CN-122010751-A - Multi-cation surfactant FCWS, preparation method and application

CN122010751ACN 122010751 ACN122010751 ACN 122010751ACN-122010751-A

Abstract

The invention discloses a polycation surfactant FCWS, a preparation method and application thereof, and belongs to the technical field of oilfield chemical additives. The preparation method comprises the steps of S1, dissolving 1, 5-diaminopentane in ethanol, adding epichlorohydrin, reacting for 24 hours at 25 ℃ to obtain an ethanol solution of an intermediate A, and S2, reacting the ethanol solution of the intermediate A with dimethyl tertiary amine organic matters at 80 ℃ for 36-48 hours to obtain the polycationic surfactant FCWS. According to the invention, the prepared multi-cation surfactant is used for modifying the propping agent, so that the sedimentation speed of the propping agent is reduced, the propping agent with excellent suspension capability is obtained, and the propping agent with excellent performance is provided for the reservoir yield increasing transformation technology. The invention is applicable to modifying silica-containing proppants.

Inventors

ZHANG WEI
LIU CHAOWU
YANG CHUNHUA
LI JIN
GENG CONG
CHE YING
TAN ZHEN
Song Zhimeng
Luan Qiulei
LI KAI
SUN YUHAN
REN YONGQIANG
XIA QIANG
WANG CHEN
TAI YUNLONG

Assignees

中国石油集团渤海钻探工程有限公司
中国石油天然气集团有限公司

Dates

Publication Date: 20260512
Application Date: 20241112

Claims (8)

1. A multi-cation surfactant FCWS, the method is characterized by comprising the following structural formula: wherein R is erucamide propyl alkane, hexadecane, octadecane or docosyl alkane.
2. The method for preparing the polycationic surfactant FCWS according to claim 1, comprising the following steps sequentially performed: S1, dissolving 1, 5-diaminopentane in ethanol, adding epichlorohydrin, and reacting for 24 hours at 25 ℃ to obtain an ethanol solution of an intermediate A; S2, reacting the ethanol solution of the intermediate A with dimethyl tertiary amine organic matters at 80 ℃ for 36-48 hours to obtain the polycation surfactant FCWS.
3. The method according to claim 2, wherein the dimethyl tertiary amine organic matter comprises erucamide propyl dimethyl tertiary, cetyl dimethyl tertiary amine, stearyl dimethyl tertiary amine or behenyl dimethyl tertiary amine.
4. The preparation method of claim 2 or 3, wherein the molar ratio of the 1, 5-diaminopentane to the epichlorohydrin is 1:4-4.2, and the molar ratio of the intermediate A to the dimethyl tertiary amine organic matter is 1:4.5-5.
5. The use of a polycationic surfactant FCWS according to claim 1, wherein the polycationic surfactant FCWS is used to modify a proppant.
6. The use of claim 5, wherein the proppant comprises quartz sand or ceramic particles.
7. The use according to claim 5 or 6, wherein the modified proppant comprises dispersing the proppant in water, adding the polycation surfactant FCWS wt% of the proppant, stirring for 1-3 hours at 20-80 ℃, precipitating, filtering, and drying to obtain the modified proppant.
8. The method according to claim 7, wherein the stirring is carried out at a speed of 10000r/min, the precipitation is carried out for 6 hours, and the drying is carried out at a temperature of 55 ℃.

Description

Multi-cation surfactant FCWS, preparation method and application Technical Field The invention belongs to the technical field of oilfield chemical additives, and relates to a modified propping agent, in particular to a polycation surfactant FCWS, a preparation method and application. Background Along with the large-scale exploitation and consumption of conventional oil and gas reservoirs, compact sandstone gas, coal bed gas, shale gas and other low-permeability, ultra-low-permeability and deep high-temperature unconventional oil and gas resources are urgently needed to be developed and utilized. Hydraulic fracturing is a key technology for improving yield of oil and gas reservoirs, and in the hydraulic fracturing process, propping agents are required to be conveyed into artificial cracks through fracturing fluid, so that the cracks are prevented from being closed after construction is finished. The migration and laying form of the propping agent in the crack greatly determine the fracturing construction effect, namely the larger the depth of the propping agent entering the crack is, the larger the effective length of the propping agent is, the larger the volume of a communication reservoir is, the better the improvement effect is, the more uniform the propping agent is laid in the crack, the better the diversion capability of the crack is, and the high yield of an oil-gas well is facilitated. A key factor affecting the migration and placement morphology of proppants in a fracture is the suspension capacity and settling rate of the proppants. The propping agent with strong suspending capability has slower sedimentation speed in the fracturing fluid, can be transported to deeper parts of the fracture, and has more uniform laying morphology. Thus, the settling rate is an important reference property for evaluating proppants, and the existing proppants have the problem of faster settling rate, so proppants with excellent properties are urgently needed. The surfactant is an amphiphilic small molecular compound with hydrophilic groups and hydrophobic groups, and is often used for changing the fluid characteristics due to the amphiphilic characteristic, and the cationic surfactant can generate an adsorption effect with the propping agent due to the structural characteristic of the positively charged groups, so that the aim of modifying the propping agent is fulfilled. The modifying ability of the surfactant to the propping agent is in direct proportion to the number of cations of the surfactant, the number of cations of the common surfactant is 1-2, and the modifying effect is poor. Disclosure of Invention The invention aims to provide a polycation surfactant FCWS, a preparation method and application thereof, so as to solve the problem of poor effect of a surfactant modified propping agent in the prior art. In order to achieve the above purpose, the technical scheme adopted by the invention is as follows: a polycationic surfactant FCWS having the structural formula: wherein R is erucamide propyl alkane, hexadecane, octadecane or docosyl alkane. The invention also provides a preparation method of the polycation surfactant FCWS, which comprises the following steps in sequence: S1, dissolving 1, 5-diaminopentane in ethanol, adding epichlorohydrin, and reacting for 24 hours at 25 ℃ to obtain an ethanol solution of an intermediate A; The reaction formula is: S2, reacting the ethanol solution of the intermediate A with dimethyl tertiary amine organic matters at 80 ℃ for 36-48 hours to obtain the polycation surfactant FCWS. The reaction formula is: Wherein R is erucamide propyl alkane, hexadecane, octadecane or docosyl alkane. As one limitation, the dimethyl tertiary amine organic matter includes erucamide propyl dimethyl tertiary, cetyl dimethyl tertiary amine, stearyl dimethyl tertiary amine, or behenyl dimethyl tertiary amine. As another limitation, the molar ratio of the 1, 5-diaminopentane to the epichlorohydrin is 1:4-4.2, and the molar ratio of the intermediate A to the dimethyl tertiary amine organic matter is 1:4.5-5. The invention also provides an application of the multi-cation surfactant FCWS, wherein the multi-cation surfactant FCWS is used for modifying proppants. As one definition, the proppants include quartz sand or ceramic grains. As another limitation, the modified propping agent specifically comprises dispersing propping agent in water, adding polycation surfactant FCWS wt% of propping agent, stirring at 20-80 ℃ for 1-3 hours, precipitating, filtering and drying to obtain the modified propping agent. As a further limitation, the stirring speed is 10000r/min, the sedimentation time is 6h, and the drying temperature is 55 ℃. By adopting the technical scheme, compared with the prior art, the invention has the following technical progress: ① The multi-cation surfactant FCWS provided by the invention has hydrophilic groups and hydrophobic groups, can change the fluid characteristics, has 4 cations, can ad