超微细粉体堵剂性能评价及应用

Performance Evaluation and Application of Ultrafine Powder Plugging Agent

对高效新型超微细粉体堵剂(基本配方为:20%数30%超微细油井水泥+10%数15%纳米碳酸钙+3%数5%超微细氧化钙+15%数20%含硅、铁和铝元素的纳米氧化物+3%数5%钠膨润土+2%数3%碳酸钠+1%数2%磷酸盐+1%数2%铁铬盐FCLS+0.5%数1%纤维素类高分子聚合物HECMC+1%数2%AMPS聚合物+1%数3%氢氧化钠,按不同的水灰比可配制成不同密度的超微细堵剂浆体)的流变性、凝固时间和岩心封堵率及形成固化体的抗压强度等性能进行了室内综合评价,并进行了现场应用。研究结果表明,密度1.4数1.8 g/cm^3堵剂浆体的黏度小于35m Pa·s,注入性好,能进入地层深部孔隙。密度大于1.6 g/cm^3时,堵剂浆体的悬浮性好,基本不分层。超微细堵剂浆体固化时间可调,施工安全,初凝时间2.7数18.5 h,终凝时间3.1数28.1 h。固化后的体积不收缩,固化体的抗压强度大于25 MPa,耐温130℃、耐盐20×10~4mg/L。堵剂对不同渗透率(20.5×10^(-3)数127×10-3μm^2)岩心的封堵率均达99.9%,且耐冲刷、高温稳定性好。堵剂具有一定的溶解性,经酸岩反应后被封堵岩心的渗透率恢复率大于50%。超微细粉体堵剂已在低渗油藏卫360块应用27井次,工艺成功率100%,增油有效率100%。

The ultrafine Powder plugging agent is a highly effective new plugging agent,composed of 20%—30% superfine oil well cement,10% —15% nano-CaCO_3,3% —5% ultrafine CaO,15% —20% nano-oxide containing silicon,iron and aluminum elements,3% —5% Na-bentonite,2% —3% NaCO_3,1% —2% Phosphate,1% —2% Fe-Cr-lignosuifonate（FCLS）,0.5% —1%HECMC,1% —2% AMPS and 1% —3% NaOH. According to different water-cement ratio,a series of ultra-fine plugging agents with different density was prepared,and its performance,such as the rheological property,the solidification time,the plugging rate to the cores,the compressive strength of the solidified body,and so on,was comprehensively evaluated by laboratory experiment,and the field application was carried out. The research results showed that the viscosity of the plugging agent with density of 1.4—1.8 g/cm3 was less than 35 m Pa·s,the injectivity of the plugging agent was good,which could be injected into deep formation pore easily. Suspension of the plugging agents was good,when the density was greater than 1.6 g/cm3,Plugging agent slurry was hardly separated. The curing time of the plugging agent slurry could be adjusted,and the construction was safe,its initial setting time was 2.7—18.5 h,final setting time was 3.1—28.1 h. after the plugging agent slurry was cured,the solidified body（SB）did not contracted,the compressive strength of the SB was over 25 MPa,the SB was resistant to high temperature of130℃ and salt of 20×104mg/L. The plugging rate of plugging agent to the cores with different permeability of 20.5×10-3—127×10-3μm2was up to 99.9%,moreover,the outwash resistance and high temperature tolerance was good. The plugging agent had certain solubility,and the permeability recovery rate of the plugged cores was over 50% after the acid rock reaction. The field squeezing and plugging technology was applied in Wei 360 block of the low permeability reservoirs for 27 well times,the technological success rate reached 100%,and the effective rate of increase in oil production reached 100%.