Low permeability oil field pressure reduction and infusion nanowetting inverter SDKX-5848--Shandong Kexing Chemical Co.,Ltd.

Low permeability oil field pressure reduction and infusion nanowetting inverter SDKX-5848

Low permeability oil field pressure reduction and infusion nanowetting inverter SDKX-5848 technical manual

Overview

Wetting inverter is a substance that controls the wetting angle of 67°C-90°C by reducing surface tension or interface tension; allowing water to spread on the surface of solid materials or penetrate into its surface to wet the solid materials or make the solid materials more easily wet. Usually it is a surfactant in oil repellent system.
In oil reservoirs, the surface of the rock is usually lipophilic. By adding surfactant substances, the surface characteristics of the rock are reversed, and the lipophilicity becomes hydrophilic. Not only can the crude oil on the surface of the rock be peeled off, but the water-distance efficiency can also be improved and the recovery rate can be achieved. And this type of substance is a wetting inverter.
The molecular structure of the surfactant as a wetting inverter is composed of long-chain lipophilic groups and hydrophilic ionic groups. The compound molecules of this structure can be adsorbed in a directionally on the interface of the two phases in the solution, thereby changing the interface properties of the two phases. When the surfactant is dissolved into the solution, the amphiphilic groups will be distributed in the solution of the liquid/solid contact surface, the liquid/liquid interface and the body phase. When polar groups combine with the surface of minerals and rocks, they will destroy the crude oil boundary layer, freeing the crude oil bounded in the boundary layer and becoming flowable oil. Polar water molecules or hydrophilic groups will occupy the surface of the particles, thereby changing the surface of minerals and rocks from oil-wet to water-wet. At the same time, the oil-water interface tension decreases, crude oil emulsification, oil droplet aggregation and other phenomena occur, which will improve the crude oil recovery rate.
With the development of surfactants, the research on surfactivity of twin connections has developed rapidly in recent years. Twin surfactants are called the next generation of surfactants because they are completely different from conventional surfactants, which are like two conventional surfactants twinned. It is precisely because of its unique structure that it has unique properties, such as very low cmc (Critical Micelle Concentration) value, good table/interface activity, good water solubility and strong salt resistance. Therefore, twin surfactants have broad application prospects.
The new and efficient wetting inverter is alkanolamide long-chain fatty acid-based twin surfactant prepared using resource-rich natural renewable oils as raw materials. Long-chain fatty acid alkanolamide made of natural raw materials is a branched and non-cyclic structure, with good biodegradability, and is an environmentally friendly surfactant with low pollution and good safety in use. It has ultra-low interfacial tension characteristics. At the same time, due to its certain carbon number distribution, it is more suitable for compatibility with alkalis and polymers than single-component products. It is an ideal surfactant oil flooding agent for ternary and binary composite flooding. This type of surfactant has no cloud point and is very soluble with other types of surfactants. It is not an ionic state in solution, so it is very affected by ions in the formation and has a good salt resistance. In addition, the anionic surfactant has good oil repellency in the three oil productions, but it has severe losses during the flow process and its salt resistance is very poor. This fatty acid-based alkanolamide-based wetting inverter can just make up for these shortcomings, improve the system's salt resistance, and further reduce the oil-water interface tension.
As the requirements for environmental protection become increasingly high, countries around the world are vigorously advocating the use of surfactants based on natural raw materials. In the petroleum industry, the impact of three oil production liquids on the ecological environment has also received great attention. Using oil crops such as soybeans and rapeseed, oily forest fruits such as oil dumplings and coptis chinensis, aquatic plants such as engineering microalgae, or natural renewable resources such as animal oils and waste catering oils as raw materials, we can synthesize surfactants that are compatible with the environment, have excellent ecology and have excellent performance. This surfactant has excellent biodegradability without branching and acyclic structure and is called an environmentally friendly surfactant.

Technical Principles

The production process routes of fatty acid alkanolamide wetting inverter include fatty acid method and methyl ester method. The synthesis route is determined as a three-step process, one step: oil and fat transesterification reaction; two steps: synthesis of fatty acid alkanolamide; three steps: synthesis of fatty acid alkanolamide sulfate salt. Then react with 1,3-propane sulfonate lactone to obtain a series of sulfonate twin-type wetting inverters of different carbon chain lengths and different coupling group lengths.

3. Product indicators and performance

name	index
Appearance	Yellow or light tan liquid
Surface tension (5000mg/L)	29mN/m
Interface tension	10-3 mN/m order of magnitude
Wetting angle	>67℃ -<90℃
Salt resistant	≤10g/L
Temperature resistance	≤ 280℃
Biodegradability	≥85%
Resistivity	≤

The new twin-type wetting inverter also has very good anti-divalent salt capabilities. As the molar concentration of calcium ions increases, the interfacial tension decreases linearly.
The twin surfactant we studied was only 1×10-5mol/L of cmc of C10-C2-C10, and the rest were between 1 and 5×10-6mol/L. The cmc of the twin-type wetting inverter is 2 to 4 orders of magnitude smaller than the corresponding conventional surfactant.
4. Research on core simulation oil flooding
The evaluation test of oil-repellent damping inverter is carried out with reference to SY/T 5908-1994 (method for determining performance of petroleum sulfonate for oil-repellent flooding) and SY/T 6424-2000 (method for testing performance of oil-repellent flooding system). The test conditions are as follows:
Test oil: dehydration and degassing crude oil from wells 98181 and wells 980113.
Experimental water: simulated formation water.
Cores for experiments: two types of artificial cores.
The artificially cemented columnar core filling model is a columnar core model that artificially cemented after loose oil sands are washed with alcohol-benzene.
The loose core filling model is a molded core made of cemented and pressed by quartz sand, clay minerals, etc. in a certain proportion.
Test model: The air permeability of the core model is comparable to the permeability of the blocks where wells 98181 and 980113 are located.
Test temperature: formation temperature 45℃.
Drive speed: Calculate the drive speed based on L·μ·υ≥1, and 0.3mL/min is selected in the test.
Single tube model
Results of oil displacement experiment of single tube model

