阅读说明：本技术 一种水性降阻剂及其制备方法 (Water-based resistance reducing agent and preparation method thereof ) 是由 任山 郭建春 鲁智勇 马应娴 路千里 唐朝钧 苟波 王继宇 张绍彬 刘彧轩 刘斌 于 2020-04-22 设计创作，主要内容包括：本发明提供了一种水性降阻剂及其制备方法,解决了现有技术中的反相乳液降阻剂存在着破乳水化时间长；乳液中的油相存在对地层岩心的油相伤害的技术问题。其制备包括下述重量份的原料：水溶性稠化剂：20份～60份；溶剂：20份～70份；悬浮助剂：0.2份～5份；悬浮剂：0.5份～3份。本发明提供的水性降阻剂,不仅具有环保、低伤害的优势,并且同时还能实现一体化作业,实现在线混配。(The invention provides a water-based resistance reducing agent and a preparation method thereof, which solve the problems that the reverse emulsion resistance reducing agent in the prior art has long demulsification hydration time; the oil phase in the emulsion has the technical problem of damage to the oil phase of the formation core. The preparation method comprises the following raw materials in parts by weight: water-soluble thickener: 20-60 parts; solvent: 20-70 parts of a solvent; suspension aid: 0.2 to 5 portions; suspending agent: 0.5 to 3 portions. The water-based resistance reducing agent provided by the invention has the advantages of environmental protection and low damage, and can realize integrated operation and on-line blending.)

1. An aqueous resistance-reducing agent is characterized in that: the preparation method comprises the following raw materials in parts by weight:

water-soluble thickener: 20-60 parts;

solvent: 20-70 parts of a solvent;

suspension aid: 0.2 to 5 portions;

suspending agent: 0.5 to 3 portions.

2. The aqueous friction reducer of claim 1, wherein: the weight parts of the raw materials are respectively as follows:

water-soluble thickener: 30-50 parts;

solvent: 35-45 parts of a solvent;

suspension aid: 2-4 parts;

suspending agent: 1 to 2 portions.

3. The aqueous friction reducer of claim 2, wherein: the weight parts of the raw materials are respectively as follows:

water-soluble thickener: 40 parts of a mixture;

solvent: 40 parts of a mixture;

suspension aid: 3 parts of a mixture;

suspending agent: 1.5 parts.

4. The aqueous resistance reducing agent according to any one of claims 1 to 3, characterized in that: the water-soluble thickening agent is a water-soluble thickening agent, and the molecular weight of the water-soluble thickening agent is 500-3000 ten thousand.

5. The aqueous friction reducer of claim 4, wherein: the water-soluble thickening agent is any one or more of a homopolymer of acrylamide, a copolymer of acrylamide, a homopolymer of methacrylamide and a copolymer of methacrylamide.

6. The aqueous friction reducer of claim 5, wherein: the solvent is polyol ether or polyol ester.

7. The aqueous friction reducer of claim 6, wherein: the suspension auxiliary agent is any one or more of low molecular polymer, carboxymethyl cellulose, hydroxypropyl methyl cellulose, polyurethane thickener, seaweed gel, xanthan gum and polyvinylpyrrolidone; the low molecular polymer is any one or more of homopolymer and copolymer of acrylonitrile, maleic acid, styrene, butadiene, isoprene and isoprene, and the molecular weight of the low molecular polymer is 2-10 ten thousand.

8. The aqueous friction reducer of claim 8, wherein: the suspending agent is any one or more of silicon dioxide, bentonite, montmorillonite, polyamide wax and polyethylene wax.

9. The method for preparing the aqueous resistance reducing agent according to any one of claims 1 to 8, wherein the method comprises the following steps: the method comprises the following steps:

s1: respectively adding a solvent, a suspension auxiliary agent and a suspending agent into a reaction kettle, starting stirring, and circularly shearing for 0.8-1.2 hours through an emulsification pump;

s2: adding polyacrylamide into the reaction kettle, starting stirring, and circularly shearing for 0.8-1.2 h through an emulsification pump to obtain a finished product.

10. The method for preparing the aqueous resistance reducing agent according to claim 9, wherein: in the step S1, the stirring speed is 900r/min to 1100 r/min; in the step S2, the stirring speed is 1100 r/min-1500 r/min.

Technical Field

The invention relates to a water-based resistance reducing agent, in particular to a water-based resistance reducing agent and a preparation method thereof.

Background

The shale gas reserves in China reach 31.6 trillion cubic meters, the shale gas resources and the recoverable reserves in Sichuan basin are located in the first place in China, and the exploitation potential is huge.

The shale gas is mainly subjected to a large-scale fracturing fluid fracturing mode in a fracturing process, and three fracturing modes of slickwater fracturing, slickwater + linear gel + gel slug type fracturing, slickwater + linear gel + gel combined slug type fracturing and continuous sand adding are basically formed in a fracturing pump injection mode in China; in the fracturing process, the type and the performance of the fracturing fluid need to be adjusted in real time and rapidly according to the reservoir conditions. At present, the drag reducer capable of realizing online preparation of slickwater is mainly based on an inverse emulsion product, and the reverse emulsion drag reducer has long demulsification hydration time; the oil phase in the emulsion has the problem of damage to the oil phase of the stratum core; meanwhile, the oil-water emulsion formed by the oil phase in the flowback liquid causes difficult treatment and high treatment cost of the flowback liquid; and the viscosity increasing effect of the inverse emulsion resistance reducing agent is limited, and the crosslinking effect of the base liquid is poor.

