A kind of multi-stage particle network cementing and repairing wall working fluid and its preparation and construction method

Abstract

The invention relates to a complex multi-level particle network cementing wall patching working fluid used in the drilling field of oil and gas fields and its preparation and construction method. The wall patching working fluid contains: 40-500 mesh multi-graded particles, 3-12mm water Dispersed fiber, polycrystalline solidification material, stabilizer, fluid loss reducer, retarder and other components are pumped to the formation after low-speed mixing and mixing, and under the action of pressure difference: multi-graded particles enter the formation In the cracks / micropores, an infiltration layer is formed to block and prevent collapse; the mesh fiber forms a tough mud cake with drilling fluid on the well wall, which is called an alternating layer, which reduces water loss, improves the strength of the mud cake, and strengthens the wall. Anti-slump and plugging effect; polycrystalline solidification material is static and solidified at the "big belly" wellbore, and the wellbore is reshaped after the wall is repaired and solidified to form an artificial well wall, preventing further collapse of the "big belly" well section and greatly reducing the well Increase the diameter expansion rate, improve the drilling fluid annulus return speed and rock-carrying efficiency, and prevent sand sinking and drill sticking.

Description

technical field [0001] The invention belongs to the technical field of petroleum drilling, and in particular relates to a multi-stage particle network cemented wall patching working fluid and a preparation and construction method thereof. Background technique [0002] During the drilling production process, when drilling complex formations, downhole abnormalities such as wellbore instability, spalling, in-situ stress deformation, and leakage are prone to occur, especially in deep wells and exploration wells. If it is not treated in time, it will lead to well wall collapse, ① a "big belly" hole will be formed, and the diameter expansion rate will be as high as 30-55%. The pressure loss increases, and the leakage rate increases; ③ mudstone immersion intensifies, resulting in uncontrollable periodic collapse. [0003] By adjusting the drilling fluid density, viscosity, inhibition and other methods, the wellbore collapse can be moderately improved, but the already formed "big b...

AI Technical Summary

Problems solved by technology

If it is not treated in time, it will lead to well wall collapse, ① a "big belly" hole will be formed, and the diameter expansion rate will be as high as 30-55%. The pressure loss increases, and the seepage rate increases; ③ Mudstone immersion intensifies, forming uncontrollable periodic collapse

[0003] By adjusting the drilling fluid density, viscosity, inhibition, etc., the wellbore collapse can be moderately improved, but the formed "big belly" wellbore cannot be changed, and the pressure bearing capacity of the formation cannot be improved.

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