Oil-resistant deformable plugging particle and preparation method thereof

Abstract

The invention discloses an oil-resistant deformable plugging particle. An inner core of the oil-resistant deformable plugging particle is an elastic-plastic rubber particle, and a shell of the oil-resistant deformable plugging particle is coated with a fluorine-containing polymer. Meanwhile, the invention also provides a preparation method of the oil-resistant deformable plugging particles. The preparation method comprises the following steps: selecting the rubber particles, cleaning, wetting the surfaces, performing ultrasonic vibration spraying and the like. Under the condition of pressure or temperature, the rubber coated with the fluorine-containing polymer can generate elastic deformation, the hole seam plugging effect is good, and the shell is coated with the fluorine-containing polymer, so that the deformable plugging particles cannot be dissolved in an oil phase, and the oil phase cannot be blocked. And the plugging agent still has good elastic deformation capability and plugging performance under long-time high-temperature and high-pressure soaking conditions in oil-based drilling fluid.

Description

technical field [0001] The present invention relates to the technical field of a plugging agent for oil-based drilling fluids, in particular to an oil-resistant deformable plugging particle and a preparation method thereof. Background technique [0002] Loss of circulation is the most common downhole complex situation in the drilling process. It not only consumes a lot of time, manpower and financial resources, but also causes serious accidents such as stuck pipe, well collapse and blowout if the lost circulation is not handled properly. Due to the complexity of lost circulation, it has always been a major engineering and technical problem plaguing oil and gas drilling at home and abroad, and it has not been completely solved so far. Foreign statistics show that the occurrence rate of lost circulation in the global oil industry accounts for about 20% to 25% of the total number of wells, and the annual cost of lost circulation is as high as 3 billion US dollars. [0003] Wit...

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Problems solved by technology

[0003] With the continuous improvement of the exploration and development of oil and gas resources, the scope of drilling and development has gradually moved to complex geological conditions such as deep ultra-deep layers, deep ocean water, and pressure depletion, which also put forward higher requirements for drilling fluid technology. Among them, oil-based drilling fluid It has gradually become the preferred drilling fluid system. However, compared with water-based drilling fluids, oil-based drilling fluids are more prone to wellbore loss, and it is difficult to deal with lost circulation on site. Once lost circulation occurs, it often causes major economic losses.

The leakage problem of oil-based drilling fluid is becoming more and more serious, which greatly limits its large-scale application

[0004] The leakage mechanism of oil-based drilling fluid is different from that of water-based drilling fluid. However, there is currently a lack of special plugging materials for oil-based drilling fluid in China. Conventional water-based drilling fluid leakage prevention and plugging materials are often used on site, such as walnut shells and sawdust. Their Strong hydrophilicity, it is easy to expand, deteriorate and degrade in the environment of oil-based drilling fluid, the durability of plugging effect is poor, and the compatibility with oil-based drilling fluid is poor, which has a great influence on the rheological properties of oil-based drilling fluid. Effective plugging cannot be formed, leading to frequent well leakage and re-leakage, and serious economic losses

Rubber particles are a kind of plugging material with good deformability, but soaking rubber particles in oil-based drilling fluid at high temperature for a long time will cause the strength and elasticity of the rubber to decrease, resulting in the inability to form effective plugging or drilling. double leak

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