CN103937483A - Guar gum cleaning fracturing fluid and its preparation method and application - Google Patents

Abstract

The invention discloses a guar gum cleaning fracturing fluid and its preparation method and application. The guar gum cleaning fracturing fluid includes 0.2-0.3% of guar gum and modified products, 0.05-0.5% of drainage aids, anti-swelling agent or clay stabilizer 0.05-0.5%, vegetable glue preservative or fungicide 0.01-0.15%, fracturing fluid demulsifier 0.02-0.15%, potassium chloride 0-2%, fracturing fluid cross-linking gel breaker 0.2- 0.6%, water 95.8-99.47%. The advantage of the present invention is that the viscosity is less than 5mpa.s and the residue of the gel-breaking solution is less than 60mg/L after 3 hours of testing by the Pinshi viscometer, which can prevent the damage to the formation due to incomplete gel-breaking or high residue, which is far superior. Due to the residue requirements of viscoelastic clean fracturing fluid and guar gum fracturing fluid, it meets the requirements of clean fracturing fluid. There are no related patents and literature reports in China.

Description

A kind of guar gum cleaning fracturing fluid and its preparation method and application

technical field

The invention relates to a guar gum cleaning fracturing fluid, a preparation method and application thereof, and belongs to the field of oilfield chemical fracturing fluids.

Background technique

The thickener guar gum or modified guar gum used in guar gum fracturing fluid is stipulated in the "General Technical Requirements for Vegetable Gum for Fracturing" (SY/T5764-2007) that the secondary product guar gum or hydroxypropyl guar gum is water-insoluble The water-insoluble matter in guar gum is not more than 20% and 8%, respectively. The method to solve the high water-insoluble matter in guar gum is basically through modification, which is the main source of fracturing fluid residue; "General Technical Requirements for Fracturing Fluid" (SY/T6376-2008) It is stipulated that the high requirement for fracturing fluid gel-breaking fluid residue is not more than 600mg/L, and the viscoelastic cleaning fracturing fluid gel-breaking fluid residue is not more than 100mg/L.

Drainage aids, anti-swelling agents or clay stabilizers, vegetable gum preservatives or fungicides, and demulsifiers often have compatibility problems with various products.

Contents of the invention

In order to solve the deficiencies in the existing guar gum fracturing fluid technology, the object of the present invention is to provide a kind of guar gum fracturing fluid and its preparation method and application, so that it can meet the "general technical requirements for fracturing fluid" (SY/T6376-2008 ), the high requirement for the residue of gel-breaking fluid is not more than 600mg/L, and the residue of gel-breaking fluid for viscoelastic clean fracturing fluid is not more than 100mg/L, meeting the conditions and requirements of clean fracturing fluid.

In order to achieve the above object, the present invention adopts the following technical solutions:

Guar gum cleaning fracturing fluid consists of the following formula by mass percentage,

The preparation method of guar gum cleans fracturing fluid, comprises the steps:

(1) Add 95.8-99.47% distilled water to the 2000ml mixer according to the total mass of guar gum cleaning fracturing fluid;

(2) Turn on the mixer until the vortex appears and you can see the paddles, slowly add 0.2-0.3% guar gum or modified guar gum to the mixer, react for 10-30 minutes, put it into a 1000ml jar, Hydrate and expand in water at 20-30°C for 45-90 minutes;

(3) Pour the guar gum solution after hydration expansion into the mixer, and then add 0.05-0.5% drainage aid, 0.05-0.5% clay stabilizer or anti-swelling agent, and 0.01-0.15% vegetable glue Preservatives or fungicides, 0.02-0.15% fracturing fluid anti-emulsifier, 0-2% potassium chloride are poured into the mixer and mixed evenly;

(4) Turn on the mixer and you can see the blades when there is a vortex, add 0.2-0.6% fracturing fluid cross-linked breaker, test the viscosity change and the residue of the breaker in the range of 20-80 degrees for 3 hours, after 3 hours Its viscosity is less than 5mpa.s, and the residue of gel breaker is less than 60ppm.

The guar gum and the modified product are one of guar gum, hydroxypropyl guar gum, and carboxymethyl guar gum, which are first-class or second-class products supplied in the market.

The drainage aid is a drainage aid developed by Shaanxi Petrochemical Research and Design Institute, model HK101, the surface tension of 0.3% distilled aqueous solution is less than 28mN/m, and the interfacial tension is less than 2mN/m.

The anti-swelling agent or clay stabilizer is an anti-swelling agent or clay stabilizer developed by Shaanxi Petrochemical Research and Design Institute, model HK104, wherein the content of hydroxypropyl quaternary ammonium salt or choline chloride is more than 40%, and 1% distilled water The anti-expansion rate of the solution to sodium soil is greater than 95%.

