Agent for leak prevention and leak stoppage while drilling and preparation process thereof

Abstract

The invention discloses an agent for leak prevention and leak stoppage while drilling and a preparation process thereof. The agent for leak prevention and leak stoppage comprises the following components: 30 + / - 1% of silicon oxide, 15 + / - 1% of alumina, 15 + / - 1% of calcium oxide, 15 + / - 1% of bentonite, 5 + / - 1% of expansion powder, 10 + / - 1% of sodium alginate and 10 + / - 1% of organic fiber. The preparation process comprises the following steps: mixing the silicon oxide, alumina, calcium oxide, bentonite, expansion powder and sodium alginate according to the above-mentioned proportion; then grinding the prepared mixture to particles with a particle size reaching 1 to 1000 [mu]m; and finally, subjecting the prepared material and the organic fiber to uniform stirring and mixing at the mass ratio of the prepared material to the organic fiber being 9: 1 so as to prepare the sample product. The agent for leak prevention and leak stoppage provided by the invention can be applied in micron-scale or even nano-scale materials for plugging while drilling, can rapidly form mud cakes or realize self-adaptive plugging of microfractures with different widths, and prevents further expansion of hydraulic fracturing action, thereby achieving the purposes of leak prevention and leak stoppage while drilling.

Description

technical field [0001] The invention relates to the technical field of oil drilling plugging, in particular to an anti-leakage plugging agent while drilling and a preparation process thereof. Background technique [0002] During oil drilling operations, due to formation defects, cracks or pores, and low formation pressure coefficients, lost circulation occurs from time to time. Well wall instability, collapse, and blowout caused by lost circulation have long been a worldwide problem in oil and gas exploration and development, and are the main technical bottleneck restricting the speed of exploration and development. At the same time, lost circulation causes huge loss of drilling fluid, and The damage caused by leakage to the reservoir is inestimable. [0003] For some formations, there are "defects" and "flaws" on the rock surface of the wellbore formation, including cleavage, layers, and fractures of the formation rock (which can guide the liquid phase into the formation)....

AI Technical Summary

Problems solved by technology

[0004] Usually, there are a large number of natural vertical micro-fractures and micro-fractures (micron-scale) smaller than 0.1mm distributed throughout the formation. The liquid phase enters the formation under differential action (when the liquid phase entry amount is greater than the formation leakage amount), and under the action of the high pressure of the mud column, a "hydraulic wedge" effect is generated on the formation to cause fractures to be generated, opened, and expanded...to "leakage". degree", resulting in induced leakage

Similarly, the continuation of the excessively high positive pressure of the mud column may lead to the further opening and expansion of the crack, and the leakage rate may therefore continue to increase and deteriorate, further inducing leakage.

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