Crosslinking agent system, low-concentration polymer crosslinked fracturing fluid and preparation methods of crosslinking agent system and low-concentration polymer crosslinked fracturing fluid

A cross-linking agent, low-concentration technology, applied in drilling compositions, chemical instruments and methods, etc., can solve problems such as productivity decline, reservoir damage, and formation seepage capacity reduction, and achieve a wide range of industrial value effects.

Inactive Publication Date: 2018-06-19
CHENGDU LEARN PRACTICES TECH CO LTD
View PDF8 Cites 10 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, high molecular polymers such as guar gum and hydroxyethyl cellulose in the commonly used fracturing fluids will leave residues in the fractures and damage the reservoir, resulting in a decrease in the seepage capacity and production capacity of the formation.

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Crosslinking agent system, low-concentration polymer crosslinked fracturing fluid and preparation methods of crosslinking agent system and low-concentration polymer crosslinked fracturing fluid
  • Crosslinking agent system, low-concentration polymer crosslinked fracturing fluid and preparation methods of crosslinking agent system and low-concentration polymer crosslinked fracturing fluid

Examples

Experimental program
Comparison scheme
Effect test

preparation example Construction

[0067] The present invention also provides a preparation method of a crosslinking agent system, comprising the following aspects:

[0068] The preparation method of the crosslinking agent main agent: disperse water-soluble high-valent metal salt, polyol, organic acid or its salt, and inorganic salt in a solvent to obtain a reaction liquid, and make the reaction liquid react under heating and acidic conditions.

[0069] Preparation method of crosslinking agent auxiliary agent: 20-60 parts of peroxide or organic acid and its salt are mixed uniformly in aqueous solution. The invention also provides a low-concentration polymer cross-linked fracturing fluid, the raw materials of which include a thickening agent and a cross-linking agent system.

[0070] As mentioned above, it can be understood that the cross-linking reaction between the thickener and the cross-linking agent system generates a cross-linked product with a spatial network structure.

[0071] It should be understood t...

Embodiment 1

[0094] The crosslinking agent main agent provided in this embodiment is mainly made of the following components in parts by weight:

[0095] Soluble metal salt: 5 parts of zirconium trichloride zirconium oxychloride;

[0096] Polyol: 8 parts of mannitol;

[0097] Carboxylic acid or its salt: 4 parts of sodium citrate;

[0098] pH regulator: 1 part of sodium carbonate;

[0099] Inorganic salt: 3 parts of potassium chloride;

[0100] Solvent: 80 parts of water.

[0101] The preparation method of crosslinking main agent comprises:

[0102] Add 5 parts of zirconium oxychloride and 8 parts of mannitol into 70 parts of water successively, continue to add 4 parts of sodium citrate, and then slowly add 1 part of water dissolved in 1 part of sodium carbonate, so that the pH value of the reaction solution is 6. The first reaction was carried out at a reaction temperature of 40°C for 3 hours, and then 3 parts of potassium chloride was added to carry out the second reaction. The reac...

Embodiment 2

[0119] The crosslinking agent main agent provided in this embodiment is mainly made of the following components in parts by weight:

[0120] Soluble metal salt: a combination of aluminum sulfate, zirconium tetrachloride, and zirconium oxychloride, 28 parts in total;

[0121] Polyol: a combination of triethylene glycol, xylitol, and triethanolamine, 30 parts in total;

[0122] Organic acid or its salt: 15 parts of sodium tartrate;

[0123]Inorganic salt: 10 parts of sodium chloride;

[0124] Solvent: 36 parts of water.

[0125] The preparation method of crosslinking main agent comprises:

[0126] Add soluble metal salts and polyols to water in sequence, continue to add organic acids or their salts, and then slowly add 36 parts of water. The first reaction is carried out at a reaction temperature of 40°C for 3 hours, and then 10 parts of sodium chloride is added. Carry out the second reaction, the reaction time is 30min, and the reaction product is the main agent of the cros...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

PUM

No PUM Login to view more

Abstract

The invention provides a crosslinking agent system, a low-concentration polymer crosslinked fracturing fluid and preparation methods of the crosslinking agent system and the low-concentration polymercrosslinked fracturing fluid. The low-concentration polymer crosslinked fracturing fluid has both high viscoelasticity of the existing polymer fracturing fluid and low damage of a clean fracturing fluid. The economical efficiency of the fracturing fluid is improved by means of low concentration, and accordingly, the low-concentration polymer crosslinked fracturing fluid is more popular with oilfields on the premise of cost decreasing, benefit increasing and reservoir protecting. A prepared base fluid has the viscosity range of 10-24 mPa.s, and is easy to prepare and pump. Delayed crosslinkingtime is 30-120 s, gel can be formed after crosslinking, viscosity is enhanced three times or more, sand carrying is facilitated, and a supporting agent can be delivered to the far end of a fracture. Therefore, the low-concentration polymer crosslinked fracturing fluid inherits various advantages of the traditional fracturing fluid, and further, the sand carrying capability and fracture conductivity of the fracturing fluid can be improved effectively.

Description

technical field [0001] The invention relates to the technical field of oil and gas field reservoir reconstruction, in particular to a crosslinking agent system, a low-concentration polymer crosslinking fracturing fluid and a preparation method thereof. Background technique [0002] Fracturing is a technological process to modify the seepage characteristics of oil layers, and it is an important technological measure for increasing the production of oil and gas wells and increasing the injection of solvent injection wells. Reservoir stimulation is one of the main measures for oil and gas well stimulation, and fracturing fluid is the main fluid in reservoir stimulation. The performance of the fracturing fluid directly affects the fracturing effect and the injection-production capacity of the well. [0003] The low-damage performance and proppant-carrying performance of fracturing fluid are the key performance indicators of fracturing fluid, which play a vital role in fracturin...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to view more

Application Information

Patent Timeline
no application Login to view more
Patent Type & Authority Applications(China)
IPC IPC(8): C09K8/68C09K8/88
CPCC09K8/685C09K8/887
Inventor 寇将侯向前任山张绍彬郭建春卢聪唐朝钧王梦莹赵彦兵
Owner CHENGDU LEARN PRACTICES TECH CO LTD
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products