The vegetable glue preservative or bactericide is a vegetable glue preservative or bactericide developed by Shaanxi Petrochemical Research and Design Institute, model HK104, wherein the content of dodecyl dimethyl benzyl ammonium chloride is more than 30%, and the temperature is 30% After 48 hours, the viscosity decrease rate of guar gum liquid was less than 15%.

The fracturing fluid demulsifier or anti-emulsifier is a vegetable glue preservative or bactericide developed by Shaanxi Petrochemical Research and Design Institute, model HK105, wherein the content of polyether demulsifier is more than 30%, and the demulsification rate or anti-emulsification rate Greater than 95%.

The potassium chloride is a Russian Ural product supplied to the market, and the potassium oxide content is more than 62%.

The guar gum cleaning fracturing fluid cross-linking gel breaker is the HK8A product developed by Shaanxi Petrochemical Research and Design Institute. It is a product composed of a low-concentration guar gum cross-linking agent and a gel breaker. The agent content is more than 40%, which can realize the cross-linking sand carrying and gel breaking of guar gum fracturing fluid, and the residue of gel breaking fluid is less than 60ppm.

The application of a guar gum cleaning fracturing fluid in oil field fracturing fluid.

The benefits of the present invention are:

(1) Realize that the residue of guar gum fracturing fluid is not more than 60mg/L, which is far lower than the industry standard "General Technical Requirements for Fracturing Fluid" (SY/T6376-2008). Elastic clean fracturing fluid gel breaker residue is not more than 100mg/L, meeting the conditions and requirements of clean fracturing fluid.

(2) Guar gum cleaning fracturing fluid can achieve good cross-linking effect, stable fracturing sand carrying performance, thorough gel breaking, reasonable price, non-corrosive and not affected by a large amount of coexisting salts; various ingredients contained in the product Complementary to each other, it can save the use of cross-linked tank trucks, directly saving more than 2,000 yuan per well.

(3) To reduce the fracturing fluid residue, the most fundamental thing is to reduce its damage to the formation, especially the damage to the low-permeability formation can be lower than that of clean fracturing fluid, and completely solve the problem of high residue of guar gum fracturing fluid The problem is that there is no report on a system that can achieve low residue and clean guar gum fracturing fluid.

Detailed ways

The present invention will be specifically introduced below in conjunction with specific embodiments.

1. Preparation of guar gum clean fracturing fluid

1. Raw material preparation:

Example 1

0.2% guar gum and modified products

0.3% drainage aid

0.3% anti-swelling agent or clay stabilizer

0.1% vegetable gum preservative or fungicide

0.15% fracturing fluid demulsifier

1% potassium chloride

97.65% water

0.3% fracturing fluid cross-linked breaker

The preparation method of the guar gum cleaning fracturing fluid cross-linked breaker is as follows:

The crosslinking agent is organic boron crosslinking agent or organic boron zirconium crosslinking agent 50-80 parts

The enzyme is mannanase or superoxide dismutase 0.1-5 parts

The gel breaker is 0-3 parts of ammonium persulfate or potassium persulfate sold on the market

10-30 parts of water

First, add water to the reactor, raise the temperature to 30°C, seal the nitrogen to replace the air, and control the fracturing at 0.1-0.3MPa; then, turn on the agitator, slowly add the cross-linking agent into the reactor, and react for 30 minutes, which is beneficial Delay cross-linking; then, slowly add gel breaker to the reactor, react for 30 minutes, which is beneficial to gel breaking; next, add enzyme to the reactor, react for 3 hours, which is beneficial for gel breaking at low temperature. Final inspection and discharge. The products produced by the above method meet the requirements of industry standards.

Example 2

0.25% guar gum and modified products 0.2% drainage aid 0.5% anti-swelling agent or clay stabilizer

0.05% vegetable gum preservative or fungicide 0.05% fracturing fluid demulsifier

0% potassium chloride 98.65% water 0.3% fracturing fluid cross-linked breaker

Example 3

0.3% guar gum and modified products 0.5% drainage aid 0.3% anti-swelling agent or clay stabilizer

0.15% vegetable gum preservative or fungicide 0.15% fracturing fluid demulsifier

2% potassium chloride 96.4% water 0.2% fracturing fluid cross-linked breaker

Example 4

0.2% guar gum and modified products 0.05% drainage aid 0.5% anti-swelling agent or clay stabilizer

