控流管路中降滤失剂的合成与性能研究

针对高压喷射钻井时，传统阴离子降滤失剂不能克服水眼黏度的问题，以2-丙烯酰胺-2-甲基丙磺酸（AMPS）、丙烯酰胺（AM）和丙烯酸钾（AA）为原料，在控流管路中共聚得到钻井液降滤失剂AMPS/AM/AA，确定AM与AMPS、AA与AMPS之间的最优投料比为7:6:1，总单体浓度为17%。考察了共聚物在淡水钻井液、盐水钻井液和饱和盐水钻井液中的降滤失及流变性能。结果表明:在控流管路中合成的聚合物黏度低于同条件下釜式反应中合成的，解决了传统阴离子降滤失剂使水眼黏度过高的问题；AMPS/AM/AA能使高矿化度水基钻井液的滤失量降低94%，在淡水基浆、盐水基浆和饱和盐水基浆中，共聚物均表现出较强的降滤失性能和较弱的增黏性能；热稳定性分析及高温老化评价表明，AMPS/AM/AA可抗330℃的高温，满足现场对高温钻井液的要求。 

Synthesis and Evaluation of a Filter Loss Reducer in Flow-control Line

In high pressure jet drilling, the viscosity of drilling fluid at bit nozzle has long been a problem associated with the use of anionic filter loss reducers. A new drilling fluid filter loss reducer has been developed through the copolymerization of 2-Acrylamido-2-methylpropane sulfonic acid (AMPS), acrylamide (AM) and potassium acrylate at an optimum ratio of 7:6:1. The total concentration of these monomers was 17%. The filtration control performance and the rheology of the copolymer in fresh water drilling fluid, saltwater drilling fluid and saturated saltwater drilling fluid were studied. The studies showed that the viscosity of the copolymer synthesized in flow-control line was lower than the viscosity of the copolymer synthesized in three-necked flask under the same conditions, solving the problem of high viscosity at the bit nozzle caused by the conventional anionic filter loss reducers. The AMPS/AM/AA copolymer can reduce the filter loss of high salinity water base drilling fluids by 94%. It showed good filtration control and viscosifying performance in fresh water base fluid, saltwater base fluid and saturated saltwater base fluid. Thermal stability analysis and high temperature aging evaluation showed that the copolymer was able to retain its stability at 330℃, satisfying the needs for high temperature drilling fluids in field operation.