Ternary composite system suitable for high-temperature and high-salinity oil reservoir, and preparation method thereof

A ternary system, high salinity technology, applied in the direction of chemical instruments and methods, drilling compositions, mining fluids, etc., can solve the problem of polymer solution viscosity reduction, so as to enhance the viscosity-increasing ability and improve recovery The effect of increasing the rate and expanding the scope of application

Active Publication Date: 2015-11-11
PETROCHINA CO LTD +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, the carboxyl group on the molecular chain of partially hydrolyzed polyacrylamide is very sensitive to salt, when Ca 2+ , Mg 2+ It is prone to phase separation when it exists, and the amide group on the molecular chain is easily hydrolyzed when the temperature is higher than 70 ° C, resulting in a significant decrease in the viscosity of the polymer solution
Therefore, high temperature (75 ~ 110 ℃) and high salinity (1 × 10 4 ~3×10 4 mg / L) Reservoir conditions prevent partially hydrolyzed polyacrylamide from being used as the main oil displacement agent on a large scale

Method used

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  • Ternary composite system suitable for high-temperature and high-salinity oil reservoir, and preparation method thereof
  • Ternary composite system suitable for high-temperature and high-salinity oil reservoir, and preparation method thereof
  • Ternary composite system suitable for high-temperature and high-salinity oil reservoir, and preparation method thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0027] Example 1. Preparation of polymers suitable for high temperature and high salinity reservoirs

[0028] (1) Dissolve 108g of benzyl alcohol in 200mL of ethanol to form an ethanol solution of benzyl alcohol, then add 70g of paraformaldehyde, lye made of 106g of sodium carbonate and 290mL of water, stir well and heat to 95-100°C for closed reaction 5-6 hours. After cooling, the reactant was poured into 500 mL of cold water, and the crude product was precipitated. The crude product was recrystallized from absolute ethanol to obtain 121 g of white crystalline compound II—tribenzyl alcohol, with a yield of 72%.

[0029] The synthetic route is as follows such as formula (1), and paraformaldehyde is depolymerized to obtain formaldehyde monomer at this reaction temperature, so the reactant in formula (1) is formaldehyde monomer:

[0030]

[0031] (2) Stir 10g of partially hydrolyzed polyacrylamide (HPAM) (degree of hydrolysis 25-30mol%) and 500mL of water evenly, heat to 40...

Embodiment 2

[0037] Example 2. Preparation of ternary composite system suitable for high temperature and high salinity reservoirs

[0038] Add 0.025-0.3wt% alkylbenzene sulfonate surfactant and 0.4-1.2wt% sodium carbonate in each polymer DQHTP solution of 1700mg / L-3700mg / L that embodiment one obtains, at 25 ℃ condition Stirring for 30 minutes, a series of ASP flooding systems suitable for high-temperature and high-salinity reservoirs with a viscosity of 2-30mPa·s were obtained, as shown in 1 in Table 1. # -5 # .

Embodiment 3

[0039]Embodiment three, the influence of ternary composite system of the present invention on oil-water interfacial tension

[0040] With alkylbenzene sulfonate (concentration is 0.025wt%-0.3wt%), sodium carbonate (concentration is 0.4wt%-1.0wt%) and the polymer that embodiment one obtains (concentration is 3200mg / L) preparation obtains a The series is suitable for the ternary compound system of high temperature and high salinity reservoirs.

[0041] Take existing two kinds of ternary composite systems as comparative example: one is made of petroleum sulfonate product PS-100 (concentration is 0.3wt%), sodium carbonate (concentration is 0.4-1.2wt%) and partially hydrolyzed polyacrylamide (concentration is 3200mg / L, degree of hydrolysis 25mol%) is prepared; Another is by heavy alkylbenzene sulfonate BHJ-Q (concentration is 0.3wt%), sodium carbonate (concentration is 0.4-1.2wt%) and part It is prepared by hydrolyzing polyacrylamide (concentration: 3200mg / L, degree of hydrolysis:...

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Abstract

The present invention discloses a ternary composite system suitable for high-temperature and high-salinity oil reservoir, and a preparation method thereof. The ternary composite system comprises a polymer, a surfactant and sodium carbonate, wherein the chemical structure formula of the polymer is defined in the specification, and the polymer has a network structure and has the effect of effective inhibition of high temperature and oxidation degradation so as to effectively improve salt resistance and strengthen thickening capacity. According to the present invention, after the polymer is introduced into the ternary composite system, the ternary composite system has good chemical stability and excellent salt resistance under the conditions of high temperature and high salinity, makes the crude oil / stratum water interface tension be reduced to an ultra-low level under the weak base sodium carbonate condition, and can improve the recovery rate by more than or equal to 20%, such that the ternary composite system of the present invention can be used for the extreme high-temperature and high-salinity oil reservoir conditions.

Description

technical field [0001] The invention relates to a three-element compound oil displacement system used in the oil exploitation process, in particular to an three-element compound system suitable for high temperature and high salinity reservoirs and a preparation method thereof. Background technique [0002] Chemical compound flooding technology is a new technology for tertiary oil recovery developed in the 1980s. It is characterized by the use of organic compounding of alkali, surfactants and polymers to give full play to the synergistic effect of various chemical agents and greatly improve oil displacement. efficiency. It is an innovative technology based on alkali flooding, polymer flooding and surfactant flooding. It has played their advantages and greatly reduced costs while enhancing oil recovery. Therefore, chemical composite flooding is considered to be another new method of tertiary oil recovery with more potential after polymer flooding. [0003] In the past 20 to ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C09K8/588E21B43/22C08J3/24C08L33/26C08K5/053C08K5/20
CPCC08J3/244C08J2333/26C08K5/053C08K5/20C08L2312/00C09K8/588C08L33/26
Inventor 程杰成伍晓林吴军政侯兆伟陈劼赵新窦绪谋金锐李建路王海峰杨勇单存龙
Owner PETROCHINA CO LTD
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