Products to solve cement slurry thickening time and strength reversal

On the premise of ensuring normal water loss performance, the fluid loss additive CG613S solves the reversal defect of common polymer fluid loss additives, preventing the reversal of thickening time and strength. It is suitable for oil well cements of different brands and batches at home and abroad. It is currently widely used in domestic Liaohe, Jidong, Dagang, Jianghan and other oilfield blocks.

Difficulties

The normal rule of cement slurry thickening time and strength is the hydration reaction rate accelerates, the thickening time shortens, and the strength increases with the increase of temperature and pressure. The thickening time and strength reversal refers to the situation where the thickening time or strength at high temperature is significantly longer or smaller than that at low temperature, especially at the two sensitive temperature points of 70℃ and 90℃. In actual construction, if the cement slurry at low top-temperature solidifies earlier than at high bottom-temperature, that will result in cement weight loss, weak strength of the bottom cement stone, and weak ability of cement slurry to stabilize the formation, which cannot effectively separate the oil, gas and water layers, thus causing gas channeling. Gas channeling will pollute the oil and gas layers, reduce the oil and gas recovery rate, corrode the casing, reduce the strength and service life of the casing, and in severe cases, oil and gas may leak at the wellhead, and even cause a blowout accident. At present, the AMPS polymer fluid loss additive on the market generally have the problems of thickening time and strength reversal, which brings certain safety hazards to on-site cementing operations.

Features of fluid loss additive CG613S which can resist reversal of thickening time and strength

Ø Under the premise of ensuring good fluid loss performance, solve the reversal defects of common polymer fluid loss additives and prevent the reversal of thickening time and strength.

Ø Mainly applicable to normal density cement slurry system.

Ø Applicable to different brands and batches of oil well cement at home and abroad.

Ø Has a slight dispersing effect, so that the cement slurry maintains good pumpability.

Ø Heat resistance up to 180℃, wide applicable temperature range.

Ø Currently widely used in domestic Liaohe, Jidong, Dagang, Jianghan and other oilfields.

Solutions

Properties of CG613S in normal density cement slurry system