双亲粒子聚合物随钻堵漏剂的合成与性能评价

Preparation and Performance Evaluation of Amphiphilic Particles Polymer Plugging Agent

首次将双亲粒子应用于随钻堵漏的研究。用浓乳液聚合界面引发制备疏水性核/亲水性壳双亲粒子。首先,通过浓乳液聚合得到聚苯乙烯胶体粒子,作为疏水性的核;然后通过界面引发使丙烯酰胺在核的表面聚合包覆,形成亲水性的聚丙烯酰胺壳层。该双亲粒子呈微粒状,并存在轻微的相互粘连或串状结构,平均粒径21.36μm。双亲粒子在淡水基浆中抗温可达180℃。含1%双亲粒子基浆的堵漏效果明显,并随粒子加量的增加,基浆漏失量减少,堵漏能力提高。随着挤注量的增加,挤注压力逐渐增大,挤注量为700 mL时的挤注压力可达14 MPa。双亲粒子可降低体系API滤失量。在加量不高于2%时,基浆流变性变化不大,可用于高温地层的随钻堵漏。

Amphiphilic particles were firstly applied in the field of leak protection. Core-shell particles with hydrophobic polystyrene cores encapsulated by hydrophilic polyacrylamide shells were prepared via interface initiation polymerization. The polystyrene colloidal particles were prepared by using a concentrated emulsion as a precursor. The polyacrylamide shell was prepared via interface initiator constituted of oxidant, cumene hydropemxide, reductant, and ferrous sulfate. The shape of amphiphilic particles was mlcm-spherical and there was slight adhesion between particles. The particle size in average was of 21.36 μm. The particles had good resistance of high temperature （180℃） in water-based slurry. The based slurry plugging with 1% amphiphilic particles had excellent plugging capability, which significantly improved with increasing amount of particles. It was found that with the increase in the amount of squeeze injection, extrusion injection pressure increased and reached the maximum of 14 MPa with 700 mL squeeze amount. The API fdtration could be reduced by amphiphilic particles. The change of slurry rheology was little when the amount of particles was no more than 2%. Amphiphilic particles could be used for drilling and plugging at high temperature.