修井液用新型油溶性暂堵剂DFA的室内性能评价

为解决渤海湾海上油田渗透性漏失"能堵不能解"的技术难题,研制出新型油溶性暂堵剂DFA.DFA为有机低分子量化合物,不溶于水,但极易溶于煤油,在煤油中的油溶率高达99.9%,而且对原油粘度基本无影响.试验表明,在堵漏修井液(海水 (1.0%～1.2%)增粘剂DFZ 2.0%粘土稳定剂HCS)中加入3%～5%的DFA暂堵剂,流变性能满足工程泵送需要,能在渗透性砂床上形成有效封堵,堵漏层承受的最大压力达到7.0 MPa;也能自行解堵,2 h内渗透率恢复值在92%以上.

Laboratory evaluation on a new oil-soluble temporary plugging agent DFA for workover fluid

To solve permeable loss problem in Bohai Gulf oilfield, a new oil-soluble temporary plugging agent DFA for workover fluid was worked out. DFA is a low molecule organic compound, with the oil solution ratio as high as 99.9%. At the same time, it plays no role in the viscosity development of crude oil. Test data showed that, when 3%~5% DFA was added into the plugging workover fluid (the formulation includes seawater, 0.1%~1.2% viscofier DFZ, 2.0%clay stabilizing agent HCS), the rheological property satisfied the engineering requirements; it sealed the permeable sands effectively with the maximum bearing pressure reaching 7.0 MPa; and the barrier broke down automatically, resulting in the permeability recovery ratio reached as high as 92% in 2 h.