0.1% vegetable gum preservative or fungicide 0.05% fracturing fluid demulsifier

0% potassium chloride 98.5% water 0.6% fracturing fluid cross-linked breaker

Example 5

0.30% guar gum and modified products 0.05% drainage aid 0.5% anti-swelling agent or clay stabilizer

0.1% vegetable gum preservative or fungicide 0.05% fracturing fluid demulsifier

0% potassium chloride 98.8% water 0.2% fracturing fluid cross-linked breaker

2. Preparation method:

(1) Add water to the 2000ml mixer;

(2) Turn on the mixer until the vortex appears and you can see the paddles, slowly add guar gum or modified guar gum into the mixer, react for 10 minutes, put it into a 1000ml jar, and put it in 30°C water for hydration Swell for 45-90 minutes;

(3) Pour the guar gum solution after hydration expansion into the mixer, and add the above-mentioned set amount of drainage aid, anti-swelling agent or clay stabilizer, fracturing fluid demulsifier, and vegetable gum preservative in sequence after opening or fungicide, potassium chloride, mix well;

(4) Turn on the mixer and the blades can be seen when there is a vortex, add guar gum to the mixer to clean the fracturing fluid cross-linked breaker (HK-8A) until the fracturing fluid surface appears slightly drummed, and test in turn In the range of 20-80 degrees for 3 hours, the viscosity changes and the residue of the gel-breaking fluid, after 3 hours, the viscosity is less than 5mpa.s, and the residue of the gel-breaking fluid is less than 60ppm.

2. Application examples of guar gum cleaning fracturing fluid

The guar gum cleaning fracturing fluid of the present invention is mainly used in oil field fracturing.

The guar gum cleaning fracturing fluid in Examples 1-5 was tested, and the test results in the laboratory are shown in Table 1.

Table 1 Fracturing fluid viscosity and gel-breaking residue

In summary, the guar gum cleaning fracturing fluid of the present invention, after 3 hours, its viscosity is less than 5mpa.s when tested by Pins viscometer, and the gel-breaking fluid residue is less than 60mg/L, which is far lower than the "General Specifications for Fracturing Fluids" (SY/T6376-2008) The viscoelastic clean fracturing fluid residue content is not more than 100mg/L, which is even lower than the guar gum fracturing fluid residue content is not more than 600mg/L, which can prevent incomplete gel breaking or high residue The formation damage is far superior to the residue requirements of viscoelastic clean fracturing fluid and guar gum fracturing fluid, and meets the requirements of clean and low slag production. There are no related patents and literature reports in China.

It should be noted that the above embodiments do not limit the present invention in any form, and all technical solutions obtained by means of equivalent replacement or equivalent transformation fall within the protection scope of the present invention.

Claims (5)

1. Guar gum cleaning fracturing fluid is characterized in that it is composed of the following mass percentage formula, . 2. the preparation method of guar gum cleaning fracturing fluid as claimed in claim 1, is characterized in that, comprises the steps: (1) Add distilled water with 95.8-99.47% of the total mass of guar gum cleaning fracturing fluid to the 2000ml mixer; (2) Turn on the mixer until the vortex appears and you can see the paddles, slowly add 0.2-0.3% guar gum or modified guar gum to the mixer, react for 10-30 minutes, put it into a 1000ml jar, Place in 20-30°C water for hydration and expansion for 45-90 minutes; (3) Pour the guar gum solution after hydration expansion into the mixer, and then add 0.05-0.5% drainage aid, 0.05-0.5% clay stabilizer or anti-swelling agent, and 0.01-0.15% vegetable glue Preservatives or fungicides, 0.02-0.15% fracturing fluid anti-emulsifier, 0-2% potassium chloride are poured into the mixer and mixed evenly; (4) Turn on the mixer and you can see the blades when there is a vortex, add 0.2-0.6% fracturing fluid cross-linked breaker, test the viscosity change and the residue of the breaker in the range of 20-80 degrees for 3 hours, after 3 hours Its viscosity is less than 5mpa.s, and the residue of gel breaker is less than 60ppm. the 3. guar gum cleaning fracturing fluid according to claim 1, is characterized in that, described guar gum and modified product are the one of guar gum, hydroxypropyl guar gum, carboxymethyl guar gum. the 4. guar gum clean fracturing fluid according to claim 1, is characterized in that, described guar gum clean fracturing fluid cross-linked gel breaker is the product that is made up of crosslinking agent and gel breaker, wherein low concentration melon gum The content of gel cross-linking agent is more than 40%, which can realize the cross-linking of guar gum fracturing fluid to carry sand and break the gel, and the residue of gel-breaking fluid is less than 60ppm. the 5. The application of a guar gum cleaning fracturing fluid in oilfield fracturing fluid. the