落叶松栲胶高温堵剂的研究

STUDY OF AMPHOTERIC LARCH EXTRACT AS A PLUGGING AGENT WITH A HIGH TEMPERATURE RESISTANCE

对落叶松栲胶高温堵剂的性能进行了研究。该堵剂的典型配方为:栲胶6.0%～8.0%、交联剂6.0%～8.0%、促进剂A 0.5%～1.5%、促进剂B 0～0.4%,pH值8～12。在25℃、51/s条件下堵剂溶液的粘度为2.0～6.0mPa·s,在120℃下,其成胶时间在4.5～24h之间可调。该堵剂能耐250℃高温,但是会脱水20%左右。堵剂的强度随着温度的升高而增强,120℃下堵剂的弹性模量G在25000～60000Pa之间,而250℃下升高至65000～80000Pa。在渗透率为1449.67×10^(-3)μm^2岩心封堵试验中,封堵率为99.92%,突破压力梯度为44.30MPa/m;而在渗透率为958.84×10^(-3)μm^2、饱和一定量原油的岩心封堵试验中,封堵率为99.42%,突破压力梯度降为14.66MPa/m,这说明该堵剂不但具有良好的封堵效果,而且具有一定的选择性。

A test was carried out to probe for the performance of amphoteric larch extract as the plugging agent with a high temperature resistance,which was typically prepared by Tannin extract of 6.0%～8.0%、crosslinking agent of 6.0%～8.0%and accelerant of A 0.5%～1.5%and B 0～0.4%respectively,with a pH of 8～12.The result showed that the agent was of a solution viscosity of 2.0～6.0 mPa·s at 25℃、5 1/s,and of a controllable profile of colloiding time of 4.5～24h at 120℃.Besides,the agent was characterized by a high temperature resistance of 250℃,with a dehydrated rate of 20%.It was also observed that the strength of the agent increased with the rising temperature,with an elasticity modulus G of 25000～60000Pa at 120℃and 65000～80000Pa at 250℃。A plugging ratio of 99.92%and breakthrough pressure gradient of 44.30MPa/m was thereafter obtained in the core plugging test with a permeability of 1449.67×10^(-3)μm^2,while they were 99.42%and 14.66 MPa/m respectively in the test of plugging the core saturated by a proportion of crude oil with a permeability of 958.84×10^(-3)μm^2,which showed that the agent was advantageous of both effective plugging and selective plugging.