新型压胶塞液研究与应用

Study and application of a new flushing fluid

固井时由于套管壁残留的少量水泥浆对钻井液造成污染,致使钻井液的粘度、切力升高,测声幅软遇阻,造成较大的经济损失。经室内研究优选出了性能良好的新型压胶塞液。结果表明,新型压胶塞液与油田常用钻井液的配伍性强,不会引起钻井液性能的变化;具有一定的粘度和切力,防止了重晶石和钻屑的沉淀,避免了测声幅仪器遇阻;新型压胶塞液中不合固相,抗温在120℃以上,有效地防止了该液在井底高温作用下发生高温胶凝或高温减稠;新型压胶塞液中含大量强缓凝的HMP-Ⅲ,能避免清洗出的水泥浆稠化;它抗盐、钙污染能力强,避免了水泥浆对其性能的破坏,有效地清洗了套管壁残留水泥浆,避免水泥浆对钻井液的污染,有效避免声幅软遇阻。现场试验30口井,成功率达100％,基本解决了油层套管测声幅软遇阻的问题。

Drilling fluid is often contaminated by residual cement slurry on casing wallafter cementing operation. With viscosity and shearing stress increases, difficulties appear in acoustic amplitude logging with more pecuniary loss. A new flushing fluid with excellent performances was developed in lab. It is compatible with conventional drilling fluids, and never alters their properties. Owing to certain viscosity and shear stress, it prevents barite particles and cuttings from setting down, and sticking of apparatus in acoustic amplitude logging was avoided. Advantages of having no solid particles and good thermal stability up to 120℃ make gelling and thickening of it at high temperature in well bottom never happen. With plenty of strong retarder HMP-Ⅲ in the flushing fluid, the cement slurry flushed out remain watery. It has strong salt and calcium resistance, never ruined by cement slurry and wipes out residual slurry effectively, without causing problems in acoustic amplitude logging operation. Trails in 30 wells were all successful (success rate is 100%).