Plugging cement slurry and igneous rock fracture developing well plugging method

Abstract

The invention provides plugging cement slurry and an igneous rock fracture developing well plugging method. The water-solid ratio of the cement slurry is (85-92):100. The cement slurry comprises the following solid components in parts by weight: 115-125 parts of cement, 40-50 parts of weight-reducing agent flyash and 5-15 parts of stabilizing agent microsilica, wherein the cement comprises 100 parts of first cement components with average particle sizes being 12-14mu m and 12-18 parts of second cement components with average particle sizes being 6-7mu m; each liter of cement slurry further comprises 4-8g of plugging agent by volume; and the plugging agent comprises 0.1-0.2 part of staple fiber, 2-4 parts of rubbers and 3.2-6 parts of packing particles by weight. The cement slurry and the method have the beneficial effects that the bridging fiber materials, elastic rubber powder materials and shell and / or saw dust packing materials are combined for use, the cement slurry is suitable for igneous rock fracture developing wells and can meet the requirements of well drilling and well cementation constructions; and the construction time is greatly shortened by adopting the plugging technology idea of integrating packing, bridging and coagulation.

Description

technical field [0001] The invention relates to the field of petroleum drilling engineering, in particular to a plugging cement slurry suitable for drilling and cementing wells with cracks in Permian igneous rocks. Background technique [0002] The Permian igneous rocks in the Tuofutai block of Tahe Oilfield are broken, easy to collapse and easy to leak, and the formation pore pressure is 1.1-1.15g / cm 3 Range, the drilling fluid density is generally 1.30~1.35g / cm during normal drilling 3 , generally enhancing the sealing ability of the drilling fluid can safely drill through the formation. However, since the cement slurry density is 1.85g / cm 3 Above, it is easy to cause serious leakage and affect the quality of cementing. Therefore, at present, the pressure-bearing plugging of the Permian system in Tahe Oilfield generally adopts bridge slurry plugging, simple cement slurry plugging, bridge slurry + cement slurry composite plugging, and the effect is not ideal, and the suc...

AI Technical Summary

Problems solved by technology

[0003] The first technical problem to be solved by the present invention is to overcome the defect that existing igneous rock fracture wells are prone to leakage during the drilling and cementing process, and the conventional plugging process cannot effectively plug it, and provide a plugging cement slurry , combined use of fiber bridging material, rubber powder elastic material, fruit shell and / or sawdust filling material, so that the pressure value of the cement slurry is greater than 8Mpa, suitable for wells with igneous rock fractures, and can meet the requirements of drilling and cementing construction

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