A powder toughening and anti-gas channeling agent for well cementing

Abstract

The invention relates to a powder toughening anti-gas-channeling agent used for well cementation. The powder toughening anti-gas-channeling agent is prepared by drying kation styrene-butadiene latex to obtain a butylbenzene powder material that is adopted as 1 part by weight of a main component, and mixing with 0.04-0.05 part by weight of an organosilane surfactant, 0.05-0.1 part by weight of sodium metasilicate pentahydrate and 0.1-0.2 part by weight of a polycarboxylic acid dispersant. Cement paste prepared by utilization of the powder toughening anti-gas-channeling agent is stable. The powder toughening anti-gas-channeling agent can be uniformly dispersed in the cement paste, be attached to cement hydrate surfaces, can form continuous film and has good anti-gas-channeling performance. The powder toughening anti-gas-channeling agent enhances toughness of hardened cement paste, reduces the elasticity modulus of the hardened cement paste, and increases the Poisson's ratio of the hardened cement paste. The hardened cement paste is improved in toughness and is suitable for needs of well cementation projects of gas exploratory wells, gas storage reservoirs, shale gas, and other unconventional energy.

Description

technical field [0001] The invention relates to a cement admixture used in the cementing field of oilfield well completion technology, which belongs to a toughening and anti-gas channeling agent. Background technique [0002] In oil and gas well cementing operations and other underground cementing operations, it is usually required to inject cement slurry containing cement, water and admixtures into the predetermined formation underground through surface pumping equipment to seal the annulus between the formation and the casing. . Typically cement slurry is pumped into the casing and returns to the annulus through the gap between the casing and the formation. The cement slurry solidifies in the annular space to form a hard cement sheath column, which can form a bond with the formation and the casing. In order to achieve a satisfactory cementing operation, it is necessary to achieve a high-strength bond to prevent fluid channeling along or within the cement sheath, which wo...

AI Technical Summary

Problems solved by technology

At present, there is no good solution to the problem of oil, gas and water channeling in China. One of the reasons is that the cement stone deformation capacity of the existing cement slurry system is insufficient.

Due to perforation, fracturing and other constructions, the cement sheath is subjected to impact and vibration. On the one hand, it will be damaged; Interlayer isolation provides channels for oil and gas fluids and formation fluids to escape into the annulus, resulting in failure of interlayer isolation

The main hazards of channeling are: directly affecting the bonding strength of cement stone; causing interlayer channeling, directly affecting the test and evaluation of oil and gas layers, polluting oil and gas layers, and reducing oil and gas recovery; In severe cases, oil and gas may be emitted from the wellhead, and even cause blowout accidents after cementing. Even if remedial techniques such as cement extrusion are used, it is difficult to be effective

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