High-temperature-resistant plugging agent and preparation method of same

Abstract

A high-temperature-resistant plugging agent and a preparation method of same. The plugging agent includes low-cost inert filler, polyester resin, asbestos powder, carbon powder, and isocyanate. The plugging agent can effectively plug a gap being smaller than 3 mm; at a high temperature of 150 DEG C, pressure bearing capacity reaches 9 MPa, so that the plugging agent can satisfy long-time high-temperature high-pressure bearing requirement. The plugging agent can control water loss to less than 80 ml at a high temperature of 180-230 DEG C. The plugging agent can be used for plugging micro-gaps in high temperature mud rocks at the deep place of an extra deep well and collapse in fractured formations. The plugging agent achieves the plugging and anti-collapse effect through the chemical functions, has great pressure-bearing capacity, greatly prolongs the period of collapse, and guarantees safety of deep well drilling.

Description

Technical field [0001] The invention relates to the field of petroleum drilling, in particular to a high temperature resistant plugging agent and a preparation method thereof. Background technique [0002] In recent years, with more and more drilling of deep wells and ultra-deep wells in complex formations, field operations have placed higher requirements on drilling fluid technology. Complex downhole problems such as collapse and diameter reduction caused by the instability of the borehole wall during the drilling process have been plagued by drilling workers. The problem of borehole wall instability in the complex formation environment of deep wells has become more prominent and complicated. [0003] At present, there are many plugging agents with different characteristics in the domestic and foreign markets. Some are based on cotton fiber, peanut shells, walnut shells and other plant fibers as main components. Plant fiber plugging agents; and some are based on asphalt-limestone ...

AI Technical Summary

Problems solved by technology

When directly using plant fibers such as cottonseed hulls for plugging, due to the inherent characteristics of these fibers: too light specific gravity, difficult to control size, easy to knot, poor fluidity and other factors, the plugging effect is poor during use and the pressure bearing capacity is weak; while particles or The plugging ability of powdered leakage stoppage agent for large cracks is limited; when using bridging leakage leakage agent, there will be phenomena of "door sealing" (the leakage prevention agent cannot enter the leaking layer) and "regurgitation" (leakage after plugging) , cannot be used in deep wells

Asphalt-based treatment agents block and anti-slump agents use their characteristics of softening and deformation in high-temperature environments to physically seal micro-cracks and play a role in blocking pressure penetration. Closely adsorbed to the rock surface, the duration of its plugging effect is short, that is, the resulting collapse period is short, which is not conducive to underground construction, and is limited by the softening point temperature of asphalt. At present, the drilling industry lacks high temperature resistant (> 180°C) asphaltene treatment agent, unable to ensure the safe drilling of deep wells and easily collapsible mudstone formations

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