Low-pressure leakage layer blocking agent and preparation method thereof

Abstract

The invention discloses a low-pressure leakage layer blocking agent and a preparation method thereof. The blocking agent is prepared by the following steps: dissolving 8.5 to 10 parts of an activatingagent in water for high-speed stirring and dissolving; weighing 50 to 75 parts of a binding material, 50 to 60 parts of a particle bridging material, 5 to 8 parts of a lightening material, 0.1 to 0.2part of a stabilizer and 1 to 1.5 parts of a slurry modifier; uniformly mixing and pouring the mixture into a slurry cup for uniformly stirring; covering the slurry cup with a cup cover; continuallystirring the mixture at the stirring speed of 12000+ / -500 r / min for 35 seconds, wherein the binding material is a mixture of sodium bentonite and blast furnace slag in the weight ratio of 1 to (7 to 9), the particle bridging material is limestone flour, and the lightening material is sepiolite fiber with the particle size of 1 to 2mm. The low-pressure leakage layer blocking agent is 1.2 to 1.4 g / cm<3> in density, and has the advantages of low density, high thixotropy, minimum inflation and high acid dissociation. By adopting the low-pressure leakage layer blocking agent, the problem of leakagedue to difficulty in lowering the density of ordinary acid-dissolved cement below 1.65 g / cm<3> is solved, so that plugging slurry is effectively prevented from pressing the stratum to cause leakage,and the plugging success rate is improved.

Description

technical field [0001] The invention relates to the technical field of leak plugging, in particular to a low pressure leak zone plugging agent and a preparation method thereof. Background technique [0002] With the continuous deepening of exploration and development of various oilfields, the formation deficit is becoming more and more serious. When drilling into low-pressure layers, leakage occurs frequently, especially when severe leakage occurs in the target layer, drilling fluid plugging often cannot be effective. The density of ordinary acid-soluble cement is difficult to reduce to 1.65g / cm 3 Below, it is easy to cause leakage, and the anti-scouring ability of the slurry is poor, so it is difficult to ensure the sealing weight. Contents of the invention [0003] The object of the present invention is to provide a low-pressure leakage layer plugging agent for sealing and temporarily sealing the malignant leakage of the target layer or the malignant leakage of the non-...

AI Technical Summary

Problems solved by technology

[0002] With the continuous deepening of exploration and development of various oilfields, the formation deficit is becoming more and more serious. When drilling into low-pressure layers, leakage occurs frequently, especially when severe leakage occurs in the target layer, the drilling fluid plugging is often ineffective

The density of ordinary acid-soluble cement is difficult to reduce to 1.65g / cm 3 Below, it is easy to cause leakage, and the slurry has poor erosion resistance, so it is difficult to ensure the sealing weight

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