A kind of plugging agent and its preparation method and application

Abstract

The invention provides a plugging agent, a preparation method and application thereof. The plugging agent includes the following components by weight: 1-8 parts of bentonite, 10-50 parts of curing agent, 0.5-4 parts of alloy fiber, 2-8 parts of expansion agent and 20-50 parts of filler; wherein: bentonite is sodium One or both of base bentonite and calcium base bentonite; the curing agent is mixed with blast furnace slag, gypsum and silicate fiber according to the mass ratio (15‑30): (1‑2): (2‑6) It is dried and ground; the alloy fiber is polyethersulfone / polytetrafluoroethylene alloy fiber modified by silica, activated calcium carbonate and titanium dioxide; the expansion agent is granular silicone rubber and sheet silicone rubber One or two of them; the filler is mixed with calcium carbonate, asphalt and nano silicon powder in a mass ratio of (4‑12): (1‑3): (2‑6). The lost circulation agent is not restricted by the leakage channel, has a wide temperature range, and the solidified sealing layer has strong cementability with the wall surface of the leakage channel, which is convenient for popularization and application.

Description

technical field [0001] The invention relates to a leak-stopping agent, in particular to a leak-stopping agent and its preparation method and application. Background technique [0002] Lost circulation refers to the fact that various working fluids (including drilling fluid, cement slurry, completion fluid and other working fluids, etc.) enter the formation along the formation loss channel under the action of positive pressure difference during the drilling operation, and enter the larger liquid-holding reservoir in the formation. A downhole complex phenomenon of space. A series of downhole complex situations such as pipe sticking, blowout, and well collapse caused by lost circulation and the resulting vicious accidents have a great impact on drilling engineering. [0003] In view of the above-mentioned lost circulation problems, especially the malignant lost circulation problems in fracture-cavity developed formations, complex fractured formations with high steep structures...

AI Technical Summary

Problems solved by technology

[0003] In view of the above-mentioned lost circulation problems, especially the malignant lost circulation problems in fracture-cavity developed formations, complex fractured formations with high steep structures, or low pressure-bearing formations with long open-hole sections, conventional bridging and polymer gel plugging agents and The special fast-hardening cement plugging agent cannot be effectively solved. The main reasons include: the bridging plugging agent relies on the physical accumulation of particles, fibers, and sheet-like materials to form a plugging layer, and its cementing ability with the rock wall of the formation is poor. The "breathing effect" of internal pressure fluctuations and the effects of temperature and fluid immersion in the well may lead to the breakage of the "blocking partition wall". In addition, the particle size distribution of the bridging material is difficult to match the size of the formation leakage channel; the polymer gel is under pressure. Low capacity and easy to degrade under high temperature, thus losing gel properties, so the leaky layer cannot be effectively sealed; cement plugging agent has low viscosity, it is difficult to stay in the leaky layer, the construction procedure is complicated and the risk is high

Images