Furthermore, the prior art inverse emulsions and suspensions using an oil phase, whether an inverse emulsion or a liquid dispersion polymer, contain an oil phase in the form of droplets in the injection fluid, and these oil droplets in the aqueous injection fluid create transport problems in the subterranean formation and multi-phase flow that result in a more complex process.

CN109652053A, a high-temperature-resistant full-suspension low-damage fracturing fluid and a preparation method thereof, discloses a high-temperature-resistant full-suspension low-damage fracturing fluid, which is prepared by using various additives and belongs to the subsequent preparation use stage of a thickening agent.

Disclosure of Invention

The invention aims to provide a waterborne resistance reducing agent which is waterborne, environment-friendly, low in damage and capable of realizing integrated operation and a preparation method thereof. The technical effects that can be produced by the preferred technical scheme in the technical schemes provided by the invention are described in detail in the following.

In order to achieve the purpose, the invention provides the following technical scheme:

the invention provides a water-based resistance reducing agent, which is prepared from the following raw materials in parts by weight:

water-soluble thickener: 20-60 parts;

solvent: 20-70 parts of a solvent;

suspension aid: 0.2 to 5 portions;

suspending agent: 0.5 to 3 portions.

Further, the weight parts of the raw materials are respectively as follows:

water-soluble thickener: 30-50 parts;

solvent: 35-45 parts of a solvent;

suspension aid: 2-4 parts;

suspending agent: 1 to 2 portions.

Further, the weight parts of the raw materials are respectively as follows:

water-soluble thickener: 40 parts of a mixture;

solvent: 40 parts of a mixture;

suspension aid: 3 parts of a mixture;

suspending agent: 1.5 parts.

Further, the water-soluble thickening agent is a water-soluble thickening agent, and the molecular weight of the water-soluble thickening agent is 500-3000 ten thousand.

Further, the water-soluble thickening agent is any one or more of a homopolymer of acrylamide, a copolymer of acrylamide, a homopolymer of methacrylamide and a copolymer of methacrylamide.

Further, the solvent is polyol ether or polyol ester.

Further, the solvent is one or more of ethylene glycol, propylene glycol, butanediol, glycerol, butanetriol, butanetetraol, pentanediol, hexanediol polyol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether polyol ether, ethylene glycol diacetate and propylene glycol diacetate polyol ester derivatives. Further, the suspension auxiliary agent is any one or more of low molecular polymer, carboxymethyl cellulose, hydroxypropyl methyl cellulose, polyurethane thickener, algin, xanthan gum and polyvinylpyrrolidone; the low molecular polymer is any one or more of homopolymer and copolymer of acrylonitrile, maleic acid, styrene, butadiene, isoprene and isoprene, and the molecular weight of the low molecular polymer is 2-10 ten thousand.

Further, the suspending agent is any one or more of silicon dioxide, bentonite, montmorillonite, polyamide wax and polyethylene wax.

The preparation method of the aqueous resistance reducing agent provided by the invention comprises the following steps:

s1: respectively adding a solvent, a suspension auxiliary agent and a suspending agent into a reaction kettle, starting stirring, and circularly shearing for 0.8-1.2 hours through an emulsification pump;

s2: adding polyacrylamide into the reaction kettle, starting stirring, and circularly shearing for 0.8-1.2 h through an emulsification pump to obtain a finished product.

Further, in the step S1, the stirring speed is 900r/min to 1100 r/min; in the step S2, the stirring speed is 1100 r/min-1500 r/min.

Based on the technical scheme, the embodiment of the invention can at least produce the following technical effects:

(1) the water-based resistance reducing agent provided by the invention is different from the traditional inverse emulsion resistance reducing agent, the powder resistance reducing agent is transformed into an emulsion-like resistance reducing agent, the problems of slow dissolving speed and oil phase damage caused by the demulsification process of the inverse emulsion resistance reducing agent are thoroughly solved, the tackifying effect is obvious, and the base liquid crosslinking effect is good.

(2) According to the water-based resistance reducing agent provided by the invention, the water-soluble powder type thickening agent is suspended in the water-based dispersion system to prepare the water-based resistance reducing agent, so that the real-time online switching of powder products in oil and gas exploitation can be realized; meanwhile, a water-soluble non-aqueous medium is adopted, and a surfactant and an oily component are not added in the system, so that the water-based resistance reducer really realizes environmental protection and low damage, and can avoid the transmission problem of oil drops in an underground stratum and multi-phase flow causing more complex process; meanwhile, because the product in the invention is the water-based resistance reducing agent, an oil-water emulsion formed by an oil phase does not exist in the return liquid, and a demulsification procedure is not needed when the return liquid is treated, so that the treatment process is simpler, and the problems of difficult treatment and high treatment cost of the return liquid can be avoided.

(3) The aqueous resistance reducing agent provided by the invention screens out a dispersion medium with a structure similar to that of a water-soluble polymer polyacrylamide and polymethacrylamide of a dispersed suspension object based on the molecular structure characteristics of the polymer polyacrylamide and the polymethacrylamide. The prepared suspension forms intermolecular force among a suspension object, a dispersion medium and a suspending agent, and is more favorable for the stability of a system.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a plot of the construction of sample 4 for an on-site on-line compounding fracture in the experimental examples.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be described in detail below. It is to be understood that the described embodiments are merely exemplary of the invention, and not restrictive of the full scope of the invention. All other embodiments, which can be derived by a person skilled in the art from the examples given herein without any inventive step, are within the scope of the present invention.

First, preparation example: