Cementing is to inject cement slurry from the casing to the well wall and the annulus of the casing and let him return to a certain height. The cement slurry then becomes cement stone to consolidate the well wall and the casing. When drilling a serious loss layer, the method of reducing the density of the drilling fluid and adding plugging materials is used to drill the hole. After the serious loss layer is drilled, the casing must be lowered to cement it, so that it will not affect the subsequent drilling When drilling other complex formations (such as strata-prone formations), the casing can also be cemented after drilling the formation; when drilling high-pressure gasoline formations, blowouts are prone to occur, and the density of the drilling fluid should be increased to balance the formation pressure. After the high-pressure oil and gas layer is drilled, the casing must be installed to cement the well to protect the high-pressure oil and gas layer; the casing that is lowered during the drilling process must be fixed by cementing operations. In addition, the cement stone outside the pipe sleeve can reduce the stratum squeezing of the sleeve pipe and play a role in protecting the sleeve pipe.
Cement slurry is the working fluid used in cementing and is composed of water, cement, additives and admixtures. Substances with an addition amount less than or equal to 5% of the cement mass are called admixtures, and substances with an addition amount greater than 5% of the cement mass are called admixtures.
Cement slurry retarder: In order to meet the construction requirements, retarder should be used to adjust the curing time of cement slurry. Cement slurry retarder mainly plays the role of retardation through two mechanisms of adsorption and chelation: (1) Adsorption mechanism, cement slurry retarder can be adsorbed on the surface of cement particles, hindering its contact with water, and also adsorbed in saturation precipitation The hydrated surface of cement affects its rate of forming a network structure in the curing stage and hardening stage, which plays a role in retardation; (2) Chelation mechanism, cement slurry retarder can form a stable five-membered ring with Ca2 + through chelation. The six-membered ring structure affects the rate of saturated precipitation of cement hydrates and plays a role in retarding setting. The copolymers of HPAM and AM, Na-AA and Na-AMPS can be used as cement slurry retarder. For more information, please consult Shandong Ruihai Mishan Chemical Co., Ltd.,
Cement slurry drag reducer: Due to the high solid content in the cement slurry, the flow resistance is very large, the cement slurry drag reducer can be used to reduce the flow resistance of the cement slurry. The mechanism of action is the same as that of the diluent for drilling fluids. They all use adsorption to increase the negative charge of the surface of the cement particles and increase the thickness of the hydration layer, so that the structure formed by the cement particles is disintegrated to play a drag reduction role. The polyacrylamide polymer model that can be used as a drag reducer for cement slurry can consult Shandong Ruihai Mishan Chemical Co., Ltd., and we will provide professional guidance.
Cement slurry fluid loss agent and plugging agent: similar to drilling fluid, specific molecular weight and other information can contact Shandong Ruihai Mishan Chemical Co., Ltd., specializing in the production of acrylamide and polyacrylamide for more than 20 years.