LS生物酶油水井解堵技术及应用

Research and application on LS biological enzyme blocking removal technique

为对油水井有机垢和无机垢形成的复合堵塞进行解堵,研制LS生物酶解堵剂.利用某油田储油罐底含有细砂颗粒的渣油模拟地层有机垢,用油砂装填岩心进行解除有机垢堵塞的物理模拟实验,测定LS生物酶作用前后被渣油污染石英片的润湿角和油/水、油/酶溶液的界面张力,并对原油的饱和烃气相色谱进行分析.结果表明：LS生物酶作用前后石英片润湿角由103.78°降至0°,油水界面张力由15.54 mN/m降至0.4×10-2mN/m,原油轻烃质量分数增加,重烃质量分数降低;LS生物酶最佳使用质量分数为6%-10%,最佳作用时间为3-4 d,能够使被有机垢堵塞的岩心的平均渗透率恢复率达到90%以上,渗透率比堵塞前平均提高27.06%,具有较好的解堵作用.某油田5口生产井应用结果表明,LS生物酶解堵后油井产量超过投产初期最高水平,含水率下降23.7%,日增液3.03 t,日增油3.82 t,措施有效期4个月以上,投入产出比为1∶8.5.

In order to remove the compound blocking resulting from organic and inorganic scaling in oil production wells or water injecting wells,LS biological enzyme was invented.The organic scaling was simulated by oil residue containing fine sand which were taken from an oilfield oil storage tank in China.The contact angle of piezoid polluted by oil residue was tested before and after LS biological action,the interface tension between oil/water,oil/enzyme were also tested,as well as the gas chromatogram of saturated hydrocarbon both before and after enzyme usage was obtained.The physical simulation test is made for removing organic blocking by using cores packing with oil sand from this oilfield.The contact angle reduced from 103.78° to 0° after LS biological enzyme action,oil/water interfacial tension reduced from 15.54 mN/m to 0.4×10-2 mN/m,the quality content of light hydrocarbon increased and that of heavy hydrocarbon decreased.The optimal concentration of LS biological enzyme is 6%～10%,the optimal action time is 3～4 d.After LS biological enzyme blocking removal,the permeability on the cores blocked by organic scale recovers to 90% or more,permeability increases more 27.06% than that before blocking,and better blocking removal effect is achieved.The field test result on one production well of this field indicated that the oil production rate after blocking removal was more than the highest rate in production history,the water cut was reduced by 23.7%,liquid production increased by 3.03 t/d,oil production increased by 3.82 t/d,useful life was more than 4 months,input-output ratio reached 1∶8.5.