水泥浆失水量对油气层损害影响的试验研究

用失水量不同的水泥浆进行岩心污染试验,研究了水泥浆失水对岩心渗透率和污染深度的影响.结果表明,水泥浆失水量对岩心污染深度影响不大,但对岩心渗透率有很大影响;随着水泥浆失水量的增加,岩心渗透率下降,试验条件下最大渗透率损害率达77.8%.现场保护油气层效果表明,对于高压低渗油气藏,固井过程中水泥浆失水量宜控制在70 mL范围以内.

Laboratory study on formation damage caused by cement slurry filtrate

In this paper, core damage tests were conducted with cement slurries of different filtration control additive doses to study how the filtrate volume affect the core permeability and damage depth into the formation. Results showed that the filtrate volume of slurry plays a minor role in damage depth in the core, but it has evident influence on the core permeability. With the filtrate volume increasing, the core permeability decreases to an maximum of 77.8% in the test condition. Field formation protection results showed that in cement job, the filtrate volume should be controlled within 70 mL in high pressure and low permeability reservoir.