Model	Column core 1	Loose core 2	Column core 3	Loose core 4
Permeability μm2	0.783	0.776	0.692	0.634
Oil repellent	0.5%	0.5%	1%	1%
Injection of segment PV	0.3	0.3	0.3	0.3
Original oil saturation %	64.70	69.64	69.47	54.52
Water repellent oil efficiency %	26.34	25.45	24.67	23.84
Total oil displacement efficiency %	41.37	38.34	40.78	37.29
Twin-type wetting inverter oil dispersion efficiency %	15.03	12.89	16.11	13.45

Experimental method:
The saturated core is loaded into a clamp, inject crude oil, displace water, and create bound water.
Use simulated formation water to replace crude oil in the core. When the water content at the core outlet end reaches 98%, stop the displacement, record the amount of oil driven out during the water flooding, and calculate the water flooding efficiency.
After injecting the twin-connected wetting inverter solution 0.3PV into the core, close the front and rear outlets and let stand for 12 hours.
Continue to re-drain with simulated formation water, record the amount of oil displaced, and calculate the oil displacement efficiency of twin-connected wetting inverter. The results of the oil dispersion experiment are shown in the table.
Double tube model
Results of oil displacement experiments for double tube model

Model	Column core 1	Loose core 2	Column core 3	Loose core 4
Permeability μm2	0.761	0.024	0.753	0.025
Oil repellent	0.5%	0.5%	1%	1%
Injection of segment PV	0.3	0.3	0.3	0.3
Original oil saturation %	64.70	69.64	69.47	54.52
Water repellent oil efficiency %	27.34	5.45	26.67	5.84
Total oil displacement efficiency %	44.87	10.73	44.81	11.16
Twin-connected wetting inverter oil displacement efficiency %	17.53	5.28	18.14	5.32

Select artificial cores with a large permeability difference, and the permeability level difference is about 10 times. Do a double-tube oil displacement experiment.
The core after saturated simulated formation water is loaded into a clamp, crude oil is injected, water is displaced, and water is created.
Use simulated formation water to replace crude oil in the core. When the water content at the core outlet end reaches 98%, stop the displacement, record the amount of oil driven out during the water flooding, and calculate the water flooding efficiency.
After injecting the twin-connected wetting inverter solution 0.3PV into the core, close the front and rear outlets and let stand for 12 hours.
Continue to re-drain with simulated formation water, record the amount of oil displaced, and calculate the oil displacement efficiency of HL-1 environmentally friendly oil displacer. The results of the oil dispersion experiment are shown in the table.
Experimental results
From the results of the oil-fighting experiments of single-tube model and double-tube model, it can be seen that
the concentration of twin-connected wetting inverter increases, and the oil-fighting efficiency also increases;
the oil-fighting efficiency of twin-connected wetting inverter in columnar cores is higher than that of loose cores, that is, when the clay content in the formation increases, the oil-fighting efficiency of twin-connected wetting inverter will be reduced;
the results of the double-tube model show that twin-connected wetting inverter is not selective;
the economical injection concentration of twin-connected wetting inverter is 0.5%;
the single-tube body mold test shows that twin-connected wetting inverter can improve the recovery rate by 12-16%, and has a high oil-fighting efficiency.
5. How to use
1. Pressure reduction and increase injection; for low-permeability injection wells, stage injection and periodic large-segment injection are carried out for low-permeability injection wells, high injection pressure, poor water quality and low permeability. The injection configuration concentration and segment plug can be used as reference; the permeability, water absorption index, injection requirements, and enhanced water flooding effect determine. a; 0.05%-0.2%; b.0.2%-0.8%; c; 1%-3 block; 50m3-30m3; 500m3-3000m3; 3000m3-15000m3.
The injection method is simple and there is no need to specifically modify the injection pipeline. You can connect the metering pump and drip injection at the water injection station.
2. Wash the well
For oil wells that have wax and scale that require regular well washing operations, they can be prepared into a 0.3% concentration aqueous solution and circulate the wells with a pump truck.
3. Reduce stickiness
Prepare into a 0.5-1% aqueous solution and mix it with crude oil in a ratio of 8:2-6:4.
4. Cleaning wax
First, wash the well with 0.3% aqueous solution, and then add 30-50 kg from the ring sleeve regularly every week according to the fluid production of the oil well.
5. Oil dispelling
The injected PV is determined according to the size of the well group and prepared into an aqueous solution of 0.5% concentration and injected from the injection well. Segment injection can be performed if conditions permit.
6. Heavy oil cold-pick
In response to the viscosity reduction problems in heavy oil wells, a 1%-2% aqueous solution can be prepared based on the viscosity of the heavy oil, calculated based on the treatment radius of 2-3 meters, inject 8-10m3 per meter of oil layer, and injected from the production well. Then close the well for 12 hours and open the well to produce normally.

7. Packaging and storage

This product has oil production polyester plastic barrel packaging; net weight 25kg; 50kg; 200kg;
storage room to prevent sun exposure.
8. Validity period;>18 months.

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