High-temperature and salt-resistant high-density spacer fluid and preparation method thereof

Abstract

The invention discloses a high-temperature-resistant and salt-tolerant spacer fluid with high density and a preparation method of the spacer fluid. The spacer fluid is prepared from solvent water, a suspension stabilizer, a cleaning agent, a fluid loss agent, a retarder, a defoamer, a weighting agent and sodium chloride, wherein the suspension stabilizer is prepared from natural mineral, modified diutan gum, a polymer, inorganic salt and white carbon black; the weighting agent is prepared from iron ore powder and micro-Mn in a weight ratio being 1:(0.05-0.20). The preparation method of the spacer fluid is simple, the suspension stabilizer is added to water slowly, hydration is performed for 5-10 min after high-speed stirring is performed for 1-2 min, then the weighting agent, the fluid loss agent, the cleaning agent and the retarder are added slowly in sequence, the mixed solution is stirred rapidly for 1-2 min, finally, the defoamer is added and uniformly stirred, and preparation is completed. The application temperature range of the high-temperature-resistant and salt-tolerant spacer fluid with high density is 30-190 DEG C, the density is adjustable in a range of 2.00-2.80 g / cm<3>, and the spacer fluid reaches saturation for salt tolerance; the spacer fluid has the advantages of little free water in a system, small fluid loss amount, high fluidity, good slurry stability and the like.

Description

technical field [0001] The invention relates to the technical field of prefluid for petroleum cementing engineering, in particular to a high-temperature-resistant, salt-resistant, high-density spacer fluid and a preparation method thereof. Background technique [0002] With the continuous deepening of exploration and development, there are more and more deep wells, ultra-deep wells, extended-reach horizontal wells, and adjustment wells, and the density of drilling fluid is getting higher and higher. Tie. At present, the density of mud used in Iraq's Halfaya and Missan blocks reaches 2.20g / cm 3 Above, and containing salt paste layer, in order to improve the displacement efficiency, it is necessary to adopt the anti-salt high-density spacer fluid system. The currently used high-density spacers use materials such as cellulose and xanthan gum as suspension stabilizers, and the suspension ability becomes weak at high temperatures, and the suspension ability is limited at high d...

AI Technical Summary

Problems solved by technology

The currently used high-density spacers use cellulose, xanthan gum and other materials as suspension stabilizers, and the suspension ability becomes weak at high temperatures, and the suspension ability is limited at high densities.

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