 678 232 66 Example 12 Core experiment 678 206 70 Embodiment 13 Core experiment 678 280 59 Embodiment 14 Core experiment 678 222 67 Embodiment 15 Core experiment 678 206 70 Example 16 Core experiment 678 180 73 Embodiment 17 Core experiment 678 230 66 Embodiment 18 Core experiment 678 212 69 Embodiment 19 Core experiment 678 186 73 Embodiment 20 Core experiment 678 164 76

[0082] The prices of chromium cross-linked weak gel, chromium gel with bulky particles and the gel of Example 1 are compared to determine the price advantage of the slag strengthening profile control agent, see Table 5.

[0083] Table 5 Price comparison of different types of gel profile control agents

[0084]

[0085] Tables 1 to 3 show that changing the solid content of the oil sludge scum or increasing the amount of the oil sludge scum too much will result in unsuccessful preparation of the gel profile control agent; Examples 5 to 20 and combined Figure 1The viscosity change curves of different raw material components of the gel profile control agent show that, to a certain extent, when the amount of oil sludge scum (20wt%) remains unchanged, the content of polyacrylamide and cross-linking agent increases, and the gel viscosity increases. Table 4 shows that the gel profile control agent prepared in the embodiment of the present application meets the specified index (≥60%); Table 5 shows that the gel profile control agent prepared in the embodiment of the present application not only makes full use of the oil sludge sludge, but also saves the production cost of the gel profile control agent.

[0086] The above description is only a specific implementation of the present application, so that those skilled in the art can understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but will conform to the widest range consistent with the principles and novel features applied for herein.

Claims

1. A gel profile control agent, characterized in that: The raw material components of the gel profile control agent include: Oil sludge with a set solid content, polyacrylamide and a cross-linking agent, wherein the ionic property of the polyacrylamide is anionic or zwitterionic; wherein, The oil sludge scum has a set solid content, and the content of the oil sludge scum is 20% by weight to 40% by weight.

2. The gel profile control agent according to claim 1, characterized in that The content of the oil sludge scum is 20 wt % to 30 wt %.

3. The gel profile control agent according to claim 1, characterized in that: The solid content is set to be 10 wt % to 20 wt %.

4. The gel profile control agent according to claim 1, characterized in that: The median size of the solid phase particles of the oil sludge scum is 40 μm to 50 μm.

5. The gel profile control agent according to claim 1, characterized in that: The oil sludge scum is produced in the following: the permeability is (100×10 -3 μm 2 )~(2000×10 -3 μm 2 )'s reservoir profile adjustment and production increase measures, and crude oil dehydration at the joint station.

6. The gel profile control agent according to claim 1, characterized in that: The content of the polyacrylamide is 0.2 wt % to 0.35 wt %.

7. The gel profile control agent according to claim 1, characterized in that: The cross-linking agent includes one of the following: an organic chromium cross-linking agent and a water-soluble phenolic resin.

8. The gel profile control agent according to claim 1 or 7, characterized in that: The content of the cross-linking agent is 0.16 wt % to 0.28 wt %.

9. The gel profile control agent according to claim 1, characterized in that: The viscosity of the gel profile control agent is 2600 mPa·s to 9000 mPa·s.

10. Use of the gel profile control agent according to any one of claims 1 to 9 in water injection well flooding.

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