Preparation And Characterization Of Copolymers As Fluid Loss Additive For Oil Well Cement Slurry At High Temperature And High Salinity Level

In cementing engineer,controlling the fluid loss of the oil well cementing slurries is very important for enveloping the oil,gas and water,that is improving the cementing quality,and is very important for protecting the energy resource.The method of adopting the fluid loss additives to control the water loss of the cement slurries is in common use.Although, there are many breeds in synthetic polymer fluid loss additives, mostly of them have no ideal performance,and adding to that the drilling stratum become more and more complex,such as high temperature and high salinity level,so according to the requirement of the cement slurry at high temperature,high pressure stratum and high salinity level,it's necessary to develop better fluid loss additive with excellent performance.In the dissertation, AM and AMPS as main bodies, cement fluid loss additives of acidamide kind(AM/AMPS , AM/AA , AM/AMPS/AA ,AM/AMPS/AA/NVP)have been synthesized. The property of the copolymers was tested as fluid loss additive.The results have shown that the Poly(AM/AMPS) had the most high thermostability;with wider blending amount,it can reduce fluid loss effectively and the cost price is low.Then, excellent to elect the Poly(AM/AMPS).Conferming AM/AMPS modified by inorganic salt,adopting free radical polymerization in water solution and redox couple system as initiator and through repeated experimental study to screening the composed terms,the polymer fluid loss additives product SDJS finally are synthesized.Meanwhile, the synthesis technics is optimized. The fourier transform infra-red (FTIR) spectrum of copolymers characterized the molecular structure of SDJS. TG analysis result indicated that SDJS had excellent thermal stability.The properties of the slurries which have been added additives SDJS are tested: fluid loss control ability,rheology, setting time and compressive strength, compatibility with other additives.The results indicated that:the SDJS has beter temperature and salt resistance,the adding amount was small, has an ideal thicken curve at high temperature and high salinity level.