A low-viscosity and high-elasticity clean fracturing fluid and its preparation method

Abstract

The invention provides a low-viscosity high-elastic cleaning fracturing fluid and a preparation method thereof. The preparation method comprises the steps of mixing di-dodecylmethylamine and chlorohydrin in a mass ratio of 0.5-1.5:1-2, and reacting at a temperature of 90-120 DEG C for 12-20 hours to obtain a di-dodecylmethylhydroxyethylammonium chloride crude product; adding a solvent into the di-dodecylmethylhydroxyethylammonium chloride crude product, and conducting evaporation concentration to obtain solid-state di-dodecylmethylhydroxyethylammonium chloride; mixing the di-dodecylmethylhydroxyethylammonium chloride and an anionic surfactant at a mass ratio of 0.2-0.5:0.5-1 to prepare the low-viscosity high-elastic cleaning fracturing fluid. The preparation method for the low-viscosity high-elastic cleaning fracturing fluid has the advantages of a simple synthesis technology and low costs, and the prepared low-viscosity high-elastic cleaning fracturing fluid has high temperature resistance and strong sand-carrying properties.

Description

technical field [0001] The invention belongs to the fields of oilfield chemistry and interface chemistry, and relates to a low-viscosity and high-elasticity clean fracturing fluid and a preparation method thereof. Background technique [0002] Reservoir stimulation technology is an offensive measure for the development of low-permeability oil and gas reservoirs, and has become the main technology for increasing single well production, and fracturing fluid is one of the key technologies for reservoir stimulation. In order to maintain the sustainable development of the group company, it is very important to increase a certain amount of proven reserves every year. With the continuous improvement of exploration, the proportion of proven low-porosity and low-permeability, unconventional, ultra-deep and offshore oil and gas reservoirs is also increasing. Especially in recent years, special lithology, complex reservoir types, complex fracture shapes, abnormal conditions, etc. have ...

AI Technical Summary

Problems solved by technology

Low-permeability and ultra-low-permeability reservoirs have low permeability, serious damage, and poor reservoir transformation effect. At present, volume transformation is facing large-scale and large-displacement construction. It is necessary to improve water efficiency, reduce operating costs, and solve the problem of instant dissolution of vegetable glue and synthetic polymers; Layers are developing towards deep layers with high temperature. Tarim faces 8,000m ultra-deep, and North China Niudong faces 230°C ultra-high temperature production demand. Higher requirements are put forward for fracturing fluid performance such as temperature resistance, delayed cross-linking, low friction resistance, and high density; very The scale of construction in tight reservoirs is getting larger and larger, and the amount of liquid entering the ground brings technical difficulties to reservoir reconstruction. There is a demand for low-concentration liquid, no residue, low friction, and strong carrying capacity; especially the drop in oil prices in the past two years Seriously, the cost problem has become a key issue restricting reservoir transformation

[0003] From the perspective of general fracturing fluid action behavior, conventional fracturing fluids will produce more polymer residues during the gel breaking process, which will block the pore throats supporting fractures, and the filter cake will reduce the effective width of fractures. Injury to the conductivity, serious fracture damage and even invalid fracturing construction, if the use of polymers is reduced and the viscosity of the fracturing fluid is reduced, the carrying capacity of the proppant will be insufficient and the downhole fractures will not be effectively supported

The above-mentioned contradictions have greatly affected the implementation of efficient fracturing operations, and in turn affected the efficient production of oil and gas reservoirs requiring fracturing stimulation as a whole.

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