KELIOIL-EXPERT IN CEMENTING ADDITIVES
A.Oil, as the blood of industry, is a strategic resource for a country’s survival and development. Therefore, oil exploitation is of great importance.
B.Process of Oil Exploitation
C.Process of Well Cementing
During a drilling operation, casing should be run into the wellbore when a certain depth is reached. Then cement slurry is injected into the annular space between the casing and the wall, during which time a rapid hardening of cement slurry within a specified time is required so as to form a cement sheath of good sealing and isolation performance. The above process is called well cementing. It aims to isolate oil-water-gas layer, support and protect casing, prolong oil-gas well’s working life and increase oil and gas output.
Well cementing is an one-off project of high cost, so low cementing quality is hard to be improved once it is completed. What’s worse, low cementing quality can lead to the damage for oil-gas wells and cause huge resources and economy loss. Therefore, it is crucial to ensure a safe cementing operation and high cementing quality. Cementing additives are vital in this process. They can optimize and improve cement slurry system’s performance, which ensures a safe operation, high quality cementing and long oil-gas well’s lifetime under various well conditions and different drilling technologies (eg. directional well and horizontal well).
The three most common additives are fluid loss additive, dispersant and retarder.
2.Fluid Loss Additive
A.Fluid loss additive, playing a significant role in a successful cementing, oil-gas well’s lifetime extension and oil output growth, is the most important additive of the largest usage amount in cement slurry design. As is known, excessive fluid loss enhances cement slurry’s density so it is unable to be pumped, and the remaining slurry in the casing will fail the cementing operation. Fluid loss additive can not only effectively control the fluid loss of cement slurry, but also prevent oil and gas layer from being polluted by the filtered fluid and thus increase the recovery efficiency.
B.Our fluid loss additive is AMPS polymer type. It is high temperature resistant and salt water resistant. Besides, It doesn’t thicken cement slurry and has good adaptability to cement and other additives. The three main series are as follows.
Retarder can effectively prolong the thickening time of cement slurry so as to ensure a successful cementing operation. Generally, bottom hole temperature and pressure will increase with the increasing well depth. While high temperature and pressure can lead to a rapid thickening of cement slurry and thus shorten the pump time, which will cause an unfavorable condition for cementing operation and make cement slurry unable to be pumped for the loss of fluidity, leading to an cementing accident eventually. Therefore, it is necessary to use retarder to prolong cement slurry’s thickening time.
Our CH210L-Moderate Temperature Retarder’s applicable temperature is below 90℃ . It can adjust the thickening time and has good adaptability to cement.
To improve the cement slurry’s displacement efficiency and ensure cementing quality, a certain amount of washing liquid needs to be injected into the casing pipe before cementing. Then the mud cake on the walls can be washed off and thus enhance cementing slurry’s interface binding force.
Our washing agents are divided into CW110L-water-based washing agent and CW210L-oil-based washing agent according to their different solvents. They can both clean water-based and oil-based slurry. Non- phosphorus, high washing efficiency and little foam are their features.
In the process of cementing operation, spacer additive can effectively separate drilling fluid from cement slurry and avoid cement slurry being polluted.
Our spacer additives include CS210S-powder type and CS210L-liquid type. They have good suspension property as well as high stability, and are easy to use.