含磷共聚物钻井液降黏剂合成及性能评价

Synthesis and Properties of Phosphoric Copolymer as Viscosity Reducer for Drilling Fluids

以丙烯酸(AA)、2-丙烯酰胺基-2-甲基丙磺酸(AMPS)和含磷化合物共聚合成了抗220℃高温的钻井液降黏剂,对含磷化合物用量、引发剂(过硫酸铵)用量和滴加温度等对钻井液降黏剂特性黏度和降黏率的影响进行了考察。结果显示,钻井液降黏剂的最佳合成条件为:含磷单体用量为反应单体总质量的6%,过硫酸铵用量为反应单体总质量的2%,滴加溶液温度为55℃。利用红外光谱(IR)对钻井液降黏剂进行了表征,并借助热分析考察了钻井液降黏剂的热稳定性,同时对其在泥浆中的降黏性能进行了室内评价。研究结果表明:研制的钻井液降黏剂可以显著降低泥浆的黏度和切力,加入0.5%降黏剂的淡水基浆,高温降黏率可以达到91.4%;具有较好的抗盐、抗钙性能,在饱和盐水泥浆和含钙泥浆中也具有很好的降黏作用和分散作用;具有较好的热稳定性。

Viscosity reducer for drilling fluid used at temperature up to 220℃ was synthesized with acrylic acid,2-acrylamido-2-methylpropanesulfanic acid and phosphorus-containing compound.The effects of phosphoric compound,initiator and dipping temperature on the polymer intrinsic viscosity and thinning rate were studied.The best synthesized condition of the viscosity reducer is ：phosphoric monomer and ammonium persulfate count 6% and 2% of total weight of reaction monomer respectively,and the dipping temperature is 55℃. The viscosity reducer was characterized with IR.Thermal stability of it was measured by thermal analysis.The mud properties of the copolymer as viscosity reducer for drilling fluids were evaluated in laboratory.The experimental results show that it could reduce viscosity and shearing force of mud.When the addition of viscosity reducer is 0.5% ,the thinning rate at high temperature will be up to 91.4% for fresh water clay mud. And it has very good salt tolerance and calcium tolerance.h has good viscosity reduction and disgregation in saturated saltwater mud and calcareous mud.Its thermal stability is also good.