Bridge plugging synergist for drilling fluid

Abstract

The invention discloses a bridge plugging synergist for drilling fluid. The bridge plugging synergist comprises the following components in percentage by mass: 20-40% of wood fibers, 35-40% of inorganic mineral fibers, 20-30% of inorganic rigid particles and 5-10% of an inorganic reinforcing agent. The inorganic rigid particles are resin sand with the particle size of 200 meshes or a compound of the resin sand and ceramic powder; the inorganic mineral fiber is a combination of brucite fibers, aluminum silicate fibers and carbon fibers, wherein the brucite fibers are 1-3 mm in length and 0.5-16[mu] m in diameter, the aluminum silicate fibers are 2-4 mm in length and 0.7-20 [mu] m in diameter, and the carbon fibers are 1-4 mm in length and 0.5-18 [mu] m in diameter; wherein the mass ratio of the brucite fibers to the aluminum silicate fibers to the carbon fibers is 5: 4: 1. According to the bridge plugging synergist disclosed by the invention, through the cooperative use of the microfibers and the microparticles, microcracks can be effectively plugged, and the compactness of a bridge plug is improved, so that the pressure bearing capacity is enhanced.

Description

technical field [0001] The invention relates to the technical field of drilling fluid plugging in petroleum drilling engineering, in particular to a bridge plugging synergist for drilling fluid. Background technique [0002] In the process of petroleum exploration and development, lost circulation is the most common complex phenomenon. With the increase of wells in complex blocks and ultra-deep wells, the problem of lost circulation has seriously restricted the exploration and development process. However, traditional leak plugging is difficult to succeed once or twice, and it is often solved after repeated plugging. The success rate is extremely low. And the occurrence of lost circulation is caused by poor formation pressure bearing capacity. In order to solve lost circulation, improve the pressure bearing capacity of formations, reduce the probability of lost circulation, thereby reducing economic losses, and promote the pace of exploration and development, the research ...

AI Technical Summary

Problems solved by technology

The biggest problem with bridging plugging is particle gradation, which often results in unreasonable gradation leading to repeated plugging failures, wasting time and financial resources, and in many cases the plugging is not complete. After plugging, the leakage rate decreases, but leakage still occurs. In case of leakage or low pressure capacity

The main reason for the above situation is that the particle size distribution is unreasonable. If the particle size is too coarse, the door will be blocked. If the particle size is too small, it is difficult for the plugging agent to effectively reside in the leakage channel.

Moreover, there are micro-cracks in the leakage channel, and it is difficult for bridge plugging materials to enter for effective plugging

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